Search results for " ATP"
showing 10 items of 180 documents
Experimental diabetic neuropathy: role of oxidative stress and mechanisms involved.
1998
Oxidative stress has been related to the development of diabetic neuropathy. Experimental diabetes (alloxan injection to mice) promotes early biochemical changes in peripheral nervous tissue, e.g., decrease in Na,K-ATPase activity and glutathione (GSH) peroxidase (GSHPx) activity. The former decrease can be reverted by inhibiting protein kinase C (PKC), since it has been reported that PKC is activated in these experimental conditions. Here we present data demonstrating that the inhibition of PKC, as early as 4 days after alloxan administration, is not able to return to normal values GSHPx activity in sciatic nerve of diabetic mice. Thus, it would fit with our previous proposal of the possib…
Decreased glutathione peroxidase activity in sciatic nerve of alloxan-induced diabetic mice and its correlation with blood glucose levels.
1993
The effect of alloxan-induced diabetes on glutathione peroxidase (GSH-Px) activity in sciatic nerve of mice has been studied. We have found, 7 days after alloxan treatment, a significant decrease in this enzymatic activity in the cytosol of sciatic nerve of diabetic mice, and moreover, that these changes remained unaltered up to 21 days after alloxan injection. No modification in the glutathione content of sciatic nerve of diabetic mice was observed throughout the experiment when compared with controls. The decrease in GSH-Px activity in this tissue shows a good correlation with the increase of blood glucose levels throughout the experiment. It is hypothesized whether a combination of mecha…
Decreasing dietary linoleic acid promotes long chain omega-3 fatty acid incorporation into rat retina and modifies gene expression
2011
International audience; Age-related macular degeneration (AMD) may be partially prevented by dietary habits privileging the consumption of ω3 long chain polyunsaturated fatty acids (ω3s) while lowering linoleic acid (LA) intake. The present study aimed to document whether following these epidemiological guidelines would enrich the neurosensory retina and RPE with ω3s and modulate gene expression in the neurosensory retina. Rat progenitors and pups were fed with diets containing low or high LA, and low or high ω3s. After scotopic single flash and 8-Hz-Flicker electroretinography, rat pups were euthanized at adulthood. The fatty acid profile of the neurosensory retina, RPE, liver, adipose tis…
Reconstitution of bacteriorhodopsin and ATP synthase from Micrococcus luteus into liposomes of the purified main tetraether lipid from Thermoplasma a…
1995
The archaebacterium Thermoplasma acidophilum is cultivated at 59 degrees C in a medium containing sulfuric acid of pH 2. The purified bipolar membrane spanning main phospholipid (MPL) of this organism can be used to produce stable liposomes of 100-500 nm in diameter either using a French pressure cell detergent dialysis or sonication. Despite a potassium diffusion potential of 186 mV very low ionic permeability of sonicated MPL liposomes was measured using the potassium binding fluorescent indicator benzofuran isophthalate PBF1, which measures net K+ uptake. The latter also remained very low, in the presence of the K(+) ionophore valinomycin and palmitic acid. Addition of valinomycin and th…
Evidence for a selective and electroneutral K+/H+-exchange in Saccharomyces cerevisiae using plasma membrane vesicles
1996
The existence of a K+/H+ transport system in plasma membrane vesicles from Saccharomyces cerevisiae is demonstrated using fluorimetric monitoring of proton fluxes across vesicles (ACMA fluorescence quenching). Plasma membrane vesicles used for this study were obtained by a purification/reconstitution protocol based on differential and discontinuous sucrose gradient centrifugations followed by an octylglucoside dilution/gel filtration procedure. This method produces a high percentage of tightly-sealed inside-out plasma membrane vesicles. In these vesicles, the K+/H+ transport system, which is able to catalyse both K+ influx and efflux, is mainly driven by the K+ transmembrane gradient and ca…
Cloning, purification, and nucleotide-binding traits of the catalytic subunit A of the V1VO ATPase from Aedes albopictus.
2007
The Asian tiger mosquito, Aedes albopictus, is commonly infected by the gregarine parasite Ascogregarina taiwanensis, which develops extracellularly in the midgut of infected larvae. The intracellular trophozoites are usually confined within a parasitophorous vacuole, whose acidification is generated and controlled by the V(1)V(O) ATPase. This proton pump is driven by ATP hydrolysis, catalyzed inside the major subunit A. The subunit A encoding gene of the Aedes albopictus V(1)V(O) ATPase was cloned in pET9d1-His(3) and the recombinant protein, expressed in the Escherichia coli Rosetta 2 (DE3) strain, purified by immobilized metal affinity- and ion-exchange chromatography. The purified prote…
Molecular Systematics of Aphids and Their Primary Endosymbionts
2001
Abstract Aphids constitute a monophyletic group within the order Homoptera (i.e., superfamily Aphidoidea). The Aphidoidea originated in the Jurassic about 150 my ago from some aphidiform ancestor whose origin can be traced back to about 250 my ago. They exhibit a mutualistic association with intracellular bacteria ( Buchnera sp.) related to Escherichia coli. Buchnera is usually considered the aphids' primary endosymbiont. The association is obligate for both partners. The 16S rDNA-based phylogeny of Buchnera from four aphid families showed complete concordance with the morphology-based phylogeny of their aphid hosts, which pointed to a single original infection in a common ancestor of aphid…
Latvijas automašīnu numura zīmju atpazīšana no video plūsmas
2015
Darba mērķis Panākt, lai atvērtā pirmkoda numura zīmju atpazīšanas risinājums darbojas ne sliktāk kā komerciālais risinājums. Darba saturs Bakalaura darbā tika pētīts vai atvērtā pirmkoda numura zīmju atpazīšanas risinājums spēj sasniegt tikpat labus rezultātus kā komerciālie risinājumi. Tiek apskatīts vispārējs numura zīmju atpazīšanas algoritms, OpenALPR uzbūve, apmācība un pielāgošana, kā arī veikta atvērtā pirmkoda risinājumu salīdzināšana ar komerciālajiem risinājumiem. Secinājumi Lai gan, izmantojot atvērtā pirmkoda numura zīmju atpazīšanas programmatūru, ir iespējams salīdzinoši precīzi veikt numura zīmes attēla pārveidošanu tekstā, pašas numura zīmes atrašanās vietas noteikšana attē…
Baļķu skaita, izmēru un formu noteikšana no fotogrāfijas
2015
Maģistra darba ietvaros tika izpetītas iespējas – kā var veikt veikt analīzi fotogrāfijām ar baļķiem. Lai mērķi sasniegt tika definētas prasības algoritmam, kuras aprakstīs – kadus paramētrus ir nepieciešams nolasīt no fotografijas, kadas ir prasības apparatūrai un kāds ir pieeņemams kļudu limenis. Papildus tika definētas prasības ievaddatiem. Tika aprakstīti iespējami soļi, kuros var sadalīt atpazīšanas algoritmu un detalizēti aprakstīts iespējams risinājums katram solim. Darba ietvaros tika izpetīti pieejamie riķi problēmas risināšanai, aprakstīti rīku priekšrocības un trūkumi. Darba rezultāta tika ieguts teoretisks pamats programmas izveidošanai un izveidots programmas pirmais prototips.
Daudzskatu sistēma cilvēka ķermeņa stāvokļa reģistrēšanai
2020
Lai varētu izveidot specifisku cilvēka pozu datu kopu, ir nepieciešams izveidot daudzskatu studiju, kas ir izstrādātā darba mērķis. Darbā ir apskatīta tēmas aktualitāte un tās nozīmība, apskatītas citas daudzskatu studijas, veikta izpēte, kāds tehniskais nodrošinājums un kāda programmatūra ir nepieciešama, salīdzinot gan interneta resursus, gan pasūtot produktus un tos testējot. Tika saskatīti lielākie izaicinājumi daudzskatu studijas izveidei no programmēšanas un theniskās puses, kas ir noteikt kameru atrašanās vietu telpā. Kā arī ir aprakstītas potenciālas ievirzes nākotnes pētijumos.