922 research outputs found
Transjugular Balloon-Assisted Retrograde Ethylene-Vinyl Alcohol Copolymer Embolization of a Main Pulmonary Artery Defect Discovered during Removal of a Malpositioned Dialytic Central Venous Catheter.
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chemical composition and antimicrobial activity of the essential oil from the bark of xylopia hypolampra
Hydrodistillation of Xylopia hypolampra Mildbr. stem bark afforded 39 mg (dry weight basis) of a pale yellow fragrant essential oil; gas chromatography-flame ionization detector and gas chromatogra..
Reply: DGUOK recessive mutations in patients with CPEO, mitochondrial myopathy, parkinsonism and mtDNA deletions
Case report: Clinical and molecular characterization of two siblings affected by Brody myopathy
Exercise-induced muscle stiffness is the hallmark of Brody disease, an autosomal recessive myopathy due to biallelic pathogenic variants in ATP2A1, encoding the sarcoplasmic/endoplasmic reticulum Ca2+ ATPase SERCA1. About 40 patients have been reported so far. Our knowledge about the natural history of this disorder, genotype–phenotype correlations and the effect of symptomatic treatment is partial. This results in incomplete recognition and underdiagnosis of the disease. Here, we report the clinical, instrumental, and molecular features of two siblings presenting childhood-onset exercise-induced muscle stiffness without pain. Both the probands display difficulty in climbing stairs and running, frequent falls, delayed muscle relaxation after exertion. Cold temperatures worsen these symptoms. No myotonic discharges were observed at electromyography. Whole Exome Sequencing analysis in the probands revealed the presence of two ATP2A1 variants: the previously reported frameshift microdeletion c.2464delC and the likely pathogenic novel splice-site variant c.324 + 1G > A, whose detrimental effect was demonstrated in ATP2A1 transcript analysis. The bi-allelic inheritance was verified by Sanger sequencing in the unaffected parents. This study expands the molecular defects associated with Brody myopathy
Comparative genomics and transcriptional profiles of Saccharopolyspora erythraea NRRL 2338 and a classically improved erythromycin over-producing strain
<p>Abstract</p> <p>Background</p> <p>The molecular mechanisms altered by the traditional mutation and screening approach during the improvement of antibiotic-producing microorganisms are still poorly understood although this information is essential to design rational strategies for industrial strain improvement. In this study, we applied comparative genomics to identify all genetic changes occurring during the development of an erythromycin overproducer obtained using the traditional mutate-and- screen method.</p> <p>Results</p> <p>Compared with the parental <it>Saccharopolyspora erythraea </it>NRRL 2338, the genome of the overproducing strain presents 117 deletion, 78 insertion and 12 transposition sites, with 71 insertion/deletion sites mapping within coding sequences (CDSs) and generating frame-shift mutations. Single nucleotide variations are present in 144 CDSs. Overall, the genomic variations affect 227 proteins of the overproducing strain and a considerable number of mutations alter genes of key enzymes in the central carbon and nitrogen metabolism and in the biosynthesis of secondary metabolites, resulting in the redirection of common precursors toward erythromycin biosynthesis. Interestingly, several mutations inactivate genes coding for proteins that play fundamental roles in basic transcription and translation machineries including the transcription anti-termination factor NusB and the transcription elongation factor Efp. These mutations, along with those affecting genes coding for pleiotropic or pathway-specific regulators, affect global expression profile as demonstrated by a comparative analysis of the parental and overproducer expression profiles. Genomic data, finally, suggest that the mutate-and-screen process might have been accelerated by mutations in DNA repair genes.</p> <p>Conclusions</p> <p>This study helps to clarify the mechanisms underlying antibiotic overproduction providing valuable information about new possible molecular targets for rationale strain improvement.</p
Modulation of cell growth and cisplatin sensitivity by membrane gamma-glutamyltransferase in melanoma cells.
The plasma membrane enzyme c-glutamyltransferase (GGT) is regarded as critical for the
maintenance of intracellular levels of glutathione (GSH). GGT expression has been implicated
in drug resistance through elevation of intracellular GSH. The dependence of intracellular
GSH on GGT expression was not conclusively ascertained. The present study was
designed to investigate the role of GGT and of intracellular GSH levels in modulating proliferation
and sensitivity to cisplatin of melanoma cells. GGT transfection resulted in
increased growth, both in vitro and in tumour xenografts. In addition, GGT-transfected cells
exhibited reduced sensitivity to cisplatin associated with lower DNA platination. A
decrease in intracellular GSH levels, rather than an increase, was observed in GGT-transfected
cells; moreover, in cysteine-deficient conditions, the expression of GGT did not provide
transfected cells with the ability of utilising extracellular GSH. In conclusion, these results
indicate that GGTactivity confers a growth advantage unrelated with intracellular glutathione
supply, and are consistent with the interpretation that cisplatin resistance is the consequence
of modifications of cellular pharmacokinetics as a result of extracellular drug
inactivation by thiol metabolites originated by GGT-mediated GSH cleavage
MICROWAVE-ASSISTED BRUCITE AND TALC REACTIONS WITH CO2 AS A PROXY FOR CARBON CAPTURE AND STORAGE BY SERPENTINE
In the last decades many studies have been focusing on Carbon Capture and Storage
(CCS) to find a possible remedy to reduce the large increase of anthropogenic carbon
dioxide (CO ). Mineral Carbonation (MC) is a potential solution for almost irreversible
chemical long-term CCS. It concerns the combination of CaO and MgO with CO forming
spontaneously and exothermically dolomite and magnesite. However, kinetic barriers
pose sever limitations for the practical exploitation of this reaction.
High fractions of MgO are available in silicates such as olivine, orthopyroxene,
clinopyroxene and serpentine. To date, data reported that serpentine polymorphs, above
all antigorite, is an excellent candidate for fixing the CO as the reaction efficiency is
approximately 92% compared to lizardite (40%) and olivine (66%). This is due to the
surface reactivity of approximately 18.7 m /g for the dehydrated antigorite compared
to10.8 m /g for dehydrated lizardite and 4.6 m /g for olivine.
The microwave assisted process for CCS is an innovative technology that can be
employed to catalyze the reaction through thermal and non-thermal mechanisms. Some
pioneering tests of direct carbonation by microwave hydrothermal equipment have been
performed on olivine, lizardite and chrysotile powders [1] but not on antigorite. The
structure of serpentine is characterized by corrugated stacked layers of silica and brucite.
For this reason, MC involves dissolution of SiO layers, dissolution/dehydration of
Mg(OH) layers, and precipitation of magnesium carbonate.
To address the chemical response of the single phases, experiments have been
performed by both a local microwave-source acting locally on a specific crystal surface
and a volume source interacting with an ensemble of grains on synthetic powders and
single crystals of pure brucite and talc. In a second step, treatments have been extended
to chrysotile, lizardite and antigorite. A characterization of the mechanism and kinetics
were performed by scanning probe microscopy on the surface of single crystals phases,
supported by Raman spectroscopy and by Scanning and Transmission Electron
Microscopy study performed on micro- and nano-sized grains.
[1] White, et al. Reaction mechanisms of magnesium silicates with carbon dioxide in
microwave fields. Final Report to the U.S. Department ofEnergy, National Energy
Technology Laboratory (2004
Unexpected phylogeographic affinities of Psammodromus algirus from Conigli islet (Lampedusa)
The only Italian population of the lacertid Psammodromus algirus is found in Conigli islet whereas the species is absent from the nearby island of Lampedusa. The phylogeographic relationships of this population were investigated. Mitochondrial DNA (12S rRNA and 16S rRNA) fragment sequences were analysed and compared with already published sequences from the whole species range. In all the analyses, the sample from Conigli grouped with those from Morocco and not with the closer Tunisian ones. Such surprising result poses serious doubts to the traditional interpretation of the enigmatic distribution pattern of this species in Italy suggesting a recent colonisation of the islet from NW Africa, probably human-mediated, rather than a land crossing from Tunisia during the Pleistocene
Case report: A novel patient presenting TRIM32-related limb-girdle muscular dystrophy
Limb-girdle muscular dystrophy autosomal recessive 8 (LGMDR8) is a rare clinical manifestation caused by the presence of biallelic variants in the TRIM32 gene. We present the clinical, molecular, histopathological, and muscle magnetic resonance findings of a novel 63-years-old LGMDR8 patient of Italian origins, who went undiagnosed for 24 years. Clinical exome sequencing identified two TRIM32 missense variants, c.1181G > A p.(Arg394His) and c.1781G > A p.(Ser594Asp), located in the NHL1 and NHL4 structural domains, respectively, of the TRIM32 protein. We conducted a literature review of the clinical and instrumental data associated to the so far known 26 TRIM32 variants, carried biallelically by 53 LGMDR8 patients reported to date in 20 papers. Our proband's variants were previously identified only in three independent LGMDR8 patients in homozygosis, therefore our case is the first in literature to be described as compound heterozygous for such variants. Our report also provides additional data in support of their pathogenicity, since p.(Arg394His) is currently classified as a variant of uncertain significance, while p.(Ser594Asp) as likely pathogenic. Taken together, these findings might be useful to improve both the genetic counseling and the diagnostic accuracy of this rare neuromuscular condition
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