Adsorption of 2,2 '-dithiodipyridine as a tool for the assembly of silver nanoparticles

Silver nanostructured thin films stabilized by 2,2’-dithiodipyridine (2dtpy) were prepared. The Ag nanoparticles were obtained by treating the complex [Ag(2dtpy)]NO3 with NaBH4 in a methanol–toluene mixture. The films were transferred to borosilicate glass slips by a dip-coating method and were found to consist of Ag nanoparticles possibly linked via 2dtpy molecules. Surface-enhanced Raman scattering (SERS) studies have offered the possibility of investigating the adsorption modes of 2dtpy at the Ag nanoparticle surfaces in the fil

Utility of Gene Panels for the Diagnosis of Inborn Errors of Metabolism in a Metabolic Reference Center

Next-generation sequencing (NGS) technologies have been proposed as a first-line test for the diagnosis of inborn errors of metabolism (IEM), a group of genetically heterogeneous disorders with overlapping or nonspecific phenotypes. Over a 3-year period, we prospectively analyzed 311 pediatric patients with a suspected IEM using four targeted gene panels. The rate of positive diagnosis was 61.86% for intermediary metabolism defects, 32.84% for complex molecular defects, 19% for hypoglycemic/hyperglycemic events, and 17% for mitochondrial diseases, and a conclusive molecular diagnosis was established in 2-4 weeks. Forty-one patients for whom negative results were obtained with the mitochondrial diseases panel underwent subsequent analyses using the NeuroSeq panel, which groups all genes from the individual panels together with genes associated with neurological disorders (1870 genes in total). This achieved a diagnostic rate of 32%. We next evaluated the utility of a tool, Phenomizer, for differential diagnosis, and established a correlation between phenotype and molecular findings in 39.3% of patients. Finally, we evaluated the mutational architecture of the genes analyzed by determining z-scores, loss-of-function observed/expected upper bound fraction (LOEUF), and haploinsufficiency (HI) scores. In summary, targeted gene panels for specific groups of IEMs enabled rapid and effective diagnosis, which is critical for the therapeutic management of IEM patients.info:eu-repo/semantics/publishedVersio

Proteins Inform Survival-Based Differences in Patients with Glioblastoma

Background: Improving the care of patients with glioblastoma (GB) requires accurate and reliable predictors of patient prognosis. Unfortunately, while protein markers are an effective readout of cellular function, proteomics has been underutilized in GB prognostic marker discovery. Methods: For this study, GB patients were prospectively recruited and proteomics discovery using liquid chromatography-mass spectrometry analysis (LC-MS/MS) was performed for 27 patients including 13 short-term survivors (STS) (≤10 months) and 14 long-term survivors (LTS) (≥18 months). Results: Proteomics discovery identified 11 941 peptides in 2495 unique proteins, with 469 proteins exhibiting significant dysregulation when comparing STS to LTS. We verified the differential abundance of 67 out of these 469 proteins in a small previously published independent dataset. Proteins involved in axon guidance were upregulated in STS compared to LTS, while those involved in p53 signaling were upregulated in LTS. We also assessed the correlation between LS MS/MS data with RNAseq data from the same discovery patients and found a low correlation between protein abundance and mRNA expression. Finally, using LC-MS/MS on a set of 18 samples from 6 patients, we quantified the intratumoral heterogeneity of more than 2256 proteins in the multisample dataset. Conclusions: These proteomic datasets and noted protein variations present a beneficial resource for better predicting patient outcome and investigating potential therapeutic targets

Non-alcoholic fatty liver in hereditary fructose intolerance

Background: Non-alcoholic fatty liver disease (NAFLD) is characterized by fat accumulation affecting >5% of the liver volume that is not explained by alcohol abuse. It is known that fructose gives rise to NAFLD and it has been recently described that the ingestion of fructose in low amounts in aldolase B deficient mice is associated with the development of fatty liver. Therefore, it is reasonable that patients with HFI (Hereditary Fructose Intolerance) present fatty liver at diagnosis, but its prevalence in patients treated and with adequate follow-up is not well documented in the literature. The aim of this study is to analyze the association between HFI and NAFLD in treated patients. Methods: A cross-sectional observational study was conducted. The population comprised 16 genetically diagnosed HFI patients aged from 3 years to 48 and in dietary treatment of fructose, sorbitol and sacarose exclusion at least for two years. Blood samples were obtained for analytical studies and anthropometric measurements of each patient were performed. Results: Patients presented a Body Mass Index (BMI) of 17.9 ± 2.9 kg/m 2 . The HOMA index and Quick index were in normal range for our population. The S-adenosyl-methionine (SAM)/S-adenosyl-L-homocysteine (SAH) ratio was increased in the patients in whom this analysis was performed. By imaging techniques it was observed that 9 of the 16 patients presented fatty liver (7 by hepatic MRI). Of these 9 patients, only 3 presented hepatomegaly. 7 of 9 patients affected by the c.448G > C mutation had fatty infiltration, of which three of them presented in addition hepatomegaly. Conclusions: There is a high prevalence of fatty liver in HFI patients and it is not related to obesity and insulin resistance. The diagnosis of fatty liver in HFI patients and, above all, the identification of new therapeutic approaches, can positively impact the quality of life of these patients

Identification of a Novel Variant in EARS2 Associated with a Severe Clinical Phenotype Expands the Clinical Spectrum of LTBL

The EARS2 nuclear gene encodes mitochondrial glutamyl-tRNA synthetase, a member of the class I family of aminoacyl-tRNA synthetases (aaRSs) that plays a crucial role in mitochondrial protein biosynthesis by catalyzing the charging of glutamate to mitochondrial tRNA(Glu). Pathogenic EARS2 variants have been associated with a rare mitochondrial disorder known as leukoencephalopathy with thalamus and brainstem involvement and high lactate (LTBL). The targeted sequencing of 150 nuclear genes encoding respiratory chain complex subunits and proteins implicated in the oxidative phosphorylation (OXPHOS) function was performed. The oxygen consumption rate (OCR), and the extracellular acidification rate (ECAR), were measured. The enzymatic activities of Complexes I-V were analyzed spectrophotometrically. We describe a patient carrying two heterozygous EARS2 variants, c.376C>T (p.Gln126*) and c.670G>A (p.Gly224Ser), with infantile-onset disease and a severe clinical presentation. We demonstrate a clear defect in mitochondrial function in the patient's fibroblasts, suggesting the molecular mechanism underlying the pathogenicity of these EARS2 variants. Experimental validation using patient-derived fibroblasts allowed an accurate characterization of the disease-causing variants, and by comparing our patient's clinical presentation with that of previously reported cases, new clinical and radiological features of LTBL were identified, expanding the clinical spectrum of this disease

Capturing threshold responses of marine benthos along gradients of natural and anthropogenic change

1. Ecologists and managers need to understand what types of communities emerge with continued human alterations to ecosystems against a background of natural change. Both natural and anthropogenic drivers are well known to affect organisms’ distributions; however, it often remains unclear where along a range of environmental and anthropogenic gradients important compositional community changes occur. 2. We used a big-data approach, including over 175,000 presence records of benthic genera for the North Sea, to identify environmental (bed shear stress, sediment grain size, temperature) and anthropogenic parameters (trawling effort) driving benthic community composition over a 21-year period. We applied a Gradient Forest analysis, based on Random Forests, to estimate the locations and importance of thresholds where small cumulative increases in the predictors drive a much greater change in genus composition than would be expected from linear effects. 3. Shear stress was the most important predictor of benthic community composition. Trawling effort, temperature gradients and sediment grain size were of intermediate importance. This corroborates that current and wave effects (typically associated with seabed substrate types) are primary determinants of benthic communities. 4. Our results suggest that a genus composition threshold for both infauna and epifaunal benthic communities is crossed when the seafloor is trawled as little as once every 4 years. Higher trawling levels corresponded with gradual compositional change without obvious thresholds, which would be consistent with chronic fishing in the North Sea over the last two centuries having caused persistent, long-term changes in ecosystem structure and functioning. This was corroborated by the large-scale spatial patterns of benthic community composition undergoing limited temporal changes during the 21-year study period. 5. Synthesis and applications. Although well established in theory, threshold effects are poorly validated in the field. We generated new information on multi-organism responses to environmental change at the scale of a continental shelf ecosystem and over a multi-decadal time period. This will help pure and applied scientists better understand the conditions under which community thresholds are crossed and provide environmental managers with empirical evidence that is expected to reduce uncertainty regarding decisions on the protection and sustainable use of the marine environment

Newborn Screening for Homocystinuria Revealed a High Frequency of MAT I/III Deficiency in Iberian Peninsula

Acessível em: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4375120/Homocystinuria due to cystathionine β-synthase deficiency or "classical homocystinuria" is a rare autosomal recessive condition resulting in altered sulfur metabolism with elevated methionine and homocysteine in plasma and homocystine in urine. This condition is characterized by a high clinical heterogeneity, which contributes to late clinical diagnosis, usually only made after irreversible damage has occurred. Treatment is effective if started before clinical symptoms. The analysis of methionine levels by tandem mass spectrometry (MS/MS) allows the newborn screening for homocystinuria, but false-positive results can be frequently obtained and lead to the unwanted identification of methionine adenosyl transferase (MAT I/III) deficiency. This latter condition is biochemically characterized by isolated persistent hypermethioninemia, accompanied in some individuals with slightly elevated levels of homocysteine in plasma. A dominant form of MAT I/III deficiency, associated with mutation p.R264H, seems to be very frequent in the Iberian Peninsula and usually has a clinically benign course. Both these metabolic disorders are screened in Galicia and Portugal since the introduction of the MS/MS technology, in 2000 and 2004, respectively, resulting in the identification of three patients with classical homocystinuria and 44 patients with MAT I/III deficiency. All but one heterozygous parent of MAT I/III patients, identified with the p.R264H mutation, are healthy adults around the age of 30/40. The implementation of a second-tier test for homocysteine in dried blood spots would considerably reduce the number of MAT I/III-deficient patients identified and improve the specificity and positive predictive value for classical homocystinuria screening

Environmental pleiotropy and demographic history direct adaptation under antibiotic selection

Evolutionary rescue following environmental change requires mutations permitting population growth in the new environment. If change is severe enough to prevent most of the population reproducing, rescue becomes reliant on mutations already present. If change is sustained, the fitness effects in both environments, and how they are associated-termed 'environmental pleiotropy'-may determine which alleles are ultimately favoured. A population's demographic history-its size over time-influences the variation present. Although demographic history is known to affect the probability of evolutionary rescue, how it interacts with environmental pleiotropy during severe and sustained environmental change remains unexplored. Here, we demonstrate how these factors interact during antibiotic resistance evolution, a key example of evolutionary rescue fuelled by pre-existing mutations with pleiotropic fitness effects. We combine published data with novel simulations to characterise environmental pleiotropy and its effects on resistance evolution under different demographic histories. Comparisons among resistance alleles typically revealed no correlation for fitness-i.e., neutral pleiotropy-above and below the sensitive strain's minimum inhibitory concentration. Resistance allele frequency following experimental evolution showed opposing correlations with their fitness effects in the presence and absence of antibiotic. Simulations demonstrated that effects of environmental pleiotropy on allele frequencies depended on demographic history. At the population level, the major influence of environmental pleiotropy was on mean fitness, rather than the probability of evolutionary rescue or diversity. Our work suggests that determining both environmental pleiotropy and demographic history is critical for predicting resistance evolution, and we discuss the practicalities of this during in vivo evolution

Clinical features and health-related quality of life in adult patients with mucopolysaccharidosis IVA: the Spanish experience

Background: Mucopolysaccharidosis (MPS) IVA or Morquio A syndrome is a progressive and disabling disease characterized by a deficiency of the enzyme N-acetylgalactosamine-6-sulphate sulphatase. Its clinical presentation is very heterogeneous and poorly understood in adults. The aim of this study was to describe the clinical manifestations of MPS IVA in adult patients in Spain and to assess their health-related quality of life (HRQoL). Results: Thirty-three patients from nine reference centres participated in the study. The median age was 32 (interquartile range [IQR]: 20.5–40.5) years. The phenotype was classical in 54.5% of patients, intermediate in 33.3% of patients, and non-classical in 12.1% of patients. The most common clinical manifestation was bone dysplasia, with a median height of 118 (IQR: 106–136) cm. Other frequent clinical manifestations were hearing loss (75.7%), ligamentous laxity (72.7%), odontoid dysplasia (69.7%), limb deformities that required orthopaedic aids (mainly hip dysplasia and genu valgus) (63.6%), and corneal clouding (60.6%). In addition, 36.0% of patients had obstructive sleep apnoea/hypopnoea syndrome and 33.3% needed non-invasive ventilation. Cervical surgery and varisation osteotomy were the most common surgical interventions (36.4% each). Almost 80% of patients had mobility problems and 36.4% used a wheelchair at all times. Furthermore, 87.9% needed help with self-care, 33.3% were fully dependent, and 78.8% had some degree of pain. HRQoL according to the health assessment questionnaire was 1.43 (IQR: 1.03–2.00) in patients with the non-classical phenotype, but 2.5 (IQR: 1.68–3.00) in those with the classical phenotype. Seven patients were initiated on enzyme replacement therapy (ERT), but two of them were lost to follow-up. Lung function improved in four patients and slightly worsened in one patient. The distance achieved in the six-minute walk test increased in the four patients who could perform it. HRQoL was better in patients treated with elosulfase alfa, with a median (IQR) of 1.75 (1.25–2.34) versus 2.25 (1.62–3.00) in patients not treated with ERT. Conclusions: The study provides real-world data on patients with MPS IVA. Limited mobility, difficulties with self-care, dependence, and pain were common, together with poor HRQoL. The severity and heterogeneity of clinical manifestations require the combined efforts of multidisciplinary teams

Rare Variants in 48 Genes Account for 42% of Cases of Epilepsy With or Without Neurodevelopmental Delay in 246 Pediatric Patients

In order to characterize the genetic architecture of epilepsy in a pediatric population from the Iberian Peninsula (including the Canary Islands), we conducted targeted exome sequencing of 246 patients with infantile-onset seizures with or without neurodevelopmental delay. We detected 107 variants in 48 different genes, which were implicated in neuronal excitability, neurodevelopment, synaptic transmission, and metabolic pathways. In 104 cases (42%) we detected variant(s) that we classified as pathogenic or likely pathogenic. Of the 48 mutated genes, 32 were dominant, 8 recessive and 8 X-linked. Of the patients for whom family studies could be performed and in whom pathogenic variants were identified in dominant or X-linked genes, 82% carried de novo mutations. The involvement of small copy number variations (CNVs) is 9%. The use of progressively updated custom panels with high mean vertical coverage enabled establishment of a definitive diagnosis in a large proportion of cases (42%) and detection of CNVs (even duplications) with high fidelity. In 10.5% of patients we detected associations that are pending confirmation via functional and/or familial studies. Our findings had important consequences for the clinical management of the probands, since a large proportion of the cohort had been clinically misdiagnosed, and their families were subsequently able to avail of genetic counseling. In some cases, a more appropriate treatment was selected for the patient in question, or an inappropriate treatment discontinued. Our findings suggest the existence of modifier genes that may explain the incomplete penetrance of some epilepsy-related genes. We discuss possible reasons for non-diagnosis and future research directions. Further studies will be required to uncover the roles of structural variants, epimutations, and oligogenic inheritance in epilepsy, thereby providing a more complete molecular picture of this disease. In summary, given the broad phenotypic spectrum of most epilepsy-related genes, efficient genomic tools like the targeted exome sequencing panel described here are essential for early diagnosis and treatment, and should be implemented as first-tier diagnostic tools for children with epilepsy without a clear etiologic basis