862 research outputs found

    Morphological changes in the kidneys of rats with experimental hemorrhagic stroke (intracerebral hemorrhage)

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    The article presents the results of the study of morphological changes in the kidneys in Wistar rats during the stroke. Hemorrhagic stroke modeling was performed by injecting 0.1-0.2 ml of autoblood through an opening in the temporal bone into the region of the inner capsule of the right hemisphere. To form a hematoma, a stereotaxic destruction was performed. The experimental group consisted of 6 animals, the control group was represented by intact rats (n=3) and rats after trepanation of the temporal bone but without the introduction of autoblood (n=3). The animals were removed from the experiment on days 3 and21. Inthe course of the study, the structural changes in the right and left kidneys were compared to determine the difference in the location of the disorders. According to the results of the histological examination of the medulla, the tendency to reduction of cytological disorders of the epithelium of the tubules of the left kidney was revealed, while in the right kidney the structural disturbances of the tubules of the nephrons and the collecting ducts of the papilla of the kidney were recorded. Based on these data, it is possible to assume renal involvement in rats on day 3 after a stroke and a frequency recovery on day 21. The described histological studies give  a new data on the development of structural changes in renal medulla in rats with hemorrhagic stroke, which can be associated with a violation of electrolyte exchanges at the level of the distal nephron segment

    Fundamentals and applications of Raman-based techniques for the design and development of active biomedical materials

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    Raman spectroscopy is an analytical method based on light–matter interactions that can interrogate the vibrational modes of matter and provide representative molecular fingerprints. Mediated by its label-free, non-invasive nature, and high molecular specificity, Raman-based techniques have become ubiquitous tools for in situ characterization of materials. This review comprehensively describes the theoretical and practical background of Raman spectroscopy and its advanced variants. The numerous facets of material characterization that Raman scattering can reveal, including biomolecular identification, solid-to-solid phase transitions, and spatial mapping of biomolecular species in bioactive materials, are highlighted. The review illustrates the potential of these techniques in the context of active biomedical material design and development by highlighting representative studies from the literature. These studies cover the use of Raman spectroscopy for the characterization of both natural and synthetic biomaterials, including engineered tissue constructs, biopolymer systems, ceramics, and nanoparticle formulations, among others. To increase the accessibility and adoption of these techniques, the present review also provides the reader with practical recommendations on the integration of Raman techniques into the experimental laboratory toolbox. Finally, perspectives on how recent developments in plasmon- and coherently-enhanced Raman spectroscopy can propel Raman from underutilized to critical for biomaterial development are provided

    Strong alkalinization of Chara cell surface in the area of cell wall incision as an early event in mechanoperception

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    AbstractMechanical wounding of cell walls occurring in plants under the impact of pathogens or herbivores can be mimicked by cell wall incision with a glass micropipette. Measurements of pH at the surface of Chara corallina internodes following microperforation of cell wall revealed a rapid (10–30s) localized alkalinization of the apoplast after a lag period of 10–20s. The pH increase induced by incision could be as large as 3 pH units and relaxed slowly, with a halftime up to 20min. The axial pH profile around the incision zone was bell-shaped and localized to a small area, extending over a distance of about 100μm. The pH response was suppressed by lowering cell turgor upon the replacement of artificial pond water (APW) with APW containing 50mM sorbitol. Stretching of the plasma membrane during its impression into the cell wall defect is likely to activate the Ca2+ channels, as evidenced from sensitivity of the incision-induced alkalinization to the external calcium concentration and to the addition of Ca2+-channel blockers, such as La3+, Gd3+, and Zn2+. The maximal pH values attained at the incision site (~10.0) were close to pH in light-dependent alkaline zones of Chara cells. The involvement of cytoskeleton in the origin of alkaline patch was documented by observations that the incision-induced pH transients were suppressed by the inhibitors of microtubules (oryzalin and taxol) and, to a lesser extent, by the actin inhibitor (cytochalasin B). The results indicate that the localized increase in apoplastic pH is an early event in mechanoperception and depends on light, cytoskeleton, and intracellular calcium

    Mineralogical and geochemical features of the Manus Basin hydrothermal sulfide ores, Bismarck Sea

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    Paragenetic mineral assemblages have been established based on mineralogical, chemical, and isotope (S, Pb) studies, and the sequence of deposition has been defined in hydrothennal sulfide structures in a typical back-arc basin. The ores in the Manus basin have a prominent Zn specialization (sphalerite, würtzite, and fe-sphalerite). An association of Fe-spbalerite and galena with Ag sulfosalts is noted that is not characteristic of typical midocean ridge hydrothennal systems. The average 34S in the sulfide minerals is 3.5%o, which corresponds to the medium-temperature sphalerite stage in hydrothermal mineral fonnation. It is suggested that the metal source is located in the relatively acid rocks of the island-arc tholeiitic series and possibly in sediments

    Cognitive impairment in primary and repeated hemorrhagic stroke and their correction with verapamil

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    The article is devoted the actual problem of modern medicine – pathogenesis and treatment of hemorrhagic stroke. In order to analyze the influence of Verapamil in preventing cognitive disorders under stroke a local hemorrhagic stroke in 60 rats was simulated there. Assessment of the cognitive function was performed by the Buresh method. We found out that rats after stroke were observed to show memory disturbances. Under stroke and after Verapamil injections the rats had a gradual decrease of disorders in primary and repeated intracerebral hemorrhage. These data suggest inhibition of calcium-dependent neurodegenerative processes in the rat cortex and cognitive disorders under Verapamil injections after stroke

    Towards enhanced optical sensor performance:SEIRA and SERS with plasmonic nanostars

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    We report the preparation and characterization of plasmonic chip-based systems comprising self-assembled gold nanostars at silicon substrates that enable concomitantly enhanced Raman (surface enhanced Raman spectroscopy; SERS) and mid-infrared (surface enhanced infrared reflection or absorption spectroscopy; SEIRA) spectral signatures. The high-aspect-ratio structure of gold nanostars provides an increased number of hot spots at their surface, which results in an electric field enhancement around the nanomaterial. Gold nanostars were immobilized at a silicon substrate via a thin gold layer, and α-ω-dimercapto polyethylene glycol (SH-PEG-SH) linkers. The Raman and IR spectra of crystal violet (CV) revealed a noticeable enhancement of the analyte vibrational signal intensity in SERS and SEIRA studies resulting from the presence of the nanostars. Enhancement factors of 2.5 × 10 3 and 2.3 × 10 3 were calculated in SERS considering the CV bands at 1374.9 cm -1 and 1181 cm -1 , respectively; for SEIRA, an enhancement factor of 5.36 was achieved considering the CV band at 1585 cm -1

    Genome-wide DNA methylation analysis for diabetic nephropathy in type 1 diabetes mellitus

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    BACKGROUND: Diabetic nephropathy is a serious complication of diabetes mellitus and is associated with considerable morbidity and high mortality. There is increasing evidence to suggest that dysregulation of the epigenome is involved in diabetic nephropathy. We assessed whether epigenetic modification of DNA methylation is associated with diabetic nephropathy in a case-control study of 192 Irish patients with type 1 diabetes mellitus (T1D). Cases had T1D and nephropathy whereas controls had T1D but no evidence of renal disease. METHODS: We performed DNA methylation profiling in bisulphite converted DNA from cases and controls using the recently developed Illumina Infinium(R) HumanMethylation27 BeadChip, that enables the direct investigation of 27,578 individual cytosines at CpG loci throughout the genome, which are focused on the promoter regions of 14,495 genes. RESULTS: Singular Value Decomposition (SVD) analysis indicated that significant components of DNA methylation variation correlated with patient age, time to onset of diabetic nephropathy, and sex. Adjusting for confounding factors using multivariate Cox-regression analyses, and with a false discovery rate (FDR) of 0.05, we observed 19 CpG sites that demonstrated correlations with time to development of diabetic nephropathy. Of note, this included one CpG site located 18 bp upstream of the transcription start site of UNC13B, a gene in which the first intronic SNP rs13293564 has recently been reported to be associated with diabetic nephropathy. CONCLUSION: This high throughput platform was able to successfully interrogate the methylation state of individual cytosines and identified 19 prospective CpG sites associated with risk of diabetic nephropathy. These differences in DNA methylation are worthy of further follow-up in replication studies using larger cohorts of diabetic patients with and without nephropathy

    A Sec14p-nodulin domain phosphatidylinositol transfer protein polarizes membrane growth of Arabidopsis thaliana root hairs

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    Phosphatidylinositol (PtdIns) transfer proteins (PITPs) regulate signaling interfaces between lipid metabolism and membrane trafficking. Herein, we demonstrate that AtSfh1p, a member of a large and uncharacterized Arabidopsis thaliana Sec14p-nodulin domain family, is a PITP that regulates a specific stage in root hair development. AtSfh1p localizes along the root hair plasma membrane and is enriched in discrete plasma membrane domains and in the root hair tip cytoplasm. This localization pattern recapitulates that visualized for PtdIns(4,5)P2 in developing root hairs. Gene ablation experiments show AtSfh1p nullizygosity compromises polarized root hair expansion in a manner that coincides with loss of tip-directed PtdIns(4,5)P2, dispersal of secretory vesicles from the tip cytoplasm, loss of the tip f-actin network, and manifest disorganization of the root hair microtubule cytoskeleton. Derangement of tip-directed Ca2+ gradients is also apparent and results from isotropic influx of Ca2+ from the extracellular milieu. We propose AtSfh1p regulates intracellular and plasma membrane phosphoinositide polarity landmarks that focus membrane trafficking, Ca2+ signaling, and cytoskeleton functions to the growing root hair apex. We further suggest that Sec14p-nodulin domain proteins represent a family of regulators of polarized membrane growth in plants
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