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891.
Correlations between the distribution of anthracycline antibiotics doxorubicin (DX) and daunorubicin (DR) in the liver of
rats injected with a single i.v. injection of each drug and the reported distribution of P-glycoprotein transporter for the
drug was histochemically examined. Immunocytochemical studies for DX or DR using monoclonal antibody that equally detects
both drugs, as well as conventional electron microscopy were employed. DX persisted for more than 5 days in the cytoplasm
and nuclei of the hepatocytes in a characteristic granular morphology on the bile capillaries. Meanwhile, DR distributed in
almost the same pattern, but more rapidly decreased to a level that almost no granular morphology in the hepatocytes was visible
24 h after the injection. Also, unknown large cells that strongly reacted with the antibody appeared in the hepatic sinusoids
near the interlobular triads rather than the central vein. The accumulation sites of DX or DR on the bile capillaries seems
to correspond to specific sites where the ATP-binding cassette transport protein P-glycoprotein for the anthracycline occurs,
suggesting a possibility that DX or DR is actually and actively excreted at these sites, possibly through P-glycoprotein.
This is supported by conventional electron microscopic studies, since no specific subcellular organelles such as lysosomes
assemble in the vicinity of the bile capillaries of the hepatocytes. 相似文献
892.
893.
Shin S Fung SM Mohan S Fung HL 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2011,879(7-8):467-474
Purposel-Arginine (ARG) is converted to nitric oxide (NO) and l-citrulline (CIT) by endothelial nitric oxide synthase which is competitively inhibited by asymmetric dimethylarginine (ADMA). We have developed a liquid chromatography–mass spectrometric method for the simultaneous determination of endogenous ARG, labeled ARG (15N4-ARG), CIT, ADMA, and its inactive isomer, symmetric dimethylarginine (SDMA) in biological samples.MethodsConcentrations of unlabeled ARG, 15N4-ARG, CIT, ADMA, and SDMA in EA.hy926 human endothelial cell lysate, cell incubation media, rat plasma or rat urine were measured by hydrophilic-interaction liquid chromatography electrospray tandem mass spectrometry. 13C6-ARG, D4-CIT and D7-ADMA were used as internal standards for ARG and 15N4-ARG, CIT, and dimethylarginines, respectively.ResultsThe calibration curves of ARG, 15N4-ARG, CIT, ADMA, and SDMA were linear and independent of several sample matrices. Intra- and inter-day variabilities for the quantification of all the compounds were below 15% in quality control samples. Application of this method to determine the uptake as well as efflux of these compounds was illustrated through in vitro cell study by exposing human endothelial cells to 15N4-ARG, which allowed the observation of generation of 15N3-CIT and 15N3-ARG in the cell lyate. Use of these isotopes adds insights into the cellular handling of endogenous vs. exogenous ARG. Application of this method for rat plasma and rat urine assays was demonstrated after ARG oral supplementation in rats.ConclusionAn LC–MS/MS method was developed to quantify 6 ARG-related compounds simultaneously, utilizing 3 separate internal standards. This assay allows concurrent monitoring of uptake, efflux and metabolic processes when isotope-labeled ARG and CIT are measured, and can be applied for determination of these compounds in rat plasma and rat urine. 相似文献
894.
The major role of the eye lens is to transmit and focus images onto the retina. For this function, the lens needs to develop and maintain the correct shape, notably, the precise curvature and high-level order and organization of its elements. The lens is mainly comprised of highly elongated fiber cells with hexagonal cross-sectional profiles that facilitate regular packing. Collectively, they form concentrically arranged layers around the anterior-posterior polar axis, and their convex curvature contributes to the spheroidal shape of the lens. Although the lens has been a popular system for developmental studies, little is known about the mechanism(s) that underlies the development of its exquisite three-dimensional cellular architecture. In this review, we will describe our recent work, which shows how planar cell polarity (PCP) operates in lens and contributes to its morphogenesis. We believe that the lens will be a useful model system to study PCP in general and gain insights into mechanisms that generate high-level cellular order during development. 相似文献
895.
Lee K Kim H Kim JM Kim JR Kim KJ Kim YJ Park SI Jeong JH Moon YM Lim HS Bae DW Kwon J Ko CY Kim HS Shin HI Jeong D 《Journal of cellular and molecular medicine》2011,15(10):2082-2094
Systemic transplantation of adipose-derived stem cells (ASCs) is emerging as a novel therapeutic option for functional recovery of diverse damaged tissues. This study investigated the effects of systemic transplantation of human ASCs (hASCs) on bone repair. We found that hASCs secrete various bone cell-activating factors, including hepatocyte growth factor and extracellular matrix proteins. Systemic transplantation of hASCs into ovariectomized mice induced an increased number of both osteoblasts and osteoclasts in bone tissue and thereby prevented bone loss. We also observed that conditioned medium from hASCs is capable of stimulating proliferation and differentiation of osteoblasts via Smad/extracellular signal-regulated kinase (ERK)/JNK (c-jun NH(2) -terminal kinase) activation as well as survival and differentiation of osteoclasts via ERK/JNK/p38 activation in vitro. Overall, our findings suggest that paracrine factors secreted from hASCs improve bone repair and that hASCs can be a valuable tool for use in osteoporosis therapy. 相似文献
896.
Shin CM Kim N Jung Y Park JH Kang GH Park WY Kim JS Jung HC Song IS 《Helicobacter》2011,16(3):179-188
Background and Aims: To determine genome‐wide DNA methylation profiles induced by Helicobacter pylori (H. pylori) infection and to identify methylation markers in H. pylori‐induced gastric carcinogenesis. Methods: Gastric mucosae obtained from controls (n = 20) and patients with gastric cancer (n = 28) were included. A wide panel of CpG sites in cancer‐related genes (1505 CpG sites in 807 genes) was analyzed using Illumina bead array technology. Validation of the results of Illumina bead array technique was performed using methylation‐specific PCR method for four genes (MOS, DCC, CRK, and PTPN6). Results: The Illumina bead array showed that a total of 359 CpG sites (269 genes) were identified as differentially methylated by H. pylori infection (p < .0001). The correlation between methylation‐specific PCR and bead array analysis was significant (p < .0001, Spearman coefficient = 0.5054). Methylation profiles in noncancerous gastric mucosae of the patients with gastric cancer showed quite distinct patterns according to the presence or absence of the current H. pylori infection; however, 10 CpG sites were identified to be hypermethylated and three hypomethylated in association with the presence of gastric cancer regardless of H. pylori infection (p < .01). Conclusions: Genome‐wide methylation profiles showed a number of genes differentially methylated by H. pylori infection. Methylation profiles in noncancerous gastric mucosae from the patients with gastric cancer can be affected by H. pylori‐induced gastritis. Differentially methylated CpG sites in this study needs to be validated in a larger population using quantitative methylation‐specific PCR method. 相似文献
897.
Kim D Kim SN Baik KS Park SC Lim CH Kim JO Shin TS Oh MJ Seong CN 《Journal of microbiology (Seoul, Korea)》2011,49(1):141-145
A metagenomic fosmid library was constructed using genomic DNA isolated from abalone intestine. Screening of a library of
3,840 clones revealed a 36 kb insert of a cellulase positive clone (pAMHElO). A shotgun clone library was constructed using
the positive clone (pAMHElO) and further screening of 3,840 shotgun clones with an approximately 5 kb insert size using a
Congo red overlay revealed only one cellulase positive clone (pAMHL9). The pAMHL9 consisted of a 5,293-bp DNA sequence and
three open reading frames (ORFs). Among the three ORFs, cellulase activity was only shown in the recombinant protein (CelAMll)
coded by ORF3, which showed 100% identity with outer membrane protein A from Vibrio alginolyticus 12G01, but no significant sequence homology to known cellulases. The expressed protein (CelAMll) has a molecular weight of
approximately 37 kDa and the highest CMC hydrolysis activity was observed at pH 7.0 and 37°C. The carboxymethyl cellulase
activity was determined by zymogram active staining and different degraded product profiles for CelAMll were obtained when
cellotetraose and cellopentaose were used as the substrates, while no substrate hydrolysis was observed on oligosaccharides
such as cellobiose and cellotriose. 相似文献
898.
In this study, cephalosporin C production by Acremonium chrysogenum M35 cultured with crude glycerol instead of rice oil and methionine was investigated. The addition of crude glycerol increased
cephalosporin C production by 6-fold in shake-flask culture, and also the amount of cysteine. In fed-batch culture without
methionine, crude glycerol resulted only in overall improvement in cephalosporin C production (about 700%). In addition, A. chrysogenum M35 became highly differentiated in fed-batch culture with crude glycerol, compared with the differentiation in batch culture.
The results presented here suggest that crude glycerol can replace methionine and plant oil as cysteine and carbon sources
during cephalosporin C production by A. chrysogenum M35. 相似文献
899.
900.
Hwan-Seok Choi Geun-Joong Kim Hyun-Jae Shin 《Biotechnology and Bioprocess Engineering》2011,16(1):153-157
Many moth pheromones and synthetic attractants have been used to monitor or decrease pest populations. However, due to their
low economic efficiencies and narrow target specificities these methods are of limited use for trapping pests in large agricultural
fields. In an effort to address this problem, we selected oak (Quercus serrata) sawdust media fermented by the yeast strain Pichia anomala, and examined its ability to attract lepidopteran moth pests for mass trapping in an apple (Malus domestica) orchard. A total of 57 taxa were trapped, including 42 species of lepidopteran pests. The most frequently caught lepidopteran
pests included Adoxophyes orana (40.0 ± 3.5 individuals/trap/week), Oraesia excavata (35.5 ± 2.5), and Adris tyrannus amurensis (35.5 ± 2.5). Notably, less fruit damage was recorded in the experimental orchard versus a trap-free neighboring control
orchard. These results suggest that adult moths might be effectively attracted and mass captured using P. anomala-fermented oak sawdust media as bait. 相似文献