Evaluation of cellular processes and identification of candidate genes critical to corneal epithelial development

The overall aim of this study was to determine factors and mechanisms that underlie the regulation of epithelial patterning and homeostasis during corneal development. Histological staining was performed in chick corneas, embryonic day (ED) 4 to 21, to evaluate changes in the overall epithelial cell morphology, in particular cell shape, cell size and the number of epithelial cell layers. Epithelial differentiation patterns were identified in frozen sections of chicken corneas after immunolocalisation of pan-cytokeratins (Pan-CK) and cytokeratin 3 (CK3). Proliferating Cell Nuclear Antigen (PCNA) and caspase 3 (active) immunolocalisation studies, as well as, TUNEL-labelling (Terminal deoxynucleotidyl transferase dUTP-biotin nick-end labelling) were performed to assess temporal and spatial localisation of cell proliferation and death in the developing corneal epithelium respectively. The expression of PCNA and CK3 were later confirmed by immunoblotting. Total RNA was isolated from epithelia at selected developmental time points and collected for microarray analysis. Gene expression profiles were analysed by appropriate mathematical methods. The sensitivity of arrays in producing data trends was validated by quantitative RT-PCR. Histological findings included changes in stratification an increase in the number of cell layers, change in cell morphology. In this study it was demonstrated that after becoming two layered by ED4, the epithelium underwent further stratification to form intermediate cell layers at about EDM. These changes were accompanied by changes in cell shape commencing at ED10. Cell proliferation appeared high throughout corneal development, with peak proliferation between ED12 and ED14 in the limbal, peripheral and central epithelium, respectively, thereafter the level of proliferation decreased. The above coincided with changes in epithelial morphology (stratification) and changes in expression of cytokeratin (CK) epithelial markers. The appearance of pan-CK labelling was first observed at ED10 and the presence of CK3 immunolabelling appeared in epithelial cells at ED12. TUNEL-labelling and caspase 3 (active) immunolocalisation demonstrated only few TUNEL-positive cells, mostly restricted in the limbal region of the corneal epithelium, in the mid and later developmental stages. Microarray analyses identified gene families and their members (including these involved in stem cell biology) likely to be relevant in the regulation of homeostasis during corneal epithelial development, as well as, differentially expressed genes that reveal changes in biological processes due to the change in time. RT-qPCR confirmed the differential expression patterns of seven genes of interest following analysis of microarray data. Patterns of cell proliferation and differentiation showed changes during the development of the corneal epithelium that reflect the interaction of a complex network of mitogenic, apoptotic and differentiation agents. The changes in gene expression profiles, detected by the microarray analyses, were consistent with the phenotypic changes in the developing chick corneal epithelium. The microarray data provided the first study to present a good overall picture of genes expression in the developing chick corneal epithelium

Biphasic Equilibrium Dialysis of Poly(N-Isopropyl Acrylamide) Nanogels Synthesized at Decreased Temperatures for Targeted Delivery of Thermosensitive Bioactives

Hydrogel nanoparticles, referred to also as nanogels, are of special interest for medical and pharmaceutical applications. Due to small size in the range below the diameter of the capillaries, they are proposed as drug delivery carriers. The aim of the study was to estimate the influence of composition and reaction conditions during synthesis of poly-N-isopropyl acrylamide cross-linked by polyethylene glycol diacrylate on the purification rates of the polymer. Six types of thermosensitive nanogels were prepared by surfactant-free dispersion polymerization and assessed in terms of process yield, composition, and size at temperatures below and over volume phase temperature. During the diffusion of impurities, in the course of dialysis, assessed by the conductometric method, the remarkable influence of temperature and initiator concentration on the process was revealed. The release rates varied in the range between 9.63 · 10−2 and 1.39 · 10−1 h−1 in the first stage of the process, whereas in the second stage they were between 2.09 · 10−2 and 6.28 · 10−2 h−1. The evaluated time to obtain acceptable purity of the preparation was estimated to be in the range of 18 days. More detailed research should be directed towards the influence of the structure of obtained material on the purification process

Myocardial Ischaemia, Coronary Atherosclerosis and Pulmonary Pressure Elevation in Antiphospholipid Syndrome Patients

Thrombotic events in antiphospholipid syndrome (APS) involve venous and arterial circulation with the possible involvement of coronary or pulmonary microcirculation.To evaluate the influence of antiphospholipid antibodies (aPL) and on myocardial ischaemia assessed by single-photon emission computerized tomography (SPECT), coronary atherosclerosis assessed by multidetector computerized tomography (MDCT) and pulmonary pressure assessed by transthoracic echocardiography (TTE) in patients with primary antiphospholipid syndrome (PAPS).TTE, SPECT (Tc 99m sestamibi) and MDCT-based coronary calcium scoring were performed in 26 consecutive PAPS patients (20 females, 6 males, aged 20-61, mean 39.7) without any signs of other autoimmunological disease and without clinical symptoms of heart disease.Out of 26 patients, TEE showed normal left and right ventricle function in 25 (96.2%) and elevated (≥ 30 mm Hg) right ventricle systolic pressure in 7 (26.9%) patients. SPECT revealed myocardial perfusion defects in 15 (57.7%) patients: exercise-induced in 6 (23.1%) and persistent in 11 (42.3%). MDCT revealed coronary calcifications in 4 (15.4%) patients. The number of plaques ranged from 1 to 11 (median 2), volume 3-201.7 mm³ (median 7), calcium scores 1.3-202.6 (median 5.7). In the group with perfusion defects or coronary calcifications (n = 15), all the patients showed elevated aCL IgG.In most of the relatively young APS patients, without any symptoms of ischemic heart disease, SPECT showed myocardial perfusion defects, and coronary calcifications in 1/6 of them. Right ventricle systolic pressure was elevated in 1/4 of APS patients. These pathologies, well known as cardiovascular risk markers, were associated with elevated levels of the IgG class of both anti-cardiolipin and antiB2 GPI antibodies. Thus, in a high percentage of APS patients, clinically silent myocardial ischaemia, pulmonary pressure elevation and coronary atherosclerosis are present and related to the presence of antiphospholipid antibodies

Jugendbewegung und Emanzipation der Frau ein Beitrag zur Rolle der weiblichen Jugend in der Jugendbewegung bis 1933

FES Bonn(Bo133)-A83-3045 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Beneficial Properties of Green Tea Catechins

Green tea (Camellia sinesis) is widely known for its anticancer and anti-inflammatory properties. Among the biologically active compounds contained in Camellia sinesis, the main antioxidant agents are catechins. Recent scientific research indicates that the number of hydroxyl groups and the presence of characteristic structural groups have a major impact on the antioxidant activity of catechins. The best source of these compounds is unfermented green tea. Depending on the type and origin of green tea leaves, their antioxidant properties may be uneven. Catechins exhibit the strong property of neutralizing reactive oxygen and nitrogen species. The group of green tea catechin derivatives includes: epicatechin, epigallocatechin, epicatechin gallate and epigallocatechin gallate. The last of these presents the most potent anti-inflammatory and anticancer potential. Notably, green tea catechins are widely described to be efficient in the prevention of lung cancer, breast cancer, esophageal cancer, stomach cancer, liver cancer and prostate cancer. The current review aims to summarize the potential anticancer effects and molecular signaling pathways of major green tea catechins. It needs to be clearly emphasized that green tea as well as green tea catechols cannot replace the standard chemotherapy. Nonetheless, their beneficial effects may support the standard anticancer approach

Usage of Converter Gas as a Substitute Fuel for a Tunnel Furnace in Steelworks

Converter gas (BOFG) is a by-product of the steel manufacturing process in steelworks. Its usage as a substitute fuel instead of natural gas for fueling a metallurgical furnace seems to be reasonable due to potential benefits as follows: CO2 emission reduction into the ambient air and savings in purchasing costs of natural gas. Results of theoretical analysis focused on implementing converter gas as a fuel for feeding a tunnel furnace for either steel plate rolling, steel sheet hardening in its real working condition or both, are discussed. The analysis was focused on the combustion chemistry of the converter gas and its potential ecological and economic benefits obtained from converter gas usage to heat up steel in a tunnel furnace. Simulations of combustion were conducted using a skeletal chemical kinetic mechanism by Konnov. The directed relation graph with error propagation aided sensitivity analysis (DRGEPSA) method was used to obtain this skeletal kinetic mechanism. Finally, the model was validated on a real tunnel furnace fueled by natural gas. Regarding exhaust emissions, it was found that nitric oxide (NO) dropped down from 275 to 80 ppm when natural gas was replaced by converter gas. However, carbon dioxide emissions increased more than three times in this case, but there is no possibility of eliminating carbon dioxide from steel manufacturing processes at all. Economic analysis showed savings of 44% in fuel purchase costs when natural gas was replaced by converter gas. Summing up, the potential benefits resulting from substituting natural gas with converter gas led to the conclusion that converter gas is strongly recommended as fuel for a tunnel furnace in the steel manufacturing process. Practical application requires testing gas burners in terms of their efficiency, which should provide the same amount of energy supplied to the furnace when fed with converter gas

Modulation of Autophagy in Cancer Cells by Dietary Polyphenols

The role of autophagy is to degrade damaged or unnecessary cellular structures. Both in vivo and in vitro studies suggest a dual role of autophagy in cancer—it may promote the development of neoplasms, but it may also play a tumor protective function. The mechanism of autophagy depends on the genetic context, tumor stage and type, tumor microenvironment, or clinical therapy used. Autophagy also plays an important role in cell death as well as in the induction of chemoresistance of cancer cells. The following review describes the extensive autophagic cell death in relation to dietary polyphenols and cancer disease. The review documents increasing use of polyphenolic compounds in cancer prevention, or as agents supporting oncological treatment. Polyphenols are organic chemicals that exhibit antioxidant, anti-inflammatory, anti-angiogenic, and immunomodulating properties, and can also initiate the process of apoptosis. In addition, polyphenols reduce oxidative stress and protect against reactive oxygen species. This review presents in vitro and in vivo studies in animal models with the use of polyphenolic compounds such as epigallocatechin-3-gallate (EGCG), oleuropein, punicalgin, apigenin, resveratrol, pterostilbene, or curcumin and their importance in the modulation of autophagy-induced death of cancer cells

Modulation of Autophagy in Cancer Cells by Dietary Polyphenols

The role of autophagy is to degrade damaged or unnecessary cellular structures. Both in vivo and in vitro studies suggest a dual role of autophagy in cancer—it may promote the development of neoplasms, but it may also play a tumor protective function. The mechanism of autophagy depends on the genetic context, tumor stage and type, tumor microenvironment, or clinical therapy used. Autophagy also plays an important role in cell death as well as in the induction of chemoresistance of cancer cells. The following review describes the extensive autophagic cell death in relation to dietary polyphenols and cancer disease. The review documents increasing use of polyphenolic compounds in cancer prevention, or as agents supporting oncological treatment. Polyphenols are organic chemicals that exhibit antioxidant, anti-inflammatory, anti-angiogenic, and immunomodulating properties, and can also initiate the process of apoptosis. In addition, polyphenols reduce oxidative stress and protect against reactive oxygen species. This review presents in vitro and in vivo studies in animal models with the use of polyphenolic compounds such as epigallocatechin-3-gallate (EGCG), oleuropein, punicalgin, apigenin, resveratrol, pterostilbene, or curcumin and their importance in the modulation of autophagy-induced death of cancer cells