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Ultrastructural analysis of differentiation of rat endoderm in vitro. Adipose vascular-stromal cells induce endoderm differentiation, which in turn induces differentiation of the vascular-stromal cells into chondrocytes.

Isolated definitive endoderm from 9-day-old rat embryos was cultivated up to 24 days in plastic and glass petri dishes and on developing vascular-stromal cells (mesenchymal cells) from epididymal white and interscapular brown adipose tissue of 4-week-old male rats. Explants were analyzed histologically and ultrastructurally. Endoderm attached to the bottom of the glass or petri dishes degenerated under one week of cultivation. Endoderm free floating in the culture medium developed into unilaminar vesicles whose flat epithelium did not differentiate. However, endoderm inoculated on developing mesenchymal cells differentiated into glandular explants or into ciliated pseudostratified columnar respiratory epithelium. The glandular explants were made up of at least four different kinds of cells whose cytoplasm showed predominantly: a) polyribosomes, b) lysosomes, c) mitochondria or d) cytoskeletal filaments. Endodermal cells differentiated only if, during cultivation, they were in contact with or in close proximity to developing mesenchymal cells. Endoderm differentiating into the respiratory epithelium in turn directed differentiation of the underlying vascular-stromal cells into lamina propria cells and chondrocytes. Cultivated vascular-stromal cells in the upper layers became thicker, ellipsoid in shape and with enlarged intercellular space. They appeared to be lamina propria cells and, together with the respiratory epithelium, built folds of respiratory mucosa. The vascular-stromal cells in the layers close to the bottom developed into chondrocytes; i.e., the cells became oval and agglomerated in nest like structures with a defined extracellular matrix. Their cytoplasm contained abundant cisternae of rough endoplasmic reticulum and numerous vacuoles with PAS positive substance. These observations showed that even developing vascular-stromal cells from adipose tissue from postlactating rats can trigger the process of definitive endoderm differentiation. Once triggered, differentiating endoderm influenced differentiation of the vascular-stromal cells into the cells and tissues of a wall of the respiratory tract.

Adipose Tissue↗

Differential proteome analysis: two-dimensional nano-LC/MS of E. coli proteome grown on different carbon sources.

Different sugars provided to bacteria as single sources of carbon and energy require the induction of different metabolic enzymes, transporters, and uptake systems in order to support growth and cell survival. Using a nano-high-performance liquid chromatography/mass spectrometry (nano-HPLC/MS) system we constructed comprehensive peptide maps for Escherichia coli grown with either lactose or glucose in minimal medium. Digested bacterial samples were separated in a two-dimensional manner by combining strong cation exchange (SCX) and reversed-phased (RP) chromatography. Peptides were eluted online to an iontrap MS instrument and further analyzed by tandem MS fragmentation. Bacterial proteins originating from the differing samples were analyzed by searching the Swiss Prot Database. Data are presented that show the ability to detect several hundred different proteins significantly expressed under both conditions. Several enzymes and binding proteins related to the lactose metabolism were only identified in the sample grown with this carbon source.

Carbon↗

Fine needle aspiration biopsy and molecular analysis in differential diagnosis of lymphoproliferative diseases of the orbit and eye adnexa.

The aim of the investigation was the assessment of the role of routine cytology and clonality evaluation using PCR in differential diagnosis of lymphoproliferative diseases of the orbit and eye adnexa. The investigations were carried out in cellular material collected via fine needle aspiration biopsy (FNAB) from 29 patients aged 31-82 years, including 17 women and 12 men. Apart from routine cytology, molecular-genetic studies were performed employing the PCR technique. In 21 cases histopathology was performed. In 2 patients, despite several attempts, FNAB failed to provide any diagnostic material for routine cytology. Based on cytology, non-Hodgkin's lymphoma was diagnosed in 11 patients and suspected in three. In 13 patients no firm diagnosis was possible based on cytological smears. The employment of PCR allowed for rendering the diagnosis more precise in 13 cases, confirming it in 13 patients, while in 3 cases the results of the above tests did not affect the final diagnosis. Clonality studies by PCR may be performed in material obtained through FNAB. Clonality assessment by PCR technique is very useful in differential diagnosis of lymphoproliferative disordes.

Adult↗

Computational methods for the analysis of differential conservation in groups of similar DNA sequences.

Multiple sequence alignments are a powerful tool for identifying the regions of DNA which have been constrained in evolutionary divergence, presumably due to their functional role. However, such constraints rarely manifest themselves as perfect conservation of a site clearly standing out in its broader environment, as they reflect the species-specific differences in proteins, as well as the ability of some proteins to interact with multiple variants of their binding sequence. In this paper we explore the use of alignment column uncertainty as an aid in locating differential phylogenetic footprints, which refer to the sites in DNA where groups of related species exhibit sequence conservation, but where the pattern may vary between the groups. We use efficient, linear-time algorithms to locate such sites. We have performed a study of the mammalian CAV2-CAV1 gene region using our software, and we conclude with several observations concerning the differential conservation and the use of computational methods for its detection. The software developed for this project is available, free of charge, by contacting the author.

Animals↗

[Comparative proteomics analysis of differentially expressed metastasis-associated proteins in human ovarian cancer cell lines].

OBJECTIVE: To find the key proteins associated with metastasis of ovarian cancer, and find potential diagnostic markers and therapeutic targets of this malignancy. METHODS: A comparative proteomic strategy, in a combination of two-dimensional electrophoresis separation and mass spectrometry identification, was adopted to search for proteome alternations in an ovarian cancer mother cell line HO-8910 and its highly metastatic cell subline HO-8910PM. RESULTS: Twenty-one significantly different spots (two-fold increase or decrease) were detected between the two cell lines, of which 17 candidate proteins were successfully identified and characterized. Compared with those in HO-8910 mother cell line, 16 proteins were significantly up-regulated, while 5 proteins down-regulated in the highly metastatic cell subline HO-8910PM. The seventeen identified proteins could be functionally classified into 7 groups as following: zinc finger protein, calcium-binding protein, DNA repair and synthesis protein, cell regulatory protein, metabolism-related protein, cell surface antigen, cell signals and transducing protein. CONCLUSIONS: The results suggest that an obviously differential proteomic expression exists between the human ovarian cancer mother cell line HO-8910 and highly metastatic cell subline HO-8910PM. It provides a clue for further identification of metastasis-related proteins, novel diagnostic markers as well as therapeutic targets of this malignancy.

Cell Line, Tumor↗

[Analysis of differential proteins in laryngeal carcinoma cell line Hep-2 with transfection of LCRG1].

BACKGROUND & OBJECTIVE: Laryngeal carcinoma-related gene 1 (LCRG1), a novel laryngeal carcinoma-related tumor suppressor gene, was cloned with mRNA differential display method. Previous researches showed LCRG1 might inhibit cell growth, proliferation, colony formation in soft agar, and tumorigenesis of laryngeal carcinoma cell line Hep-2. This study was to screen the proteins associated with the tumor suppressive function of LCRG1 by comparative proteomics method. METHODS: The whole cellular proteins of Hep-2/LCRG1 and Hep-2/pcDNA3.1(+) cells were extracted and separated by two-dimensional gel electrophoresis (2-DE) technology. After electrophoresis, the gels were stained by Coomassie Brilliant Blue G-250, and analyzed using PDQuest software. The differentially expressed proteins were cut from the gels, analyzed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), or electrospray ionization-quadrupole time-of-flight MS/MS (ESI-Q-TOF MS/MS), and identified through searching database with Mascot software. RESULTS: The well-resolved, reproducible 2-DE patterns of Hep-2/LCRG1 and Hep-2/pcDNA3.1(+) cells were established. The total protein spots were 1,075+/-43 in Hep-2/LCRG1 cells and 1,027+/-23 in Hep-2/pcDNA3.1(+) cells, with an average matching rate of 91%. Using mass spectrometry technology, 20 differential protein spots between the 2 cell lines were identified. Among them, 16 were identified by MALDI-TOF-MS, and 4 were identified by ESI-Q-TOF MS/MS. Some of the identified proteins were characterized as members of cellular transcription and metabolism enzymes. CONCLUSIONS: In this study, 2-DE gels of Hep-2/LCRG1 cell line with high expression of LCRG1 mRNA and vector control Hep-2/pcDNA3.1(+) cell line were established; some differential proteins related to LCRG1 were identified by mass spectrometry. These data will help to illustrate the molecular mechanism of LCRG1.

Adaptor Proteins, Signal Transducing↗

[Flow cytometry analysis and differentiation study of selected nestin positive cells].

OBJECTIVE: To verify the hypothesis that selected nestin positive cells derived from human fetal pancreas (according as medical ethnics) have surface markers similar to bone marrow mesenchymal stem cells (MSCs), and that these cells have multilineage potential. METHOD: The cell surface markers were determined by flow cytometry, and then the potential that these cells might be differentiated into adipocytes and osteoplasts were explored. RESULT: These cells have similar surface markers as MSCs of bone marrow origin. These cells was induced to differentiate into adipocytes and osteoplasts. CONCLUSION: Selected nestin positive cells derived from human fetal pancreas have certain characteristics of MSCs.

Adipocytes↗

Analysis of differential selective forces acting on the coat protein (P3) of the plant virus family Luteoviridae.

The coat protein (CP) of the family Luteoviridae is directly associated with the success of infection. It participates in various steps of the virus life cycle, such as virion assembly, stability, systemic infection, and transmission. Despite its importance, extensive studies on the molecular evolution of this protein are lacking. In the present study, we investigate the action of differential selective forces on the CP coding region using maximum likelihood methods. We found that the protein is subjected to heterogeneous selective pressures and some sites may be evolving near neutrality. Based on the proposed 3-D model of the CP S-domain, we showed that nearly neutral sites are predominantly located in the region of the protein that faces the interior of the capsid, in close contact with the viral RNA, while highly conserved sites are mainly part of beta-strands, in the protein's major framework.

Capsid Proteins↗

Differential profiling analysis of proteins involved in anti-proliferative effect of interferon-alpha on renal cell carcinoma cell lines by protein biochip technology.

Interferon-alpha (IFN) is widely used for the treatment of progressive renal cell carcinoma (RCC), but its effective response rate is only about 15%. New biomarkers of RCC contributing to the effective IFN treatment are needed to establish a sensitivity test for evaluating if the IFN is effective or not against RCC. All the proteins expressed in the IFN-susceptible and -resistant RCC cell lysates were analyzed by surface enhanced laser desorption ionization (SELDI) mass spectrometry using ProteinChip technology and their different protein expression were detected by the comparison of the profiles between them. We detected the following candidate markers that exhibited peak shifts: a) in the IFN-susceptible cell lines, a candidate marker with a molecular weight of 5,688 Da was detected on a hydrophobic (H4) chip: b) in the IFN-resistant cell lines, candidate markers each with a molecular weight of 8,049, 3,157, 3,993, and 8,959 Da were detected on strong anion exchange (SAX2, pH 9.0, two types) chips, H4 chip, and weak cation exchange (WCX, pH 9.0) chips, respectively. IFN treatment produced no weight increase in these four proteins, and c) candidate marker with a molecular weight of 1,623 Da that was expressed in both cell lines after the IFN treatment was detected on the H4 chip. These data suggest that the ProteinChip system is very useful in identifying proteins showing unique peaks in the RCC cell lines with different IFN susceptibility, and the comparison of these proteins measured in RCC cell lysates may help to identify the IFN sensitivity. Furthermore, the discovery of a susceptibility and or a inhibitory factor may eventually lead to the development of a novel drug targeting the respective factor for the improvement of anticancer chemotherapy.

Antineoplastic Agents↗

Differential proteomic analysis in the study of prokaryotes stress resistance.

Proteomic technologies are powerful tools to study the physiological response of bacteria to various environmental stress conditions. Complex protein toolkits coordinated by regulatory networks have evolved to accommodate bacterial survival under several stressing conditions, such as varying temperature or pH, and changes in nutrient availability. This manuscript provides an overview of the major achievements obtained by 2D gel based and non-gel based proteomic approaches for the study of adaptive response in bacteria. As an example, a study carried out on Streptococcus thermophilus response to various stresses is here reported. In this investigation, we used combined proteomic strategies to define proteomic maps useful to highlight protein profile variations following environmental challenges.

Adaptation, Physiological↗

[Analysis of differential express gene between keloid and normal skin by suppression subtractive hybridization].

OBJECTIVE: To compare gene express difference of keloid and normal skin tissues by using the suppression subtractive hybridization (SSH) so as to find the differential express gene in keloid. METHODS: mRNA extracted from keloid and normal skin tissues was used as the template to synthesis cDNA of keloid and normal skin. The cDNA of keloid served as a tester, the cDNA of normal skin as a driver. cDNA was digested with Rsa I. Adaptor-ligated tester cDNA was prepared. Then first hybridization, second hybridization and PCR amplification were done. Differentially expressed cDNA was selectively amplified during these reactions. After SSH, the PCR mixture was ligated with T-vector. The positive clones were selected and the insert gene fragments were analyzed. Southern hybridization identified the keloid differential express genes. The positive clones of Southern hybridization were selected, and these sequences were analyzed. The results were compared with that of GeneBank. RESULTS: Thirteen differential genes were found in keloid, of which 11 gene clones have been known their function, and 2 clones have not known their function. CONCLUSION: Keloid differentially expressed gene was screened successfully by SSH.

DNA, Complementary↗

[Differentiation and analysis of original meaning of classical channel theories].

OBJECTIVE: To probe into the original meanings of manifestation and root cause, root and knot, Genliu infusion, Benshu, pathway of qi, four sea, Guan-He Shu and other classical channel theories. METHODS: Based on Huangdi Neijing (The Yellow Emperor's Internal Classic) and other classical literatures, combined with medical books in bamboo slip and the silk and opinions of annotation experts of successive dynasties, deeply analyze and study. RESULTS: Classical channel theories are involved in some theories of channel structures, with 3 original meanings: expounding the origin, the end and running of channels, expounding bi-directional running of channel-qi, and expounding the affinity relation of six channels, six qi, six zang-organs and six fu-organs. CONCLUSION: Classical channel theories stress emphasize concentric running of channels, and concentric arrangement of channel acupoints, bi-directional running of channel-qi, and each affinity of six channels.

Humans↗

The application of differential thermal analysis and thermogravimetric analysis to dating bone remains.

Thirty-four samples of bone remains of known time since death were studied by using DTA, TGA, and derivative-TGA techniques. The DTA patterns enable us to distinguish recent from old (more than 100 years) bones. The TGA curve is also significant for an extreme series. Both DTA and TGA curves show a correlation that allows us to obtain patterns with high significance for the extreme series. They also make evident the decomposition grade that bone organic material undergoes during the postmortem putrefactive process.

Age Determination by Skeleton↗

Halichondrin B and homohalichondrin B, marine natural products binding in the vinca domain of tubulin. Discovery of tubulin-based mechanism of action by analysis of differential cytotoxicity data.

Data generated in the new National Cancer Institute drug evaluation program, which is based on inhibition of cell growth in 60 human tumor cell lines, were used to compare new compounds with agents of known mechanism of action in terms of their differential cytotoxicity. Two marine natural products, halichondrin B and homohalichondrin B, appeared repeatedly when the data base was probed with known antimitotic agents. We confirmed that both compounds were highly cytotoxic (IC50 values for L1210 murine leukemia cells of 0.3 and 1 nM, respectively), with accumulation of cells arrested in mitosis at toxic concentrations, that both inhibited the polymerization of purified tubulin, and that both inhibited microtubule assembly dependent on microtubule-associated proteins. Limited amounts of homohalichondrin B, the less active agent, were available, so only halichondrin B was studied in detail. Halichondrin B did not interfere with colchicine binding to tubulin, but it was a noncompetitive inhibitor of the binding of vinblastine to tubulin (apparent Ki, 5.0 microM). Halichondrin B was therefore compared with other agents which interfere with the binding of vinca alkaloids to tubulin (vinblastine, maytansine, dolastatin 10, phomopsin A, rhizoxin) in terms of its effects on tubulin polymerization, inhibition of GTP hydrolysis, inhibition of nucleotide exchange, and stabilization of tubulin, as well as the quantitative assessment of its effects on vinca alkaloid binding and inhibition of cell growth. Since halichondrin B was originally isolated from the same organism as the phosphatase inhibitor okadaic acid, and since it is about 50-fold more effective than okadaic acid as an inhibitor of L1210 cell growth, perturbations of cellular microtubules observed following treatment with okadaic acid should be interpreted cautiously.

Animals↗