Skolotāja profesionālā identitāte un pedagoģiskā meistarība

Grāmata “Skolotāja profesionālā identitāte un pedagoģiskā meistarība” paredzēta studentiem, absolventiem, skolotājiem, skolotāju skolotājiem, tālākizglītotājiem, izglītības darbiniekiem un citiem interesentiem. Tās saturs atklāj izglītības sistēmas elastību un atvērtību sadarbībai un ir virzīts uz skolotāju kompetenču, pedagoģiskās meistarības un profesionālās identitātes pilnveidi, karjeras attīstību mainīgos apstākļos

The effect of chronic cigarette smoking on microvascular function, insulin resistance and inflammatory state

Cigarette smoking, a major risk factor for cardiovascular disease, can induce proinflammatory state and endothelial injury - the earliest manifestations of atherosclerotic changes. The aim of the study was to assess cutaneous vascular reactivity, insulin resistance and circulating levels of inflammatory cytokines in 20 healthy habitual smokers and 24 healthy non-smokers. The groups were matched for age. We used laser Doppler imaging with iontophoretic application of 1% acethylcholine solution and local heating 44 °C on the dorsum of the palm. Serum monocyte chemotactic protein-1, tumour necrosis factor-alpha and interleukin-6 were measured by xMAP technology. Insulin resdistance was assessed by HOMA-IR method. Local heating-induced neurally-mediated and endotheliumdependent vasodilatation was significantly decreased in elderly smokers vs. elderly non-smokers (p < 0.05). Young smokers showed significantly reduced endothelium-dependent vasodilatation vs. young non-smokers (p < 0.05). Ach-induced vasodilatation was significantly decreased in the elderly smokers and elderly non-smokers groups vs. young smokers and young non-smokers groups (p < 0.05). The level of tumour necrosis factor-alpha was significantly higher in both groups of smokers vs. non-smokers (p < 0.05). The level of monocyte chemotactic protein-1 was slightly higher in smokers. Only the elderly smokers group exhibited a tendency to higher values of HOMA-IR. Data showed that long-lasting cigarette smoking significantly impairs peripheral microvascular function due to increased inflammatory response.publishersversionPeer reviewe

Influence of Migraine on Axon Reflex-Mediated and Endothelial-Dependent Vasodilatation in the Skin

Publisher Copyright: © 2020 Aelita Plinta et al., published by Sciendo.The aim of the study was to evaluate the changes in skin blood flow as a result of local heating tests in migraine patients during the interictal period, measured by laser Doppler perfusion imaging (LDI). The aim of the study was also to estimate the correlations between the results of these tests and interleukin (IL)-8 levels. Twelve migraine patients during their interictal period were compared with twelve healthy control subjects. Only women were included in the study. Both groups were matched with regard of their age, body mass index and blood pressure. For the purpose of measuring cutaneous microvascular blood flow, heating (+44 °C) of the dorsal side of the palm as a response to the local LDI was used. IL-8 was measured in serum by ELISA method. The findings suggested that migraine patients have a cutaneous vasomotor dysfunction during the interictal period. The results showed a significant decrease in the initial peak of vasodilation and the second peak of vasodilation (plateau phase). Also there were significant changes observed in the length of the time interval required to reach the first and second vasodilation peak. It is known that migraine patients have a shorter time interval to reach the first perfusion peak (axonal reflex-mediated) and longer time interval to reach the second peak (endothelium-dependent). The results confirmed the correlation between proinflammatory chemokine IL-8 levels, and the time interval till the second peak of blood flow in all study subjects.publishersversionPeer reviewe

Cancer microcell initiation and determination

Funding Information: This project was supported by the University of Latvia Donor SIA “Mikrotīkls.” The University of Latvia Foundation administered this donation. Funding Information: This research was accomplished with the support of the Institute of Cardiology and Regenerative Medicine, University of Latvia. The cell culture cultivation was carried out in cooperation with the Latvian Biomedical Research and Study Centre. The confocal microscopy was carried out in collaboration with Carl Zeiss Microscopy Democenter Oberkochen, Germany. Publisher Copyright: © 2021, The Author(s).Background: Cancer remains one of the leading causes of death worldwide, despite the possibilities to detect early onset of the most common cancer types. The search for the optimal therapy is complicated by the cancer diversity within tumors and the unsynchronized development of cancerous cells. Therefore, it is necessary to characterize cancer cell populations after treatment has been applied, because cancer recurrence is not rare. In our research, we concentrated on small cancer cell subpopulation (microcells) that has a potential to be cancer resistance source. Previously made experiments has shown that these cells in small numbers form in specific circumstances after anticancer treatment. Methods: In experiments described in this research, the anticancer agents’ paclitaxel and doxorubicin were used to stimulate the induction of microcells in fibroblast, cervix adenocarcinoma, and melanoma cell lines. Mainly for the formation of microcells in melanoma cells. The drug-stimulated cells were then characterized in terms of their formation efficiency, morphology, and metabolic activity. Results: We observed the development of cancer microcells and green fluorescent protein (GFP) transfection efficiency after stress. In the time-lapse experiment, we observed microcell formation through a renewal process and GFP expression in the microcells. Additionally, the microcells were viable after anticancer treatment, as indicated by the nicotinamide adenine dinucleotide hydrogen phosphate (NADPH) enzyme activity assay results. Taken together, these findings indicate that cancer microcells are viable and capable of resisting the stress induced by anticancer drugs, and these cells are prone to chemical substance uptake from the environment. Conclusion: Microcells are not only common to a specific cancer type, but can be found in any tumor type. This study could help to understand cancer emergence and recurrence. The appearance of microcells in the studied cancer cell population could be an indicator of the individual anticancer therapy effectiveness and patient survival.publishersversionPeer reviewe

Relationship of vasodilatory responsiveness and insulin resistance indices with concentrations of biomarkers of vascular endothelial (dys)function in chronic cigarette smokers

Pētījuma mērķis ir noskaidrot smēķēšanas ierosināta iekaisuma un oksidatīvā stresa ietekmi uz insulīna rezistences un endotēlija disfunkcijas attīstību un to savstarpējo sakarību. Pētījumā piedalījās 128 dalībnieki (starp kuriem 52 personām konstatējām dislipidēmiju), kuriem tika noteiktas ar endotēlija funkcijām saistītu signālmolekulu seruma koncentrācijas, vazodilatācijas intensitāte ādas mikrocirkulācijā un insulīna rezistenci raksturojoši rādītāji. Rezultāti parādīja, ka smēķēšanas kumulatīvais efekts būtiski sekmē insulīna rezistences attīstību personām ar dislipidēmiju, bet smēķēšanas akūtais efekts caur iekaisuma signālmolekulām īslaicīgi samazina šūnu insulīna jutību neatkarīgi no dislipidēmijas.The aim of this study was to determine the effect of cigarette smoking induced inflammation and oxidative stress on development of insulin resistance, endothelial dysfunction and the correlation with each other. Vasodilatory responsiveness of cutaneous microcirculation and biomarkers of endothelial function and insulin resistance were examined in 128 volunteers (52 of them had dyslipidemia). The results show that cigarette smoking cumulative effect significantly promotes the development of insulin resistance in dyslipidemic individuals. Smoking induced increase in the biomarkers of inflammation temporarely can reduce the insulin sensitivity independently of dyslipidemia

Morphological and Immunocytochemical Characterization of Paclitaxel-Induced Microcells in Sk-Mel-28 Melanoma Cells

Biomarkers, including proteins, nucleic acids, antibodies, and peptides, are essential for identifying diseases such as cancer and differentiating between healthy and abnormal cells in patients. To date, studies have shown that cancer stem cells have DNA repair mechanisms that deter the effects of medicinal treatment. Experiments with cell cultures and chemotherapy treatments of these cultures have revealed the presence of small cells, with a small amount of cytoplasm that can be intensively stained with azure eosin, called microcells. Microcells develop during sporosis from a damaged tumor macrocell. After anticancer therapy in tumor cells, a defective macrocell may produce one or more microcells. This study aims to characterize microcell morphology in melanoma cell lines. In this investigation, we characterized the population of cancer cell microcells after applying paclitaxel treatment to a Sk-Mel-28 melanoma cell line using immunocytochemical cell marker detection and fluorescent microscopy. Paclitaxel-treated cancer cells show stronger expression of stem-associated ALDH2, SOX2, and Nanog markers than untreated cells. The proliferation of nuclear antigens in cells and the synthesis of RNA in microcells indicate cell self-defense, promoting resistance to applied therapy. These findings improve our understanding of microcell behavior in melanoma, potentially informing future strategies to counteract drug resistance in cancer treatment

Neopterin, cellular adhesion molecules and myeolperoxidase in patients with stable and unstable angina pectoris

Recent data indicate that the serum level of neopterin, a marker of inflammation and immune modulator secreted by monocytes/macrophages, is elevated in patients with acute coronary syndrome (ACS) and seems to be a prognostic marker for major cardiovascular events. Soluble cellular adhesion molecules (sCAMs) and myeloperoxidase (MPO) levels are also related to ACS. The aim of the present study was to evaluate differences in serum levels of neopterin, sCAMs and MPO between coronary artery disease and metabolic syndrome (CAD-MetS) patients with stable and unstable angina pectoris (SAP, UAP), and to clarify the relationships between neopterin and other biomarkers. The study included 60 patients with CAD-MetS who were classified into two groups, 30 patients with SAP and 30 patients with UAP. Twenty healthy subjects were selected as controls (C). Serum soluble vascular cell adhesion molecule-1 (sVCAM-1), intercellular cell adhesion molecule-1 (sICAM-1), sE-selectin and MPO levels were measured by Luminex xMAP technology, and serum neopterin concentrations were measured by radioimmunoassay. Results: Serum levels of neopterin, MPO, sVCAM-1, sICAM-1, and sE-selectin were significantly higher in patients with UAP in comparison with the group of healthy controls (P < 0.05). Patients with SAP also had higher levels of these biomarkers than those in healthy controls (P < 0.05), except for sE-selectin. The biomarker level did not differ between the two patient groups, except for MPO, which was significantly higher in the USP group (P < 0.05). Neopterin was significantly correlated only with sVCAM-1 (P < 0.05). In conclusion, CAD-Met patients with SAP had more apparent raised levels of serum sICAM-1 and sVCAM-1, simultaneously with higher MPO and neopterin concentrations, in comparison to those in healthy subjects. However, UAP is also associated with more substantial changes in MPO and significantly increased sE-selectin levels. Neopterin concentration was had a close correlation only with sVCAM-1.publishersversionPeer reviewe

Relation of endothelial dysfunction and adipokines levels to insulin resistance in metabolic syndrome patients

Funding Information: The work was supported by the National Research Programme in Medicine 2006–2009, project No. 8, “Modern approaches in early diagnostics, prevention and treatment of diabetes mellitus and obesity-caused diseases”. This study was supported by grant No. 07-VP-8 from the Latvian Council of Science.Obese metabolic syndrome (MS) patients were categorised into three groups: 44 with type 2 diabetes mellitus (T2DM)(D); 20 with T2DM and coronary artery disease (CAD) (DC), and 26 with MS alone (M). Eighteen healthy subjects were selected as controls (C). Insulin resistance (IR) was assessed by HOMA-IR. Adiponectin, tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), and interleukin-8 (IL-8) concentrations were measured by xMAP technology. Endothelin-1 (ET-1) was determined by ELISA. We used laser Doppler imaging for evaluating cutaneous endothelium-dependent vasodilatation in the hand. D and DC groups had significantly elevated IR compared with M or C group (P < 0.01). TNF-α, IL-6, IL-8, MCP-1 and ET-1 levels in DC were significantly elevated compared with other groups (P < 0.001). IL-6, IL-8, MCP-1 and ET-1 in D group were higher than those in C group (P < 0.05). TNF-α, IL-6, IL-8, MCP-1 and ET-1 concentrations were correlated with HOMA-IR indexes and adiponectin levels. All patients had lower adiponectin concentrations than controls (P < 0.001), but there were no differences between the patient groups. Only D and DC groups demonstrated a significant and similar decrease in LDI-Ach marker compared to C group (P < 0.001). LDI-Ach values were significantly correlated with HOMA-IR indexes and adiponectin levels (P < 0.001). Our findings show that obese MS patients have significantly increased HOMA-IR, TNF-α, IL-6, MCP-1 and IL-8 levels, decreased adiponectin concentration, and endothelial dysfunction, but the presence of T2DM and CAD in these patients is associated with more pronounced endothelial dysfunction and increased production of inflammatory cytokines and chemokines.publishersversionPeer reviewe