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Cold induction of cspA, the paradigm Escherichia coli cold-shock gene, is mainly subject to posttranscriptional control, partly promoted by cis-acting elements of its transcript, whose secondary structure at 37 degrees C and at cold-shock temperature has been elucidated here by enzymatic and chemical probing. The structures, which were also validated by mutagenesis, demonstrate that cspA mRNA undergoes a temperature-dependent structural rearrangement, likely resulting from stabilization in the cold of an otherwise thermodynamically unstable folding intermediate. At low temperature, the "cold-shock" structure is more efficiently translated and somewhat less susceptible to degradation than the 37 degrees C structure. Overall, our data shed light on a molecular mechanism at the basis of the cold-shock response, indicating that cspA mRNA is able to sense temperature downshifts, adopting functionally distinct structures at different temperatures, even without the aid of trans-acting factors. Unlike with other previously studied RNA thermometers, these structural rearrangements do not result from melting of hairpin structures.
Assuntos
Temperatura Baixa , Proteínas de Escherichia coli/fisiologia , Escherichia coli/genética , Proteínas de Choque Térmico/fisiologia , Biossíntese de Proteínas , RNA Mensageiro/fisiologia , Regiões 5' não Traduzidas , Aclimatação , Proteínas e Peptídeos de Choque Frio , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica , Proteínas de Choque Térmico/genética , Modelos Genéticos , Conformação de Ácido Nucleico , RNA Mensageiro/químicaRESUMO
Objective: The present study is aimed at introducing and evaluating MaterniCode, a state-of-the-art bioinformatic pipeline for noninvasive prenatal testing (NIPT) that leverages the Ion Torrent semiconductor sequencing platform. The initiative strives to revolutionize prenatal diagnostics by offering a rapid and cost-effective method without sacrificing accuracy. Methods: Two distinct bioinformatic strategies were employed for fetal sex determination, one of which achieved 100% accuracy. We analyzed 1225 maternal blood samples for fetal aneuploidies, benchmarking against the industry standard Illumina VeriSeq™ NIPT Solution v2. The capability of MaterniCode to detect and characterize complex chromosomal anomalies was also assessed. Results: MaterniCode achieved near-perfect accuracy in fetal sex determination through chromosome Y (chrY )-specific gene analysis, whereas the alternative method, employing the ratio of high-quality mapped reads on chrY relative to all reads, delivered 100% accuracy. For fetal aneuploidy detection, both the integrated WisecondorX and NIPTeR algorithms demonstrated a 100% sensitivity and specificity rate, consistent with Illumina VeriSeq™ NIPT Solution v2. The pipeline also successfully identified and precisely mapped significant chromosomal abnormalities, exemplified by a 2.4 Mb deletion on chromosome 13 and a 3 Mb duplication on chromosome 2. Conclusion: MaterniCode has proven to be an innovative and highly efficient tool in the domain of NIPT, demonstrating excellent sensitivity and specificity. Its robust capability to effectively detect a wide range of complex chromosomal aberrations, including rare and subtle variations, positions it as a promising and valuable addition to prenatal diagnostic technologies. This enhancement to diagnostic precision significantly aids clinicians in making informed decisions during pregnancy management.
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Purpose: To characterize microbial keratitis diversity utilizing species richness and Shannon Diversity Index. Methods: Corneal impression membrane was used to collect samples. All swabs were processed and analyzed by Biolab Laboratory (level V-SSN Excellence: ISO 9001:2015), Biolab Srl (Ascoli Piceno, Italy). DNA extraction, library preparation, and sequencing were performed in all samples. After sequencing, low-quality and polyclonal sequences were filtered out by the Ion software. At this point, we employed Kraken2 for microbial community analysis in keratitis samples. Nuclease-free water and all the reagents included in the experiment were used as a negative control. The primary outcome was the reduction in bacterial DNA (microbial load) at T1, expressed as a percentage of the baseline value (T0). Richness and Shannon alpha diversity metrics, along with Bray-Curtis beta diversity values, were calculated using the phyloseq package in R. Principal coordinate analysis was also conducted to interpret these metrics. Results: 19 samples were included in the study. The results exhibited a motley species richness, with the highest recorded value surpassing 800 species. Most of the samples displayed richness values ranging broadly from under 200 to around 600, indicating considerable variability in species count among the keratitis samples. Conclusions: A significant presence of both typical and atypical bacterial phyla in keratitis infections, underlining the complexity of the disease's microbial etiology.
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Biodiversidade , Ceratite , Ceratite/microbiologia , Humanos , Bactérias/genética , Bactérias/classificação , Bactérias/isolamento & purificação , DNA Bacteriano/genética , Microbiota/genéticaRESUMO
Kidney transplantation is the treatment of choice for end-stage renal disease, given the better quality of life of transplanted patients when compared to patients on maintenance dialysis. In spite of surgical improvements and new immunosuppressive regimens, part of the transplanted grafts still develop chronic dysfunction. Ultrasonography, both in B-mode and with Doppler ultrasound, is an important diagnostic tool in case of clinical conditions which might impair kidney function. Even though ultrasonography is considered fundamental in the diagnosis of vascular and surgical complications of the transplanted kidney, its role is not fully understood in case of parenchymal complications of the graft. The specificity of Doppler ultrasound is low both in case of acute complications such as acute tubular necrosis, drug toxicity and acute rejection, and in case of chronic conditions such as chronic allograft nephropathy. Single determinations of resistance indices present low diagnostic accuracy, which is higher in case of successive measurements performed during the follow-up of the graft. Modern techniques including tissue pulsatility index, maximal fractional area and contrast-enhanced ultrasound increase the diagnostic power of ultrasonography in case of parenchymal complications of the transplanted kidney.
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Nefropatias/diagnóstico por imagem , Nefropatias/etiologia , Transplante de Rim/efeitos adversos , Transplante de Rim/diagnóstico por imagem , Ultrassonografia Doppler em Cores , Doença Aguda , Doença Crônica , Rejeição de Enxerto/diagnóstico por imagem , Humanos , Necrose Tubular Aguda/diagnóstico por imagem , Necrose Tubular Aguda/etiologiaRESUMO
The progressive decline in the incidence of graft rejection has made urological, surgical, parenchymal and vascular complications of kidney transplant more frequent. The latter, although accounting for only 5-10% of all post-transplant complications, are a frequent cause of graft loss. Ultrasonography, both in B-mode and with Doppler ultrasound, is an important diagnostic tool in case of clinical conditions which might impair kidney function. Even though ultrasonography is considered fundamental in the diagnosis of parenchymal and surgical complications of the transplanted kidney, its role is not fully understood in case of vascular complications of the graft. The specificity of Doppler ultrasound is very important in case of stenosis of the transplanted renal artery, pseudoaneurysms, arteriovenous fistulas, and thrombosis with complete or partial artery or vein occlusion. Doppler and color determinations present high diagnostic accuracy, which is higher in case of successive measurements performed during the follow-up of the graft. Modern techniques including contrast-enhanced ultrasound increase the diagnostic power of ultrasonography in case of vascular complications of the transplanted kidney, planted kidney.
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Transplante de Rim/efeitos adversos , Ultrassonografia Doppler em Cores , Doenças Vasculares/diagnóstico por imagem , Doenças Vasculares/etiologia , Humanos , Rim/irrigação sanguíneaRESUMO
Long-term stored (LTS) whole blood collection can be an important source of DNA without collection costs, but there is a lack of information on methods useful to extract genomic DNA from such type of biological material. Here we report a simple and fast revisited phenol/chloroform extraction method from LTS whole blood. Protocol reliability was assessed by comparison with proteinase K and silica-gel membrane spin column-based DNA extraction methods using LTS -20 °C whole blood from 1980, and by testing it on 82 whole blood samples, collected from 1980 to 1995, with high quality (A(260/280) = 1.79 ± 0.32 O.D., A(260/230) = 1.45 ± 0.52 O.D.) and quantity results. Genotyping efficiency was also checked by performing RFLP-PCR and ASP-PCR of p53 Pro72Arg (rs1042522) SNP and hTERT MNS16A VNTR, respectively, resulting in 100% of samples successfully typed. In addition to the goodness and the efficiency of method proposed here, this protocol achieves working time reduction combining extraction and purification steps, allowing to work at room temperature. Furthermore, phenol is able to inactivate any potential nuclease and potential infective sources from the first step on. Based on these results we also conclude that LTS -20 °C whole blood samples may be considered a reliable and potential resource for future genotyping studies and retrospective analysis in a genetic epidemiological setting.
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Clorofórmio , Criopreservação , DNA/isolamento & purificação , Fenol , Adulto , DNA/sangue , Feminino , Genes p53 , Genótipo , Humanos , Repetições Minissatélites , Epidemiologia Molecular , Polimorfismo de Nucleotídeo Único , Estudos Retrospectivos , Telomerase/genéticaRESUMO
The Pompe model is the term used by the Pompe community to describe the relationship that exists between the patient community, the medical/scientific community, and industry. The development of the Pompe model represented a new paradigm for the involvement of patients in new treatments-and also for scientists and pharmaceutical companies. It saw patients developing a sense of agency, of involvement in the process of treatment development rather than powerless recipients or (if lucky) occasional spectators. At the same time, as described below, it benefited the other partners in the process with the result that the different components of the model added up to more than the sum of their parts. However, in order for this to happen, each part had to undergo a transformation in mindset. The development of enzyme replacement therapy (ERT) for Pompe disease represented a unique set of circumstances and individuals that helped to bring about this change and, in doing so, created a model that has had far wider applications.
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Protein Y (PY) is an Escherichia coli cold-shock protein which has been proposed to be responsible for the repression of bulk protein synthesis during cold adaptation. Here, we present in vivo and in vitro data which clarify the role of PY and its mechanism of action. Deletion of yfiA, the gene encoding protein PY, demonstrates that this protein is dispensable for cold adaptation and is not responsible for the shutdown of bulk protein synthesis at the onset of the stress, although it is able to partially inhibit translation. In vitro assays reveal that the extent of PY inhibition changes with different mRNAs and that this inhibition is related to the capacity of PY of binding 30S subunits with a fairly strong association constant, thus stimulating the formation of 70S monomers. Furthermore, our data provide evidence that PY competes with the other ribosomal ligands for the binding to the 30S subunits. Overall these results suggest an alternative model to explain PY function during cold shock and to reconcile the inhibition caused by PY with the active translation observed for some mRNAs during cold shock.
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Proteínas de Bactérias/metabolismo , Resposta ao Choque Frio/genética , Proteínas de Escherichia coli/metabolismo , Escherichia coli/genética , Proteínas Ribossômicas/metabolismo , Ribossomos/metabolismo , Adaptação Fisiológica , Proteínas de Bactérias/genética , Clonagem Molecular , Escherichia coli/fisiologia , Proteínas de Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica , Ligantes , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Ribossômicas/genética , Análise de Sequência de DNA , TemperaturaRESUMO
BACKGROUND: Telomerase, encoded by TERT, is the ribonucleoprotein polymerase that maintains telomere ends and it plays a crucial role in cellular senescence. TERT single nucleotide polymorphisms (SNPs) have been associated both with various malignancies and telomere length (TL). The association of TERT SNPs with longevity remains uncertain and varies with ethnicity. The aim of this study was to investigate whether the functional variable number of tandem repeat (VNTR) MNS16A of TERT is associated with longevity. METHODS: MNS16A genotypes have been determined for 1072 unrelated healthy individuals from Central Italy (18-106 years old) divided into three gender-specific age classes defined according to demographic information and accounting for the different survivals between sexes: for men (women), the first class consists of individuals <66 years old (<73 years old), the second class of individuals 66-88 years old (73-91 years old), and the third class of individuals >88 years old (>91 years old). TL was assessed using genomic DNA from whole blood of 72 selected individuals by a multiplex real-time PCR assay. RESULTS: MNS16A appears associated to longevity, showing significant associations in Comparison 2 (Age Class 3 vs. Age Class 2) under both additive (odds ratio [O.R.] 0.749; p=0.019) and dominant (O.R. 0.579; p=0.011) models. The MNS16A*L allele is significantly underrepresented in Age Class 3 (O.R. 0.759; p=0.020) compared to Age Class 2. A significant telomere attrition is reported along the three age classes (p=0.0001), that remains significant only in L*/L* genotype carriers (p=0.002) when the analysis was conducted according to MNS16A genotype. CONCLUSIONS: The TERT MNS16A*L allele appears negatively associated with longevity. The concomitant significant telomere cross sectional attrition rate observed for L*/L* genotype suggests that this polymorphism could influence human longevity by affecting TL.
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Predisposição Genética para Doença , Longevidade/genética , Repetições Minissatélites/genética , Polimorfismo de Nucleotídeo Único , Telomerase/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Fatores de Risco , População Branca/genética , Adulto JovemRESUMO
The association of TP53 P72R (rs1042522) with longevity remains uncertain and varies with ethnicity. Here, we tested its association with longevity in a cross-sectional population of Central Italy (18-106 years, N = 1,072), by integrating demographic information and frequency data to account for the different survival rates between sexes through the application of a genetic-demographic approach. rs1042522 affects females longevity, showing significant associations in Comparison 2 (Age Class 3 [>91 years] vs Age Class 2 [73-91 years]) under both additive (odds ratio [OR] 0.574; p = .006) and dominant (OR 0.513; p = .006) models. The TP53*P72 allele is significantly underrepresented in Age Class 3 only in women (OR 0.575; p = .008). The genetic-demographic approach demonstrated that the frequency of female TP53*P72 carriers underwent a significant reduction after 82 years (OR 0.586; p = .002). The same analyses gave nonsignificant results in men. The discrepancies among the results obtained on rs1042522 for longevity could result from the pleiotropic effects of p53 and the potential ethnic variation of its functional variants.
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Genes p53/genética , Expectativa de Vida , Longevidade/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Estudos Transversais , Demografia , Feminino , Humanos , Itália , Pessoa de Meia-Idade , Fatores Sexuais , Adulto JovemRESUMO
Since the pioneer experiments conducted by Friedrich Miescher in 1861, extraordinary advances have been achieved in the field of DNA handling. Today nucleic acids can be extracted from any type of biological material such as tissues, cells and viruses. Moreover, increasing knowledge of human genome is paving the way to an effective employment of pharmacogenomics and genetic-based predictive tests in medicine. In this context, the recovery of DNA from different sources of biological samples (e.g. archived formalin-fixed autopsy tissues, dried blood spots, frozen serum or plasma, long-term stored whole blood) is also an emerging field in genetic epidemiology studies. Thus, given the crucial role played by DNA in bio-medical research and in its related applications, here we review the main relevant issued patents and recently published advances in the field of DNA extraction and purification from human specimens.