Rationally designed chromosome fusion does not prevent rapid growth of Vibrio natriegens.

DNA replication is essential for the proliferation of all cells. Bacterial chromosomes are replicated bidirectionally from a single origin of replication, with replication proceeding at about 1000 bp per second. For the model organism, Escherichia coli, this translates into a replication time of about 40 min for its 4.6 Mb chromosome. Nevertheless, E. coli can propagate by overlapping replication cycles with a maximum short doubling time of 20 min. The fastest growing bacterium known, Vibrio natriegens, is able to replicate with a generation time of less than 10 min. It has a bipartite genome with chromosome sizes of 3.2 and 1.9 Mb. Is simultaneous replication from two origins a prerequisite for its rapid growth? We fused the two chromosomes of V. natriegens to create a strain carrying one chromosome with a single origin of replication. Compared to the parental, this strain showed no significant deviation in growth rate. This suggests that the split genome is not a prerequisite for rapid growth.

An Optimized Genotyping Workflow for Identifying Highly SCRaMbLEd Synthetic Yeasts.

Synthetic Sc2.0 yeast strains contain hundreds to thousands of loxPsym recombination sites that allow restructuring of the Saccharomyces cerevisiae genome by SCRaMbLE. Thus, a highly diverse yeast population can arise from a single genotype. The selection of genetically diverse candidates with rearranged synthetic chromosomes for downstream analysis requires an efficient and straightforward workflow. Here we present loxTags, a set of qPCR primers for genotyping across loxPsym sites to detect not only deletions but also inversions and translocations after SCRaMbLE. To cope with the large number of amplicons, we generated qTagGer, a qPCR genotyping primer prediction tool. Using loxTag-based genotyping and long-read sequencing, we show that light-inducible Cre recombinase L-SCRaMbLE can efficiently generate diverse recombination events when applied to Sc2.0 strains containing a linear or a circular version of synthetic chromosome III.

Emergence of fractal geometries in the evolution of a metabolic enzyme.

Fractals are patterns that are self-similar across multiple length-scales1. Macroscopic fractals are common in nature2-4; however, so far, molecular assembly into fractals is restricted to synthetic systems5-12. Here we report the discovery of a natural protein, citrate synthase from the cyanobacterium Synechococcus elongatus, which self-assembles into Sierpinski triangles. Using cryo-electron microscopy, we reveal how the fractal assembles from a hexameric building block. Although different stimuli modulate the formation of fractal complexes and these complexes can regulate the enzymatic activity of citrate synthase in vitro, the fractal may not serve a physiological function in vivo. We use ancestral sequence reconstruction to retrace how the citrate synthase fractal evolved from non-fractal precursors, and the results suggest it may have emerged as a harmless evolutionary accident. Our findings expand the space of possible protein complexes and demonstrate that intricate and regulatable assemblies can evolve in a single substitution.

A supernumerary synthetic chromosome in Komagataella phaffii as a repository for extraneous genetic material.

BACKGROUND: Komagataella phaffii (Pichia pastoris) is a methylotrophic commercially important non-conventional species of yeast that grows in a fermentor to exceptionally high densities on simple media and secretes recombinant proteins efficiently. Genetic engineering strategies are being explored in this organism to facilitate cost-effective biomanufacturing. Small, stable artificial chromosomes in K. phaffii could offer unique advantages by accommodating multiple integrations of extraneous genes and their promoters without accumulating perturbations of native chromosomes or exhausting the availability of selection markers. RESULTS: Here, we describe a linear "nano"chromosome (of 15-25 kb) that, according to whole-genome sequencing, persists in K. phaffii over many generations with a copy number per cell of one, provided non-homologous end joining is compromised (by KU70-knockout). The nanochromosome includes a copy of the centromere from K. phaffii chromosome 3, a K. phaffii-derived autonomously replicating sequence on either side of the centromere, and a pair of K. phaffii-like telomeres. It contains, within its q arm, a landing zone in which genes of interest alternate with long (approx. 1-kb) non-coding DNA chosen to facilitate homologous recombination and serve as spacers. The landing zone can be extended along the nanochromosome, in an inch-worming mode of sequential gene integrations, accompanied by recycling of just two antibiotic-resistance markers. The nanochromosome was used to express PDI, a gene encoding protein disulfide isomerase. Co-expression with PDI allowed the production, from a genomically integrated gene, of secreted murine complement factor H, a plasma protein containing 40 disulfide bonds. As further proof-of-principle, we co-expressed, from a nanochromosome, both PDI and a gene for GFP-tagged human complement factor H under the control of PAOX1 and demonstrated that the secreted protein was active as a regulator of the complement system. CONCLUSIONS: We have added K. phaffii to the list of organisms that can produce human proteins from genes carried on a stable, linear, artificial chromosome. We envisage using nanochromosomes as repositories for numerous extraneous genes, allowing intensive engineering of K. phaffii without compromising its genome or weakening the resulting strain.

Design, construction, and functional characterization of a tRNA neochromosome in yeast.

Here, we report the design, construction, and characterization of a tRNA neochromosome, a designer chromosome that functions as an additional, de novo counterpart to the native complement of Saccharomyces cerevisiae. Intending to address one of the central design principles of the Sc2.0 project, the ∼190-kb tRNA neochromosome houses all 275 relocated nuclear tRNA genes. To maximize stability, the design incorporates orthogonal genetic elements from non-S. cerevisiae yeast species. Furthermore, the presence of 283 rox recombination sites enables an orthogonal tRNA SCRaMbLE system. Following construction in yeast, we obtained evidence of a potent selective force, manifesting as a spontaneous doubling in cell ploidy. Furthermore, tRNA sequencing, transcriptomics, proteomics, nucleosome mapping, replication profiling, FISH, and Hi-C were undertaken to investigate questions of tRNA neochromosome behavior and function. Its construction demonstrates the remarkable tractability of the yeast model and opens up opportunities to directly test hypotheses surrounding these essential non-coding RNAs.

Glycosyltransferases Expression Changes in Leuconostoc mesenteroides subsp. mesenteroides ATCC 8293 Grown on Different Carbon Sources.

Leuconostoc mesenteroides strains are common contributors in fermented foods producing a wide variety of polysaccharides from sucrose through glycosyltransferases (GTFs). These polymers have been proposed as protective barriers against acidity, dehydration, heat, and oxidative stress. Despite its presence in many traditional fermented products and their association with food functional properties, regulation of GTFs expression in Ln. mesenteroides is still poorly understood. The strain Ln. mesenteroides ATCC 8293 contains three glucansucrases genes not found in operons, and three fructansucrases genes arranged in two operons, levLX and levC-scrB, a Glycoside-hydrolase. We described the first differential gene expression analysis of this strain when cultivated in different carbon sources. We observed that while GTFs are expressed in the presence of most sugars, they are down-regulated in xylose. We ruled out the regulatory effect of CcpA over GTFs and did not find regulatory elements with a direct effect on glucansucrases in the condition assayed. Our findings suggest that only operon levLX is repressed in xylose by LexA and that both fructansucrases operons can be regulated by the VicK/VicR system and PerR. It is essential to further explore the effect of environmental conditions in Ln. mesenteroides bacteria to better understand GTFs regulation and polymer function.

Diseño de un bipedestador semiautomático reajustable para el desplazamiento de personas con paraplejia / Design of a semi-automatic adjustable standing frame for paraplegics

Introducción: La paraplejia es una condición de salud ocasionada por lesiones lumbares que conlleva a las personas a permanecer la mayor parte de su tiempo postradas, ocasionando problemas de respiración, variaciones en la presión arterial y la aparición de úlceras en sus partes de apoyo. Objetivo: Desarrollar un sistema mecatrónico que permita la bipedestación de personas con condición de paraplejias. Métodos: La investigación se realizó en dos etapas, el desarrollo de un sistema mecatrónico y una fase de validación de uso por usuarios con discapacidad motora. Resultados: Las pruebas de funcionamiento muestran que los atractivos más importantes del equipo son su capacidad de ajuste (permitiendo su uso a personas con diferencias antropométricas) y su operatividad. Conclusiones: El bipedestador diseñado cumplió las condiciones requeridas para realizar la transición a condición bípeda, con las medidas de seguridad en las partes críticas que garantizan la estabilidad del usuario. Además, el bipedestador posee mecanismos sencillos de operar, acorde con sus capacidades. La validación del implemento demostró que es de un tamaño adecuado y de fácil utilización, además al ser reajustable para su uso independientemente de la condición morfométrica.(AU)

Introduction: Paraplegia is an impairment in motor functioning of the lower extremities. Caused by lumbar lesions, it deprives its sufferers from their ability to move about, which results in breathing problems, arterial pressure variations and the appearance of ulcers in pressure areas. Objective: Develop a mechatronic system permitting the bipedal locomotion of paraplegics. Methods: The study was structured into two stages: development of a mechatronic system and validation of its use by people with motor disability. Results: Function tests show that the most attractive features of the device are its adjustability (allowing use by anthropometrically different people) and its operability. Conclusions: The standing frame designed met the conditions required for the transition to bipedal condition, with safety measures in its critical parts which ensure user stability. Additionally, its mechanisms are easy to operate, in keeping with its capabilities. Validation of the device showed that its size is appropriate, its operation simple, and it may be readjusted for use in different morphometric conditions(AU)

Definition of the Metagenomic Profile of Ocean Water Samples From the Gulf of Mexico Based on Comparison With Reference Samples From Sites Worldwide.

Computational and statistical analysis of shotgun metagenomes can predict gene abundance and is helpful for elucidating the functional and taxonomic compositions of environmental samples. Gene products are compared against physicochemical conditions or perturbations to shed light on the functions performed by the microbial community of an environmental sample; however, this information is not always available. The present study proposes a method for inferring the metabolic potential of metagenome samples by constructing a reference based on determining the probability distribution of the counts of each enzyme annotated. To test the methodology, we used marine water samples distributed worldwide as references. Then, the references were utilized to compare the annotated enzymes of two different water samples extracted from the Gulf of Mexico (GoM) to distinguish those enzymes with atypical behavior. The enzymes whose annotation counts presented frequencies significantly different from those of the reference were used to perform metabolic reconstruction, which naturally identified pathways. We found that several of the enzymes were involved in the biodegradation of petroleum, which is consistent with the impact of human hydrocarbon extraction activity and its ubiquitous presence in the GoM. The examination of other reconstructed pathways revealed significant enzymes indicating the presence of microbial communities characterizing each ocean depth and ocean cycle, providing a fingerprint of each sampled site.

Development and Assessment of Nano-Technologies for Cancer Treatment: Cytotoxicity and Hyperthermia Laboratory Studies.

Cancer treatment by magnetic hyperthermia offers numerous advantages, but for practical applications many variables still need to be adjusted before developing a controlled and reproducible cancer treatment that is bio-compatible (non-damaging) to healthy cells. In this work, Fe3O4 and CoFe2O4 were synthesized and systematically studied for the development of efficient therapeutic agents for applications in hyperthermia. The biocompatibility of the materials was further evaluated using HepG2 cells as biological model. Colorimetric and microscopic techniques were used to evaluate the interaction of magnetic nano-materials (MNMs) and HepG2 cells. Finally, the behavior of MNMs was evaluated under the influence of an alternating magnetic field (AMF), observing a more efficient temperature increment for CoFe2O4, a desirable behavior for biomedical applications since lower doses and shorter expositions to alternating magnetic field might be required.

Interrelación entre enfisema y disfunción diastólica ventricular izquierda: nuestra experiencia en el Hospital Privado Centro Médico de Córdoba / Interrelation between emphysema and diastolic dysfunction left ventricular: our experience in the Hospital Private Medical Center of Córdoba

Introducción: Las consecuencias hemodinámicas de la hiperinflación y el enfisema se producen por compresión cardíaca debido a elevadas presiones intratorácicas, lo que produciría disfunción diastólica ventricular izquierda subclínica. Nuestro objetivo es correlacionar el porcentaje de enfisema con parámetros de función pulmonar y con el tamaño de las cámaras cardíacas, función sistólica ventricular global y función diastólica ventricular izquierda, en la enfermedad pulmonar obstructiva crónica. Materiales y Métodos: participaron pacientes con enfermedad pulmonar obstructiva crónica moderada y severa asistidos en un Servicio de Neumonología del Hospital Privado Centro Médico de Córdoba, desde el 01 de enero al 31 de octubre de 2014. Se cuantificó el volumen y porcentaje de enfisema por tomografía computada de alta resolución, se realizaron espirometría, prueba de marcha de seis minutos, determinación de volúmenes pulmonares y ecocardiograma Doppler color. Resultados: Se encontró correlación negativa y significativa del porcentaje de enfisema con el porcentaje del valor teórico del VEF1 postbroncodilatador (p = 0.005) y el cociente VEF1/CVF postbroncodilatador (p = 0.004) y; además, entre el cociente VEF1/CVF postbroncodilatador y el volumen del enfisema en cm3 (p = 0.000). De un subgrupo de 20 pacientes. Siete pacientes (35%) presentaron diagnóstico de disfunción diastólica ventricular izquierda de grado I. Se encontraron correlaciones negativas pero no significativas entre el porcentaje de enfisema con función sistólica ventricular global y el tamaño de las cámaras cardíacas. Conclusiones: Se destaca la utilidad del ecocardiograma para reducir el sub diagnóstico de disfunción diastólica ventricular izquierda. Se destaca la importancia que tendrían la hiperinflación y el enfisema en el deterioro del patrón de llenado diastólico ventricular izquierdo y en la reducción del tamaño de las cámaras cardíacas con disminución en la tolerancia al ejercicio.

Interrelationship between Emphysema and Left Ventricular Diastolic Dysfunction: our experience in the Hospital Privado Centro Médico de Córdoba

Introduction: The hemodynamic consequences of hyperinflation and emphysema are produced by cardiac compression due to high intrathoracic pressures, which could produce subclinical left ventricular diastolic dysfunction. Our purpose is to correlate the percentage of emphysema with lung function parameters and cardiac chamber sizes, the global ventricular systolic function and the left ventricular diastolic function, in cases of chronic obstructive pulmonary disease. Materials and Methods: The participants were patients with moderate and severe chronic obstructive pulmonary disease treated in the Pulmonology Service of the Hospital Privado Centro Médico de Córdoba from January 1st to October 13th, 2014. We quantified the volume and percentage of emphysema by high resolution computed tomography and carried out a spirometry, a Six Minute Walk Test, measurement of pulmonary volumes and color Doppler echocardiography. Results: We found a significant negative correlation between the percentage of emphysema and the percentage of the post-bronchodilator FEV1 theoretical value (p = 0.005) and the post-bronchodilator FEV1/FVC (Forced Expiratory Volume in First Second/Forced Vital Capacity) quotient (p = 0.004), and, also, between the post-bronchodilator FEV1/FVC quotient and the emphysema volume in cm3 (p = 0.000). Out of a sub-group of 20 patients, seven patients (35%) were diagnosed with grade I left ventricular diastolic dysfunction. We found negative, but not significant correlations between the percentage of emphysema and global ventricular systolic function and cardiac chamber sizes. Conclusions: We should emphasize the usefulness of the echocardiography in reducing sub-diagnoses of left ventricular diastolic dysfunction. We should also stress on the importance hyperinflation and emphysema would have in the impairment of the left ventricular diastolic filling pattern and in the decrease in cardiac chamber sizes, with a decrease in exercise tolerance.

Unequivocal Experimental Evidence of the Relationship between Emission Energies and Aurophilic Interactions.

In this paper, we describe experimental evidence of a change in the emission energy as a function of the Au-Au distance. We have employed a luminescent complex exhibiting an aurophilic interaction, which is weak enough to allow its length to be modified by external pressure but rigid enough to confer structural stability on the complex. By determining the crystal structures and emission characteristics over a range of pressures, we have identified an exponential relationship between the energy of the emitted light and the metal-metal distances under pressure. This result can be indirectly related to the repulsive branch of the fitted function representing the energy of the system in the ground state at different Au-Au distances. The relativistic nature of gold appears to play an important role in the behavior of this complex.

Estudio de mutaciones germinales en pacientes con feocromocitomas y paragangliomas atendidos en un hospital universitario de tercer nivel: ¿qué pacientes se estudian y qué resultados se encuentran? / Study of germline mutations in patients with pheochromocytoma and paraganglioma in a tertiary level university hospital: Which patients have been studied and what results have been found?

Introducción: Las actuales guías de práctica clínica recomiendan considerar el estudio genético en todos los pacientes con diagnóstico de feocromocitoma o paraganglioma (PPGL). El objetivo de nuestro trabajo es conocer el porcentaje de solicitud de estudio genético en el PPGL en un hospital universitario no especializado, los factores implicados en dicha solicitud, cuántos de ellos presentan mutación germinal, cuáles son los genes afectados y qué variables se relacionan con la presencia de mutaciones. Material y métodos: Se incluyó a todos los pacientes con PPGL diagnosticados en el área sanitaria de un hospital universitario de tercer nivel entre 2010 y 2015. Se recogieron las variables: edad, localización, único o múltiple, secreción hormonal, cuadro sindrómico, antecedentes familiares y servicio responsable. Se comparó a los pacientes con estudio genético realizado (GEN+) frente a aquellos no estudiados (GEN-), y pacientes con mutación (MUT+) frente a aquellos sin mutación predisponente (MUT-). Resultados: Se incluyó a 39 pacientes (21 mujeres y 18 varones con edad media 53,9±17,8 años). Se hizo estudio genético al 54% y estos eran más jóvenes, con antecedentes familiares, múltiples, secretores y con mayor frecuencia vistos por Endocrinología. Hubo menos paragangliomas de cabeza y cuello unilaterales. Un 33% tenía mutación germinal (3 RET, 3 SDHB, un SDHD) y estos eran más jóvenes, más sindrómicos, múltiples o con antecedentes familiares. Conclusiones: Aunque las guías de práctica clínica recomiendan considerar la realización de un estudio genético a todos los pacientes con PPGL, en nuestra Área de Salud se solicitó en el 54% de ellos. Un 33% de ellos presentaron mutación germinal predisponente

Introduction: Current clinical practice guidelines recommend that a genetic study is considered in all patients diagnosed with pheochromocytoma or paraganglioma (PPGL). Our study objective was to know how many patients with PPGL undergo genetic studies at a non-specialized university hospital, the clinical factors involved in the decision to make the study, how many patients are found germline mutation, which are the affected genes, and what variables are related to presence of mutations. Material and methods: All patients diagnosed with PPGL at a tertiary university hospital from 2010 to 2015 were enrolled. Age and sex, tumor location and multiplicity, hormone secretion, presence of a clinical syndrome, family history, and medical department in charge were recorded and used to compare patients with (GEN+) and without (GEN-) genetic study, as well as patients with (MUT+) and without (MUT-) germline mutations. Results: Thirty-nine patients were enrolled (21 females and 18 males with a mean age of 53.9±17.8 years). A genetic study was performed in 54% of patients with PPGL. These were younger, were more frequently seen by endocrinologists, and had more often a family history related to PPGL, multiple PPGLs, or hormonally functional tumors. Unilateral head and neck paragangliomas were less common. Germline mutations (3 RET, 3 SDHB, 1 SDHD) were found in 33% of patients, who were younger and more frequently had a clinical syndrome, multiple PPGLs. and a family history of PPGL. Conclusion: Although current clinical practice guidelines recommend that genetic studies are considered in all patients diagnosed with PPGL, studies was requested for 54% of such cases in our healthcare area. Predisposing germline mutations were found in 33% of studies

Study of germline mutations in patients with pheochromocytoma and paraganglioma in a tertiary level university hospital: Which patients have been studied and what results have been found? / Estudio de mutaciones germinales en pacientes con feocromocitomas y paragangliomas atendidos en un hospital universitario de tercer nivel: ¿qué pacientes se estudian y qué resultados se encuentran?

INTRODUCTION: Current clinical practice guidelines recommend that a genetic study is considered in all patients diagnosed with pheochromocytoma or paraganglioma (PPGL). Our study objective was to know how many patients with PPGL undergo genetic studies at a non-specialized university hospital, the clinical factors involved in the decision to make the study, how many patients are found germline mutation, which are the affected genes, and what variables are related to presence of mutations. MATERIAL AND METHODS: All patients diagnosed with PPGL at a tertiary university hospital from 2010 to 2015 were enrolled. Age and sex, tumor location and multiplicity, hormone secretion, presence of a clinical syndrome, family history, and medical department in charge were recorded and used to compare patients with (GEN+) and without (GEN-) genetic study, as well as patients with (MUT+) and without (MUT-) germline mutations. RESULTS: Thirty-nine patients were enrolled (21 females and 18 males with a mean age of 53.9±17.8 years). A genetic study was performed in 54% of patients with PPGL. These were younger, were more frequently seen by endocrinologists, and had more often a family history related to PPGL, multiple PPGLs, or hormonally functional tumors. Unilateral head and neck paragangliomas were less common. Germline mutations (3 RET, 3 SDHB, 1 SDHD) were found in 33% of patients, who were younger and more frequently had a clinical syndrome, multiple PPGLs. and a family history of PPGL. CONCLUSION: Although current clinical practice guidelines recommend that genetic studies are considered in all patients diagnosed with PPGL, studies was requested for 54% of such cases in our healthcare area. Predisposing germline mutations were found in 33% of studies.

Long-term apoptosis-related protein expression in the diabetic mouse ovary.

Emerging evidence has shown that oocytes from diabetic ovaries exhibit delayed maturation, mitochondrial dysfunction and meiotic defects, which are related increased apoptosis. The main objective of the present study was to analyze the apoptosis pathways activated during follicular loss at multiple time points in a diabetic mouse model. Twenty BALB/c mice were used in this study, and diabetes mellitus was induced by streptozotocin injection. Three diabetic and two control animals were sacrificed on days 15, 20, 70 and 80 posttreatment. The ovaries were then removed; one was used for follicular counting, TUNEL, immunohistochemistry and immunofluorescence, while the other was used for Western blot analysis. The proteins studied were BAX, BCL2, t-BID, FAS, FASL, active caspase 8, active caspase 9 and active caspase 3. Follicular apoptosis decreased over time, with the highest values observed at 15 days posttreatment. Granulosa cells were positive for active caspase 3, which showed constant expression levels at all time points. FAS, FASL, t-BID and active caspase 8 showed strong cytoplasmic immunostaining in the oocytes and granulosa cells of the diabetic mice, with significant increases observed at 15, 20 and 70 days posttreatment. BAX expression was slightly higher in the diabetic mouse ovaries than in the control ovaries at 15, 20 and 70 days posttreatment, whereas the highest active caspase 9 expression was at observed 20 days posttreatment. Low BCL2 protein levels were detected in the diabetic mouse ovaries at all time points. This study describes for the first time the behavior of apoptosis-related proteins in the diabetic mouse ovary and shows not only that the FAS/FASL pathway contributes to follicular loss but also that antral follicles are the most affected.

Genomic Investigation of a Legionellosis Outbreak in a Persistently Colonized Hotel.

OBJECTIVES: A long-lasting legionellosis outbreak was reported between November 2011 and July 2012 in a hotel in Calpe (Spain) affecting 44 patients including six deaths. Intensive epidemiological and microbiological investigations were performed in order to detect the reservoirs. METHODS: Clinical and environmental samples were tested for the presence and genetic characterization of Legionella pneumophila. Six of the isolates were subjected to whole-genome sequencing. RESULTS: Sequencing of 14 clinical and 260 environmental samples revealed sequence type (ST) 23 as the main responsible strain for the infections. This ST was found in the spa pool, from where it spread to other hotel public spaces, explaining the ST23 clinical cases, including guests who had not visited the spa. Uncultured clinical specimens showed profiles compatible with ST23, ST578, and mixed patterns. Profiles compatible with ST578 were obtained by direct sequencing from biofilm samples collected from the domestic water system, which provided evidence for the source of infection for non ST23 patients. Whole genome data from five ST23 strains and the identification of different STs and Legionella species showed that different hotel premises were likely colonized since the hotel opening thus explaining how different patients had been infected by distinct STs. CONCLUSIONS: Both epidemiological and molecular data are essential in the investigation of legionellosis outbreaks. Whole-genome sequencing data revealed significant intra-ST variability and allowed to make further inference on the short-term evolution of a local colonization of L. pneumophila.

Phylogenetic analysis of environmental Legionella pneumophila isolates from an endemic area (Alcoy, Spain).

Environmental surveillance of Legionella pneumophila is a key component of the control measures established in urban settlements to ensure water safety and quality, with the aim of minimizing and limiting opportunistic infections in humans. In this work, we present results on the detection and genetic characterization of these bacteria in the outbreak-recurrent region of Alcoy (Comunidad Valenciana, Spain) using water and biofilm samples. We were particularly interested in studying the presence and distribution of L. pneumophila in the absence of outbreak or sporadic cases of legionellosis and in comparing the efficacy of culturing from water samples with a biofilm-based detection procedure using molecular amplification. To this end, water samples were taken from 120 sites distributed all around the city and its surroundings, as well as 60 biofilm swabs from half of the sampling sites. L. pneumophila could be isolated from water in just 4 of the locations. Touchdown PCR was applied to DNA extracted from water and also biofilm swabs, as a rapid method for both routine and outbreak investigations. L. pneumophila was detected by this method in 14 of the sites in which both water and biofilms were taken, although 13 of them tested positive using only the biofilm samples. These results show a ten-fold increase in the success rate of Legionella detection over water samples. The application of this method to study the presence of L. pneumophila in the water-supply system and risk facilities of Alcoy revealed different strains distributed in different areas of the city. Sequence Type ST578, endemic in the area and responsible for most clinical cases, was detected in one of the sampling sites. The number of positive samples correlated with water temperature but not with chlorine levels. The direct analysis of biofilm swabs improves the detection rate and genetic characterization of L. pneumophila and can complement analyses based on bacterial culture.

Satisfacción laboral del personal de enfermería del área administrativa / Job satisfaction of nursing staff in the administrative area

Resumen

Introducción: existen factores de motivación intrínsecos del trabajo, vinculados directamente con la satisfacción laboral, así como factores extrínsecos que no pueden ser controlados o modificados directamente por el trabajador.

Objetivo: determinar el grado de satisfacción laboral del personal de enfermería del área administrativa de un hospital de segundo nivel en el estado de Aguascalientes.

Metodología estudio descriptivo, transversal, prospectivo y connacional; realizado mediante una muestra no probabilística por conveniencia integrada por 40 enfermeras del área administrativa. Se utilizó un instrumento denominado Cédula de evaluación de! grado de satisfacción laboral (Briseño 1988) modificado y validado con la prueba K-R 20 con un resultado de 0.96. El análisis de datos se realizó con el paquete estadístico Minitab versión 15.

Resultados: 43% del personal de enfermería de nivel administrativo refiere estar muy satisfecho, 38% bastante satisfecho, 16% poco satisfecho y 3% nada satisfecho.

Conclusiones: las variables con mayor satisfacción fueron: el trabajo, el salario, los compañeros, el servicio y el tumo. Los rubros con menor satisfacción son: con jefes y superiores, posibilidades de ascenso, incentivos y organización en el trabajo. En el cruce de variables que mostraron mayor dependencia fueron salario y posibilidades de ascenso, tipo de trabajo y jefes y superiores, tipo de trabajo con servicio, compañeros y organización.

Abstract

Introduction: There are motivational factors inherent to work directly related to job satisfaction, and extrinsic factors that cannot be controlled or directly modified by the employee.

Objective: To determine the level of job satisfaction among nursing staff in the administrative area of a second level of attention hospital in the State of Aguascalientes.

Methodology: Descriptive, transversal, prospective and correlational study. It was performed using a non probabilistic, convenience sample consisting of 40 nurses from the administrative area. An instrument called «Assessment of job satisfaction level form¼ (Briseno 1988) was used; it was modified and validated with the KR 20 test with a score of 0.96. Data analysis was performed using the statistical package Minitab version 15.

Results: 43% of the nursing administration staff refers to be very satisfied, 38% are fairly satisfied, 16% are a little satisfied and 3% are not satisfied.

Conclusions: The variables with greater satisfaction levels were: work, salary, co-workers, Service and shift. The items with lowest satisfaction level are: bosses and superiors, promotion opportunities, incentives and work organization. In the Crossing of variables the ones that showed greater dependence were salary and promotion opportunities, type of work and bosses and superiors, kind of work with Service area, co-workers and organization.

[Autoantibodies in GAD65 in Mexican adults with diabetes types 1 and 2 and their siblings]. / Autoanticuerpos GAD65 en adultos mexicanos con diabetes tipos 1 y 2 y en sus familiares.

BACKGROUND: Pancreatic cell destruction causing type 1 diabetes is associated to diverse autoantibodies. Antibodies against glutamic acid decarboxylase have been found in type 1 (DM1) and type 2 diabetic patients (DM2). Their presence in siblings is unknown. OBJECTIVE: To determine the presence of anti-GAD65 autoantibodies in diabetic patients and their siblings. PARTICIPANTS AND METHOD: Sixty-eight individuals were included and distributed in four groups: group 1 DM1, group 2 DM2, group 3 and 4 healthy siblings of patients from groups 1 and 2. Anti-GAD65, peptide C, serum glucose, total cholesterol and triglycerides were obtained. Body mass index and hip-waist ratio were measured. RESULTS: Anti-GAD65 antibodies were positive in 23% of DM1, in 14% of DM2, and in 7.7% and 9.5% in siblings of both groups, respectively. Using Mann-Whitney's U the mean of anti-GAD65 in diabetic type 1 and 2 patients was p = 0.022; between DM1 and their siblings and between DM2 and their siblings there was no statistical significance. C peptide was low in cases of positive anti-GAD65 of DM1 and DM2; and it was normal in patients with negative anti-GAD65. CONCLUSIONS: Anti-GAD65 autoantibodies are more frequent in type 1 diabetic patients. There were no meaningful differences regarding the presence of anti-GAD65 in patients and their siblings.

Early tissue patterning recreated by mouse embryonic fibroblasts in a three-dimensional environment.

Cellular self-organization studies have been mainly focused on models such as Volvox, the slime mold Dictyostelium discoideum, and animal (metazoan) embryos. Moreover, animal tissues undergoing regeneration also exhibit properties of embryonic systems such as the self-organization process that rebuilds tissue complexity and function. We speculated that the recreation in vitro of the biological, biophysical, and biomechanical conditions similar to those of a regenerative milieu could elicit the intrinsic capacity of differentiated cells to proceed to the development of a tissue-like structure. Here we show that, when primary mouse embryonic fibroblasts are cultured in a soft nanofiber scaffold, they establish a cellular network that causes an organized cell contraction,proliferation, and migration that ends in the formation of a symmetrically bilateral structure with a distinct central axis. A subset of mesodermal genes (brachyury, Sox9, Runx2) is upregulated during this morphogenetic process. The expression of brachyury was localized first at the central axis, extending then to both sides of the structure. The spontaneous formation of cartilage-like tissue mainly at the paraxial zone followed expression ofSox9 and Runx2. Because cellular self-organization is an intrinsic property of the tissues undergoing development,this model could lead to new ways to consider tissue engineering and regenerative medicine.