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Numerous in vitro experiments have confirmed that a dysfunctional endothelium is characterized by, inter alia, a higher affinity for binding of platelets and leukocytes. However, there is still no direct evidence for greater interaction between platelets and intact endothelium in in vivo animal models of diabetes. Therefore, the present study examines the pro-adhesive properties of endothelium change in vivo as an effect of streptozotocin (STZ)-induced diabetes and the role of two key platelet receptors: GPIb-IX-V and GPIIb/IIIa. Mice of C57BL strain with streptozotocin-induced diabetes were used in the study. Flow cytometry was used to assess basal activation and reactivity of platelets. Adhesion of platelets to the vascular wall was visualized with the use of intravital microscopy in mesentery. The contribution of GPIIb/IIIa and GPIb-IX-V was evaluated by the injection of Fab fragments of respective antibodies. The integrity of the endothelium and vWf expression were evaluated histochemically. Basal activation and reactivity of platelets in streptozotocin-diabetic mice were elevated. Blood platelets adhered more often to the vascular wall of diabetic mice than nondiabetic animals: 11.9 (6.4; 32.8) plt/min/mm2 (median [IQR]) vs 2.7 (1.3; 6.4) plt/min/mm2. The injection of anti-GPIbα antibodies decreased the number of adhering platelets from 89.5 (34.0; 113.1) plt/min/mm2 (median [IQR]) in mice treated with isotype antibodies to 3.1 (1.7; 5.6) plt/min/mm2 in mice treated with blocking antibodies. The effect of GPIIb/IIIa blockage was not significant. Immunohistochemistry revealed a higher expression of vWF in the endothelium of STZ mice, but no substantial changes in endothelial morphology were detected. To conclude, the study shows that the platelets interact more frequently with the mesenteric vascular bed in mice with 1-month STZ-induced diabetes than in healthy mice. These interactions are mediated via platelet GPIb-IX-V and are driven by increased expression of vWF in endothelial cells. [ABSTRACT FROM AUTHOR]

Background: The heterogeneity of melanoma needs to be addressed and combination therapies seem to be necessary to overcome intrinsic and acquired resistance to newly developed immunotherapies and targeted therapies. Although the role of WNT/β-catenin pathway in melanoma was early demonstrated, its contribution to the lack of the melanoma patient response to treatment was only recently recognized. Using patient-derived melanoma cell populations, we investigated the influence of pentoxifylline on melanoma cells with either high or low expression of β-catenin. Findings: Our results indicate that pentoxifylline inhibits the activity of the canonical WNT pathway in melanoma cell populations with high basal activity of this signalling. This is supported by lowered overall activity of transcription factors TCF/LEF and reduced nuclear localisation of active β-catenin. Moreover, treatment of β-cateninhigh melanoma cell populations with pentoxifylline induces downregulation of genes that are targets of the WNT/β-catenin pathway including connective tissue growth factor (CTGF) and microphthalmia-associated transcription factor (MITF-M), a melanocyte- and melanoma cell-specific regulator. Conclusions: These results suggest that pentoxifylline, a drug approved by the FDA in the treatment of peripheral arterial disease, might be tested in a subset of melanoma patients with elevated activity of β-catenin. This pharmaceutical might be tested as an adjuvant drug in combination therapies when the response to immunotherapy is prevented by high activity of the WNT/β-catenin pathway. [ABSTRACT FROM AUTHOR]

In diabetes-related states of chronic hyperglycaemia elevated concentrations of glucose may alter the functioning of platelet enzymes involved in arachidonic acid metabolism, including prostaglandin H2synthase (cyclooxygenase) (PGHS, COX). Therefore, the principal aim of this study was to assess the effects of experimental chronic hyperglycaemia on platelet PGHS-1 (COX-1) expression and activity. Blood platelet activation and reactivity were assessed in Sprague–Dawley rats with the 5-month streptozotocin (STZ) diabetes. The PGHS-1 abundance in platelets was evaluated with flow cytometry and Western blotting, while its activity monitored using a high resolution respirometry and the peroxidase fluorescent assay. The production of prostaglandin E2(PGE2) and thromboxane B2(TXB2) in platelets were assayed immunoenzymatically. Circulating platelets from diabetic were characterised by increased size, elevated ‘priming’ and altered reactivity, compared to non-diabetic animals. Both Western blot analysis and flow cytometry revealed significantly elevated expressions of platelet PGHS-1 in STZ-diabetic rats (p < 0.05). We also observed significantly elevated platelet PGHS-1-related arachidonic acid metabolism in diabeticvs.non-diabetic animals, with the use of polarographic (p < 0.05) and total activity assay (p < 0.001). Such increases were accompanied by the elevated production of PGE2(p < 0.001) and TXB2(p < 0.05) in diabetic animals. The increased PGHS-1-dependent oxygen consumption and the total activity of PGHS-1 in diabetic animals remained very significant (p < 0.001) also upon adjusting for blood platelet PGHS-1 abundance. Therefore, our results further contribute to the explanation of the increased metabolism of arachidonic acid observed in diabetes. [ABSTRACT FROM PUBLISHER]

Wstęp: Możliwości określenia mechanizmów związanych z rozwojem atopowego zapalenia skóry (AZS) na podstawie obserwacji klinicznych u ludzi, zwłaszcza we wczesnych jego etapach, są znacząco ograniczone. Dlatego też eksperymentalne modele AZS są ważnym i użytecznym narzędziem pozwalającym na zdobycie wiedzy o etiopatogenezie AZS, a także umożliwiającym opracowanie nowych sposobów leczenia. Cel: Celem badania była walidacja mysiego modelu AZS. Materiały i Metody: Badanie przeprowadzono na samcach myszy C57BL/6 (8-12 tygodni). Indukcja AZS polegała na aplikowaniu na ogoloną skórę karku myszy alergenu - owoalbuminy (OVA) w dawce 1 ug/uL przez okres 63 dni. Po tym czasie myszy poddano eutanazji, pobrano krew, skórę, śledzionę i węzły chłonne, a następnie zmierzono ekspresję wybranych markerów AZS (qPCR, ELISA) oraz przeprowadzono ocenę histopatologiczną skóry myszy (barwienie H&E). Doświadczenia wykonano po uzyskaniu zgody wydanej przez Lokalną Komisję Etyczną ds. Doświadczeń na Zwierzętach w Łodzi (nr 49/ŁB 216/2021). Wyniki: W skórze myszy z AZS wywołanym OVA zauważono zwiększoną ekspresję interleukiny 1β i TNF-alfa. Ponadto, obraz histopatologiczny skóry myszy z grupy badanej pozwolił zaobserwować hiperplazję naskórka oraz nacieki komórkami układu immunologicznego - neutrofilami. Podsumowanie: W wyniku badań otrzymano model AZS indukowany roztworem OVA u myszy, który w przyszłości posłuży do testowania nowych substancji łagodzących objawy tej choroby. [ABSTRACT FROM AUTHOR]

Abstract: The role of cyclooxygenase-2 (COX-2) in restoring the functions of impaired endothelium is attracting considerable attention, notably the function of COX-2-derived vasodilatory prostaglandins is disputed in the context of the regulation function in the impaired vascular beds. We have examined the hypothesis that COX-2 activity contributes more to vasodilation in hyperglycemic animals than in healthy counterparts, and that COX-2 derived vasodilatory prostaglandins (PGI2 and PGE2) are responsible for this effect. Using the Langendorff heart perfusion system, the effects of COX-2 inhibition were monitored on both basal and bradykinin-induced coronary flows in Sprague–Dawley rats given 8-week streptozotocin-induced diabetes and in age-matched controls (n=15). Secretions of PGI2 and PGE2, both total and the COX-2 dependent pools, have also been compared. The selective COX-2 inhibitor, N-[2-(cyclohexyloxy)-4-nitrophenyl]-methanesulfonamide (NS-398), had no effect on coronary flow in the diabetic group of animals. Thus, the compensatory role of COX-2 in regulation of vascular tone in experimental diabetes found in other experimental models was not confirmed. However, COX-2 activity significantly contributed to PGI2 synthesis in healthy rats, with prostacyclin secretion being two-fold decreased by NS-398. Contrary to our hypothesis, neither prostacyclin nor PGE2 production differed between the experimental groups under the basal conditions. Bradykinin had no effect on the secretion of PGI2 in either group, but increased PGE2 synthesis in healthy animals, although not in the streptozotocin group. PGE2 production in response to bradykinin was COX-2-dependent in control animals. We conclude that, in rats with 8-week streptozotocin-induced diabetes, the activity of COX-2 in coronary vasculature is not significantly enhanced. [Copyright &y& Elsevier]

Nitroxides as stabile organic radicals were used initially as spin labels in spectroscopy of electron paramagnetic resonance (EPR) with respect to parameters such as pH of an intercellular environment, oxygenation of cells and tissues, fluidity of biological membranes, conformational state and topography of proteins. Nitroxides have also been used in biology and medicine as contrast agents in magnetic resonance imaging (MRI). When their antioxidant activities were discovered, an era of research on the potential utility of these agents began. Nitroxides can modulate the redox state of the cell by participation in oxidation/reduction reactions. Therefore, they are extensively examined in various models of oxidative stress. The antioxidant effect of nitroxides is a result of their ability to catalyze dismutation of superoxide radical (superoxide dismutase-like activity), inhibit lipid peroxidation, prevent Fenton and Haber-Weiss reactions by oxidation of transition metal ions to a higher oxidative state, and confer catalase-like activity on heme proteins. In the present paper the antioxidative mechanisms of nitroxides are presented. The relation between structure, function and the rate of nitroxide reduction inside cells and tissues is also presented. The application of nitroxides in chemoprevention and radioprotection is discussed. [ABSTRACT FROM AUTHOR]

In diabetes-related states of chronic hyperglycaemia elevated concentrations of glucose may alter the functioning of platelet enzymes involved in arachidonic acid metabolism, including prostaglandin H2 synthase (cyclooxygenase) (PGHS, COX). Therefore, the principal aim of this study was to assess the effects of experimental chronic hyperglycaemia on platelet PGHS-1 (COX-1) expression and activity. Blood platelet activation and reactivity were assessed in Sprague-Dawley rats with the 5-month streptozotocin (STZ) diabetes. The PGHS-1 abundance in platelets was evaluated with flow cytometry and Western blotting, while its activity monitored using a high resolution respirometry and the peroxidase fluorescent assay. The production of prostaglandin E2 (PGE2) and thromboxane B2 (TXB2) in platelets were assayed immunoenzymatically. Circulating platelets from diabetic were characterised by increased size, elevated 'priming' and altered reactivity, compared to non-diabetic animals. Both Western blot analysis and flow cytometry revealed significantly elevated expressions of platelet PGHS-1 in STZ-diabetic rats (p < 0.05). We also observed significantly elevated platelet PGHS-1-related arachidonic acid metabolism in diabetic vs. non-diabetic animals, with the use of polarographic (p < 0.05) and total activity assay (p < 0.001). Such increases were accompanied by the elevated production of PGE2 (p < 0.001) and TXB2 (p < 0.05) in diabetic animals. The increased PGHS-1-dependent oxygen consumption and the total activity of PGHS-1 in diabetic animals remained very significant (p < 0.001) also upon adjusting for blood platelet PGHS-1 abundance. Therefore, our results further contribute to the explanation of the increased metabolism of arachidonic acid observed in diabetes.

Objective: To assess the hearing impairment in people over 60 years old using hearing aids. This was a single-center study, but it is planned to extend it further to the whole country., Materials and Methods: The study was focused on patients with hearing aids. During the assessment 57 people were included in the observation in order to control the status of their hearing loss and benefit from traditional hearing aids as well as the possibility to apply the auditory implants in case of a little benefit from hearing aids. The otoscopy and pure tone audiometry were performed as well as the questionnaires on demographic and epidemiological data of patients were collected as well as the quality of their life with hearing aids was subjectively assessed., Results: The results show that 91% of patients have sensorineural hearing loss (SHL), the remaining 9%--severe mixed hearing loss. Severe SHL was found in 22 patients, the moderate hearing loss was observed in 37%, and the profound SHL was the case in 5 patients. Minimal SHL was observed in 7% of patients (n=4). More than 73% of the study subjects were male (n=38). The average age of the patients who completed the survey was 74 years old. Thirty-five patients used their hearing aid over 3 years and less than 70% of them used it every day all day. Hearing aid was not actively used by 10 patients. Over the last year 51.92% of the patients underwent a hearing examination., Conclusions: The bone anchored hearing aid was suggested to 2% of subjects and the cochlear implant was offered to 10 patients. The data analysis shows the need to educate and inform the elderly about alternative methods of hearing loss treatment., (Copyright © 2013 Polish Otorhinolaryngology - Head and Neck Surgery Society. Published by Elsevier Urban & Partner Sp. z.o.o. All rights reserved.)