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1

Characterization of human hepatocytes isolated from non-transplantable livers

100%
Laba A., Ostrowska A., Patrzalek D., Paradowski L., Lange A.
Archivum Immunologiae et Therapiae Experimentalis
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2005
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vol. 53
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issue 5
442-453
EN
The successful use of hepatocytes depends on a reliable demonstration of the functional and morphological integrity of isolated cells. Herein we investigated whether the isolation and cryopreservation of primary human hepatocytes can compromise cell viability and liver-specific characteristics. Hepatocytes were isolated from encapsulated human liver segments by a modified 2-step perfusion technique. Isolated cells were Percoll-purified, cryopreserved, and stored in liquid nitrogen for 1?12 months. For rapid assessment of fresh and cryopreserve/thawed hepatocyte yield and viability, the cells were stained with trypan blue or labeled with fluorochromes. For immunocytochemical analysis, the cells were labeled with monoclonal antibodies for the presence of the following antigens and chemokines: CD3, CD45Ro, CD45Ra, CD34, CD68, CD90, CD95, CD20, HLA-DR, Ki67, PCNA, Bcl-2, p53, CXCR3, CXCR4, and SDF-1. The cells were tested for several specific functions, such as ureagenesis, energy status, MTT activity, lactate dehydrogenase leakage, and total CYP450 content. Assessment of both freshly isolated (Percoll-purified) and cryopreserved/thawed hepatocytes revealed a low constitutive level of contamination by non-parenchymal cells compared with crude (unpurified) preparations and tissue sections. All viable hepatocytes showed intact morphology and retained CYP450 protein, energy status, and urea synthesis. Modifications in hepatocyte preparations, such as depletion of dead, damaged, and non-parenchymal cells, improves cell purity, which can be adapted to further evaluation of hepatocyte immunogenicity. These data illustrate the importance and feasibility of human hepatocyte banking.
2
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Effects of social rearing conditions on conditioned suppression in rats

100%
Walasek G., Wesierska M., Werka T.
Acta Neurobiologiae Experimentalis
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2002
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vol. 62
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issue 1
25-31
EN
Twenty-two rats were reared in standard conditions during the first two months of their life. Then the animals were divided into two groups exposed to different rearing conditions. Twelve animals (Group SO) were housed socially, six animals per cage, and for three weeks they were subjected to sensory stimulation in an enriched environment. The other ten subjects were kept individually (Group IN); one rat per mesh cage, in conditions of relatively impoverished sensory stimulation. In both groups the training of the conditioned emotional response (CER) was performed when animals were three months old. In contrast to IN subjects, the rats subjected to permanent social contacts and reared in the enriched environment (Group SO) revealed almost equally low instrumental response rates in trials with the conditioned stimulus (CS) paired with nociceptive foot-shock (US), and in periods when no CS and/or US were applied. The results suggested that early exposure to an enriched environment caused a later decrease of the animals? capability to differentiate between the aversive CS and cues of the experimental context. This cognitive impairment was probably a secondary effect of fear generalized to the entire experimental situation.
3

A two step procedure to fractionate mouse testicular macrophages with a different cytokine profile

88%
Bryniarski K., Szewczyk K., Ptak M., Bobek M., Ptak W.
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EN
Cells isolated enzymatically from interstitial tissue of mouse male gonads are composed of macrophages, Leydig cells, and myofibroblasts. They can be separated on density gradients either by sedimentation (Ficoll) or flotation (Percoll) into several fractions according to different buoyant density containing mixtures of different cells. Macrophages (FcR+, esterase+) present in cell mixtures can by highly enriched in a single step to 95% purity by rosetting with opsonized erythrocytes followed by sedimentation on Lymphoprep. Separate fractions of highly purified (over 95%) macrophages obtained by successive use of density gradients and rosetting differ significantly in the production of cytokines, such as cells from fractions at lower density produce little IL-6, cells from fractions at higher density are poor producers of TNF-alpha whereas TMf in intermediate fractions produce significant amounts of both cytokines. These differences may suggest that particular subpopulations of testicular macrophages play different biological roles in the testis.
4

Xanthohumol and other prenylated flavonoids of hop cones ? biological and technological aspects

75%
Golabczak J., Gendaszewska-Darmach E.
Biotechnologia
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2010
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issue 1
82-96
EN
Hops, the female inflorescences of the hop plant (Humulus lupulus) are used in the brewing industry to add bitterness and aroma to beer. This raw material is a rich source of terpenoid essential oils and terpenophenolic resins (bitter acids, prenylated flavonoids). Xanthohumol is the most abundant (80-90%) of total amount of prenylated flavonoids in hop cones (up to 1% w/w). Xanthohumol has received much attention in recent years as a cancer chemopreventive agent because of its ability to inhibit initiation, promotion and progression stages of carcinogenesis. It's beneficial effects on health also include antibacterial, antioxidant, and antiinflamattory properties. Hydrophobic xanthohumol cannot be extracted with carbon dioxide under condition used for common hop extract destined for the application in the brew house (300 bar, 50?). This flavonoid remains in the waste product of the hops (spent hops) processing industry. Diverse extraction methods of spent hops by ethanol and supercritical CO2 at different pressures lead to the residues that contain more than 30% xanthohumol. The multistep process extraction and separation of xanthohumol from natural source (raw or waste hops) with organic solvent have been also conducted. Recently, a synthetic route to xanthohumol has also been described. The purpose of this review is to provide an overview of the chemistry, biosynthesis, biological activities, and biotechnological aspects of xanthohumol.
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