Since the end of the twentieth century, discussion on dwelling rehabilitation versus its demolition and new construction has been steadily increasing in intensity, which is especially due to the ...necessity for the regeneration of urban centres. However, rehabilitation is not always considered the most economical solution, and demolition and new construction may constitute a better option. In the present work, a multi-family building in Seville, Spain, is used as a case study. After having suffered damage from a construction failure, it is assessed for its complete rehabilitation. Defective maintenance has worsened the bad condition of the building. A model is proposed, from the project budget perspective, that allows the environmental (Ecological Footprint indicator) and the economic (project's bill of quantities) assessment of the recovery of the dwelling. In the case study, the rehabilitation Ecological Footprint and the project cost are 0.06gha/m2 of floor area (457.22EUR/m2) and 0.14gha/m2 (576.33EUR/m2) for a new building on the same plot, respectively. It can be deduced that, even with a severely damaged building, the repair and retrofit work incurs a lower economic and environmental impact than that of the total replacement with a new construction.
An overview on transcriptional regulators in Streptomyces Romero-Rodríguez, Alba; Robledo-Casados, Ivonne; Sánchez, Sergio
Biochimica et biophysica acta,
August 2015, 2015-Aug, 2015-08-00, Letnik:
1849, Številka:
8
Journal Article
Recenzirano
Streptomyces are Gram-positive microorganisms able to adapt and respond to different environmental conditions. It is the largest genus of Actinobacteria comprising over 900 species. During their ...lifetime, these microorganisms are able to differentiate, produce aerial mycelia and secondary metabolites. All of these processes are controlled by subtle and precise regulatory systems. Regulation at the transcriptional initiation level is probably the most common for metabolic adaptation in bacteria. In this mechanism, the major players are proteins named transcription factors (TFs), capable of binding DNA in order to repress or activate the transcription of specific genes. Some of the TFs exert their action just like activators or repressors, whereas others can function in both manners, depending on the target promoter. Generally, TFs achieve their effects by using one- or two-component systems, linking a specific type of environmental stimulus to a transcriptional response. After DNA sequencing, many streptomycetes have been found to have chromosomes ranging between 6 and 12Mb in size, with high GC content (around 70%). They encode for approximately 7000 to 10,000 genes, 50 to 100 pseudogenes and a large set (around 12% of the total chromosome) of regulatory genes, organized in networks, controlling gene expression in these bacteria. Among the sequenced streptomycetes reported up to now, the number of transcription factors ranges from 471 to 1101. Among these, 315 to 691 correspond to transcriptional regulators and 31 to 76 are sigma factors. The aim of this work is to give a state of the art overview on transcription factors in the genus Streptomyces.
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•Regulation at the transcriptional level is used for metabolic adaptation in bacteria.•Diverse processes in Streptomyces biology are controlled by precise regulatory systems.•Manipulation of Streptomyces transcription factors could impact secondary metabolite production.•Streptomyces uses both one- or two-component systems to respond to an environmental stimuli.
Scope
The aim is to analyze whether the probiotic Lactobacillus fermentum CECT5716 (LC40) can prevent endothelial dysfunction and hypertension induced by tacrolimus in mice.
Methods and results
...Tacrolimus increases systolic blood pressure (SBP) and impairs endothelium‐dependent relaxation to acetylcholine and these effects are partially prevented by LC40. Endothelial dysfunction induced by tacrolimus is related to both increased nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX2) and uncoupled endothelial nitric oxide synthase (eNOS)‐driven superoxide production and Rho‐kinase‐mediated eNOS inhibition. LC40 treatment prevents all the aortic changes induced by tacrolimus. LC40 restores the imbalance between T‐helper 17 (Th17)/regulatory T (Treg) cells induced by tacrolimus in mesenteric lymph nodes and the spleen. Tacrolimus‐induced gut dysbiosis, that is, it decreases microbial diversity, increases the Firmicutes/Bacteroidetes (F/B) ratio and decreases acetate‐ and butyrate‐producing bacteria, and these effects are prevented by LC40. Fecal microbiota transplantation (FMT) from LC40‐treated mice to control mice prevents the increase in SBP and the impaired relaxation to acetylcholine induced by tacrolimus.
Conclusion
LC40 treatment prevents hypertension and endothelial dysfunction induced by tacrolimus by inhibiting gut dysbiosis. These effects are associated with a reduction in vascular oxidative stress, mainly through NOX2 downregulation and prevention of eNOS uncoupling, and inflammation possibly because of decreased Th17 and increased Treg cells polarization in mesenteric lymph nodes.
Lactobacillus fermentum CECT5716 (LC40) treatment prevented hypertension and endothelial dysfunction induced by tacrolimus by inhibiting gut dysbiosis. These effects were associated with a reduction in vascular oxidative stress, mainly through NOX2 downregulation and prevention of eNOS uncoupling, and inflammation possibly because of decreased T‐helper 17 cells (Th17) and increased regulatory T (Treg) cells polarization in mesenteric lymph nodes.
Background
Amoxicillin (AX) is nowadays the β‐lactam that more frequently induces immediate allergic reactions. Nevertheless, diagnosis of AX allergy is occasionally challenging due to risky in vivo ...tests and non‐optimal sensitivity of in vitro tests. AX requires protein haptenation to form multivalent conjugates with increased size to be immunogenic. Knowing adduct structural features for promoting effector cell activation would help to improve in vitro tests. We aimed to identify the optimal structural requirement in specific cellular degranulation to AX using well‐precised nanoarchitectures of different lengths.
Method
We constructed eight Bidendron Antigens (BiAns) based on polyethylene glycol (PEG) linkers of different lengths (600–12,000 Da), end‐coupled with polyamidoamine dendrons that were terminally multi‐functionalized with amoxicilloyl (AXO). In vitro IgE recognition was studied by competitive radioallergosorbent test (RAST) and antibody–nanoarchitecture complexes by transmission electron microscopy (TEM). Their allergenic activity was evaluated using bone marrow‐derived mast cells (MCs) passively sensitized with mouse monoclonal IgE against AX and humanized RBL‐2H3 cells sensitized with polyclonal antibodies from sera of AX‐allergic patients.
Results
All BiAns were recognized by AX‐sIgE. Dose‐dependent activation responses were observed in both cellular assays, only with longer structures, containing spacers in the range of PEG 6000–12,000 Da. Consistently, greater proportion of immunocomplexes and number of antibodies per complex for longer BiAns were visualized by TEM.
Conclusions
BiAns are valuable platforms to study the mechanism of effector cell activation. These nanomolecular tools have demonstrated the importance of the adduct size to promote effector cell activation in AX allergy, which will impact for improving in vitro diagnostics.
The use of BiAns demonstrates the importance of adduct size and distance between determinants to promote effector cell activation in AX allergy. Optimal effector cell activation is showed with the biggest BiAns, which involves a greater number of immunocomplex and antibodies. BiAns are versatile nanoplatforms that can be applied to different allergies, valuable for improving in vitro allergy tests. Abbreviations: AX, amoxicillin; AXO, amoxicilloyl; BiAn, bidendron antigen; MoAb, monoclonal antibody; RBL, rat basophilic leukemia cell
Despite the advances in understanding the regulatory networks for secondary metabolite production in
Streptomyces
, the participation of the two-component systems (TCS) in this process still requires ...better characterization. These sensing systems and their responses to environmental stimuli have been described by evaluating mutant strains with techniques that allow in-depth regulatory responses. However, defining the stimulus that triggers their activation is still a task. The transmembrane nature of the sensor kinases and the high content of GC in the streptomycetes represent significant challenges in their study. In some examples, adding elements to the assay medium has determined the respective ligand. However, a complete TCS description and characterization requires specific amounts of the involved proteins that are most difficult to obtain. The availability of enough sensor histidine kinase concentrations could facilitate the identification of the ligand–protein interaction, and besides would allow the establishment of its phosphorylation mechanisms and determine their tridimensional structure. Similarly, the advances in the development of bioinformatics tools and novel experimental techniques also promise to accelerate the TCSs description and provide knowledge on their participation in the regulation processes of secondary metabolite formation. This review aims to summarize the recent advances in the study of TCSs involved in antibiotic biosynthesis and to discuss alternatives to continue their characterization.
Key points
• TCSs are the environmental signal transducers more abundant in nature.
• The Streptomyces have some of the highest number of TCSs found in bacteria.
• The study of signal transduction between SHKs and RRs domains is a big challenge.
To date, non-invasive prenatal diagnosis (NIPD) of monogenic disorders has been limited to cases with a paternal origin. This work shows a validation study of the Droplet Digital PCR (ddPCR) ...technology for analysis of both paternally and maternally inherited fetal alleles. For the purpose, single nucleotide polymorphisms (SNPs) were studied with the only intention to mimic monogenic disorders.
NIPD SNP genotyping was performed by ddPCR in 55 maternal plasma samples. In 19 out of 55 cases, inheritance of the paternal allele was determined by presence/absence criteria. In the remaining 36, determination of the maternally inherited fetal allele was performed by relative mutation dosage (RMD) analysis.
ddPCR exhibited 100% accuracy for detection of paternal alleles. For diagnosis of fetal alleles with maternal origin by RMD analysis, the technology showed an accuracy of 96%. Twenty-nine out of 36 were correctly diagnosed. There was one FP and six maternal plasma samples that could not be diagnosed.
In this study, ddPCR has shown to be capable to detect both paternal and maternal fetal alleles in maternal plasma. This represents a step forward towards the introduction of NIPD for all pregnancies independently of the parental origin of the disease.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
probiotics contained in dietary supplements or functional foods are well-known for their beneficial properties exerted on host health and diverse pathological situations. Their capacity to improve ...inflammatory bowel disease (IBD) and regulate the immune system is especially remarkable. Although bacteria-host interactions have been thought to occur directly, the key role that extracellular vesicles (EVs) derived from probiotics play on this point is being unveiled. EVs are lipid bilayer-enclosed particles that carry a wide range of cargo compounds and act in different signalling pathways. Notably, these EVs have been recently proposed as a safe alternative to the utilisation of live bacteria since they can avoid the possible risks that probiotics may entail in vulnerable cases such as immunocompromised patients. Therefore, this review aims to give an updated overview of the existing knowledge about EVs from different
strains, their mechanisms and effects in host health and different pathological conditions. All of the information collected suggests that EVs could be considered as potential tools for the development of future novel therapeutic approaches.
Arsenosugars are the predominant species of arsenic in most seaweed. The analysis of these compounds is hampered by the lack of calibration standards needed in their unambiguous identification and ...quantification. This affects the availability of reliable information on their potential toxicity, which is scarce and controversial.
Knowing the potential of centrifugal partition chromatography (CPC) as a preparative separation technique applied to a number of natural compounds, the aim of this work is to investigate the feasibility of CPC in the case of isolation and purification of arsenosugars from algae extracts. Several biphasic solvents systems have been studied to evaluate the distribution of the As species. Given the physical characteristics of these compounds, the presence of strong acids, the formation of ionic pairs or the presence of salts at high ionic strength have been considered. System 1-BuOH/EtOH/sat.(NH4)2SO4/water at a volume ratio 0.2:1:1:1 originates adequate distribution constants of analytes that allows the required separation. The total arsenic content and the arsenic speciation of the eluted solutions from CPC were analyzed by ICP-MS and IC-ICP-MS, respectively.
The developed CPC procedure allows us to obtain of the three arsenosugars with a purity of 98.7 % in PO4-Sug, 90.4 % in SO3-Sug and 96.1 % in SO4-Sug.
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•The behaviour of arsenosugars on CPC is studied for first time.•A series of 44 biphasic solvents systems have been studied to determine species distribution.•The KD values of arsenosugars have been determined in favorable solvent systems.•CPC was assessed as an isolate method of arsenosugars from algae water extract.•CPC allows to obtain the three arsenosugars with a purity between 90.4 and 98.7 %.
Streptomyces
species are a wide and diverse source of many therapeutic agents (antimicrobials, antineoplastic and antioxidants, to name a few) and represent an important source of compounds with ...potential applications in medicine. The effect of nitrogen, phosphate and carbon on the production of secondary metabolites has long been observed, but it was not until recently that the molecular mechanisms on which these effects rely were ascertained. In addition to the specific macronutrient regulatory mechanisms, there is a complex network of interactions between these mechanisms influencing secondary metabolism. In this article, we review the recent advances in our understanding of the molecular mechanisms of regulation exerted by nitrogen, phosphate and carbon sources, as well as the effects of their interconnections, on the synthesis of secondary metabolites by members of the genus
Streptomyces.
Scope
Obesity is characterized by a dysfunction in the adipose tissue and an inflammatory subclinical state leading to insulin resistance and increased risk of cardiovascular diseases. It is also ...associated with intestinal dysbiosis that contributes to inflammation development. Lippia citriodora (LCE) contains high levels of polyphenolpropanoids and has shown promising results in obesity. The aim of this study is to investigate a well‐characterized extract of LCE in a model of metabolic syndrome in mice, focusing on its effects on metabolic tissues, endothelial dysfunction, and microbiome.
Methods
Mice are fed a high fat diet (HFD) for six weeks and treated daily with LCE (1, 10, and 25 mg kg−1). Glucose and lipid metabolism is investigated. The inflammatory state in the metabolic tissues and the intestinal microbiota composition are characterized, as well as the endothelium‐dependent vasodilator response to acetylcholine.
Results
LCE reduces fat accumulation and improves plasma glycemic and lipid profiles, as well as the inflammatory process and vascular dysfunction. Moreover, LCE lessens intestinal dysbiosis, as it reduces the Firmicutes/Bacteroidetes ratio and increases Akkermansia abundance in comparison with untreated HFD mice.
Conclusion
The antiobesity therapeutic properties of LCE are most probably mediated by the synergic effects of its bioactive compounds.
The aim of this study is the evaluation of Lippia Citriodora extract (LCE) treatment on diet‐induced obesity in mice. LCE administration ameliorates induced obesity, enhancing the inflammatory status and the vascular functionality. Furthermore, it is the first time that LCE treatment is shown to modulate the gut microbiota. These findings support the use of LCE as a new functional food in metabolic syndrome.
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