Lessons learned from a study based on the AHP method for the assessment of sustainability in neighborhoods.

The Analytic Hierarchy Process (AHP) is a method that allows complex decisions to be made from impartiality, making it suitable for reaching a consensus among experts seeking to solve a problem. This method has been successfully applied in other investigations, and its use has been extended to several disciplines. This technical paper presents the lessons learned from a study that relied on the AHP method to determine priority aspects for sustainable neighborhoods. The research is developed in three replicable phases. In each of them, aspects that are recommended to be considered are detailed, for example, in the formulation of the hierarchical structure, selection of experts, expert survey design, and information processing for the determination of weights and levels of importance.•The utilization of software to apply the AHP method can help researchers to optimize time and resources.•Social networks proved to be more effective than conventional methods for identifying and contacting experts.•Subjective sustainability issues can be prioritized by expert consensus.

Iterative Level-0: A new and fast algorithm to traverse mating networks calculating the inbreeding and relationship coefficients.

In population medical genetics, the study of autosomal recessive disorders in highly endogamous populations is a major topic where calculating the inbreeding and relationship coefficients on mating networks is crucial. However, a challenge arises when dealing with large and complex mating networks, making their traversal difficult during the calculation process. For this calculation, we propose using Iterative Level-0 (IL0) as a new and faster algorithm that traverses mating networks more efficiently. The purpose of this work is to explain in detail the IL0 algorithm and prove its superiority by comparing it with two algorithms based on the best-known algorithms in the area: Depth First Search (DFS) and Breadth First Search (BFS). A Cytoscape application has been developed to calculate the inbreeding and relationship coefficients of individuals composing any mating network. In this application, the IL0 proposal together with DFS-based and BFS-based algorithms have been implemented. Any user can access this freely available Cytoscape application (https://apps.cytoscape.org/apps/inbreeding) that allows the comparison between the IL0 proposal and the best-known algorithms (based on DFS and BFS). In addition, a diverse set of mating networks has been collected in terms of complexity (number of edges) and species (humans, primates, and dogs) for the experiments. The runtime obtained by the IL0, DFS-based, and BFS-based algorithms when calculating the inbreeding and relationship coefficients proved the improvement of IL0. In fact, a speedup study reflected that the IL0 algorithm is 7.60 to 127.50 times faster than DFS-based and BFS-based algorithms. Moreover, a scalability study found that the growth of the IL0 runtime has a linear dependence on the number of edges of the mating network, while the DFS-based and BFS-based runtimes have a quadratic dependence. Therefore, the IL0 algorithm can solve the problem of calculating the inbreeding and relationship coefficients many times faster (up to 127.50) than the two algorithms based on the famous DFS and BFS. Furthermore, our results demonstrate that IL0 scales much better as the complexity of mating networks increases.

Pneumolysin as a target for new therapies against pneumococcal infections: A systematic review.

BACKGROUND: This systematic review evaluates pneumolysin (PLY) as a target for new treatments against pneumococcal infections. Pneumolysin is one of the main virulence factors produced by all types of pneumococci. This toxin (53 kDa) is a highly conserved protein that binds to cholesterol in eukaryotic cells, forming pores that lead to cell destruction. METHODS: The databases consulted were MEDLINE, Web of Science, and Scopus. Articles were independently screened by title, abstract, and full text by two researchers, and using consensus to resolve any disagreements that occurred. Articles in other languages different from English, patents, cases report, notes, chapter books and reviews were excluded. Searches were restricted to the years 2000 to 2021. Methodological quality was evaluated using OHAT framework. RESULTS: Forty-one articles describing the effects of different molecules that inhibit PLY were reviewed. Briefly, the inhibitory molecules found were classified into three main groups: those exerting a direct effect by binding and/or blocking PLY, those acting indirectly by preventing its effects on host cells, and those whose mechanisms are unknown. Although many molecules are proposed as toxin blockers, only some of them, such as antibiotics, peptides, sterols, and statins, have the probability of being implemented as clinical treatment. In contrast, for other molecules, there are limited studies that demonstrate efficacy in animal models with sufficient reliability. DISCUSSION: Most of the studies reviewed has a good level of confidence. However, one of the limitations of this systematic review is the lack of homogeneity of the studies, what prevented to carry out a statistical comparison of the results or meta-analysis. CONCLUSION: A panel of molecules blocking PLY activity are associated with the improvement of the inflammatory process triggered by the pneumococcal infection. Some molecules have already been used in humans for other purposes, so they could be safe for use in patients with pneumococcal infections. These patients might benefit from a second line treatment during the initial stages of the infection preventing acute respiratory distress syndrome and invasive pneumococcal diseases. Additional research using the presented set of compounds might further improve the clinical management of these patients.

Analysis of the Embodied Energy and CO2 Emissions of Ready-Mixed Concrete: A Case Study in Cuenca, Ecuador.

Concrete is the most commonly construction material used worldwide. In contrast to other countries, Ecuador lacks studies that determine the environmental impact of the production of construction materials. This research presents a quantification of embodied energy and CO2 emissions associated with the concrete production, using as a case study a ready-mixed concrete plant in the city of Cuenca, Ecuador. The study was based on the Life Cycle Assessment methodology established by ISO 14040 and ISO 14044, and the 2006 Intergovernmental Panel of Experts on Climate Change (IPCC) Guidelines for National Greenhouse Gas Inventories. The production of ready-mixed concrete was considered for one year, with a "gate to gate" approach including the "transport of raw material" to the concrete plant and the subsequent "transport of final product" to the construction site. The results revealed that to produce 1 m3 of ready-mixed concrete, its production required 568.69 MJ of energy, accompanied by 42.83 kg CO2. Indirect transport generates the greatest environmental impact, especially the "transport of raw materials", which represents approximately 80% of the embodied energy and 79% of CO2 emission.

PhageCocktail: An R package to design phage cocktails from experimental phage-bacteria infection networks.

BACKGROUND AND OBJECTIVE: Phage therapy is a resurgent strategy used in medicine and the food industry to lyse bacteria that cause damage to health or spoil a food product. Frequently, phage-bacteria infection networks have a large size, making it impossible to manually study all possible phage cocktails. Thus, this article presents an R package called PhageCocktail to automatically design efficient phage cocktails from phage-bacteria infection networks. METHODS: This R package includes four different methods for designing phage cocktails: ExhaustiveSearch, ExhaustivePhi, ClusteringSearch, and ClusteringPhi. These four methods are explained in detail and are evaluated using 13 empirical phage-bacteria infection networks. More specifically, runtime and expected success (fraction of lysed bacteria) are analyzed. RESULTS: The four methods have variations in terms of runtime and quality of the results. ExhaustiveSearch always provides the best possible phage cocktail, but its runtime could be long. ExhaustivePhi only focuses on one cocktail size, the one estimated as the best; thus, its runtime is less than ExhaustiveSearch, but it can produce cocktails with more phages than necessary. ClusteringSearch and ClusteringPhi are very fast (generally, less than one millisecond), providing always immediate results due to clustering techniques, but their accuracies can be lower, yielding cocktails with lower expected successes. CONCLUSIONS: The larger the phage-bacteria infection network is, the more complex its analysis is. Thus, this tool eases this task for scientists and other users while designing phage cocktails of good quality. This R package includes four different methods; therefore, users may choose among them, considering their preferences in speed and accuracy of results.

Systematic analysis of putative phage-phage interactions on minimum-sized phage cocktails.

The application of bacteriophages as antibacterial agents has many benefits in the "post-antibiotic age". To increase the number of successfully targeted bacterial strains, phage cocktails, instead of a single phage, are commonly formulated. Nevertheless, there is currently no consensus pipeline for phage cocktail development. Thus, although large cocktails increase the spectrum of activity, they could produce side effects such as the mobilization of virulence or antibiotic resistance genes. On the other hand, coinfection (simultaneous infection of one host cell by several phages) might reduce the potential for bacteria to evolve phage resistance, but some antagonistic interactions amongst phages might be detrimental for the outcome of phage cocktail application. With this in mind, we introduce here a new method, which considers the host range and each individual phage-host interaction, to design the phage mixtures that best suppress the target bacteria while minimizing the number of phages to restrict manufacturing costs. Additionally, putative phage-phage interactions in cocktails and phage-bacteria networks are compared as the understanding of the complex interactions amongst bacteriophages could be critical in the development of realistic phage therapy models in the future.

Computational design of phage cocktails based on phage-bacteria infection networks.

The misuse and overuse of antibiotics have boosted the proliferation of multidrug-resistant (MDR) bacteria, which are considered a major public health issue in the twenty-first century. Phage therapy may be a promising way in the treatment of infections caused by MDR pathogens, without the side effects of the current available antimicrobials. Phage therapy is based on phage cocktails, that is, combinations of phages able to lyse the target bacteria. In this work, we present and explain in detail two innovative computational methods to design phage cocktails taking into account a given phage-bacteria infection network. One of the methods (Exhaustive Search) always generates the best possible phage cocktail, while the other method (Network Metrics) always keeps a very reduced runtime (a few milliseconds). Both methods have been included in a Cytoscape application that is available for any user. A complete experimental study has been performed, evaluating and comparing the biological quality, runtime, and the impact when additional phages are included in the cocktail.

New Insights into the Genome Organization of Yeast Double-Stranded RNA LBC Viruses.

The yeasts Torulaspora delbrueckii (Td) and Saccharomyces cerevisiae (Sc) may show a killer phenotype that is encoded in dsRNA M viruses (V-M), which require the helper activity of another dsRNA virus (V-LA or V-LBC) for replication. Recently, two TdV-LBCbarr genomes, which share sequence identity with ScV-LBC counterparts, were characterized by high-throughput sequencing (HTS). They also share some similar characteristics with Sc-LA viruses. This may explain why TdV-LBCbarr has helper capability to maintain M viruses, whereas ScV-LBC does not. We here analyze two stretches with low sequence identity (LIS I and LIS II) that were found in TdV-LBCbarr Gag-Pol proteins when comparing with the homologous regions of ScV-LBC. These stretches may result from successive nucleotide insertions or deletions (indels) that allow compensatory frameshift events required to maintain specific functions of the RNA-polymerase, while modifying other functions such as the ability to bind V-M (+)RNA for packaging. The presence of an additional frameshifting site in LIS I may ensure the synthesis of a certain amount of RNA-polymerase until the new compensatory indel appears. Additional 5'- and 3'-extra sequences were found beyond V-LBC canonical genomes. Most extra sequences showed high identity to some stretches of the canonical genomes and can form stem-loop structures. Further, the 3'-extra sequence of two ScV-LBC genomes contains rRNA stretches. The origin and possible functions of these extra sequences are here discussed.

A New Pipeline for Designing Phage Cocktails Based on Phage-Bacteria Infection Networks.

In recent years, the spread of antibiotic-resistant bacteria and efforts to preserve food microbiota have induced renewed interest in phage therapy. Phage cocktails, instead of a single phage, are commonly used as antibacterial agents since the hosts are unlikely to become resistant to several phages simultaneously. While the spectrum of activity might increase with cocktail complexity, excessive phages could produce side effects, such as the horizontal transfer of genes that augment the fitness of host strains, dysbiosis or high manufacturing costs. Therefore, cocktail formulation represents a compromise between achieving substantial reduction in the bacterial loads and restricting its complexity. Despite the abovementioned points, the observed bacterial load reduction does not increase significantly with the size of phage cocktails, indicating the requirement for a systematic approach to their design. In this work, the information provided by host range matrices was analyzed after building phage-bacteria infection networks (PBINs). To this end, we conducted a meta-analysis of 35 host range matrices, including recently published studies and new datasets comprising Escherichia coli strains isolated during ripening of artisanal raw milk cheese and virulent coliphages from ewes' feces. The nestedness temperature, which reflects the host range hierarchy of the phages, was determined from bipartite host range matrices using heuristic (Nestedness Temperature Calculator) and genetic (BinMatNest) algorithms. The latter optimizes matrix packing, leading to lower temperatures, i.e., it simplifies the identification of the phages with the broadest host range. The structure of infection networks suggests that generalist phages (and not specialist phages) tend to succeed in infecting less susceptible bacteria. A new metric (Φ), which considers some properties of the host range matrices (fill, temperature, and number of bacteria), is proposed as an estimator of phage cocktail size. To identify the best candidates, agglomerative hierarchical clustering using Ward's method was implemented. Finally, a cocktail was formulated for the biocontrol of cheese-isolated E. coli, reducing bacterial counts by five orders of magnitude.

Corrigendum: Diversity and Local Coadaptation of Escherichia coli and Coliphages From Small Ruminants.

[This corrects the article DOI: 10.3389/fmicb.2020.564522.].

Diversity and Local Coadaptation of Escherichia coli and Coliphages From Small Ruminants.

Bacteriophages are highly specific predators that drive bacterial diversity through coevolution while striking tradeoffs among preserving host populations for long-term exploitation and increasing their virulence, structural stability, or host range. Escherichia coli and other coliform bacteria present in the microbiota of milk and during early ripening of raw milk cheeses have been linked to the production of gas, manifested by the appearance of eyes, and the development of off-flavors; thus, they might cause early blowing and cheese spoilage. Here, we report the characterization of coliphages isolated from manure from small ruminant farms and E. coli strains isolated from goat and sheep raw milk cheese. Additionally, the virulence and host range of locally isolated and laboratory collection phages were determined by comparing the susceptibility of E. coli strains from different sources. In agreement with the high genetic diversity found within the species E. coli, clustering analysis of whole-cell protein revealed a total of 13 distinct profiles but none of the raw milk cheese isolates showed inhibition of growth by reference or water-isolated coliphages. Conversely, 10 newly isolated phages had a broad host range (i.e., able to lyse ≥50% of bacterial hosts tested), thus exhibiting utility for biocontrol and only one cheese-isolated E. coli strain was resistant to all the phages. Whereas there was a high positive correlation between bacterial susceptibility range and lysis intensity, the phages virulence decreased as range increased until reaching a plateau. These results suggest local gene-for-gene coevolution between hosts and phages with selective tradeoffs for both resistance and competitive ability of the bacteria and host-range extension and virulence of the phage populations. Hence, different phage cocktail formulations might be required when devising long-term and short-term biocontrol strategies.

Early blowing in raw goats' milk cheese: gas production capacity of Enterobacteriaceae species present during manufacturing and ripening.

The aim of this study was to identify the main Enterobacteriaceae species responsible for early gas blowing during curdling and the first week of ripening in raw goats' milk cheese. Two batches of raw goats' milk cheese were selected. One of them showed early blowing within the first 24 h of cheese ripening while the other showed no alteration. Although initial levels of Enterobacteriaceae were similar in defective and non-defective cheese, their dynamics (growth and disappearance rates of the species detected) were different. Klebsiella oxytoca and Enterobacter cloacae were the main species in the defective curd, whereas Buttiauxela spp. was predominant in normal curd. Hafnia alvei was the prevailing isolated species for both normal and defective cheese throughout the ripening process. The highest gas production was rendered by K. oxytoca and H. alvei, mainly isolated from curd and cheese. However, other species relevant in milk or curd, like Pantoea ssp. or Buttiauxela spp. were considered as low gas producers. The analysis of digitalized images of cheese showed that most of the cheese eyes were formed before the first week of ripening, although this process continued during maturation.According to the species found in the defective and non-defective cheese, their proportions at different ripening stages, their ability to produce gas and eye formation, K. oxytoca might be considered the most likely responsible for early blowing in raw goats' milk cheeses; while H. alvei increased the eyes number in the later stages of the ripening period.

Terapeutas ocupacionales: influencia del género en su desempeño laboral / Occupational therapies: gender influence in their work performance

Esta investigación se fundamenta desde una perspectiva y enfoque de género. Su objetivo fue analizar la influencia del género en el desempeño laboral de los Terapeutas Ocupacionales en la ciudad de Temuco, basándose en las percepciones y vivencias de dichos profesionales. La metodología utilizada corresponde al enfoque cualitativo, utilizando como sustento teórico la fenomenología. La muestra del estudio fue intencional y estuvo constituida por 10 profesionales, siendo elnúmero de hombres y mujeres iguales en cantidad. Se utilizó la entrevista semiestructurada como instrumento de recolección de datos analizando la información obtenida a través del análisis de contenido y análisis de discurso. Los tópicos abordados consideran la relación entre trabajo y género y hacen referencia a: diferencias salariales, costos laborales, manejo de poder y estatus de minoría. Los resultados obtenidos señalan que existe influencia del género en el desempeño laboral de los Terapeutas Ocupacionales en todas las determinantes analizadas, principalmente en costos laborales y estatus de minoría. Con respecto al impacto en el desempeño existen opiniones divididas, y a que el 80 por ciento de la muestra femenina considera que existe influencia de género en el desempeño laboral, frente al 60 por ciento masculino que no visualiza influencias en su quehacer determinados por la variable de género. Sin embargo, se hace necesario destacar que lo anterior no está determinado por la disciplina, sino que por las construcciones culturales de la sociedad, por lo que debemos ser más críticos con los fenómenos derivados de género, considerando que es una categoría de análisis inherente al ser humano.

This research is based on a gender perspective and approach. Its objective was to analyze the gender’s influence on the performance of Occupational Therapists’s work in the city of Temuco, based on the perceptions and experiences of these professionals. The methodology used corresponds to the qualitative approach, using the phenomenology as theoretical support. The sample of the study was intentional and was constituted by 10 professionals, being the number of men and women equal in quantity. The semi - structured interview was used as an instrument of data collection by analyzing the information obtained through content analysis and discourse analysis. The topics covered consider the relationship between work and gender and refer to: wage differences, labor costs, power management and minority status. The results obtained indicate that there is gender influence in the occupational therapists’ workperformance in all the determinants analyzed, mainly in labor costs and minority status. With regard to the impact on performance, there are divided opinions, since 80 percent of the female sample considers that there is gender influence in the labor performance, compared to the male 60 percent that does not visualize influences in their work determined by the gender variable. However, it is necessary to emphasize that the above is not determined by the discipline, but by the cultural constructions of the society, reason why we must be more critical with the phenomena derived from gender, considering that it is a category of analysis inherent to the human being.

Incorporating equity issues into the development of Colombian clinical practice guidelines: suggestions for the GRADE approach / Incorporando equidad al desarrollo de guías de práctica clínica colombianas: sugerencias para la aproximación Grade

Objective To propose how to incorporate equity issues, using the GRADE approach, into the development and implementation of Colombian Clinical Practice Guidelines. Methodology This proposal was developed in four phases: 1. Included a literature review and the development of a preliminary proposal about how to include equity issues; 2. Involved an informal discussion to reach a consensus on improving the first proposal; 3. Was a survey of the researchers' acceptance levels of the proposal, and; 4. A final informal consensus was formed to adjust the proposal. Results A proposal on how to incorporate equity issues into the GRADE approach was developed. It places particular emphasis on the recognition of disadvantaged populations in the development and implementation of the suggested guideline. PROGRESS-Plus is recommended for use in exploring the various categories of disadvantaged people. The proposal suggests that evidence be rated differentially by giving higher ratings to studies that consider equity issues than those that do not. The proposal also suggests the inclusion of indicators to monitor the impacts of the implementation of CPGs on disadvantaged people. Conclusions A consideration of equity in the development and implementation of clinical practice guidelines and quality assessments of the evidence would achieve more in the participation of potential actors in the process and reflect on the effectiveness of the proposed interventions across all social groups.(AU)

Objetivo Proponer como incorporar temas de equidad en el desarrollo e implementación de guías de práctica clínica colombianas utilizando el acercamiento GRADE. Metodología Esta propuesta fue desarrollada en 4 fases: una revisión de la literatura y desarrollo de una propuesta preliminar sobre como incluir temas de equidad, discusión informal para alcanzar un consenso que mejore la primera propuesta; una encuesta sobre los niveles de aceptación de la propuesta y un consenso informal final para ajustar la propuesta. Resultados Se desarrolló una propuesta sobre como incorporar temas de equidad con el acercamiento GRADE. Este hace énfasis especial en el reconocimiento de poblaciones en desventaja al desarrollar e implementar guías. Se recomienda el uso del PROGRESS-Plus para explorar las categorías de las poblaciones en desventaja. La propuesta sugiere una calificación diferencial de la evidencia dando clasificaciones superiores a los estudios que toman en consideración temas de equidad. Esta propuesta también sugiere la inclusión de indicadores que monitoreen el impacto de la implementación de GPC en personas en desventaja. Conclusiones Tener en cuenta la equidad en el desarrollo e implementación de las guías de práctica clínica y la evaluación de calidad de la evidencia puede lograr más en la participación de los actores potenciales del proceso y reflejarse en la efectividad de las intervenciones propuestas en todos los grupos sociales.(AU)

Incorporating equity issues into the development of Colombian clinical practice guidelines: suggestions for the GRADE approach.

Objective To propose how to incorporate equity issues, using the GRADE approach, into the development and implementation of Colombian Clinical Practice Guidelines. Methodology This proposal was developed in four phases: 1. Included a literature review and the development of a preliminary proposal about how to include equity issues; 2. Involved an informal discussion to reach a consensus on improving the first proposal; 3. Was a survey of the researchers' acceptance levels of the proposal, and; 4. A final informal consensus was formed to adjust the proposal. Results A proposal on how to incorporate equity issues into the GRADE approach was developed. It places particular emphasis on the recognition of disadvantaged populations in the development and implementation of the suggested guideline. PROGRESS-Plus is recommended for use in exploring the various categories of disadvantaged people. The proposal suggests that evidence be rated differentially by giving higher ratings to studies that consider equity issues than those that do not. The proposal also suggests the inclusion of indicators to monitor the impacts of the implementation of CPGs on disadvantaged people. Conclusions A consideration of equity in the development and implementation of clinical practice guidelines and quality assessments of the evidence would achieve more in the participation of potential actors in the process and reflect on the effectiveness of the proposed interventions across all social groups.

Improved detection of Escherichia coli and coliform bacteria by multiplex PCR.

BACKGROUND: The presence of coliform bacteria is routinely assessed to establish the microbiological safety of water supplies and raw or processed foods. Coliforms are a group of lactose-fermenting Enterobacteriaceae, which most likely acquired the lacZ gene by horizontal transfer and therefore constitute a polyphyletic group. Among this group of bacteria is Escherichia coli, the pathogen that is most frequently associated with foodborne disease outbreaks and is often identified by ß-glucuronidase enzymatic activity or by the redundant detection of uidA by PCR. Because a significant fraction of essential E. coli genes are preserved throughout the bacterial kingdom, alternative oligonucleotide primers for specific E. coli detection are not easily identified. RESULTS: In this manuscript, two strategies were used to design oligonucleotide primers with differing levels of specificity for the simultaneous detection of total coliforms and E. coli by multiplex PCR. A consensus sequence of lacZ and the orphan gene yaiO were chosen as targets for amplification, yielding 234 bp and 115 bp PCR products, respectively. CONCLUSIONS: The assay designed in this work demonstrated superior detection ability when tested with lab collection and dairy isolated lactose-fermenting strains. While lacZ amplicons were found in a wide range of coliforms, yaiO amplification was highly specific for E. coli. Additionally, yaiO detection is non-redundant with enzymatic methods.

Survival of child after lion attack.

BACKGROUND: Injuries to humans caused by attacks from large predators are very rare, especially in the United States, Europe, or Latin America. A few cases were reported on accidents in zoos or animal farms, being very uncommon in children. The purposes of this report include describing the case of a child who sustained an attack by a lion named "Bang-Bang", which resulted in injuries to the head, chest, and abdomen, as well as the subsequent neurosurgical treatment and providing a review of the literature. CASE DESCRIPTION: We report the case of an 8-year-old boy who was attacked by a lion during a circus show. The patient underwent an emergent neurosurgical procedure, including parietal craniectomy, cleaning, and extensive surgical debridement of the wounds. Despite open severe head trauma with brain damage as well as thorax and abdomen trauma, the child survived, with minimal neurological sequelae. CONCLUSIONS: Human injury resulting from encounters with nondomesticated animals is increasingly rising throughout the world. This case highlights the potentially violent and aggressive nature of wild mammals held in captivity. Unusual wild animal attacks and the complex injuries that result may pose a challenge to surgeons practicing in resource-limited settings. In this sense, the best treatment in the mentioned case is the prevention of human injuries by these animals. In addition, to attend to these infrequent cases, the authors emphasize the importance of a multidisciplinary approach to achieve the best cosmetic and functional results.

Organization of ribonucleoside diphosphate reductase during multifork chromosome replication in Escherichia coli.

Ribonucleoside diphosphate reductase (RNR) is located in discrete foci in a number that increases with the overlapping of replication cycles in Escherichia coli. Comparison of the numbers of RNR, DnaX and SeqA protein foci with the number of replication forks at different growth rates reveals that fork : focus ratios augment with increasing growth rates, suggesting a higher cohesion of the three protein foci with increasing number of forks per cell. Quantification of NrdB and SeqA proteins per cell showed: (i) a higher amount of RNR per focus at faster growth rates, which sustains the higher cohesion of RNR foci with higher numbers of forks per cell; and (ii) an equivalent amount of RNR per replication fork, independent of the number of the latter.

Correlation between ribonucleoside-diphosphate reductase and three replication proteins in Escherichia coli.

BACKGROUND: There has long been evidence supporting the idea that RNR and the dNTP-synthesizing complex must be closely linked to the replication complex or replisome. We contributed to this body of evidence in proposing the hypothesis of the replication hyperstructure. A recently published work called this postulate into question, reporting that NrdB is evenly distributed throughout the cytoplasm. Consequently we were interested in the localization of RNR protein and its relationship with other replication proteins. RESULTS: We tagged NrdB protein with 3xFLAG epitope and detected its subcellular location by immunofluorescence microscopy. We found that this protein is located in nucleoid-associated clusters, that the number of foci correlates with the number of replication forks at any cell age, and that after the replication process ends the number of cells containing NrdB foci decreases.We show that the number of NrdB foci is very similar to the number of SeqA, DnaB, and DnaX foci, both in the whole culture and in different cell cycle periods. In addition, interfoci distances between NrdB and three replication proteins are similar to the distances between two replication protein foci. CONCLUSIONS: NrdB is present in nucleoid-associated clusters during the replication period. These clusters disappear after replication ends. The number of these clusters is closely related to the number of replication forks and the number of three replication protein clusters in any cell cycle period. Therefore we conclude that NrdB protein, and most likely RNR protein, is closely linked to the replication proteins or replisome at the replication fork. These results clearly support the replication hyperstructure model.

Costo directo de la farmacoterapia de la leucemia aguda en el Hospital Clínico Regional de Valdivia, Chile: análisis del período 2003 a 2006 / Direct costs of pharmacotherapy for acute leukemia at a Regional Hospital in Chile

Background: In Chile, leukemia is one of the diseases whose treatment is guaranteed by a special law called AUGE (universal access and explicit guaranties). Therefore, the knowledge of its treatment costs is of utmost importance. Aim: To determine and to characterize the direct costs of pharmacotherapy for leukemia at a regional hospital in Chile. Material and methods: Data were retrospectively obtained from electronic and manual records of the hospital for all patients treated for leukemia between 2003 and 2006. Patients were classified into four groups: pediatric and adult patients treated for acute lymphocytic leukemia (ALL children and ALL adults, respectively), and pediatric and adult patients treated for acute myelogenous leukemia (AML children and AML adults, respectively). Results: Total accumulated costs of pharmacotherapy for acute leukemia between 2003 and 2006 were 304,724,845 Chilean pesos (USD 574,952). The higher total or per patient costs, were generated by drugs for chemotherapy compared to other required medications. The exception were AML children, where support drugs, such as antimicrobials, ant emetic drugs and colony stimulating factors, generated the higher costs per patient. Among ALL adults, AML children and AML adults, the costs were concentrated in the first 6 months of treatment. NO children followed this tendency concentrating the costs between the seventh and twenty-fourth months. Conclusions: Annual costs of pharmacotherapy per patient for acute leukemia in this regional hospital were approximately USD 4,717. Chemotherapy was the item with the greatest impact on cost.