scholarly journals Specific Accumulation of Iodine by the Operculum of the Strawberry Conch Strombus luhuanus

1997 ◽  
Vol 63 (4) ◽  
pp. 646-647 ◽  
Author(s):  
Toshiaki Ishii
Keyword(s):  
Specific Accumulation ◽  
Strombus Luhuanus

THE AUTORADIOGRAPHIC DISTRIBUTION PATTERN AFTER ADMINISTRATION OF DIETHYLSTILBOESTROL COMPARED WITH THAT OF NATURAL OESTROGENS

1963 ◽  
Vol 43 (4) ◽  
pp. 561-570 ◽  
Author(s):  
Gösta Bengtsson ◽  
Sven Ullberg
Keyword(s):  
Distribution Pattern ◽  
Adrenal Cortex ◽  
Natural Compounds ◽  
Ovarian Follicles ◽  
Interstitial Tissue ◽  
Specific Accumulation ◽  
Natural And Synthetic

ABSTRACT The distribution in mice of 14C- and 3H-diethylstilboestrol has been investigated autoradiographically. The results have been compared with those which have been previously reported for natural oestrogens. Many similarities have been demonstrated between the synthetic and natural compounds. Thus a specific accumulation has been observed in the endometrium, the granulosa layer of large ovarian follicles, the adrenal cortex. the interstitial tissue of the testes, and the hypophysis. Natural and synthetic oestrogens differ widely concerning the penetration into and the distribution within the foetus.

scholarly journals Contribution of the Cytoplasmic Determinants of Vpu to the Expansion of Virus-Containing Compartments in HIV-1-Infected Macrophages

2019 ◽  
Vol 93 (11) ◽  
Author(s):  
Olivier Leymarie ◽  
Leslie Lepont ◽  
Margaux Versapuech ◽  
Delphine Judith ◽  
Sophie Abelanet ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Viral Particle ◽  
Transmembrane Domain ◽  
Immune Surveillance ◽  
Restriction Factor ◽  
Viral Particles ◽  
Protein Functions ◽  
Specific Accumulation ◽  
Model Cell ◽  
Hiv 1

ABSTRACTHIV-1 infection of macrophages leads to the sequestration of newly formed viruses in intracellular plasma membrane-connected structures termed virus-containing compartments (VCCs), where virions remain infectious and hidden from immune surveillance. The cellular restriction factor bone marrow stromal cell antigen 2 (BST2), which prevents HIV-1 dissemination by tethering budding viral particles at the plasma membrane, can be found in VCCs. The HIV-1 accessory protein Vpu counteracts the restriction factor BST2 by downregulating its expression and removing it from viral budding sites. Numerous studies described these Vpu countermeasures in CD4+T cells or model cell lines, but the interplay between Vpu and BST2 in VCC formation and HIV-1 production in macrophages is less explored. Here, we show that Vpu expression in HIV-1-infected macrophages enhances viral release. This effect is related to Vpu’s ability to circumvent BST2 antiviral activity. We show that in absence of Vpu, BST2 is enriched in VCCs and colocalizes with capsid p24, whereas Vpu expression significantly reduces the presence of BST2 in these compartments. Furthermore, our data reveal that BST2 is dispensable for the formation of VCCs and that Vpu expression impacts the volume of these compartments. This Vpu activity partly depends on BST2 expression and requires the integrity of the Vpu transmembrane domain, the dileucine-like motif E59XXXLV64and phosphoserines 52 and 56 of Vpu. Altogether, these results highlight that Vpu controls the volume of VCCs and promotes HIV-1 release from infected macrophages.IMPORTANCEHIV-1 infection of macrophages leads to the sequestration of newly formed viruses in virus-containing compartments (VCCs), where virions remain infectious and hidden from immune surveillance. The restriction factor BST2, which prevents HIV-1 dissemination by tethering budding viral particles, can be found in VCCs. The HIV-1 Vpu protein counteracts BST2. This study explores the interplay between Vpu and BST2 in the viral protein functions on HIV-1 release and viral particle sequestration in VCCs in macrophages. The results show that Vpu controls the volume of VCCs and favors viral particle release. These Vpu functions partly depend on Vpu’s ability to antagonize BST2. This study highlights that the transmembrane domain of Vpu and two motifs of the Vpu cytoplasmic domain are required for these functions. These motifs were notably involved in the control of the volume of VCCs by Vpu but were dispensable for the prevention of the specific accumulation of BST2 in these structures.

scholarly journals Fibrillar pharmacology of functionalized nanocellulose

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sam Wong ◽  
Simone Alidori ◽  
Barbara P. Mello ◽  
Bryan Aristega Almeida ◽  
David Ulmert ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Fluorescent Dyes ◽  
Pharmacokinetic Profile ◽  
Water Soluble ◽  
Size Exclusion ◽  
Hydroxyl Groups ◽  
Target Tissue ◽  
Exclusion Chromatography ◽  
Specific Accumulation

AbstractCellulose nanocrystals (CNC) are linear organic nanomaterials derived from an abundant naturally occurring biopolymer resource. Strategic modification of the primary and secondary hydroxyl groups on the CNC introduces amine and iodine group substitution, respectively. The amine groups (0.285 mmol of amine per gram of functionalized CNC (fCNC)) are further reacted with radiometal loaded-chelates or fluorescent dyes as tracers to evaluate the pharmacokinetic profile of the fCNC in vivo. In this way, these nanoscale macromolecules can be covalently functionalized and yield water-soluble and biocompatible fibrillar nanoplatforms for gene, drug and radionuclide delivery in vivo. Transmission electron microscopy of fCNC reveals a length of 162.4 ± 16.3 nm, diameter of 11.2 ± 1.52 nm and aspect ratio of 16.4 ± 1.94 per particle (mean ± SEM) and is confirmed using atomic force microscopy. Size exclusion chromatography of macromolecular fCNC describes a fibrillar molecular behavior as evidenced by retention times typical of late eluting small molecules and functionalized carbon nanotubes. In vivo, greater than 50% of intravenously injected radiolabeled fCNC is excreted in the urine within 1 h post administration and is consistent with the pharmacological profile observed for other rigid, high aspect ratio macromolecules. Tissue distribution of fCNC shows accumulation in kidneys, liver, and spleen (14.6 ± 6.0; 6.1 ± 2.6; and 7.7 ± 1.4% of the injected activity per gram of tissue, respectively) at 72 h post-administration. Confocal fluorescence microscopy reveals cell-specific accumulation in these target tissue sinks. In summary, our findings suggest that functionalized nanocellulose can be used as a potential drug delivery platform for the kidneys.

scholarly journals Antioxidant Properties of Ergosterol and Its Role in Yeast Resistance to Oxidation

Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1024
Author(s):  
Sebastien Dupont ◽  
Paul Fleurat-Lessard ◽  
Richtier Gonçalves Cruz ◽  
Céline Lafarge ◽  
Cédric Grangeteau ◽  
...  
Keyword(s):  
Computational Study ◽  
Antioxidant Properties ◽  
Beneficial Effects ◽  
Tert Butyl Hydroperoxide ◽  
Resistance To Oxidation ◽  
Specific Accumulation ◽  
The Subject

Although the functions and structural roles of sterols have been the subject of numerous studies, the reasons for the diversity of sterols in the different eukaryotic kingdoms remain unclear. It is thought that the specificity of sterols is linked to unidentified supplementary functions that could enable organisms to be better adapted to their environment. Ergosterol is accumulated by late branching fungi that encounter oxidative perturbations in their interfacial habitats. Here, we investigated the antioxidant properties of ergosterol using in vivo, in vitro, and in silico approaches. The results showed that ergosterol is involved in yeast resistance to tert-butyl hydroperoxide and protects lipids against oxidation in liposomes. A computational study based on quantum chemistry revealed that this protection could be related to its antioxidant properties operating through an electron transfer followed by a proton transfer mechanism. This study demonstrates the antioxidant role of ergosterol and proposes knowledge elements to explain the specific accumulation of this sterol in late branching fungi. Ergosterol, as a natural antioxidant molecule, could also play a role in the incompletely understood beneficial effects of some mushrooms on health.

Tissue-specific accumulation of carotenoids in carrot roots

Planta ◽  
2006 ◽  
Vol 224 (5) ◽  
pp. 1028-1037 ◽  
Author(s):  
Malgorzata Baranska ◽  
Rafal Baranski ◽  
Hartwig Schulz ◽  
Thomas Nothnagel
Keyword(s):  
Tissue Specific ◽  
Specific Accumulation

Organ- and species-specific accumulation of metals in two land snail species (Gastropoda, Pulmonata)

2013 ◽  
Vol 449 ◽  
pp. 470-481 ◽  
Author(s):  
Magdalena Boshoff ◽  
Kurt Jordaens ◽  
Thierry Backeljau ◽  
Suzanna Lettens ◽  
Filip Tack ◽  
...  
Keyword(s):  
Land Snail ◽  
Snail Species ◽  
Specific Accumulation ◽  
Accumulation Of Metals ◽  
Species Specific

scholarly journals Synaptic and epidermal accumulations of human acetylcholinesterase are encoded by alternative 3'-terminal exons.

1995 ◽  
Vol 15 (6) ◽  
pp. 2993-3002 ◽  
Author(s):  
S Seidman ◽  
M Sternfeld ◽  
R Ben Aziz-Aloya ◽  
R Timberg ◽  
D Kaufer-Nachum ◽  
...  
Keyword(s):  
Neuromuscular Junctions ◽  
Gene Transcript ◽  
Dna Encoding ◽  
Tissue Specific ◽  
Evolutionarily Conserved ◽  
Low Salt ◽  
Catalytically Active ◽  
Specific Accumulation ◽  
The Brain ◽  
Muscle Ache

Tissue-specific heterogeneity among mammalian acetylcholinesterases (AChE) has been associated with 3' alternative splicing of the primary AChE gene transcript. We have previously demonstrated that human AChE DNA encoding the brain and muscle AChE form and bearing the 3' exon E6 (ACHE-E6) induces accumulation of catalytically active AChE in myotomes and neuromuscular junctions (NMJs) of 2- and 3-day-old Xenopus embryos. Here, we explore the possibility that the 3'-terminal exons of two alternative human AChE cDNA constructs include evolutionarily conserved tissue-recognizable elements. To this end, DNAs encoding alternative human AChE mRNAs were microinjected into cleaving embryos of Xenopus laevis. In contrast to the myotomal expression demonstrated by ACHE-E6, DNA carrying intron 14 and alternative exon E5 (ACHE-I4/E5) promoted punctuated staining of epidermal cells and secretion of AChE into the external medium. Moreover, ACHE-E6-injected embryos displayed enhanced NMJ development, whereas ACHE-I4/E5-derived enzyme was conspicuously absent from muscles and NMJs and its expression in embryos had no apparent effect on NMJ development. In addition, cell-associated AChE from embryos injected with ACHE-I4/E5 DNA was biochemically distinct from that encoded by the muscle-expressible ACHE-E6, displaying higher electrophoretic mobility and greater solubility in low-salt buffer. These findings suggest that alternative 3'-terminal exons dictate tissue-specific accumulation and a particular biological role(s) of AChE, associate the 3' exon E6 with NMJ development, and indicate the existence of a putative secretory AChE form derived from the alternative I4/E5 AChE mRNA.

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