85 research outputs found
Intracranial delivery of AAV9 gene therapy partially prevents retinal degeneration and visual deficits in CLN6-Batten disease mice
Batten disease is a family of rare, fatal, neuropediatric diseases presenting with memory/learning decline, blindness, and loss of motor function. Recently, we reported the use of an AAV9-mediated gene therapy that prevents disease progression in a mouse model of CLN6-Batten disease (Cln6nclf), restoring lifespans in treated animals. Despite the success of our viral-mediated gene therapy, the dosing strategy was optimized for delivery to the brain parenchyma and may limit the therapeutic potential to other disease-relevant tissues, such as the eye. Here, we examine whether cerebrospinal fluid (CSF) delivery of scAAV9.CB.CLN6 is sufficient to ameliorate visual deficits in Cln6nclf mice. We show that intracerebroventricular (i.c.v.) delivery of scAAV9.CB.CLN6 completely prevents hallmark Batten disease pathology in the visual processing centers of the brain, preserving neurons of the superior colliculus, thalamus, and cerebral cortex. Importantly, i.c.v.-delivered scAAV9.CB.CLN6 also expresses in many cells throughout the central retina, preserving many photoreceptors typically lost in Cln6nclf mice. Lastly, scAAV9.CB.CLN6 treatment partially preserved visual acuity in Cln6nclf mice as measured by optokinetic response. Taken together, we report the first instance of CSF-delivered viral gene reaching and rescuing pathology in both the brain parenchyma and retinal neurons, thereby partially slowing visual deterioration
Observation of coherent many-body Rabi oscillations
A two-level quantum system coherently driven by a resonant electromagnetic
field oscillates sinusoidally between the two levels at frequency
which is proportional to the field amplitude [1]. This phenomenon, known as the
Rabi oscillation, has been at the heart of atomic, molecular and optical
physics since the seminal work of its namesake and coauthors [2]. Notably, Rabi
oscillations in isolated single atoms or dilute gases form the basis for
metrological applications such as atomic clocks and precision measurements of
physical constants [3]. Both inhomogeneous distribution of coupling strength to
the field and interactions between individual atoms reduce the visibility of
the oscillation and may even suppress it completely. A remarkable
transformation takes place in the limit where only a single excitation can be
present in the sample due to either initial conditions or atomic interactions:
there arises a collective, many-body Rabi oscillation at a frequency
involving all N >> 1 atoms in the sample [4]. This is true even
for inhomogeneous atom-field coupling distributions, where single-atom Rabi
oscillations may be invisible. When one of the two levels is a strongly
interacting Rydberg level, many-body Rabi oscillations emerge as a consequence
of the Rydberg excitation blockade. Lukin and coauthors outlined an approach to
quantum information processing based on this effect [5]. Here we report initial
observations of coherent many-body Rabi oscillations between the ground level
and a Rydberg level using several hundred cold rubidium atoms. The strongly
pronounced oscillations indicate a nearly complete excitation blockade of the
entire mesoscopic ensemble by a single excited atom. The results pave the way
towards quantum computation and simulation using ensembles of atoms
Biallelic Loss-of-Function Variants in BICD1 Are Associated with Peripheral Neuropathy and Hearing Loss
Hearing loss and peripheral neuropathy are two clinical entities that are genetically and phenotypically heterogeneous and sometimes co-occurring. Using exome sequencing and targeted segregation analysis, we investigated the genetic etiology of peripheral neuropathy and hearing loss in a large Ashkenazi Jewish family. Moreover, we assessed the production of the candidate protein via western blotting of lysates from fibroblasts from an affected individual and an unaffected control. Pathogenic variants in known disease genes associated with hearing loss and peripheral neuropathy were excluded. A homozygous frameshift variant in the BICD1 gene, c.1683dup (p.(Arg562Thrfs*18)), was identified in the proband and segregated with hearing loss and peripheral neuropathy in the family. The BIDC1 RNA analysis from patient fibroblasts showed a modest reduction in gene transcripts compared to the controls. In contrast, protein could not be detected in fibroblasts from a homozygous c.1683dup individual, whereas BICD1 was detected in an unaffected individual. Our findings indicate that bi-allelic loss-of-function variants in BICD1 are associated with hearing loss and peripheral neuropathy. Definitive evidence that bi-allelic loss-of-function variants in BICD1 cause peripheral neuropathy and hearing loss will require the identification of other families and individuals with similar variants with the same phenotype
Glucose-6-Phosphate Dehydrogenase Deficiency in an Endemic Area for Malaria in Manaus: A Cross-Sectional Survey in the Brazilian Amazon
BACKGROUND: There is a paucity of information regarding glucose-6-phosphate dehydrogenase (G6PD) deficiency in endemic areas for malaria in Latin America. METHODOLOGY/PRINCIPAL FINDINGS: This study determined the prevalence of the G6PD deficiency in 200 male non-consanguineous individuals residing in the Ismail Aziz Community, on the outskirts of Manaus (Brazilian Amazon). Six individuals (3%) were deficient using the qualitative Brewer's test. Gel electrophoresis showed that five of these patients were G6PD A(-). The deficiency was not associated with the ethnic origin (P = 0.571). In a multivariate logistic regression analysis, G6PD deficiency protected against three or more episodes of malaria (P = 0.049), independently of the age, and was associated with a history of jaundice (P = 0.020) and need of blood transfusion (P = 0.045) during previous treatment for malarial infection, independently of the age and the previous malarial exposure. CONCLUSIONS/SIGNIFICANCE: The frequency of G6PD deficiency was similar to other studies performed in Brazil and the finding of a predominant G6PD A(-) variant will help the clinical management of patients with drug-induced haemolysis. The history of jaundice and blood transfusion during previous malarial infection may trigger the screening of patients for G6PD deficiency. The apparent protection against multiple malarial infections in an area primarily endemic for Plasmodium vivax needs further investigation
Composition, Diversity, and Origin of the Bacterial Community in Grass Carp Intestine
Gut microbiota has become an integral component of the host, and received increasing attention. However, for many domestic animals, information on the microbiota is insufficient and more effort should be exerted to manage the gastrointestinal bacterial community. Understanding the factors that influence the composition of microbial community in the host alimentary canal is essential to manage or improve the microbial community composition. In the present study, 16S rRNA gene sequence-based comparisons of the bacterial communities in the grass carp (Ctenopharyngodon idellus) intestinal contents and fish culture-associated environments are performed. The results show that the fish intestinal microbiota harbors many cellulose-decomposing bacteria, including sequences related to Anoxybacillus, Leuconostoc, Clostridium, Actinomyces, and Citrobacter. The most abundant bacterial operational taxonomic units (OTUs) in the grass carp intestinal content are those related to feed digestion. In addition, the potential pathogens and probiotics are important members of the intestinal microbiota. Further analyses show that grass carp intestine holds a core microbiota composed of Proteobacteria, Firmicutes, and Actinobacteria. The comparison analyses reveal that the bacterial community in the intestinal contents is most similar to those from the culture water and sediment. However, feed also plays significant influence on the composition of gut microbiota
G6PD deficiency in Latin America: systematic review on prevalence and variants
Plasmodium vivax radical cure requires the use of primaquine (PQ), a drug that induces haemolysis in glucose-6-phosphate dehydrogenase deficient (G6PDd) individuals, which further hampers malaria control efforts. The aim of this work was to study the G6PDd prevalence and variants in Latin America (LA) and the Caribbean region. A systematic search of the published literature was undertaken in August 2013. Bibliographies of manuscripts were also searched and additional references were identified. Low prevalence rates of G6PDd were documented in Argentina, Bolivia, Mexico, Peru and Uruguay, but studies from Curaçao, Ecuador, Jamaica, Saint Lucia, Suriname and Trinidad, as well as some surveys carried out in areas of Brazil, Colombia and Cuba, have shown a high prevalence (> 10%) of G6PDd. The G6PD A-202A mutation was the variant most broadly distributed across LA and was identified in 81.1% of the deficient individuals surveyed. G6PDd is a frequent phenomenon in LA, although certain Amerindian populations may not be affected, suggesting that PQ could be safely used in these specific populations. Population-wide use of PQ as part of malaria elimination strategies in LA cannot be supported unless a rapid, accurate and field-deployable G6PDd diagnostic test is made available
Functional Dicer Is Necessary for Appropriate Specification of Radial Glia during Early Development of Mouse Telencephalon
Early telencephalic development involves transformation of neuroepithelial stem cells into radial glia, which are themselves neuronal progenitors, around the time when the tissue begins to generate postmitotic neurons. To achieve this transformation, radial precursors express a specific combination of proteins. We investigate the hypothesis that micro RNAs regulate the ability of the early telencephalic progenitors to establish radial glia. We ablate functional Dicer, which is required for the generation of mature micro RNAs, by conditionally mutating the Dicer1 gene in the early embryonic telencephalon and analyse the molecular specification of radial glia as well as their progeny, namely postmitotic neurons and basal progenitors. Conditional mutation of Dicer1 from the telencephalon at around embryonic day 8 does not prevent morphological development of radial glia, but their expression of Nestin, Sox9, and ErbB2 is abnormally low. The population of basal progenitors, which are generated by the radial glia, is disorganised and expanded in Dicer1-/- dorsal telencephalon. While the proportion of cells expressing markers of postmitotic neurons is unchanged, their laminar organisation in the telencephalic wall is disrupted suggesting a defect in radial glial guided migration. We found that the laminar disruption could not be accounted for by a reduction of the population of Cajal Retzius neurons. Together, our data suggest novel roles for micro RNAs during early development of progenitor cells in the embryonic telencephalon
IMF-By dependence of transient ionospheric flow perturbation associated with sudden impulses: SuperDARN observations
Hexavalent Chromium Reduction under Fermentative Conditions with Lactate Stimulated Native Microbial Communities
This work conducted by ENIGMA- Ecosystems and Networks Integrated with Genes and Molecular Assemblies (http://enigma.lbl.gov), a Scientific Focus Area Program at Lawrence Berkeley National Laboratory. The submitted manuscript has been authored by a contractor of the U.S. Government under contract DE-AC05-00OR22725. Accordingly, the U.S. Government retains a nonexclusive, royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for U.S. Government purposes.Conceived and designed the experiments: ACS JJM MP TJP SDB AVP DAE. Performed the experiments: ACS JJM ZKY. Analyzed the data: ACS JJM TY JDVN JZ DAE. Contributed reagents/materials/analysis tools: DAE TCH APA. Wrote the paper: ACS JJM DAE.Microbial reduction of toxic hexavalent chromium (Cr(VI)) in-situ is a plausible bioremediation strategy in electron-acceptor limited environments. However, higher Cr(VI) may impose stress on syntrophic communities and impact community structure and function. The study objectives were to understand the impacts of Cr(VI) concentrations on community structure and on the Cr(VI)-reduction potential of groundwater communities at Hanford, WA. Steady state continuous flow bioreactors were used to grow native communities enriched with lactate (30 mM) and continuously amended with Cr(VI) at 0.0 (No-Cr), 0.1 (Low-Cr) and 3.0 (High-Cr) mg/L. Microbial growth, metabolites, Cr(VI), 16S rRNA gene sequences and GeoChip based functional gene composition were monitored for 15 weeks. Temporal trends and differences in growth, metabolite profiles, and community composition were observed, largely between Low-Cr and High-Cr bioreactors. In both High-Cr and Low-Cr bioreactors, Cr(VI) levels were below detection from week 1 until week 15. With lactate enrichment, native bacterial diversity substantially decreased as Pelosinus spp., and Sporotalea spp., became the dominant groups, but did not significantly differ between Cr concentrations. The Archaea diversity also substantially decreased after lactate enrichment from Methanosaeta (35%), Methanosarcina (17%) and others, to mostly Methanosarcina spp. (95%). Methane production was lower in High-Cr reactors suggesting some inhibition of methanogens. Several key functional genes were distinct in Low-Cr bioreactors compared to High-Cr. Among the Cr resistant microbes, Burkholderia vietnamiensis, Comamonas testosterone and Ralstonia pickettii proliferated in Cr amended bioreactors. In-situ fermentative conditions facilitated Cr(VI) reduction, and as a result 3.0 mg/L Cr(VI) did not impact the overall bacterial community structure.Yeshttp://www.plosone.org/static/editorial#pee
How arguments are constructed and used in the Social Sciences
This unit will enable you to understand how arguments are constructed and used in the Social Sciences. Using extracts from a Radio 4 broadcast you will look at the different viewpoints that are taken by the participants and analyse how the different arguments are being put together
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