425 research outputs found

    Morphology and function of human Leydig cells in vitro. Immunocytochemical and radioimmunological analyses

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    The aim of our study was to show whether the cells isolated from testes of patients underwent bilateral orchiectomy for prostatic cancer are able to grown in vitro, and if so, are functionally active. Immuncytochemistry was performed to show the functional status of human cultured cells. In detail, immunolocalization of luteinizing hormone receptors (LHR), mitochondria, and cytoskeletal elements was demonstrated. Moreover, radioimmunological assay was used to measure testosterone secretion by cultured Leydig cells. Using Nomarski interference contrast and fine immunofluorescence analysis the positive immunostaining for LHR was observed in almost all Leydig cells, however it was of various intensity in individual cells. Testosterone measurement revealed significant difference between testosterone secretion by hCG-stimulated and unstimulated Leydig cells (p<0.05). Moreover, testosterone levels were significantly higher in 24- and 48-hour-cultures than in those of 72 hrs (p<0.05). Morphological analysis of Leydig cells in culture revealed the presence of mononuclear and multinucleate cells. The latter cells occurred in both hCG-stimulated and unstimulated cultures. In Leydig cells labeled with a molecular marker MitoTtracker, an abundance of mitochondria and typical distribution of microtubules and microfilaments were observed irrespective of the number of nuclei within the cell, suggesting no functional differences between mono- and multinucleate human Leydig cells in vitro. Since the percentage of multinucleate cells was similar in both hCG-stimulated and unstimulated cultures (23.70% and 22.80%), respectively, the appearance of these cell population seems to be independent of hormonal stimulation

    The barriers and facilitators to the use of lifestyle apps: a systematic review of qualitative studies

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    Background: Mobile-health applications are revolutionising the way healthcare is being delivered. However, current research focusses on apps aimed at monitoring of conditions rather than the prevention of disease. Healthcare apps that prevent disease can be classified as lifestyle apps (LAs) and encompass mindfulness, exercise, and diet apps. In order for widespread implementation of these apps, perspectives of the user must be taken into consideration. Therefore, this systematic literature review identifies the barriers and facilitators to the use of LAs from a user’s perspective. Objective: To both identify the facilitators to the use of LAs from a user perspective as well as identify the barriers to the use of LAs from a user perspective. Methods: A systematic literature review was conducted following PRISMA guidelines. Qualitative articles focussed on a healthy non-diseased population were obtained. Two independent researchers coded the articles, and themes were identified. Results: Our results found that there were five barriers and five facilitators to app use. The facilitators included (1) motivational aspects to the user, (2) effective marketing and communication, (3) user-centred design and content, (4) humanising technology, and (5) accessibility. The five barriers identified were (1) a non-conducive, (2) poor marketing and branding, (3) controlling and invasive, (4) disengaging content, and (5) inaccessibility. Conclusions: By overcoming the barriers of LAs and encouraging the facilitators found, users are more likely to engage with this method of health promotion. Future research must be conducted on the barriers and facilitators to development and distribution of apps in order for LAs to be implemented in widespread healthcare practice

    Neutralizing Anti-Interleukin-1β Antibodies Reduce Ischemia-Related Interleukin-1β Transport Across the Blood-Brain Barrier in Fetal Sheep

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    Hypoxic ischemic insults predispose to perinatal brain injury. Pro-inflammatory cytokines are important in the evolution of this injury. Interleukin-1β (IL-1β) is a key mediator of inflammatory responses and elevated IL-1β levels in brain correlate with adverse neurodevelopmental outcomes after brain injury. Impaired blood-brain barrier (BBB) function represents an important component of hypoxic-ischemic brain injury in the fetus. In addition, ischemia-reperfusion increases cytokine transport across the BBB of the ovine fetus. Reducing pro-inflammatory cytokine entry into brain could represent a novel approach to attenuate ischemia-related brain injury. We hypothesized that infusions of neutralizing IL-1β monoclonal antibody (mAb) reduce IL-1β transport across the BBB after ischemia in the fetus. Fetal sheep were studied 24-h after 30-min of carotid artery occlusion. Fetuses were treated with placebo- or anti-IL-1β mAb intravenously 15-min and 4-h after ischemia. Ovine IL-1β protein expressed from IL-1β pGEX-2T vectors in E. Coli BL-21 cells was produced, purified, and radiolabeled with 125I. BBB permeability was quantified using the blood-to-brain transfer constant (Ki) with 125I-radiolabeled-IL-1β. Increases in anti-IL-1β mAb were observed in the brain of the mAb-treated group (P \u3c 0.001). Blood-to-brain transport of 125I-IL-1β was lower (P \u3c 0.04) across brain regions in the anti-IL-1β mAb treated than placebo-treated ischemic fetuses. Plasma 125I-IL-1β counts were higher (P \u3c 0.001) in the anti-IL-1β mAb than placebo-treated ischemic fetuses. Systemic infusions of anti-IL-1β mAb reduce IL-1β transport across the BBB after ischemia in the ovine fetus. Our findings suggest that conditions associated with increases in systemic pro-inflammatory cytokines and neurodevelopmental impairment could benefit from an anti-cytokine therapeutic strategy

    Bacterial expression and secretion of various single-chain Fv genes encoding proteins specific for a Salmonella serotype B O-antigen.

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    Active single-chain Fv molecules encoded by synthetic genes have been expressed and secreted to the periplasm of Escherichia coli using the ompA secretory signal. Four different constructs were developed to investigate the effects of peptide linker design and VL-VH orientation on expression, secretion, and binding to a Salmonella O-polysaccharide antigen. Peptide linker sequences derived from the elbow regions of the Fab molecule were used alone or in combination with the flexible (GGGGS)2 sequence. VL and VH domain order in the single chain molecules had a profound effect on the level of secretion but hardly influenced total expression levels, which were approximately 50 mg/liter, chiefly in the form of inclusion bodies. With VL in the NH2-terminal position, the amount of secreted product obtained was 2.4 mg/liter, but when VH occupied this position the yield was less than 5% of this value. Enzyme immunoassays of the four products showed domain order and linker sequence affected antigen binding by less than an order of magnitude. Attempts to express active Fv from dicistronic DNA were unsuccessful, but active Fv was obtained from single-chain Fv by enzymic cleavage at a site in the elbow linker peptide. The thermodynamic binding parameters of intact and cleaved single-chain Fvs determined by titration microcalorimetry were similar to those of bacterially produced Fab and mouse IgG

    Ischemia–reperfusion impairs blood–brain barrier function and alters tight junction protein expression in the ovine fetus

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    The blood–brain barrier is a restrictive interface between the brain parenchyma and the intravascular compartment. Tight junctions contribute to the integrity of the blood–brain barrier. Hypoxic–ischemic damage to the blood–brain barrier could be an important component of fetal brain injury. We hypothesized that increases in blood–brain barrier permeability after ischemia depend upon the duration of reperfusion and that decreases in tight junction proteins are associated with the ischemia-related impairment in blood–brain barrier function in the fetus. Blood–brain barrier function was quantified with the blood-to-brain transfer constant (Ki) and tight junction proteins by Western immunoblot in fetal sheep at 127 days of gestation without ischemia, and 4, 24, or 48 h after ischemia. The largest increase in Ki (P \u3c 0.05) was 4 h after ischemia. Occludin and claudin-5 expressions decreased at 4 h, but returned toward control levels 24 and 48 h after ischemia. Zonula occludens-1 and -2 decreased after ischemia. Inverse correlations between Ki and tight junction proteins suggest that the decreases in tight junction proteins contribute to impaired blood–brain barrier function after ischemia. We conclude that impaired blood–brain barrier function is an important component of hypoxic–ischemic brain injury in the fetus, and that increases in quantitatively measured barrier permeability (Ki) change as a function of the duration of reperfusion after ischemia. The largest increase in permeability occurs 4 h after ischemia and blood–brain barrier function improves early after injury because the blood–brain barrier is less permeable 24 and 48 than 4 h after ischemia. Changes in the tight junction molecular composition are associated with increases in blood–brain barrier permeability after ischemia

    Study of deuterium plasma interaction with a tungsten target within RPI-IBIS facility

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    The paper presents results of experimental research on the interaction of a pulsed plasma-ion stream with a tungsten (W) target. The pulsed deuterium plasma was produced within the RPI-IBIS (Multi-Rod Plasma Injector) facility at IPJ in Swierk. Measurements were carried out by means of optical spectroscopy and corpuscular diagnostic techniques. Structural changes in the irradiated targets were investigated with a SEM. Before experiments with the W-target there were determined operational conditions, when clean deuterium plasma streams can be generated. For that purpose a so-called “slow or PID (Plasma Ion Deposition) mode” of the RPI-IBIS operation was chosen. Particular attention was paid to the identification of spectral lines from WI and WII species. The obtained results, i.e. optical spectra and other characteristics have demonstrated applicability of the RPI-IBIS facility for research on the interaction of plasma streams with W-targets, e.g. those constituting some internal parts of fusion facilities.Представлено результати експериментальних досліджень по взаємодії імпульсного плазмово-іонного потоку з вольфрамовою мішенню. Імпульсні дейтерієві потоки плазми генерувались в СПІ-ІБІС (стержневий плазмовий інжектор), який знаходиться в ІЯП у Шверку. Виміри проводились за допомогою оптичної спектроскопії та корпускулярної діагностики. Структурні зміни облучаємої мішені досліджувались за допомогою SEM. Перед експериментами з вольфрамовою мішенню визначались робочі умови, коли генерувались чисті дейтерієві плазмові потоки. Був вибраний так званий режим “повільний або PID-моди” (плазмового іонного осадження). Частична увага приділялась ідентифікації спектральних ліній WI та WII. Отримані результати, оптичні спектри та інші характеристики, продемонстрували можливість застосовувати установку СПІ-ІБІС для досліджень взаємодії плазмових потоків з W-мішенню, які складають деякі внутрішні частини термоядерного реактору.Представлены результаты экспериментальных исследований по взаимодействию импульсного плазменно-ионного потока с вольфрамовой мишенью. Импульсные дейтериевые потоки плазмы генерировались внутри СПИ-ИБИС (стержневой плазменный инжектор), который расположен в ИЯП в Шверке. Измерения проводились с помощью оптической спектроскопии и корпускулярной диагностики. Структурные изменения облучаемой мишени исследовались с помощью SEM. Перед экспериментами с вольфрамовой мишенью определялись рабочие условия, когда генерировались чистые дейтериевые плазменные потоки. Для этой цели был выбран так называемый режим “медленной или PID-моды” (плазменного ионного осаждения). Частичное внимание уделялось идентификации спектральных линий WI и WII. Полученные результаты, оптические спектры и другие характеристики, продемонстрировали применимость установки СПИ-ИБИС для исследований взаимодействия плазменных потоков с W-мишенью, которые составляют некоторые внутренние части термоядерного реактора

    Role of N-acetylcysteine in the management of COPD

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    The importance of the underlying local and systemic oxidative stress and inflammation in chronic obstructive pulmonary disease (COPD) has long been established. In view of the lack of therapy that might inhibit the progress of the disease, there is an urgent need for a successful therapeutic approach that, through affecting the pathological processes, will influence the subsequent issues in COPD management such as lung function, airway clearance, dyspnoea, exacerbation, and quality of life. N-acetylcysteine (NAC) is a mucolytic and antioxidant drug that may also influence several inflammatory pathways. It provides the sulfhydryl groups and acts both as a precursor of reduced glutathione and as a direct reactive oxygen species (ROS) scavenger, hence regulating the redox status in the cells. The changed redox status may, in turn, influence the inflammation-controlling pathways. Moreover, as a mucolytic drug, it may, by means of decreasing viscosity of the sputum, clean the bronchi leading to a decrease in dyspnoea and improved lung function. Nevertheless, as successful as it is in the in vitro studies and in vivo studies with high dosage, its actions at the dosages used in COPD management are debatable. It seems to influence exacerbation rate and limit the number of hospitalization days, however, with little or no influence on the lung function parameters. Despite these considerations and in view of the present lack of effective therapies to inhibit disease progression in COPD, NAC and its derivatives with their multiple molecular modes of action remain promising medication once doses and route of administration are optimized
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