523 research outputs found

    Functional ultrastructure and cytochemistry of vitellogenesis and mature vitellocytes of the digenean Cainocreadium labracis (Dujardin, 1845), parasite of Dicentrarchus labrax (L., 1758)

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    Vitellogenesis and vitellocytes of Cainocreadium labracis were studied by transmission electron microscopy (TEM) and TEM cytochemistry. Four developmental stages were distinguished during vitellogenesis: (I) stem cell of high nucleo-cytoplasmic ratio; (II) early differentiation with chief activity focused on the beginning of protein synthesis and shell globule formation; (III) advanced differentiation with rapid intensification of protein synthesis, progressive fusion of single shell globules into large globule clusters, and formation of unsaturated lipid droplets surrounded by β-glycogen particles; and (IV) mature vitellocyte. Early vitellogenesis with vitellocyte maturation consists of: (1) increase in cell volume; (2) increased development of large, parallel cisternae of GER with production of proteinaceous granules; (3) development of small Golgi complexes that package granules; and (4) within vacuoles, progressive enlargement of proteinaceous granules into shell globule clusters formed during vitellogenesis. Three types of inclusions accumulate in large amounts in mature vitelline cells: (1) shell globule clusters, importantcomponentintheformationofeggshell;(2)numerousunsaturatedlipiddroplets.Thoughfewer,therearealsodiphasic droplets consisting of saturated and unsaturated lipids in the same droplet, and (3) a relatively small amount of β-glycogen particles, usually surround a few groups of lipid droplets. The β-glycogen and lipid droplets are nutritive reserves for embryogenesis. General pattern and functional ultrastructure of vitellogenesis greatly resemble those observed in some lower cestodes, such as bothriocephalideans and diphyllobothrideans. Variations and differences in the amount of lipids and of glycogen during vitellogenesis in lower cestodes and other trematodes are compared and discussed

    Muscle-specific deletion of SOCS3 increases the early inflammatory response but does not affect regeneration after myotoxic injury

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    Myosin heavy chain gene expression and muscle fiber oxidative capacity in muscles from uninjured control and SOCS3 MKO mice. qRT-PCR using primers to detect MyHCIIb (A), MyHCIIx (B), MyHCI (C), and MyHCIIa (D) was performed on RNA extracted from snap frozen muscles following dissection. Data are expressed as mean ± SEM and compared with an unpaired two-tailed Student’s t test. n = 8 mice/genotype. (E) Representative succinate dehydrogenase (SDH)-reacted TA muscle sections from uninjured muscles of 12-week-old control and SOCS3 MKO mice. Quantification of SDH intensity was determined by analysis of SDH reacted TA muscle sections. Data are expressed as mean ± SEM and compared with an unpaired two-tailed Student’s t test. n = 5 mice/genotype. Scale bar = 100 μm. (PDF 145 kb

    Ageing prolongs inflammatory marker expression in regenerating rat skeletal muscles after injury

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    <p>Abstract</p> <p>Background</p> <p>Some of the most serious consequences of normal ageing relate to its effects on skeletal muscle, particularly significant wasting and associated weakness, termed "sarcopenia". The underlying mechanisms of sarcopenia have yet to be elucidated completely but an altered muscle inflammatory response after injury is a likely contributing factor. In this study we investigated age-related changes in the expression of numerous inflammatory markers linked to successful muscle regeneration.</p> <p>Methods</p> <p>Right extensor digitorum longus (EDL) muscles from young (3 month), adult (12 month) and old (24 month) male F344 rats were injected with bupivacaine hydrochloride to cause complete muscle fibre degeneration, then excised 12, 24, 36, and 72 hours later (n = 5/age group/time point). We used qRT-PCR to quantify the mRNA expression levels of the inflammatory markers TNFα, IFNγ, IL1, IL18, IL6, and CD18 as well as regenerative markers MyoD and myogenin.</p> <p>Results</p> <p>Inflammatory markers were all increased significantly in all age groups after myotoxic injury. There was a trend for expression of inflammatory markers to be higher in uninjured muscles of old rats, especially at 72 hours post injury where the expression levels of several markers was significantly higher in old compared with young and adult rats. There was also a decrease in the expression of regenerative markers in old rats at 72 hours post injury.</p> <p>Conclusion</p> <p>Our findings identify a prolonged inflammatory signature in injured muscles from old compared with young and adult rats together with a blunted expression of key markers of regeneration in muscles of old rats. Importantly, our findings identify potential targets for future therapeutic strategies for improving the regenerative capacity of skeletal muscle during ageing.</p

    Proving termination of programs automatically with AProVE

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    AProVE is a system for automatic termination and complexity proofs of Java, C, Haskell, Prolog, and term rewrite systems (TRSs). To analyze programs in high-level languages, AProVE automatically converts them to TRSs. Then, a wide range of techniques is employed to prove termination and to infer complexity bounds for the resulting TRSs. The generated proofs can be exported to check their correctness using automatic certifiers. For use in software construction, we present an AProVE plug-in for the popular Eclipse software development environment

    Targeted delivery of C/EBPα -saRNA by pancreatic ductal adenocarcinoma-specific RNA aptamers inhibits tumor growth in vivo

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    The 5-year survival rate for pancreatic ductal adenocarcinoma (PDAC) remains dismal despite current chemotherapeutic agents and inhibitors of molecular targets. As the incidence of PDAC constantly increases, more effective multidrug approaches must be made. Here, we report a novel method of delivering antitumorigenic therapy in PDAC by upregulating the transcriptional factor CCAAT/enhancer-binding protein-α (C/EBPα), recognized for its antiproliferative effects. Small activating RNA (saRNA) duplexes designed to increase C/EBPα expression were linked onto PDAC-specific 2′-Fluropyrimidine RNA aptamers (2′F-RNA) - P19 and P1 for construction of a cell type–specific delivery vehicle. Both P19- and P1-C/EBPα-saRNA conjugates increased expression of C/EBPα and significantly suppressed cell proliferation. Tail vein injection of the saRNA/aptamer conjugates in PANC-1 and in gemcitabine-resistant AsPC-1 mouse-xenografts led to reduced tumor size with no observed toxicity. To exploit the specificity of the P19/P1 aptamers for PDAC cells, we also assessed if conjugation with Cy3 would allow it to be used as a diagnostic tool on archival human pancreatic duodenectomy tissue sections. Scoring pattern from 72 patients suggested a positive correlation between high fluorescent signal in the high mortality patient groups. We propose a novel aptamer-based strategy for delivery of targeted molecular therapy in advanced PDAC where current modalities fail

    Hyaluronic Acid Enhances Gene Delivery into the Cochlea

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    Abstract Cochlear gene therapy can be a new avenue for the treatment of severe hearing loss by inducing regeneration or phenotypic rescue. One necessary step to establish this therapy is the development of a safe and feasible inoculation surgery, ideally without drilling the bony cochlear wall. The round window membrane (RWM) is accessible in the middle-ear space, but viral vectors placed on this membrane do not readily cross the membrane to the cochlear tissues. In an attempt to enhance permeability of the RWM, we applied hyaluronic acid (HA), a nontoxic and biodegradable reagent, onto the RWM of guinea pigs, prior to delivering an adenovirus carrying enhanced green fluorescent protein (eGFP) reporter gene (Ad-eGFP) at the same site. We examined distribution of eGFP in the cochlea 1 week after treatment, comparing delivery of the vector via the RWM, with or without HA, to delivery by a cochleostomy into the perilymph. We found that cochlear tissue treated with HA-assisted delivery of Ad-eGFP demonstrated wider expression of transgenes in cochlear cells than did tissue treated by cochleostomy injection. HA-assisted vector delivery facilitated expression in cells lining the scala media, which are less accessible and not transduced after perilymphatic injection. We assessed auditory function by measuring auditory brainstem responses and determined that thresholds were significantly better in the ears treated with HA-assisted Ad-eGFP placement on the RWM as compared with cochleostomy. Together, these data demonstrate that HA-assisted delivery of viral vectors provides an atraumatic and clinically feasible method to introduce transgenes into cochlear cells, thereby enhancing both research methods and future clinical application.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98453/1/hum%2E2011%2E086.pd

    The tomato Prf complex is a molecular trap for bacterial effectors based on Pto transphosphorylation

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    The bacteria Pseudomonas syringae is a pathogen of many crop species and one of the model pathogens for studying plant and bacterial arms race coevolution. In the current model, plants perceive bacteria pathogens via plasma membrane receptors, and recognition leads to the activation of general defenses. In turn, bacteria inject proteins called effectors into the plant cell to prevent the activation of immune responses. AvrPto and AvrPtoB are two such proteins that inhibit multiple plant kinases. The tomato plant has reacted to these effectors by the evolution of a cytoplasmic resistance complex. This complex is compromised of two proteins, Prf and Pto kinase, and is capable of recognizing the effector proteins. How the Pto kinase is able to avoid inhibition by the effector proteins is currently unknown. Our data shows how the tomato plant utilizes dimerization of resistance proteins to gain advantage over the faster evolving bacterial pathogen. Here we illustrate that oligomerisation of Prf brings into proximity two Pto kinases allowing them to avoid inhibition by the effectors by transphosphorylation and to activate immune responses

    Quantum geometry and the Schwarzschild singularity

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    In homogeneous cosmologies, quantum geometry effects lead to a resolution of the classical singularity without having to invoke special boundary conditions at the singularity or introduce ad-hoc elements such as unphysical matter. The same effects are shown to lead to a resolution of the Schwarzschild singularity. The resulting quantum extension of space-time is likely to have significant implications to the black hole evaporation process. Similarities and differences with the situation in quantum geometrodynamics are pointed out.Comment: 31 pages, 1 figur
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