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Day Culture (day + culture)
Terms modified by Day Culture Selected AbstractsDifferential expression of mast cell characteristics in human myeloid cell linesEXPERIMENTAL DERMATOLOGY, Issue 9 2004Pia Welker Abstract:, In order to better understand the mechanisms governing display of mast cell characteristics in human myeloid cells, we have studied the mast cell phenotype in human promyelocytic (HL-60) and myelocytic (U-937, TPH-1) vs. basophilic (KU-812) and mast cell (HMC-1) lines, in part also in skin mast cells and blood monocytes, at mRNA and protein level before and after stimulation with mast cell growth factors. In unstimulated cells, mRNA for the stem cell factor (SCF) receptor c-kit and the gamma chain of the high-affinity IgE receptor (Fc,RI) was noted in all cells studied. Like mast and basophilic cells, THP-1 cells expressed the Fc,RI, and , chains and weakly histidine decarboxylase (HDC), but they lacked mRNA for mast cell-specific proteases [tryptase, chymase, carboxypeptidase A (CPA)]. In contrast, HL-60 and U-937 cells lacked Fc,RI,, but expressed tryptase and chymase, HL-60 cells also CPA. KU-812 cells failed to express the basophil-specific marker 2D7. After a 10-day culture with SCF or fibroblast supernatants, baseline mRNA expression of most mast cell characteristics was upregulated, whereas c-kit mRNA expression decreased in all but THP-1 cells. Differential mRNA expression of Fc,RI vs. protease (tryptase) was confirmed at protein level by immunocytochemistry and enzymatic activity. KU-812 cells are thus closest to skin mast cells in that they express all molecules studied, except for chymase, followed by THP-1 cells that lack all mast cell proteases. In contrast, HL-60 and U-937 cells fail to express the Fc,RI, and , chains but express most mast cell proteases. The selective and differential expression of mast cell characteristics in human myeloid cell lines suggests that induction of the mast cell phenotype is regulated by several independent genes and that mast cells and basophils branch off at early and distinct points of myeloid development. [source] Cage culture of the Pacific white shrimp Litopenaeus vannamei (Boone, 1931) at different stocking densities in a shallow eutrophic lakeAQUACULTURE RESEARCH, Issue 2 2009Maria Lourdes A Cuvin-Aralar Abstract Postlarvae of Litopenaeus vannamei were acclimated and stocked in lake-based cages at the following stocking densities: 10, 20, 30 and 40 shrimp m,2. Another set of shrimp was stocked in concrete tanks as reference samples at 30 shrimp m,2. Significant differences were observed among stocking densities throughout the 95-day culture. The final weight at harvest decreased with increasing stocking density: mean weights of 23.3, 15.8, 13.0, 10.9 and 14.6 g for the 10, 20, 30, 40 shrimp m,2 and reference tanks were observed respectively. There were no significant differences in survival throughout the culture period, ranging between 69% and 77%. Daily growth rates (range: 0.11,0.24 g day,1) and specific growth rates (range: 3.54,4.34%) also differed significantly among stocking densities, both increasing with decreasing stocking density. The feed conversion ratio in the cages did not differ among the stocking densities, ranging from 1.53 to 1.65. The relationship between stocking density and mean individual weight at harvest followed the equation y=81.06x,0.54 (R2=0.938) and that of stocking density and production (in g m,2) is y=58.01x,0.46 (R2=0.834). [source] Mesenchymal stem cell interaction with a non-woven hyaluronan-based scaffold suitable for tissue repairJOURNAL OF ANATOMY, Issue 5 2008G. Pasquinelli Summary The fabrication of biodegradable 3-D scaffolds enriched with multipotent stem cells seems to be a promising strategy for the repair of irreversibly injured tissues. The fine mechanisms of the interaction of rat mesenchymal stem cells (rMSCs) with a hyaluronan-based scaffold, i.e. HYAFF®11, were investigated to evaluate the potential clinical application of this kind of engineered construct. rMSCs were seeded (2 × 106 cells cm,2) on the scaffold, cultured up to 21 days and analysed using appropriate techniques. Light (LM), scanning (SEM) and transmission (TEM) electron microscopy of untreated scaffold samples showed that scaffolds have a highly porous structure and are composed of 15-µm-thick microfibres having a rough surface. As detected by trypan blue stain, cell adhesion was high at day 1. rMSCs were viable up to 14 days as shown by CFDA assay and proliferated steadily on the scaffold as revealed by MTT assay. LM showed rMSCs in the innermost portions of the scaffold at day 3. SEM revealed a subconfluent cell monolayer covering 40 ± 10% of the scaffold surface at day 21. TEM of early culture showed rMSCs wrapping individual fibres with regularly spaced focal contacts, whereas confocal microscopy showed polarized expression of CD44 hyaluronan receptor; TEM of 14-day cultures evidenced fibronexus formation. Immunohistochemistry of 21-day cultures showed that fibronectin was the main matrix protein secreted in the extracellular space; decorin and versican were seen in the cell cytoplasm only and type IV collagen was minimally expressed. The expression of CD90, a marker of mesenchymal stemness, was found unaffected at the end of cell culture. Our results show that HYAFF®11 scaffolds support the adhesion, migration and proliferation of rMSCs, as well as the synthesis and delivery of extracellular matrix components under static culture conditions without any chemical induction. The high retention rate and viability of the seeded cells as well as their fine modality of interaction with the substrate suggest that such scaffolds could be potentially useful when wide tissue defects are to be repaired as in the case of cartilage repair, wound healing and large vessel replacement. [source] ATP and UTP at low concentrations strongly inhibit bone formation by osteoblasts: A novel role for the P2Y2 receptor in bone remodelingJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 3 2002Astrid Hoebertz Abstract There is increasing evidence that extracellular nucleotides act on bone cells via multiple P2 receptors. The naturally-occurring ligand ATP is a potent agonist at all receptor subtypes, whereas ADP and UTP only act at specific receptor subtypes. We have reported that the formation and resorptive activity of rodent osteoclasts are stimulated powerfully by both extracellular ATP and its first degradation product, ADP, the latter acting at nanomolar concentrations, probably via the P2Y1 receptor subtype. In the present study, we investigated the actions of ATP, ADP, adenosine, and UTP on osteoblastic function. In 16,21 day cultures of primary rat calvarial osteoblasts, ADP and the selective P2Y1 agonist 2-methylthioADP were without effect on bone nodule formation at concentrations between 1 and 125 ,M, as was adenosine. However, UTP, a P2Y2 and P2Y4 receptor agonist, known to be without effect on osteoclast function, strongly inhibited bone nodule formation at concentrations ,,1 ,M. ATP was inhibitory at ,,10 ,M. Rat osteoblasts express P2Y2, but not P2Y4 receptor mRNA, as determined by in situ hybridization. Thus, the low-dose effects of extracellular nucleotides on bone formation and bone resorption appear to be mediated via different P2Y receptor subtypes: ADP, signalling through the P2Y1 receptor on both osteoclasts and osteoblasts, is a powerful stimulator of osteoclast formation and activity, whereas UTP, signalling via the P2Y2 receptor on osteoblasts, blocks bone formation by osteoblasts. ATP, the ,universal' agonist, can simultaneously stimulate resorption and inhibit bone formation. These findings suggest that extracellular nucleotides could function locally as important negative modulators of bone metabolism, perhaps contributing to bone loss in a number of pathological states. J. Cell. Biochem. 86: 413,419, 2002. © 2002 Wiley-Liss, Inc. [source] Studies on the effects of gentamicin on rat metanephric development in vitroNEPHROLOGY, Issue 1-2 2000Luise A Cullen SUMMARY: Reduced nephron endowment has been associated with increased risk of developing essential hypertension and chronic renal failure. Both in vivo and in vitro exposure of developing rat metanephroi to gentamicin has been reported to inhibit metanephric development resulting in reduced nephron endowment. The aim of the present study was to confirm that gentamicin results in reduced nephron endowment in vitro, and to extend understanding of the mechanisms responsible for this reduced endowment. Embryonic day 14 (E14) rat metanephroi were cultured for up to 4 days in serum-free medium with or without 50 ,g/mL gentamicin. Metanephroi cultured in the presence of gentamicin were 25% smaller than control metanephroi after 2 days culture and 30% smaller after 4 days (P < 0.001). This decrease in total metanephric volume was reflected in reduced volumes of ureteric duct epithelium, mesenchyme/interstitium and nephron epithelia. The reduced volume of ureteric duct epithelium in gentamicin-treated metanephroi was associated with a 30% reduction in the number of ureteric duct branch points at 2 days. Metanephroi cultured with gentamicin contained 20% fewer glomeruli than control metanephroi (P < 0.005) at 4 days. These glomeruli were 30% smaller than control glomeruli (P < 0.05). Qualitative observations of Pax-2 immunostained mesenchymal condensates indicated no difference in condensate size, location or morphology. These results confirm that in vitro exposure of developing rat metanephroi to gentamicin results in reduced nephron endowment. The defect in nephrogenesis centres around the inhibition of ureteric duct branching. [source] T cells and eosinophils in bronchial smooth muscle cell death in asthmaCLINICAL & EXPERIMENTAL ALLERGY, Issue 6 2009K. Solarewicz-Madejek Summary Background Bronchial smooth muscle cells (SMC) proliferate, express adhesion molecules, secrete cytokines and thus efficiently contribute to the pathogenesis of asthma. Objective The aim of the study was to investigate whether, and by which mechanism, T cells and eosinophils can cause death of airway SMC. Methods The T cell- and eosinophil-induced cell death was analysed in primary human bronchial SMC cultures as well as in bronchial biopsy specimens from non-asthmatic and asthmatic individuals. Results Bronchial SMC death showed characteristic morphological features of apoptosis in 3,6 days cultures with inflammatory cytokines (IFN-,, TNF-,), soluble death ligands [sFasL, TNF-related apoptosis-inducing ligand (TRAIL)] and activated T-helper type 1 (Th1) and Th2 cell supernatants. The recombinant eosinophil cationic protein induced SMC necrosis within 1 h. Resting SMC expressed the death receptors TNFR1, TNFR2, Fas, TRAILR1, TRAILR2 and membrane FasL as a death-inducing ligand. IFN-, and TNF-, up-regulated TNFR1, TNFR2, Fas and membrane FasL on SMC. TNF-, up-regulated TRAILR1 and TRAILR2; sFasL up-regulated TNFR2. The intracellular caspase-3 activation in SMC was significantly increased by IFN-,, sFasL, TRAIL, Th1 and Th2 cell supernatants. Increased expression of TRAIL in asthmatics, but not in non-asthmatic individuals was demonstrated in situ. The apoptosis receptors TRAILR1 and TRAILR2 were expressed in SMC and epithelial cells both in healthy and asthmatic biopsies. Prominent apoptosis of SMC was observed in fatal asthma, but not intermittent asthma biopses. Conclusion The demonstration of bronchial SMC death both by apoptosis and necrosis indicates the essential role of T cells and eosinophils in the bronchial tissue injury particularly in the severe asthma. [source] | |||||||||||||