Triclosan-induced genes Rv1686c-Rv1687c and Rv3161c are not involved in triclosan resistance in Mycobacterium tuberculosis

A key issue towards developing new chemotherapeutic approaches to fight Mycobacterium tuberculosis is to understand the mechanisms underlying drug resistance. Previous studies have shown that genes Rv1686c-Rv1687c and Rv3161c, predicted to encode an ATP-binding cassette transporter and a dioxygenase respectively, are induced in the presence of triclosan and other antimicrobial compounds. Therefore a possible role in drug resistance has been suggested for the products of these genes although no functional studies have been done. The aim of the present study was to clarify the role of Rv1686c-Rv1687c and Rv3161c in M. tuberculosis resistance to triclosan and other drugs. To this end, deficient mutants and overproducing strains for both systems were constructed and their minimal inhibitory concentration (MIC) against over 20 compounds, including triclosan, was evaluated. Unexpectedly, no differences between the MIC of these strains and the wild-type H37Rv were observed for any of the compounds tested. Moreover the MIC of triclosan was not affected by efflux pump inhibitors that inhibit the activity of transporters similar to the one encoded by Rv1686c-Rv1687c. These results suggest that none of the two systems is directly involved in M. tuberculosis resistance to triclosan or to any of the antimicrobials tested

Is Trabecular Bone Score Valuable In Bone Microstructure Assessment After Gastric Bypass In Women With Morbid Obesity?

Introduction: The effects of bariatric surgery on skeletal health raise many concerns. Trabecular bone score (TBS) is obtained through the analysis of lumbar spine dual X-ray absorptiometry (DXA) images and allows an indirect assessment of skeletal microarchitecture (MA). The aim of our study was to evaluate the changes in bone mineral density (BMD) and alterations in bone microarchitecture assessed by TBS in morbidly obese women undergoing Roux-en-Y gastric bypass (RYGB), over a three-year follow-up. Material/Methods: A prospective study of 38 morbidly obese white women, aged 46.3 +/- 8.2 years, undergoing RYGB was conducted. Biochemical analyses and DXA scans with TBS evaluation were performed before and at one year and three years after surgery. Results: Patients showed normal calcium and phosphorus plasma concentrations throughout the study. However, 25-hydroxyvitamin D (25(OH)D-3) decreased, and 71% of patients had a vitamin D deficiency at three years. BMD at femoral neck and lumbar spine (LSBMD) significantly decreased 13.53 +/- 5.42% and 6.03 +/- 6.79%, respectively, during the three-year follow-up; however Z-score values remained above those for women of the same age. TBS was within normal ranges at one and three years (1.431 +/- 106 and 1.413 +/- 85, respectively), and at the end of the study, 73.7% of patients had normal bone MA. TBS at three years correlated inversely with age (r = -0.41, p = 0.010), body fat (r = -0.465, p = 0.004) and greater body fat deposited in trunk (r = -0.48, p = 0.004), and positively with LSBMD (r = 0.433, p = 0.007), fat mass loss (r = 0.438, p = 0.007) and lean mass loss (r = 0.432, p = 0.008). In the regression analysis, TBS remained associated with body fat ( = -0.625, p = 0.031; R-2 = 0.47). The fracture risk, calculated by FRAX((R)) (University of Sheffield, Sheffield, UK), with and without adjustment by TBS, was low. Conclusion: Women undergoing RYGB in the mid-term have a preserved bone MA, assessed by TBS

Isolo : a new concept of privacy

Isolo es un conjunto de cuatro productos interactivos, diseñados por los estudiantes del Grado de Diseño de EINA, que exploran y aplican el concepto “privacidad”. Los proyectos ofrecen diferentes formas de aislamiento respetando los hábitos de los usuarios y recreando atmósferas de intimidad, desde el individuo hasta el colectivo. Los proyectos presentados son: Köllen Eget es un espacio de trabajo adaptado a los nuevos hábitos de trabajo y al uso de las de las nuevas tecnologías. La interactividad del producto permite reorganizar el espacio y generar un ambiente personalizado, adaptándose a cada usuario gracias a la iluminación, la acústica y la presencia de diferentes elementos móviles. Còdol es un separador de espacios que contempla el contraste entre el vacío y la plenitud. Consigue crear un ambiente privado dentro de un entorno interior y concurrido gracias a su estructura envolvente de paneles móviles con propiedades acústicas y tonalidades suaves. Petal es una silla versátil y adaptable al usuario, inspirada en las formas orgánicas de las flores. En cada lateral hay un panel flexible que permite ser regulado en diferentes posiciones y de esta manera convertirlo en un espacio del almacenamiento personalizado acorde con las necesidades del usuario. Kodama es un panel decorativo, que se presenta como una arboleda de influencia oriental coronada por los elementos más distintivos de todo el conjunto: los asientos, que están colocados aleatoriamente por toda la estructura a disposición del usuario.Isolo és un conjunt de quatre productes interactius, dissenyats pels estudiants del Grau de Disseny d’EINA, que exploren i apliquen el concepte “privacitat”. Els projectes ofereixen diferents formes d’aïllament respectant els hàbits dels usuaris i recreant atmosferes d’intimitat, des de l’individu fins al col·lectiu. Els projectes presentats són: Köllen Eget és un espai de treball adaptat als nous hàbits de treball i a l’ús de les noves tecnologies. La interactivitat del producte permet reorganitzar l’espai i generar un ambient personalitzat, adaptant-se a cada usuari a través de la il·luminació, l’acústica i la presència de diferents elements mòbils. Còdol és un separador d’espais que contempla el contrast entre el buit i el ple. Aconsegueix crear un ambient privat dins d’un entorn interior i concorregut gràcies a la seva estructura envoltant de panells mòbils amb propietats acústiques i tonalitats suaus. Petal és una cadira versàtil i adaptable a l’usuari, inspirada en les formes orgàniques de les flors. A cada lateral hi ha un panell flexible que permet ser regulat en diferents posicions i d’aquesta manera convertir-lo en un espai d’emmagatzematge personalitzat d’acord amb les necessitats de l’usuari. Kodama és un panell decoratiu, que es presenta com una arbreda d’influència oriental, coronada pels elements més distintius de tot el conjunt: els seients, que estan disposats aleatòriament per tota l’estructura a disposició de l’usuari.Isolo is a set of four interactive products, designed by students on the EINA Bachelor’s Degree in Design, that explore and apply the concept of “privacy”. The projects offer different forms of isolation, respecting users’ habits and recreating atmospheres of intimacy, from the individual to the group. The projects presented are: Köllen Eget is a workspace adapted to new working habits and the use of new technologies. The interactivity of the product allows users to reorganise their space and create a personalised ambience, adapting to each user through light, sound and the presence of different mobile elements. Còdol is a space divider that considers the contrast between empty and full. It manages to create a private ambience in an interior and busy environment thanks to its structure, surrounded by moveable panels with sound properties and soft tones. Petal is a versatile chair that is adaptable to the user, inspired by the organic shapes of flowers. On each side is a flexible panel that can be regulated in different positions, so turning it into a personalised storage space in line with your needs. Kodama is a decorative panel displayed as an Oriental-influenced woodland crowned by the most distinctive elements of the entire piece: the seats, which are placed at random throughout the whole structure for use by the user

Follow-Up Study Confirms the Presence of Gastric Cancer DNA Methylation Hallmarks in High-Risk Precursor Lesions

Intestinal metaplasia confers an increased risk of progression to gastric cancer. However, some intestinal metaplasia patients do not develop cancer. The development of robust molecular biomarkers to stratify patients with advanced gastric precursor lesions at risk of cancer progression will contribute to guiding programs for prevention. Starting from a genome-wide methylation study, we have simplified the detection method regarding candidate-methylation tests to improve their applicability in the clinical environment. We identified CpG methylation at the ZNF793 and RPRM promoters as a common event in intestinal metaplasia and intestinal forms of gastric cancer. Furthermore, we also showed that Helicobacter pylori infection influences DNA methylation in early precursor lesions but not in intestinal metaplasia, suggesting that therapeutic strategies to prevent epigenome reprogramming toward a cancer signature need to be adopted early in the precursor cascade. To adopt prevention strategies in gastric cancer, it is imperative to develop robust biomarkers with acceptable costs and feasibility in clinical practice to stratified populations according to risk scores. With this aim, we applied an unbiased genome-wide CpG methylation approach to a discovery cohort composed of gastric cancer (n = 24), and non-malignant precursor lesions (n = 64). Then, candidate-methylation approaches were performed in a validation cohort of precursor lesions obtained from an observational longitudinal study (n = 264), with a 12-year follow-up to identify repression or progression cases. H. pylori stratification and histology were considered to determine their influence on the methylation dynamics. As a result, we ascertained that intestinal metaplasia partially recapitulates patterns of aberrant methylation of intestinal type of gastric cancer, independently of the H. pylori status. Two epigenetically regulated genes in cancer, RPRM and ZNF793, consistently showed increased methylation in intestinal metaplasia with respect to earlier precursor lesions. In summary, our result supports the need to investigate the practical utilities of the quantification of DNA methylation in candidate genes as a marker for disease progression. In addition, the H. pylori-dependent methylation in intestinal metaplasia suggests that pharmacological treatments aimed at H. pylori eradication in the late stages of precursor lesions do not prevent epigenome reprogramming toward a cancer signature

Estudio de la implicación de los genes Rv0576-Rv0577 en la tinción con rojo neutro y la virulencia de Mycobacterium tuberculosis

Consultable des del TDXTítol obtingut de la portada digitalitzadaEl conocimiento de los factores de virulencia de Mycobacterium tuberculosis es primordial para el desarrollo de nuevos fármacos y vacunas, esenciales para combatir esta enfermedad infecciosa que causa anualmente 1,7 millones de muertes. Una característica distintiva de las cepas virulentas de M. tuberculosis es la capacidad de fijar el colorante rojo neutro en su forma ácida. En trabajos anteriores se refutó la relación, ampliamente aceptada hasta el momento, entre este comportamiento y el sulfolípido (un componente de la envuelta celular); y se determinó que el gen Rv0577, cotranscrito con el posible regulador transcripcional Rv0576, confería a M. smegmatis (una micobacteria saprófita) el fenotipo rojo neutro positivo de las cepas virulentas de M. tuberculosis. En el presente trabajo, mediante fusiones transcripcionales y el análisis con microchips, se ha demostrado que el gen Rv0576 es, efectivamente, un regulador transcripcional que reprime la expresión del operón Rv0576-Rv0577. Sin embargo, el estudio de cepas mutantes y complementadas en estos genes ha mostrado que ninguno de estos dos genes es necesario para la tinción con rojo neutro de M. tuberculosis, ni para la virulencia en el modelo de infección murino. Asimismo se ha comprobado que M. tuberculosis, in vitro, forma poblaciones celulares heterogéneas para el carácter rojo neutro y para la síntesis de dimicocerosatos de ftiocerol, unos lípidos de la envuelta celular relacionados con la virulencia del bacilo. Los mutantes espontáneos rojo neutro negativos revierten, con cierta frecuencia, al fenotipo salvaje; mientras que no se ha detectado reversión en los mutantes en la síntesis de dimicocerosatos de ftiocerol, que se acumulan con las sucesivas resiembras de M. tuberculosis, hasta resultar en la población mayoritaria. Estas observaciones, y la relación de la tinción con rojo neutro y de los dimicocerosatos de ftiocerol con la virulencia de M. tuberculosis, ponen de manifiesto la necesidad de comprobar estos fenotipos antes de realizar el análisis de la virulencia de una determinada cepa o mutante de M. tuberculosis.The identification of Mycobacterium tuberculosis virulence factors is necessary to develop new drugs and vaccines, urgently needed to fight an infectious disease that causes 1.7 million deaths annually. A unique feature of the virulent strains of M. tuberculosis is their ability to fix the neutral red stain in its acid form. Although sulfolipid (a component of the cell envelope) was first recognized as the molecule responsible for the neutral red uptake, recent studies have refuted this relationship, and have established that the Rv0577 gene, which constitutes a single operon together with the putative transcriptional regulator Rv0576, provides M. smegmatis (a saprophytic mycobacteria) with the neutral red positive phenotype characteristic of M. tuberculosis virulent strains. In the present work, by means of transcriptional fusions and microarray analysis, we have proved that the Rv0576 gene indeed behaves as a transcriptional regulator that represses the expression of the Rv0576-Rv0577 operon. However, studies of mutant and complemented strains in these genes have shown that none of them is necessary either for the neutral red reaction of M. tuberculosis or for virulence in the murine infection-model. We have also proved that, in vitro, M. tuberculosis forms heterogeneous cell populations regarding the neutral red character and the synthesis of phthiocerol dimycocerosates, a cell-wall lipid related to the virulence of the bacillus. Reversion of the spontaneous neutral red mutants to the wild-type phenotype occurs at certain frequency, whereas reversion of the mutants in the synthesis of phthiocerol dimycocerosates has not been detected and they accumulate with successive cultures of M. tuberculosis, becoming the bulk of the population. As both the neutral red character and phthiocerol dimycocerosates are related to M. tuberculosis virulence, it would be prudent to check these phenotypes before analyzing the virulence of a certain strain or mutant of M. tuberculosis

Triclosan-induced genes Rv1686c-Rv1687c and Rv3161c are not involved in triclosan resistance in Mycobacterium tuberculosis

A key issue towards developing new chemotherapeutic approaches to fight Mycobacterium tuberculosis is to understand the mechanisms underlying drug resistance. Previous studies have shown that genes Rv1686c-Rv1687c and Rv3161c, predicted to encode an ATP-binding cassette transporter and a dioxygenase respectively, are induced in the presence of triclosan and other antimicrobial compounds. Therefore a possible role in drug resistance has been suggested for the products of these genes although no functional studies have been done. The aim of the present study was to clarify the role of Rv1686c-Rv1687c and Rv3161c in M. tuberculosis resistance to triclosan and other drugs. To this end, deficient mutants and overproducing strains for both systems were constructed and their minimal inhibitory concentration (MIC) against over 20 compounds, including triclosan, was evaluated. Unexpectedly, no differences between the MIC of these strains and the wild-type H37Rv were observed for any of the compounds tested. Moreover the MIC of triclosan was not affected by efflux pump inhibitors that inhibit the activity of transporters similar to the one encoded by Rv1686c-Rv1687c. These results suggest that none of the two systems is directly involved in M. tuberculosis resistance to triclosan or to any of the antimicrobials tested

Neutral-red reaction is related to virulence and cell wall methyl-branched lipids in Mycobacterium tuberculosis.

Searching for virulence marking tests for Mycobacterium tuberculosis, Dubos and Middlebrook reported in 1948 that in an alkaline aqueous solution of neutral-red, the cells of the virulent H37Rv M. tuberculosis strain fixed the dye and became red in color, whereas the cells of the avirulent H37Ra M. tuberculosis strain remained unstained. In the 1950 and 1960s, fresh isolates of M. tuberculosis were tested for this neutral-red cytochemical reaction and it was reported that they were neutral-red positive, whereas other mycobacteria of diverse environmental origins that were non-pathogenic for guinea pigs were neutral-red negative. However, neutral-red has not really been proven to be a virulence marker. To test if virulence is in fact correlated to neutral-red, we studied a clinical isolate of M. tuberculosis that was originally neutral-red positive but, after more than 1 year passing through culture mediums, turned neutral-red negative. We found that, in comparison to the original neutral-red positive strain, this neutral-red negative variant was attenuated in two murine models of experimental tuberculosis. Lipid analysis showed that this neutral-red negative natural mutant lost the capacity to synthesize pthiocerol dimycocerosates, a cell wall methyl-branched lipid that has been related to virulence in M. tuberculosis. We also studied the neutral-red of different gene-targeted M. tuberculosis mutants unable to produce pthiocerol dimycocerosates or other cell wall methyl-branched lipids such as sulfolipids, and polyacyltrehaloses. We found a negative neutral-red reaction in mutants that were deficient in more than one type of methyl-branched lipids. We conclude that neutral-red is indeed a marker of virulence and it indicates important perturbations in the external surface of M. tuberculosis cells

Is Trabecular Bone Score Valuable In Bone Microstructure Assessment After Gastric Bypass In Women With Morbid Obesity?

Introduction: The effects of bariatric surgery on skeletal health raise many concerns. Trabecular bone score (TBS) is obtained through the analysis of lumbar spine dual X-ray absorptiometry (DXA) images and allows an indirect assessment of skeletal microarchitecture (MA). The aim of our study was to evaluate the changes in bone mineral density (BMD) and alterations in bone microarchitecture assessed by TBS in morbidly obese women undergoing Roux-en-Y gastric bypass (RYGB), over a three-year follow-up. Material/Methods: A prospective study of 38 morbidly obese white women, aged 46.3 +/- 8.2 years, undergoing RYGB was conducted. Biochemical analyses and DXA scans with TBS evaluation were performed before and at one year and three years after surgery. Results: Patients showed normal calcium and phosphorus plasma concentrations throughout the study. However, 25-hydroxyvitamin D (25(OH)D-3) decreased, and 71% of patients had a vitamin D deficiency at three years. BMD at femoral neck and lumbar spine (LSBMD) significantly decreased 13.53 +/- 5.42% and 6.03 +/- 6.79%, respectively, during the three-year follow-up; however Z-score values remained above those for women of the same age. TBS was within normal ranges at one and three years (1.431 +/- 106 and 1.413 +/- 85, respectively), and at the end of the study, 73.7% of patients had normal bone MA. TBS at three years correlated inversely with age (r = -0.41, p = 0.010), body fat (r = -0.465, p = 0.004) and greater body fat deposited in trunk (r = -0.48, p = 0.004), and positively with LSBMD (r = 0.433, p = 0.007), fat mass loss (r = 0.438, p = 0.007) and lean mass loss (r = 0.432, p = 0.008). In the regression analysis, TBS remained associated with body fat ( = -0.625, p = 0.031; R-2 = 0.47). The fracture risk, calculated by FRAX((R)) (University of Sheffield, Sheffield, UK), with and without adjustment by TBS, was low. Conclusion: Women undergoing RYGB in the mid-term have a preserved bone MA, assessed by TBS