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Preparation Protocol (preparation + protocol)

Distribution by Scientific Domains
Chemistry54%
Medical Sciences27%

Kinds of Preparation Protocol

  • sample preparation protocol
    		•

    Selected Abstracts

    A strategy for correlative microscopy of large skin samples: towards a holistic view of axillary skin complexity

    EXPERIMENTAL DERMATOLOGY, Issue 1 2008
    Katrin Wilke
    Abstract:, Knowledge about the structural elements of skin and its appendices is an essential prerequisite for understanding their complex functions and interactions. The hence necessary morphological description across several orders of scale not only requires the investigation at the light microscopic level but also ultrastructural investigation, ideally on the identical sample. For a correlative and multimodal observation one unique preparation protocol is mandatory. As a compromise between sample sizes of >500 ,m in diameter on the one hand and optimal preservation of antigenicity and morphology on the other, we developed a new preparation protocol that allows (i) 3D reconstruction of the resin-embedded sample by confocal light microscopy prior to (ii) direct immunolocalization of target proteins within selected sample planes by light and fluorescence microscopy or transmission electron microscopy. Alternatively, (iii) serial cryosections of the frozen sample can be taken for characterizing the sample in toto. With this unique approach we were able to fully demonstrate the structural complexity of axillary skin samples, increasing the structural resolution from 3D reconstruction of the whole gland up to ultrastructural investigations at the subcellular level. We could demonstrate that axillary sweat glands are not separately distributed, as has been assumed to date; instead, they seem to be intricately twisted into one another. This promotes the concept of a complex axillary sweat gland organ instead of single sweat gland entities. [source]

    Comparison of chronic renal failure rats and modification of the preparation protocol as a hyperphosphataemia model

    NEPHROLOGY, Issue 2 2008
    KAZUHIRO TERAI
    SUMMARY: Background: Several animal models with chronic renal failure have been established and used for demonstrating complications including hyperphosphataemia. Although long-time feeding is required to cause hyperphosphataemia in animals, a few modifications have been reported to provide more useful models for research. Methods: Three separate experiments were carried out in the present study. First, characteristics of commonly used subnephrectomized (5/6Nx) rats and rats fed an adenine diet (0.75% adenine in normal diet) were compared as hyperphosphataemia models. Next, using adenine-diet rats, the inhibitory effect of sevelamer hydrochloride (Sev) on serum phosphorus elevation was examined. Third, oral adenine dosing for induction of hyperphosphataemia and validation as a model using Sev were examined. Results: Serum phosphorus in 5/6Nx rats became elevated in 8,17 weeks, but the levels and time points of elevation differed among animals. In adenine-fed rats, the elevation was more clearly demonstrated with less diversity at 4 weeks. The data revealed a potential shorter model preparation period and the importance of controlling feeding amounts. Oral adenine dosing induced hyperphosphataemia by 12 days, and Sev treatment was inhibitory. After a maintenance period of over a month (no treatments), Sev-treated rats showed hyperphosphataemia as did oral adenine-dosed control rats. The serum phosphorus levels significantly decreased on further Sev treatment. Conclusion: Oral dosing with adenine made the model preparation period definitely shorter, and its usefulness as a hyperphosphataemia model was revealed using Sev. [source]

    Analysis of secondary metabolites from eschscholtzia californica by high-performance liquid chromatography

    PHYTOCHEMICAL ANALYSIS, Issue 4 2006
    Maya Klvana
    Abstract A rapid and precise analytical HPLC method has been developed for screening the major benzophenanthridine alkaloids produced by cell cultures of Eschscholtzia californica, namely, sanguinarine, chelirubine, macarpine, chelerythrine and chelilutine. Separation was achieved on a C18 reversed-phase column with gradient elution using acetonitrile and 50 mm phosphoric acid. Detection was performed by both fluorescence (,ex 330 nm, ,em 570 nm) and photodiode array, leading to good selectivity and precision in determining peak purity. A simple and quick sample preparation protocol was elaborated involving a methanolic extraction for the measurement of intracellular concentrations of the alkaloids and a solid phase extraction for their quantification in culture medium. Owing to the non-availability of commercially standards, a method for the purification of chelirubine, macarpine and chelilutine by semi-preparative HPLC was developed. Coupled together, the isolation method and the analytical method were highly reliable for screening the alkaloids of interest produced by E. californica. Copyright © 2006 John Wiley & Sons, Ltd. [source]

    A novel miniature mixing device for polymeric blends and nanocomposites

    POLYMER ENGINEERING & SCIENCE, Issue 11 2009
    Martin Sentmanat
    A new miniature mixer has been developed to monitor and optimize the preparation protocol of various polymeric compounds and blend systems. The effect of mixing time and other basic processing parameters on the shear and extensional rheological properties of said compounds and blends is examined to understand the effect of undermixed and/or overmixed conditions on the rheological properties and thus the quality of the final products. Results from the new miniature mixer are compared with the results from other conventional mixing techniques to assess the scalability of the new mixing protocol. Two examples are used, those of polymer blending and nanocomposite formation. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers. [source]

    Improved integration of LOPA with HAZOP analyses,

    PROCESS SAFETY PROGRESS, Issue 4 2009
    Dick Baum
    Abstract Integrating Layer of Protection Analysis (LOPA) with Hazard and Operability Analysis (HAZOP) has many advantages over performing these studies separately. The merits include: fewer actions from the combined effort compared to performing only a HAZOP; team continuity resulting from the combined effort as opposed to two separate teams having possibly differing points of view; and, ultimately, a time and cost savings realized by the combination. This integration defines the risk associated with a given scenario, enabling better decisions that impact business assurance. By using the Center for Chemical Process Safety guidelines to define the independent protection layers upfront, the gray areas can often be reduced or eliminated; thereby enabling a more thorough LOPA. Examples include taking credit if a unit has two independent operators (outside and inside) responding to critical alarms, or taking credit for centralized control rooms that may allow immediate operator interaction and response. This article shows how the guidelines have been used successfully in joint HAZOP/LOPA studies, and describes an initial preparation protocol that can ensure high-quality results. © 2009 American Institute of Chemical Engineers Process Saf Prog, 2009 [source]

    Selective imaging of positively charged polar and nonpolar lipids by optimizing matrix solution composition

    RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 20 2009
    Yuki Sugiura
    Previous studies have shown that matrix-assisted laser desorption/ionization,imaging mass spectrometry (MALDI-IMS) is useful for studying the distribution of various small metabolites, particularly lipids. However, in this technique, selective ionization of the target molecules is imperative, particularly when analyzing small molecules. Since the sample clean-up procedures available for the MALDI-IMS of small metabolites are limited, the tissue sample will contain numerous molecular species other than the target molecules. These molecules will compete for ionization resulting in severe ion suppression. Hence, it is necessary to develop and optimize a sample preparation protocol for the target molecules. In this study, through model experiments using reference compounds, we optimized the composition of the matrix solution used for positively charged lipids in terms of the concentration of the organic solvent and presence/absence of alkali metal salts. We demonstrated that a high concentration of organic solvent in the matrix solution favors the preferential detection of lipids over peptides. The presence of alkali metal salts in the matrix solution was favorable for the detection of polar lipids, while a salt-free matrix solution was suitable for the detection of nonpolar lipids. Furthermore, potassium salts added to the matrix solution caused merging of various lipid adducts (adducts with proton, sodium, and potassium) into one single potassiated species. Using the optimized protocols, we selectively analyzed phosphatidylcholine (PC) and triacylglycerol (TG) with different fatty acid compositions in a rat kidney section. Copyright © 2009 John Wiley & Sons, Ltd. [source]

    Application of hyphenated mass spectrometry techniques for the analysis of urinary free glucocorticoids

    RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 18 2009
    Angela Cuzzola
    Alteration of levels of glucocorticoids in plasma and urine can be related to several diseases. In particular, the determination of endogenous glucocorticoids in urine has been reported to provide information on cortisol and cortisone status, on the activities of steroid hormone enzymes and on glucocorticoid metabolism. In this study, the application of hyphenated mass spectrometry techniques (GC/MS without derivatization and LC/MS) for the simultaneous analysis of free urinary cortisol (F), cortisone (E), tetrahydrocortisol (THF), allo-tetrahydrocortisol (A-THF) and tetrahydrocortisone (THE) was evaluated. A sample preparation protocol by solid-phase extraction, mass spectrometry parameters and chromatographic conditions for both techniques were carefully optimized in terms of extracting phase and solvents, matrix effects, recovery, sensitivity and compound resolution. Baseline separation was achieved for the five underivatized analytes both in GC and LC. The LC/MS/MS technique was more suitable for the analysis of urine samples, being less influenced by matrix effects and showing excellent sensitivity and selectivity. A preliminary application of the reported method for the diagnosis of metabolic diseases was also described. The determination of each analyte in its free form, described for the first time in the paper, offers new perspectives in the application of glucocorticoid analysis for diagnostic purposes. Copyright © 2009 John Wiley & Sons, Ltd. [source]

    Validated protocol for FoxP3 reveals increased expression in type 1 diabetes patients,

    CYTOMETRY, Issue 2 2009
    Jean Grant
    Abstract Background FoxP3 has become a key identifier of regulatory T cells. Investigators have used a variety of antibodies and methods for detecting FoxP3 by flow cytometry. To standardize FoxP3 antibody staining for use in clinical trial samples, we tested various antibodies from different vendors, cell preparation protocols and fix/perm reagents, and cell isolation procedures. Using this optimized staining protocol, we evaluated clinical specimens from patients with multiple sclerosis (MS) or type 1 diabetes. Methods FoxP3 antibodies from eBioscience (236A/E7 and PCH101) and BioLegend (206D) were evaluated along with their respective methods and fix/perm reagents for preparation and staining of FoxP3 for flow cytometry. Fresh washed blood and frozen or fresh PBMC were evaluated. Upon optimization of the protocol, clinical samples (frozen PBMC) from patients with MS or type 1 diabetes and healthy control donors were evaluated with the BioLegend antibody. Results Clone 206D from BioLegend yielded optimal staining and the fix/perm reagents from both eBioscience and BioLegend were comparable. Data were also comparable between cells separated by Ficoll (fresh or frozen) and washed blood samples, allowing this protocol to be applicable to different types of samples. We validated this protocol using clinical samples and saw a significant increase in FoxP3 expression in the patients with type 1 diabetes but not in the MS. Conclusions The results from this study will allow the assessment of FoxP3 by flow cytometry on samples from clinical sites that are analyzed in real time on fresh blood or frozen PBMC. © 2008 Clinical Cytometry Society [source]

    Efficacy of prepackaged, low residual test meals with 4L polyethylene glycol versus a clear liquid diet with 4L polyethylene glycol bowel preparation: A randomized trial

    JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 6 2009
    Dong Il Park
    Abstract Background and study aims:, A prepackaged low residue one-day diet (breakfast, lunch and dinner) has been recently developed to improve patient tolerance for bowel preparation prior to colonoscopy. The aims of this study were to evaluate the efficacy and tolerability of bowel preparation protocols based on a low residue diet and 4L polyethylene glycol (PEG) solution, and to compare these new options with the traditional liquid diet and the PEG 4L lavage. Methods:, A total of 214 patients (mean age: 54.1 years; 120 male, 94 female) from four university hospitals were included in the analysis. Patients were randomized to receive a clear liquid diet and the PEG 4L regimen (106 patients) or the low residue test meals and the PEG 4L regimen (TM-PEG 4L, 108 patients). The colon cleansing efficacy of the different preparations was rated using the Ottawa bowel preparation scale. Results:, No significant differences were observed between the treatment groups according to the Ottawa cleansing scale findings (PEG 4L: 2.97 vs TM-PEG 4L: 2.46, P = 0.063). The overall tolerability was higher in the TM-PEG 4L group than in the PEG 4L group (P = 0.036). No difference was found when the two groups were compared with regard to adverse events (P = 0.599). Conclusions:, A prepackaged low residue one-day diet provided cleansing efficacy similar to that of a clear liquid diet and offered the benefit of improved tolerability compared to the conventional PEG 4L regimen. [source]

    A suite of tools to analyse and publish 2-DE data

    PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 23-24 2008
    Christine Hoogland Dr.
    Abstract Bioinformatics tools may assist scientists in all steps of a typical 2-DE gel analysis workflow, that is, from the description of the sample preparation protocols, going through the gel image analysis and protein identification, to the publication of Internet-ready 2-DE gel databases. This short communication highlights in a single and summarised view, this workflow and the current bioinformatics solutions developed by the Proteome Informatics Group at the Swiss Institute of Bioinformatics. [source]

    Analysis of a bioactive , -(1,,,3) polysaccharide (Curdlan) using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

    RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 9 2003
    T.-W. D. Chan
    This paper focuses on the development of MALDI sample preparation protocols for the analysis of a bioactive , -(1,,,3) polysaccharide, i.e. Curdlan. The crude Curdlan sample was first separated into a low molecular weight water-soluble portion and a high molecular weight water-insoluble portion. The water-soluble portion was analyzed using a standard MALDI sample preparation method developed for dextran analysis. Two low-mass (<4000,Da) polysaccharide distributions differing by 16,Da were observed. For the analysis of the water-insoluble portion, several sample preparation protocols were evaluated using GPC-fractionated samples. A sample preparation method based on the deposition of the analyte solution with a mixture of 2,5-dihydroxybenzoic acid (DHB) and 3-aminoquinoline (3AQ) matrices in dimethyl sulfoxide (DMSO) at elevated temperature of 70°C was found to reliably produce good MALDI spectra. MALDI analysis of the water-insoluble Curdlan portion gave number-average (Mn) and weight-average (Mw) molecular weights and polydispersity of 8000,Da, 8700,Da, and 1.10, respectively. Copyright © 2003 John Wiley & Sons, Ltd. [source]