183 research outputs found
Suppression of apoptosis in the liver by systemic and local delivery of small-interfering RNAs
RNA interference (RNAi) is a sequence-specific gene-silencing mechanism triggered by double-stranded RNA. RNAi was shown to allow transient or stable knockdown of gene expression in a broad range of species and has been used successfully for functional genomic screens in mammalian cells and Caenorhabditis elegans. Standard therapeutic use of RNAi in clinical settings in humans has been hampered by the lack of effective methods to deliver the small-interfering RNAs (siRNAs) or short-hairpin RNA expression vectors into the diseased organs. In mice, systemic delivery of siRNAs by hydrodynamic intravascular injection leads to highly efficient uptake of siRNAs into the liver. Several groups demonstrated therapeutic use of RNAi in mouse models of acute liver failure or hepatitis B virus replication. This chapter will focus on the technical background of hydrodynamic and portal vein delivery techniques in mice and will give practical guidance for using these techniques for siRNA delivery into the liver
Prediction of geomagnetic storm strength from inner heliospheric in situ observations
Prediction of the effects of coronal mass ejections (CMEs) on Earth strongly depends on knowledge of the interplanetary magnetic field southward component, B z . Predicting the strength and duration of B z inside a CME with sufficient accuracy is currently impossible, forming the so-called B z problem. Here, we provide a proof-of-concept of a new method for predicting the CME arrival time, speed, B z , and resulting disturbance storm time (Dst) index on Earth based only on magnetic field data, measured in situ in the inner heliosphere (<1 au). On 2012 June 12–16, three approximately Earthward-directed and interacting CMEs were observed by the Solar Terrestrial Relations Observatory imagers and Venus Express (VEX) in situ at 0.72 au, 6° away from the Sun–Earth line. The CME kinematics are calculated using the drag-based and WSA–Enlil models, constrained by the arrival time at VEX, resulting in the CME arrival time and speed on Earth. The CME magnetic field strength is scaled with a power law from VEX to Wind. Our investigation shows promising results for the Dst forecast (predicted: −96 and −114 nT (from 2 Dst models); observed: −71 nT), for the arrival speed (predicted: 531 ± 23 km s−1; observed: 488 ± 30 km s−1), and for the timing (6 ± 1 hr after the actual arrival time). The prediction lead time is 21 hr. The method may be applied to vector magnetic field data from a spacecraft at an artificial Lagrange point between the Sun and Earth or to data taken by any spacecraft temporarily crossing the Sun–Earth line
Efecto de los compuestos fenólicos extraídos de semillas de girasol sobre la actividad lipoxigenasa nativa.
Extracts of lipoxygenase were obtained from sunflower seeds using 12 different extraction mixtures, and lipoxygenase activity and content of phenolic compounds in the extracts were determined. The content of phenolic compounds was determined as the ratio of optical densities at 320/280nm. Statistical analysis of the results for the extracts showed a significant correlation between the lipoxygenase activity and the OD320nm/OD280nm ratio with r = 0.619. However, after dialysis of the extracts, no correlation was found.Efecto de los compuestos fenólicos extraídos de semillas de girasol sobre la actividad lipoxigenasa nativa. Se obtuvieron extractos de lipoxigenasa de semillas de girasol usando 12 mezclas de extracción diferentes, y se determinó la actividad lipoxigenasa y el contenido en compuestos fenólicos. Este último se llevó a cabo mediante medida de la relación de absorbancias a 320/280nm. El análisis estadístico de los resultados para los extractos mostró una correlación entre la actividad lipoxigenasa y la relación OD320nm/OD280nm con r = 0,619. Sin embargo, después de la diálisis de los extractos, no se observó esta correlación
Bacteriological studies of blood, tissue fluid, lymph and lymph nodes in patients with acute dermatolymphangioadenitis (DLA) in course of ‘filarial’ lymphedema
Filarial lymphedema is complicated by frequent episodes of dermatolymphangioadenitis (DLA). Severe systemic
symptoms during attacks of DLA resemble those of septicemia. The question we asked was whether bacterial isolates
can be found in the peripheral blood of patients during the episodes of DLA. Out of 100 patients referred to us with
‘filarial’ lymphedema 14 displayed acute and five subacute symptoms of DLA. All were on admission blood
microfilariae negative but had a positive test in the past. Blood bacterial isolates were found in nine cases, four acute
(21%) and five subacute (26%). In 10 acute cases blood cultures were found negative. Six blood isolates belonged to
Bacilli, four to Cocci and one was Sarcina. To identify the sites of origin of bacterial dissemination, swabs taken from
the calf skin biopsy wounds and tissue fluid, lymph and lymph node specimens were cultured. Swabs from the calf
skin biopsy wound contained isolates in nine (47%) cases. They were Bacilli in nine, Cocci in three, Acinetobacter and
Erwinia in two cases. Tissue fluid was collected from 10 patients and contained Bacilli in four (40%) and
Staphylococci in three (30%). Lymph was drained in four patients and contained isolates in all samples (100%). They
were Staphylococcus epidermis, xylosus and aureus, Acinetobacter, Bacillus subtilis and Sarcina. Three lymph nodes
were biopsied and contained Staphylococcus chromogenes, xylosus, Enterococcus and Bacillus cereus. In six cases the
same phenotypically defined species of bacteria were found in blood and limb tissues or fluids. In the ‘control’ group of patients with lymphedema without acute or subacute changes all blood cultures were negative. Interestingly, swabs
from biopsy wound of these patients contained isolates in 80%, tissue fluid in 68%, lymph in 70% and lymph nodes
in 58% of cases. In healthy controls, tissue fluid did not contain bacteria, and lymph isolates were found only in 12%
of cases. This study demonstrates that patients with acute episodes of DLA reveal bacteriemia in a high percentage
of cases. Diversity of blood and tissue bacterial isolates in these patients points to a breakdown of the skin immune
barrier in lymphedema and subsequently indiscriminate bacterial colonization of deep tissues and spread to an blood
circulation. © 1999 Elsevier Science B.V. All rights reserved
Frontal sinus variation in large samples of extant species of the genera Pan, Gorilla and Homo
Frontal pneumatisation is not present in all primates, and among extant species, ethmoidally-derived frontal sinuses are present only in the genera Pan, Gorilla and Homo. A simple and repeatable method is described here to quantify variation in the shape, size and bilateral variation of the frontal sinuses. This has allowed the first large study of these variables, including analyses of large samples of P. paniscus, P. troglodytes, G. gorilla and of several geographically diverse populations of H. sapiens. Frontal sinus shape and size are potential phylogenetic markers in primate systematics. We suggest that, in contrast to an allometric relationship between endocranial and frontal sinus form in Pan and Gorilla, H. sapiens is autapomorphic in having highly variable, supero-inferiorly large frontal sinuses, whose size is unrestricted by variation in cranial form. However, we also describe differences in frontal pneumatisation between those taxa. H. sapiens differs from the other taxa in having relatively smaller frontal sinuses that are more variable in shape and size. In P. troglodytes, P. paniscus and G. gorilla, the shape and size of frontal pneumatisation correlates positively with the overall size of the braincase. This suggests that the large space available in the bone structures of the non-human primates analysed allows the sinuses to develop under only slight constraint (if any) from surrounding structures. In H. sapiens, a significant correlation is observed between the asymmetry in the anterior extension of the frontal lobes of the brain and the shape and extension of the frontal sinuses. We suggest that the more vertical orientation of the H. sapiens frontal bone, its reduced thickness, the reduction of the supraorbital tori and the increased influence of the frontal lobes appear to have modified the integration between the skull, brain and sinuses in the frontal region in our species compared to our nearest extant relatives. Our results reduce the possibility of a strong functional origin for the variation in size and shape of the frontal sinuses in the primates analysed
Consumer credit in comparative perspective
We review the literature in sociology and related fields on the fast global growth of consumer credit and debt and the possible explanations for this expansion. We describe the ways people interact with the strongly segmented consumer credit system around the world—more specifically, the way they access credit and the way they are held accountable for their debt. We then report on research on two areas in which consumer credit is consequential: its effects on social relations and on physical and mental health. Throughout the article, we point out national variations and discuss explanations for these differences. We conclude with a brief discussion of the future tasks and challenges of comparative research on consumer credit.Accepted manuscrip
Guidance on noncorticosteroid systemic immunomodulatory therapy in noninfectious uveitis: fundamentals of care for uveitis (focus) initiative
Topic: An international, expert-led consensus initiative to develop systematic, evidence-based recommendations for the treatment of noninfectious uveitis in the era of biologics.
Clinical Relevance: The availability of biologic agents for the treatment of human eye disease has altered practice patterns for the management of noninfectious uveitis. Current guidelines are insufficient to assure optimal use of noncorticosteroid systemic immunomodulatory agents.
Methods: An international expert steering committee comprising 9 uveitis specialists (including both ophthalmologists and rheumatologists) identified clinical questions and, together with 6 bibliographic fellows trained in uveitis, conducted a Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol systematic reviewof the literature (English language studies from January 1996 through June 2016; Medline [OVID], the Central Cochrane library, EMBASE,CINAHL,SCOPUS,BIOSIS, andWeb of Science). Publications included randomized controlled trials, prospective and retrospective studies with sufficient follow-up, case series with 15 cases or more, peer-reviewed articles, and hand-searched conference abstracts from key conferences. The proposed statements were circulated
among 130 international uveitis experts for review.Atotal of 44 globally representativegroupmembersmet in late 2016 to refine these guidelines using a modified Delphi technique and assigned Oxford levels of evidence.
Results: In total, 10 questions were addressed resulting in 21 evidence-based guidance statements covering the following topics: when to start noncorticosteroid immunomodulatory therapy, including both biologic and nonbiologic agents; what data to collect before treatment; when to modify or withdraw treatment; how to select agents based on individual efficacy and safety profiles; and evidence in specific uveitic conditions. Shared decision-making, communication among providers and safety monitoring also were addressed as part of the recommendations. Pharmacoeconomic considerations were not addressed.
Conclusions: Consensus guidelines were developed based on published literature, expert opinion, and practical experience to bridge the gap between clinical needs and medical evidence to support the treatment of patients with noninfectious uveitis with noncorticosteroid immunomodulatory agents
Frontal sinuses and human evolution
The frontal sinuses are cavities inside the frontal bone located at the junction between the face and the cranial vault and close to the brain. Despite a long history of study, understanding of their origin and variation through evolution is limited. This work compares most hominin species? holotypes and other key individuals with extant hominids. It provides a unique and valuable perspective of the variation in sinuses position, shape, and dimensions based on a simple and reproducible methodology. We also observed a covariation between the size and shape of the sinuses and the underlying frontal lobes in hominin species from at least the appearance of Homo erectus. Our results additionally undermine hypotheses stating that hominin frontal sinuses were directly affected by biomechanical constraints resulting from either chewing or adaptation to climate. Last, we demonstrate their substantial potential for discussions of the evolutionary relationships between hominin species. Variation in frontal sinus shape and dimensions has high potential for phylogenetic discussion when studying human evolution
Adenoviral Vector Driven by a Minimal Rad51 Promoter Is Selective for p53-Deficient Tumor Cells
Background: The full length Rad51 promoter is highly active in cancer cells but not in normal cells. We therefore set out to assess whether we could confer this tumor-selectivity to an adenovirus vector. Methodology/Principal Findings: Expression of an adenovirally-vectored luciferase reporter gene from the Rad51 promoter was up to 50 fold higher in cancer cells than in normal cells. Further evaluations of a panel of truncated promoter mutants identified a 447 bp minimal core promoter element that retained the full tumor selectivity and transcriptional activity of the original promoter, in the context of an adenovirus vector. This core Rad51 promoter was highly active in cancer cells that lack functional p53, but less active in normal cells and in cancer cell lines with intact p53 function. Exogenous expression of p53 in a p53 null cell line strongly suppressed activity of the Rad51 core promoter, underscoring the selectivity of this promoter for p53-deficient cells. Follow-up experiments showed that the p53-dependent suppression of the Rad51 core promoter was mediated via an indirect, p300 coactivator dependent mechanism. Finally, transduction of target cells with an adenovirus vector encoding the thymidine kinase gene under transcriptional control of the Rad51 core promoter resulted in efficient killing of p53 defective cancer cells, but not of normal cells, upon addition of ganciclovir. Conclusions/Significance: Overall, these experiments demonstrated that a small core domain of the Rad51 promoter ca
Chromium and nickel in Pteridium aquilinum from environments with various levels of these metals
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