Culture-independent studies of cystic fibrosis lung microbiota have provided few mechanistic insights into the polymicrobial basis of disease. Deciphering the specific contributions of individual ...taxa to CF pathogenesis requires comprehensive understanding of their ecophysiology at the site of infection. We hypothesize that only a subset of CF microbiota are translationally active and that these activities vary between subjects. Here, we apply bioorthogonal non-canonical amino acid tagging (BONCAT) to visualize and quantify bacterial translational activity in expectorated sputum. We report that the percentage of BONCAT-labeled (i.e. active) bacterial cells varies substantially between subjects (6-56%). We use fluorescence-activated cell sorting (FACS) and genomic sequencing to assign taxonomy to BONCAT-labeled cells. While many abundant taxa are indeed active, most bacterial species detected by conventional molecular profiling show a mixed population of both BONCAT-labeled and unlabeled cells, suggesting heterogeneous growth rates in sputum. Differentiating translationally active subpopulations adds to our evolving understanding of CF lung disease and may help guide antibiotic therapies targeting bacteria most likely to be susceptible.
Individuals with Down syndrome (DS) exhibit higher risk for celiac disease (CD) than general population. Although literature suggests CD could be associated with behavioural problems in both ...paediatric and adult age, such association has been poorly explored in children and adolescents DS. Therefore, the current study aimed to investigate differences in emotional/behavioural difficulties, adaptive skills and sleep problems between children with DS with and without CD.
Data were retrospectively collected from a database including data from 381 individuals with DS (3-18 years). The final sample included 65 participants, 27 with co-occurring CD and 38 age, IQ, sex and body mass index-matched controls without CD. Emotional/behavioural difficulties, adaptive skills and sleep problems were assessed through parent report questionnaires.
No group differences emerged in emotional/behavioural difficulties, whereas participants in the CD group showed better adaptive skills in the practical domain than control group. Weak differences emerged in sleep problems.
Youth with DS and co-occurring CD do not exhibit more emotional and behavioural problems than youth with DS without co-occurring CD but exhibit better adaptive skills in the practical domain.
We have characterized a homodimeric tRNA endonuclease from the euryarchaeota
(FERAC), a facultative anaerobe which can grow at temperatures ranging from 35 to 42 °C. This enzyme, contrary to the ...eukaryal tRNA endonucleases and the homotetrameric
(METJA) homologs, is able to cleave minimal BHB (bulge-helix-bulge) substrates at 30 °C. The expression of this enzyme in
(SCHPO) enables the use of its properties as effectors by inserting BHB motif introns into hairpin loops normally seen in mRNA transcripts. In addition, the FERAC endonuclease can create proteins with new functionalities through the recombination of protein domains.
Hepatitis E virus (HEV) can cause chronic infection and liver cirrhosis in immunocompromised individuals. The frequency and clinical importance of HEV was studied retrospectively in a cohort of 236 ...Swedish allogeneic hematopoietic stem cell transplantation (HSCT) recipients. In blood samples collected at 6 months after HSCT, HEV RNA was identified in 8/236 (3.4%) patients, and 11/236 (4.7%) patients had detectable anti-HEV IgG and/or IgM, eight of whom were HEV RNA negative. Two of the patients with positive HEV RNA died with ongoing signs of hepatitis: one of acute liver and multiple organ failure, the other of unrelated causes. The remaining six patients with HEV RNA had cleared the infection at 7-24 (median 8.5) months after HSCT. HEV infection was associated with elevated alanine aminotransferase at 6 months after HSCT (OR 15, 1.3-174, p = 0.03). Active graft-versus-host disease of the liver at 6 months after HSCT was present in 3/8 (38%) patients with HEV RNA, but was not significantly associated with HEV infection. In conclusion, HEV infection is an important differential diagnosis in patients with elevated liver enzymes after HSCT. Although spontaneous clearance was common, the clinical course may be severe.
Evolution of introns in the archaeal world Tocchini-Valentini, Giuseppe D; Fruscoloni, Paolo; Tocchini-Valentini, Glauco P
Proceedings of the National Academy of Sciences - PNAS,
03/2011, Volume:
108, Issue:
12
Journal Article
Peer reviewed
Open access
The self-splicing group I introns are removed by an autocatalytic mechanism that involves a series of transesterification reactions. They require RNA binding proteins to act as chaperones to ...correctly fold the RNA into an active intermediate structure in vivo. Pre-tRNA introns in Bacteria and in higher eukaryote plastids are typical examples of self-splicing group I introns. By contrast, two striking features characterize RNA splicing in the archaeal world. First, self-splicing group I introns cannot be found, to this date, in that kingdom. Second, the RNA splicing scenario in Archaea is uniform: All introns, whether in pre-tRNA or elsewhere, are removed by tRNA splicing endonucleases. We suggest that in Archaea, the protein recruited for splicing is the preexisting tRNA splicing endonuclease and that this enzyme, together with the ligase, takes over the task of intron removal in a more efficient fashion than the ribozyme. The extinction of group I introns in Archaea would then be a consequence of recruitment of the tRNA splicing endonuclease. We deal here with comparative genome analysis, focusing specifically on the integration of introns into genes coding for 23S rRNA molecules, and how this newly acquired intron has to be removed to regenerate a functional RNA molecule. We show that all known oligomeric structures of the endonuclease can recognize and cleave a ribosomal intron, even when the endonuclease derives from a strain lacking rRNA introns. The persistance of group I introns in mitochondria and chloroplasts would be explained by the inaccessibility of these introns to the endonuclease.
Abtract
Background
The life expectancy of people with Down syndrome (DS) has significantly increased in the last decades. We describe the congenital malformations and main comorbidities of a cohort ...of children and young people with DS and analyse their differences according to age and gender groups.
Methods
This retrospective cross‐sectional study was conducted at DS centre of Bambino Gesù Children's Hospital in Rome (Italy). The period for reviewing all electronic health records ran from July 2016 to September 2017. We collected data on clinical conditions and compared them with the general paediatric population. Moreover, we compared the main comorbidities, dental diseases and body mass index data between age groups.
Results
Seven hundred sixty‐three children and young people with DS included in this study were aged 7.45 ± 5.49 years. Gender distribution included 58.19% male patients. The majority of our population (71.04%) came from central regions of Italy. Respiratory diseases (19%), congenital heart defects (72.23%), malocclusions (58.62%), astigmatism (20.31%), farsightedness (16.51%), near‐sightedness (12.19%) and autoimmune hypothyroidism (3.28%) were more frequent in our population compared with the typical paediatric population. Upper respiratory tract infections and underweight were significantly more frequent in the youngest children, whereas dental diseases, refractive errors, obesity and autoimmune hypothyroidism increased over age.
Conclusions
Children and young people with DS present a high prevalence of potentially treatable medical conditions making multidisciplinary teams a mandatory need for this population.
Members of the three kingdoms of life contain tRNA genes with introns. The introns in pre-tRNAs of Bacteria are self-splicing, whereas introns in archaeal and eukaryal pre-tRNAs are removed by ...splicing endonucleases. We have studied the structures of the endonucleases of Archaea and the architecture of the sites recognized in their pre-tRNA substrates. Three endonuclease structures are known in the Archaea: a homotetramer in some Euryarchaea, a homodimer in other Euryarchaea, and a heterotetramer in the Crenarchaeota. The homotetramer cleaves only the canonical bulge-helix-bulge structure in its substrates. Variants of the substrate structure, termed bulge-helix-loops, appear in the pre-tRNAs of the Crenarcheota and Nanoarcheota. These variant structures can be cleaved only by the homodimer or heterotetramer forms of the endonucleases. Thus, the structures of the endonucleases and their substrates appear to have evolved together.
We have detected two paralogs of the tRNA endonuclease gene of Methanocaldococcus jannaschii in the genome of the crenarchaeote Sulfolobus solfataricus. This finding has led to the discovery of a ...previously unrecognized oligomeric form of the enzyme. The two genes code for two different subunits, both of which are required for cleavage of the pre-tRNA substrate. Thus, there are now three forms of tRNA endonuclease in the Archaea: a homotetramer in some Euryarchaea, a homodimer in other Euryarchaea, and a heterotetramer in the Crenarchaea and the Nanoarchaea. The last-named enzyme, arising most likely by gene duplication and subsequent "subfunctionalization," requires the products of both genes to be active.
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