410 research outputs found

    Prospects for Non-Traditional Plant Species Cultivated for Forage in Lithuania

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    The changing climate and increasing number of animal species raised, especially in the organic farming systems, require a new approach to the expansion of the range of plant species grown for forage. In Lithuania’s agroclimatic conditions, such plant species as amaranth (Amaranthus spp.), proso millet (Panicum miliaceum), foxtail millet or chumiza (Setaria italica) can be successfully grown for grain and produce almost the same yield and even better chemical composition than conventional oats or barley. In 2006-2007, two trials were conducted at the Lithuanian Institute of Agriculture, where one amaranth, three proso millet, two foxtail millet and some other species’ cultivars and accessions were grown for green mass and dry matter yield. Using almost the same agrotechnics as for spring cereals, two cuts were taken annually. Green mass, dry matter yield and chemical composition showed that many of the tested cultivars and accessions of the non-traditional plants for our agroclimatic region in both dry 2006 and wet 2007 year produced rather high yield and can be used as forage for many animal species as green mass, hay or silage

    Firing Pattern Formation by Transient Calcium Current in Model Motoneuron

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    Firing properties of neurons are important in signal detection and generation in nervous system. Spinal cord motoneurons have membrane properties adapted to muscle properties. In this work we explored the relation between the first interspike interval and the amplitude of injected current. It was shown that increased sensitivity of firing frequency to the injected current at higher firing frequencies is due to the transient calcium current. Particularly, the specific density of N-type channels and the speed of their deactivation define the steepness and onset of the second range in frequency versus current relation

    Human herpesvirus-6 and-7 in the brain microenvironment of persons with neurological pathology and healthy people

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    Funding Information: This research was supported by the Latvian Council of Science Grant Nr.478/2012 and fundamental and applied research project of the Latvian Council of Science LZP-2020/2-0069. The authors would like to thank Svetlana Chapenko for nPCR data curation, and Silvija Roga, certified pathologist, and Ojars Teteris certified pathologist, for collecting of study material. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.During persistent human beta-herpesvirus (HHV) infection, clinical manifestations may not appear. However, the lifelong influence of HHV is often associated with pathological changes in the central nervous system. Herein, we evaluated possible associations between immunoex-pression of HHV-6,-7, and cellular immune response across different brain regions. The study aimed to explore HHV-6,-7 infection within the cortical lobes in cases of unspecified encephalo-pathy (UEP) and nonpathological conditions. We confirmed the presence of viral DNA by nPCR and viral antigens by immunohistochemistry. Overall, we have shown a significant increase (p < 0.001) of HHV antigen expression, especially HHV-7 in the temporal gray matter. Although HHV-infected neurons were found notably in the case of HHV-7, our observations suggest that higher (p < 0.001) cell tropism is associated with glial and endothelial cells in both UEP group and controls. HHV-6, predominantly detected in oligodendrocytes (p < 0.001), and HHV-7, predominantly detected in both astrocytes and oligodendrocytes (p < 0.001), exhibit varying effects on neural homeostasis. This indicates a high number (p < 0.001) of activated microglia observed in the temporal lobe in the UEP group. The question remains of whether human HHV contributes to neurological diseases or are markers for some aspect of the disease process.Peer reviewe

    Auto and crosscorrelograms for the spike response of LIF neurons with slow synapses

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    An analytical description of the response properties of simple but realistic neuron models in the presence of noise is still lacking. We determine completely up to the second order the firing statistics of a single and a pair of leaky integrate-and-fire neurons (LIFs) receiving some common slowly filtered white noise. In particular, the auto- and cross-correlation functions of the output spike trains of pairs of cells are obtained from an improvement of the adiabatic approximation introduced in \cite{Mor+04}. These two functions define the firing variability and firing synchronization between neurons, and are of much importance for understanding neuron communication.Comment: 5 pages, 3 figure

    Supercritical fluid technologies to fabricate proliposomes

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    Proliposomes are stable drug carrier systems designed to form liposomes upon addition of an aqueous phase. In this review, current trends in the use of supercritical fluid (SCF) technologies to prepare proliposomes are discussed. SCF methods are used in pharmaceutical research and industry to address limitations associated with conventional methods of pro/liposome fabrication. The SCF solvent methods of proliposome preparation are eco-friendly (known as green technology) and, along with the SCF anti-solvent methods, could be advantageous over conventional methods; enabling better design of particle morphology (size and shape). The major hurdles of SCF methods include poor scalability to industrial manufacturing which may result in variable particle characteristics. In the case of SCF anti-solvent methods, another hurdle is the reliance on organic solvents. However, the amount of solvent required is typically less than that used by the conventional methods. Another hurdle is that most of the SCF methods used have complicated manufacturing processes, although once the setup has been completed, SCF technologies offer a single-step process in the preparation of proliposomes compared to the multiple steps required by many other methods. Furthermore, there is limited research into how proliposomes will be converted into liposomes for the end-user, and how such a product can be prepared reproducibly in terms of vesicle size and drug loading. These hurdles must be overcome and with more research, SCF methods, especially where the SCF acts as a solvent, have the potential to offer a strong alternative to the conventional methods to prepare proliposomes

    Characteristics of the dual nature of the P27 protein in oral leukoplakias and cancer

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    Publisher Copyright: © 2022 Madara Dzudzilo et al., published by Sciendo.Dysregulation of the cell cycle is an important factor in a potentially malignant oral disorder. There have not been many studies on the role of the cell cycle regulator p27 in oral non-homogenous leukoplakia. The aim of our study was to characterise the p27 protein in homogenous and non-homogenous oral leukoplakias (OL), in comparison with healthy mucosa and squamous cell carcinoma tissues. The current study included 25 patients with OL, 15 cases with oral squamous cell carcinoma, and 15 samples of healthy oral mucosa, both as comparison groups. Immunohistochemical p27 antigen expression was determined by a standard EnView imaging system. The expression level of p27 in nodular and verrucous leukoplakia was lower than in homogenous OL but higher than in erythroleukoplakia. There was a statistically significant difference (p < 0.05) between the expression of p27 in healthy mucosa and homogenous OL. There was a significantly lower amount of p27 positive cells in oral cancer than in OL (p < 0.0001); however, its intracytoplasmic presence was diagnosed. Our study proved the instability of p27 protein and its dual nature in non-homogenous OL and OSCC, and therefore, it can be used as a predictive marker for the clinical course of these conditions.publishersversionPeer reviewe

    Evaluation of Clinical Manifestations of Hemorrhoidal Disease, Carried Out Surgeries and Prolapsed Anorectal Tissues : Associations with ABO Blood Groups of Patients

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    Funding Information: This research received funding (Nr. 6-DN-20/2/2023) from Riga Stradiņš University Department of Doctoral Studies for the purchase of reagents and coverage of the article processing charge. Publisher Copyright: © 2023 by the authors.Hemorrhoidal disease (HD) is a chronic multifactorial disease. Increased abdominal pressure, along with hyperperfusion, neovascularization, overexpression of inflammatory mediators, and dysbiosis, contributes to the development of HD. The deterioration of the anchoring connective tissue with reduced collagen content and altered collagen ratios, dilatation of blood vessels and thrombosis, muscle injury, and inflammation gradually lead to clinically manifesting prolapse and bleeding from hemorrhoids. The associations of the ABO blood types with a disease have been investigated for the upper gastrointestinal tract only. This study aimed to evaluate HD clinical manifestations, surgeries carried out, and the status of prolapsed anorectal tissues by exploring the associations with the patients’ ABO blood groups. Clinical and various morphological methods, combined with extensive bioinformatics, were used. The blood type 0, grade III and IV HD individuals constituted the largest group in a moderately-sized cohort of equally represented males and females studied and submitted to surgical treatment of hemorrhoids. There were significantly more complaints reported by HD females compared to males (p = 0.0094). The Longo technique appeared mostly used, and there were proportionally more surgeries performed below the dentate line for HD individuals with blood type 0 compared to other blood type patients (24% vs. 11%). HD males were found to present with significantly more often inflamed rectal mucosa (p < 0.05). Loosening and weakening of collagenous components of the rectal wall combined with vascular dilation and hemorrhage was found to differ in 0 blood type HD individuals compared to other types. HD males were demonstrated to develop the ruptures of vascular beds significantly more often when compared to HD females (p = 0.0165). Furthermore, 0 blood type HD males were significantly more often affected by a disease manifested with tissue hemorrhage compared to the 0 blood type HD females (p = 0.0081). Collectively, the local status of chronically injured anorectal tissue should be considered when applying surgical techniques. Future studies could include patients with HD grades I and II to gain a comprehensive understanding of the disease progression, allowing for a comparison of tissue changes at different disease stages.Peer reviewe

    Curcumin effect on copper transport in HepG2 cells

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    Funding Information: Acknowledgments: The authors appreciate the support and advice of Uldis Berkis. The authors gratefully acknowledge the financial support from EU 7th Framework program project “Unlocking infectious disease research potential at R¯ıga Stradin,š University” (BALTINFECT) (grant agreement No. 316275). Publisher Copyright: © 2018 by the authors. Licensee MDPI, Basel, Switzerland. Copyright: Copyright 2018 Elsevier B.V., All rights reserved.Background and Objective: In Wilson’s disease, copper metabolism is impaired due to defective copper transporting protein ATP7B, resulting in copper accumulation in liver and brain and causing damage to liver and brain tissues. Published data suggest that one of the possible treatments for Wilson’s disease is curcumin—a compound found in the root of Curcuma longa. In this study, we tested whether curcumin affects copper transport and excretion in HepG2 hepatocytes carrying wildtype ATP7B. Materials and Methods: We examined the impact of 5 µM and 25 µM curcumin on the transport of copper in HepG2 cells incubated with 20 µM and 100 µM CuCl2, as well as copper excretion from cells. First, immunofluorescent staining and co-localization analysis were carried out in HepG2 cells using confocal laser scanning microscope and Nikon NIS Elements software. Second, a concentration of copper extracted into cell culture medium was determined using atomic absorption spectrometry. Results: The analysis of the co-localization between Golgi complex and ATP7B revealed that both 5 µM and 25 µM doses of curcumin improve the ability of liver cells to transport copper to plasma membrane at 20 µM CuCl2, but not at 100 µM CuCl2 concentration. However, atomic absorption spectrometry showed that curcumin rather promotes copper absorption into liver cell line HepG2 than excretion of it. Conclusions: Curcumin accelerates the transport of copper within liver cells, but does not promote copper excretion from HepG2 cells.publishersversionPeer reviewe

    Neuron dynamics in the presence of 1/f noise

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    Interest in understanding the interplay between noise and the response of a non-linear device cuts across disciplinary boundaries. It is as relevant for unmasking the dynamics of neurons in noisy environments as it is for designing reliable nanoscale logic circuit elements and sensors. Most studies of noise in non-linear devices are limited to either time-correlated noise with a Lorentzian spectrum (of which the white noise is a limiting case) or just white noise. We use analytical theory and numerical simulations to study the impact of the more ubiquitous "natural" noise with a 1/f frequency spectrum. Specifically, we study the impact of the 1/f noise on a leaky integrate and fire model of a neuron. The impact of noise is considered on two quantities of interest to neuron function: The spike count Fano factor and the speed of neuron response to a small step-like stimulus. For the perfect (non-leaky) integrate and fire model, we show that the Fano factor can be expressed as an integral over noise spectrum weighted by a (low pass) filter function. This result elucidates the connection between low frequency noise and disorder in neuron dynamics. We compare our results to experimental data of single neurons in vivo, and show how the 1/f noise model provides much better agreement than the usual approximations based on Lorentzian noise. The low frequency noise, however, complicates the case for information coding scheme based on interspike intervals by introducing variability in the neuron response time. On a positive note, the neuron response time to a step stimulus is, remarkably, nearly optimal in the presence of 1/f noise. An explanation of this effect elucidates how the brain can take advantage of noise to prime a subset of the neurons to respond almost instantly to sudden stimuli.Comment: Phys. Rev. E in pres

    Correlation of Soluble CD44 Expression in Saliva and CD44 Protein in Oral Leukoplakia Tissues

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    Funding Information: Doctoral student Grant for R?ga Stradi?? University (RSU). This publication has been implemented with the support of the project no. 8.2.2.0/20/I/004 ?Support for involving doctoral students in scientific research and studies? at R?ga Stradi?? University. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.The aim of this study was to determine whether and how pan‐CD44 protein expression in leukoplakia tissues correlates with positive SolCD44 test presence and their role in oral leukoplakia. SolCD44 and total protein expression in saliva were determined using an OncAlert® Oral Cancer Rapid test. Comparison of paired associations of total protein, SolCD44, mean number of CD44 expressed epithelial layers in leukoplakia tissue, and macrophages below the basement membrane between control group and patients with leukoplakia showed statistically significant results (p < 0.0001). It is shown that the total protein indicates low or elevated risk of possible malignant transformation processes in leukoplakia. Statistically significant differences between higher total protein level and clinical forms of oral leukoplakia (p <0.0001), as well as CD44‐labeled epithelial cell layer decrease (p < 0.0001), were found. This possibly points to the onset of the stemness loss in leukoplakia tissue. CD9 antigen expression in the exosomes of the oral epithelium explained the intercellular flow of SolCD44 and other fluids in the leukoplakia area. We conclude that the OncAlert® Oral Cancer Rapid test is a valuable screening method in daily clinical practice, in terms of complementing clinical diagnostics methods and to assess the potential for early malignancy.Peer reviewe
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