Objective To evaluate the factors affecting the measurement of lung tumor activity concentration (AC) with FDG-PET. Methods High count Monte-Carlo simulations,based on VIP-Man (marked VHP atlas) added with spherical lung tumors of different diameter and activity,were performed to generate the essentially noiseless projection data for PET. The factors related with the measurement of tumor AC were evaluated. Results Using the maximum value in the tumor region of interest (ROI) generally resulted in the over-estimation of AC,and the degree of over-estimation would also increase as the noise became severer. For the small tumors with low AC,the proper partial volume correction was needed. Drawing ROI after post-reconstruction filtering could improve the reproducibility of AC measurement compared with no filtering first. Conclusion The accuracy and reliability of AC measurement depends strongly on factors including tumor size,post-reconstruction filter,noise level,ROI definition,PVE correction,etc.

Objective: To evaluate the possibility of self-assembly oligopeptide(T2) for dental enamel biomimetics, especially for the prism’s crystal texture since it could prompt calcium phosphate precipitated in gel carrier. Methods:SEM (Scaning electron microscope) and TEM (Transmission electron microscope) were used to observe the morphologic presentation and ED(Electron diffraction) to crystal texture comparing with the human molar enamel powder. Results: (a) Flake-like and needle-like octacalcium phosphate precipitated in the gel carrier with self-assemble oligopeptide(T2). They transformed into rod-like hydroxyapatite crystals gradually in the following 2-4 weeks. (b) The rod-like hydroxyapatite may arrange or grow into bundles which are similar to the human enamel prisms in both appearance and size. (c) The rod-like hydroxyapatite showed polycrystal while the enamel prisms showed monocrystal under examination of ED. Conclusion:The self-assemble oligopeptide(T2) could regulate the speed of nucleation and crystallization of hydroxyapatite in morphology and crystalline size. Thus, the self-assembly oligopeptide and the gel carrier mineralization system could be primarily applied in biomimetic use for the crystallization of hydroxyaptite in dental prism in vitro.

Although alterations in fatty acid composition of phospholipids in plasma membranes had no effect on activities of plasma membrane ATPases of a self-flocculating fusant of Schizosaccharomyces pombe and Saccharomyces cerevisiae cells grown in the absence of ethanol (basal enzymes), they significantly affected the susceptibilities of the enzymes to in vivo activation induced by ethanol: the maximal values for the activated enzymes in cells pregrown with 0.6 mmol/L palmitic, linoleic or linolenic acid respectively were 3.6, 1.5 and 1.2-fold higher than their respective basal levels (in cells grown without ethanol), whereas the corresponding value for cells pregrown in the absence of fatty acid was 2.3-fold, with the concentrations of ethanol for the above maximal in vivo activation of enzymes being 7%, 6%, 6% and 7% (V/V) respectively. The Km values for ATP, the pH profiles, and the sensitivities to orthovanadate of the basal and the activated plasma membrane ATPases were essentially identical; however, the v(max) values of activated enzymes increased significantly. It was found that the characteristics of phospholipid fatty acid composition of plasma membrane leading to the enhanced ethanol tolerance of this strain, were also efficacious to increase the percentage of activation of plasma membrane ATPase per unit of ethanol. These data support a close correlation between the ethanol tolerance of this strain and the sensitivity of its plasma membrane ATPase to the in vivo ethanol-induced activation.
Adenosine Triphosphatases ; antagonists & inhibitors ; metabolism ; Cell Membrane ; chemistry ; enzymology ; Enzyme Activation ; Ethanol ; pharmacology ; Fatty Acids ; analysis ; Phospholipids ; analysis ; Saccharomyces cerevisiae ; drug effects ; enzymology ; growth & development ; Schizosaccharomyces ; drug effects ; enzymology ; growth & development

Ca2+ at 1.64 mmol/L markedly increased ethanol tolerance of a self-flocculating fusant of Schizosaccharomyces pombe and Saccharomyces cerevisiae. After 9 h of exposure to 20% (V/V) ethanol at 30 degrees C , no viability remained for the control whereas 50.0% remained for the cells both grown and incubated with ethanol in Ca2+ -added medium. Furthermore, when subjected to 15% (V/V) ethanol at 30 degrees C, the equilibrium nucleotide concentration and plasma membrane permeability coefficient (P' ) of the cells both grown and incubated with ethanol in Ca2+ -added medium accounted for only 50.0% and 29.3% those of the control respectively, indicating that adding Ca2+ can markedly reduce plasma membrane permeability of yeast cells under ethanol stress as compared with the control. Meanwhile, high viability levels acquired by the addition of Ca2+ exactly corresponded to the striking decreases in extracellular nucleotide concentration and P' achieved with identical approach. Therefore, the enhancing effect of Ca2+ on ethanol tolerance of this strain is closely related to its ability to decrease plasma membrane permeability of yeast cells subjected to ethanol stress.
Calcium ; pharmacology ; Cell Membrane ; drug effects ; metabolism ; Cell Membrane Permeability ; drug effects ; Ethanol ; pharmacology ; Saccharomyces cerevisiae ; drug effects ; growth & development ; metabolism ; Schizosaccharomyces ; drug effects ; growth & development ; metabolism ; Temperature

A combination of three amino acids including 1.0 g/L isoleucine, 0.5 g/L methionine and 2.0 g/L phenylalanine was found to enhance ethanol tolerance of a self-flocculating fusant of Schizosaccharomyces pombe and Saccharomyces cerevisiae. When subjected to 20% (V/V) ethanol for 9 h at 30 degrees C, all cells died whereas 57% remained viable for the cells grown in the presence of the three amino acids. Based on the analysis of protein amino acid composition of plasma membranes and the determination of plasma membrane fluidity by measuring fluorescence anisotropy using diphenylhexatriene as a probe, it was found that the significantly increased ethanol tolerance of cells grown with the three amino acids was due to the incorporation of the supplementary amino acids into the plasma membranes, thus resulting in enhanced ability of the plasma membranes to efficiently counteract the fluidizing effect of ethanol when subjected to ethanol stress. This is the first time to report that plasma membrane fluidity can be influenced by protein amino acid composition of plasma membranes.
Amino Acids ; analysis ; physiology ; Cell Membrane ; chemistry ; Culture Media ; Drug Tolerance ; Ethanol ; pharmacology ; Flocculation ; Membrane Fluidity ; Saccharomyces cerevisiae ; chemistry ; drug effects ; growth & development ; Schizosaccharomyces ; chemistry ; drug effects ; growth & development

Investigation was undertaken for the purpose of examining any possible correlation between flocculence of a self-flocculating fusant of Schizosaccharomyces pombe mutant and Saccharomyces cerevisiae mutant (called fusant SPSC for short) and the tolerance of this strain to ethanol. When exposed to 18% (V/V) ethanol for 7 h at 30 degrees C, 52%, 37% and 9% of viability levels remained for the cells of fusant SPSC and its two parental strains, Sch. pombe mutant and S. cerevisiae mutant respectively. Analysis of phospholipid fatty acid composition of plasma membrane showed that the content of palmitic acid of each flocculating yeast (fusant SPSC or Sch. pombe mutant) was around 2-fold higher than that of free S. cerevisiae mutant, with remarkably lower contents of palmitoleic and oleic acids than the latter. When 0.1 mol/L sodium citrate was initially included in the medium in which cells of each flocculating yeast were grown, free cells rather than aggregates were finally obtained. Furthermore, the content of palmitic acid in the phospholipid fatty acid composition of the plasma membranes of the free cells of each flocculating yeast was found to decrease significantly, with a marked increase in the contents of palmitoleic and oleic acids. As a result, the characteristics of the phospholipid fatty acid composition of the plasma membranes of the free cells of each flocculating yeast were similar to those of S. cerevisiae mutant. Meanwhile, the disappearance of flocculence of each flocculating yeast caused by the action of sodium citrate brought about a steeply decreased tolerance of the free cells to ethanol, thus being equivalent to that of S. cerevisiae mutant. These data suggest that the stronger ethanol tolerance of each flocculating yeast is related to the higher content of palmitic acid in the phospholipid fatty acid composition of the plasma membranes. Thus, the enhancement by flocculence on the tolerance of yeast cells to ethanol as well as its mechanism are first reported in this work.
Bioreactors ; microbiology ; Carbohydrates ; Cell Membrane ; metabolism ; Drug Tolerance ; Ethanol ; metabolism ; pharmacology ; Fatty Acids ; metabolism ; Fermentation ; Flocculation ; Phospholipids ; metabolism ; Saccharomyces cerevisiae ; drug effects ; metabolism ; Schizosaccharomyces ; drug effects ; metabolism ; Zea mays ; metabolism

Objective To investigate the potential of adult mesenchymal stem cells (MSCs) derived from human bone marrow to undergo cardiomyogenic differentiation after exposure to 5-azacytidine (5-aza) in vitro. Methods A small bone marrow aspirate was taken from the iliac crest of human volunteers, and hMSCs were isolated by 1.073g/mL Percoll and propagated in the right cell culturing medium as previously described. The phenotypes of hMSCs were characterized with the use of flow cytometry. The hMSCs were cultured in cell culture medium (as control) and medium mixed with 5-aza for cellular differentiation. We examined by immunohistochemistry at 21 days the inducement of desmin, cardiac-specific cardiac troponin I (cTnI), GATA 4 and connexin-43 respectively. Results The hMSCs are fibroblast-like morphology and express CD44+ CD29+ CD90+ / CD34- CD45- CD31- CD11a. After 5-aza treatment, 20-30% hMSCs connected with adjoining cells and coalesced into myotube structures after 14days. Twenty-one days after 5-aza treatment, immunofluorescence showed that some cells expressed desmin,GATA4, cTnI and connexin-43 in 5,10 μmol/L 5-aza groups, but no cardiac specific protein was found in neither 3μmol/L 5-aza group nor in the control group. The ratio of cTnI positively stained cells in 10 μmol/L group was higher than that in 5 μmol/L group (65.3 ± 4.7% vs 48.2 ± 5.4%, P ＜ 0.05). Electron microscopy revealed that myofilaments were formed. The induced cells expressed cardiac-myosin heavy chain (MyHC) gene by reverse transcription-polymerase chain reaction (RT-PCR). Conclusions Theses findings suggest that hMSCs from adult bone marrow can be differentiated into cardiac-like muscle cells with 5-aza inducement in vitro and the differentiation is in line with the 5-aza concentration. (J Geriatr Cardiol 2004;1(2) :101-107. )

OBJECTIVETo investigate the effect of iNOS gene on cell apoptosis and insulin secretion of pancreas islet in rats by RNA inference (RNAi).

METHODSIslets obtained from thirty Wistar rats were randomly divided into five groups, and siRNA oligo was purchased from Genepharma in Shanghai. The cultured islets were transfected with iNOS siRNA, and then were divided into five groups. Islet cultured only was taken as blank control group, and cultured with TNF-alpha + IL-1 beta as cytokine group. Islet transfected with negative or iNOS siRNA were taken as negative transfection control group or RNAi group, while that transfected with iNOS siRNA and cultured with TNF-alpha + IL-1 beta as RNAi + cytokine group. Expression of iNOS mRNA was evaluated by RT-PCR and iNOS protein was evaluated by Western blot to detect the effect of RNAi. The expression of apoptosis correlated gene, Bax, Fas were analyzed, and the apoptotic cells were identified by TUNEL method meanwhile. Insulin secretion index assay the function of the islets.

RESULTS500 - 600 IEQ islets could be extracted from every rat. RNAi attenuated the expression of iNOS and restrained the synthesis of iNOS protein.With treatment of cytokines IL-1 beta and TNF-alpha, the level of iNOS increased remarkably, the expression of Bax and Fas ascended distinctly, and insulin secretion index decreased strikingly. While, the expression of apoptosis gene and amount of apoptotic cells descended in group of RNAi + cytokine, and insulin secretion index were satisfying.

CONCLUSIONThe apoptosis from cytokines to islets mediated by iNOS could be suppressed by RNAi, which leaded to favorable function and survival of islets.

Animals ; Apoptosis ; Cell Proliferation ; Cells, Cultured ; Islets of Langerhans ; metabolism ; pathology ; Nitric Oxide Synthase Type II ; genetics ; metabolism ; RNA Interference ; Rats ; Rats, Wistar

A processing method to enhance thrombolytic effect of Carthamus tinctorius using a fermentation technology with bacillus sp. C2-13 was investigated. The fibrinolysis and anticoagulation activity of thrombolytic extracts from an optimized fermentation process was studied using a carrageenan induced mice model. The fermented extracts resulted in significantly better thrombolytic activity, suggesting that the process was promising for use in the study and preparation of nature medicines.
Animals ; Bacillus ; Carthamus tinctorius ; chemistry ; microbiology ; Drugs, Chinese Herbal ; isolation & purification ; pharmacology ; Female ; Fermentation ; Fibrinolysis ; drug effects ; Fibrinolytic Agents ; pharmacology ; Male ; Mice ; Partial Thromboplastin Time ; Prothrombin Time ; Rats ; Rats, Sprague-Dawley ; Thrombin Time

Objective To verify the determination of iodine in foodstuff by dry ashing As3+-Ce4+catalytic speetrophotometry.Methods The mixture of foodstuff powder and the solution of K2CO3,ZnSO4,KClO3 and NaCl was heated and dried at 105℃ for 3 hours,then heated by a adjustable electric heater for around 0.5 hour,transferred into muffle fumace to eremated at 600℃ for 4 hours.The dissolved ash was measured by As3+-Ce4+catalytic speetrophotometry.The linear range of the calibration and sensitivity were tested;The precision and accuracy for three kinds of iodine in samples of difierent pumpkins were tested:The iodine contents of standard urine samples and the American standard materials were tested as well.Results This testing covers iodine ranged from 4.4 ng to 250 ng.The relevance coefficient of standard curve was from-0.9997 to-0.9993.The pumpkin iodine contents detected were 45.8,145.0,195.6 μg/kg,with constant variables of 4.3%,3.0%and 3.9%respectively.The recovery was 96.8%,97.8%and 97.6%for three kinds of iodine in samples[(47.2±2.6),(71.9 4-3.3),(95.9±2.4)μg/kg].The relative error was-6.5%when the American standard materials were assessed.The relative error were 11.0%.10.7%and 10.7%when the standard urine samples of three kinds were tested.Conclusion This method,easy to be pefformed with better precision and accuracy,is suitable to measure food iodine as well as total iodine in urine.