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PubMed1997

Clear detection and typing of herpes simplex virus types 1 and 2 by an indirect ELISA assay: comparison with three different combined methods--capture ELISA, restriction enzymes, and polymerase chain reaction.

The severity and recurrences of Herpes Simplex Virus (HSV) infection depend on the type of the infectious agent (HSV-1 or HSV-2), which induces the necessity of a nonambiguous detecting typing. The commonly used capture ELISA technique has to be often supported by DNA analysis to confirm the detection and the typing of HSV viruses in exposed patients. In this report, we describe a rapid and cheap indirect ELISA method using anti-HSV monospecific polyclonal antibodies prepared in the laboratory. The typing of the studied samples was clear, did not need series of dilution, and allowed the immediate classification of viruses without further control examination. We tested 51 specimens, which were typed 25 HSV-1 and 26 HSV-2 strains. The comparison with capture ELISA, restriction enzyme and polymerase chain reaction analysis definitely allowed our method to be assessed as a useful tool for a routine diagnostic.

Antibodies, Viral↗

PubMed1998

Dendritic cell/macrophage precursors capture exogenous antigen for MHC class I presentation by dendritic cells.

Presentation of MHC class I antigens by professional antigen-presenting cells (APC) is an important pathway in priming cytotoxic T lymphocyte responses in vivo. This study sought to identify the nature of the professional APC responsible for indirect class I presentation by examining a special feature of professional APC, namely their ability to process exogenous forms of antigen for class I presentation. Incubation of highly purified bone marrow-derived precursor cells with chicken ovalbumin (OVA) led to the efficient presentation of the major class I-restricted OVA determinant by mature dendritic cells (DC), but not by macrophages (Mphi) derived from the precursor population. DC as well as macrophages were, however, able to mediate class II presentation of OVA, suggesting that macrophages were deficient in class I processing but not in capturing exogenous OVA. The majority of mature DC, i.e. over 80 %, generated from the precursor cells pulsed with OVA, presented the class I OVA epitope. Upon maturation, class I presentation of OVA by DC was greatly reduced, suggesting that class I processing of exogenous antigen is modulated during DC maturation in a manner similar to class II antigen processing. This study shows that bone marrow-derived DC/ME progenitors capture exogenous antigen for class I presentation, and that cells of the DC lineage can be functionally distinguished from cells of the macrophage lineage based on their ability to process exogenous antigen for class I presentation.

Amino Acid Sequence↗

PubMedDate not supplied

The potential use of laser capture microdissection to selectively obtain distinct populations of cells for proteomic analysis--preliminary findings.

Proteomics-based studies offer a powerful complementary approach to DNA/RNA-based investigations and are now being applied to investigate aspects of many diseases including cancer. However, the heterogeneous nature of tissue samples often makes interpretation difficult. We have undertaken a study into the potential use of a novel laser capture microdissection (LCM) system to isolate cells of interest for subsequent proteomic analysis. Retrieval of selected cells is achieved by activation of a transfer film placed in contact with a tissue section, by a laser beam (30 or 60 microm diameter) which is focused on a selected area of tissue using an inverted microscope. The precise area of film targeted by the laser bonds to the tissue beneath it and these cells are then lifted free of surrounding tissue. Although the technique has been shown to be readily compatible with subsequent analysis of nucleic acids, little information is yet available regarding the application of protein-based analyses to the captured tissue. We report here preliminary data regarding the potential use of the LCM system in combination with two-dimensional electrophoresis to examine protein profiles of selected tissue areas. Electrophoretic profiles of proteins from normal and malignant renal tissue samples showed little change following LCM, nine selected proteins showed identical mass spectrometric sequencing profiles, and two selected proteins retained antigenicity. Dissection of epithelial tissue from a sample of normal human cervix resulted in enrichment of some proteins compared with analysis of the whole tissue. LCM will be a valuable adjunct to proteomic studies although further detailed validation is necessary.

Amino Acid Sequence↗

PubMed2002

Encephalitogenic T cells use LFA-1 for transendothelial migration but not during capture and initial adhesion strengthening in healthy spinal cord microvessels in vivo.

LFA-1 on the surface of encephalitogenic T cells has been suggested to be involved in the pathogenesis of experimental autoimmune encephalomyelitis. By applying a novel technique of intravital fluorescence microscopy that enables us to visualize the interaction of circulating encephalitogenic T lymphoblasts within the healthy spinal cord white matter microvasculature in vivo, we investigated the possible involvement of LFA-1 on circulating encephalitogenic T cells in their multi-step interaction with the blood-brain barrier endothelium in vivo. LFA-1 was found to mediate neither the G-protein-independent capture nor the G-protein-dependent initial adhesion strengthening of encephalitogenic T cell blasts within spinal cord microvessels. In contrast, blocking of LFA-1 on encephalitogenic T lymphoblasts resulted in a significantly reduced number of T cells firmly adhering within spinal cord microvessels 2 h after injection and in a significantly reduced number of T cells subsequently migrating across the vascular wall into the spinal cord parenchyme. Our study provides the first direct evidence that encephalitogenic T cells use LFA-1 for transendothelial migration but not for capture and initial adhesion in spinal cord microvessels in vivo.

Animals↗

PubMed2001

Laser capture microdissection and proteomics: possibilities and limitation.

Tissue heterogeneity has always limited the information available from analysis of biological samples in the study of disease. Several approaches have been developed to address this problem, with laser capture microdissection (LCM) emerging as one of the methods of choice. LCM has been extensively used in combination with mutation detection studies and analyses of gene expression at the mRNA level and its potential in proteomics-based research is beginning to be realised. Here we review the progress made to date in the analysis of proteins in LCM-captured material and evaluate the scope and limitations of this approach.

Antibodies↗

PubMed2001

Clinical experience with a new specimen capturing bone marrow biopsy needle.

The SNARECOIL needle is a specimen capturing bone marrow biopsy needle that incorporates a tiny internal capturing coil. It was developed to minimize postinsertion needle manipulation and to facilitate specimen recovery. Forty-four patients underwent 50 bone marrow biopsy procedures with the SNARECOIL needle for a variety of hematologic indications. Second and third procedures were done for follow-up or staging. Each procedure retrieved a specimen with an average length of 2.1 cm. Fifty-two percent of the specimens were > or =2.0 cm in length. The majority of specimens demonstrated intact marrow architecture enabling a pathologic diagnosis in every case. Delicate cores of nontrabeculated marrow were recovered in three cases. The SNARECOIL bone marrow biopsy needle reliably retrieves intact bone marrow core specimens for pathologic interpretation.

Biopsy, Needle↗

PubMed2001

Capture-recapture estimation of unreported work-related musculoskeletal disorders in Connecticut.

BACKGROUND: Estimates of the extent of musculoskeletal disorders (MSD) are usually based upon workers' compensation reports, although recent reports indicate that there may be widespread under-reporting of MSD. METHODS: An estimate of the incidence of arm and hand work-related MSD was made using capture-recapture analysis of the overlap between state workers' compensation reports and physician reports in Connecticut for 1995. The resulting estimate was compared to a population-based survey of MSD. RESULTS: There was very small overlap between the two state injury reporting systems: 6.7% of 793 reported workers' compensation cases, or 8% of 661 physician's reports. The estimate for MSD not captured by either system was 13,285, resulting in 14,686 (95% CI: 9,733-18,453) total reported and non-reported cases. This compares to an estimate of 13,775 cases (95% CI: 8,800-18,800) based on a phone survey. CONCLUSIONS: This analysis points to substantial under-reporting of MSD in Connecticut: estimates of unreported cases exceed those officially reported by a factor of 11:1. The findings have an important bearing on injury prevention programs and policy making.

Connecticut↗

PubMed1991

Widespread release of peptides in the central nervous system: quantitation of tannic acid-captured exocytoses.

Tannic acid methods have been applied to capture the exocytosis of peptide-containing granules from peptidergic neurons. The captured exocytoses have been quantitated to assess the proportion and amount of peptide released at different parts of the neuronal membrane. Examination of hypothalamic synaptic boutons shows that only about one-half of the peptidergic vesicles is exocytosed into the synaptic cleft and also that exocytosis also occurs from undilated peptidergic axons. Study of the magnocellular neurosecretory system reveals that all parts of their extensive terminal arborization appear to be equally capable to exocytose peptide. Only about one-half of their peptide is released from their nerve endings, which about the capillaries. The remainder is released much deeper in the lobules of secretory tissue where its principal target(s) could be the pituicytes and/or neurosecretory axons. Dendrites of magnocellular neurons are also capable of releasing peptide by exocytosis and dendrites could release sufficient oxytocin and vasopressin to account for the peptide known to be released into the hypothalamus. We conclude that peptidergic neurons release substantial amounts of peptides from all of their processes and that this must be taken into account when considering what functions those peptides might serve.

Animals↗

PubMed2004

Prevalences of polyarteritis nodosa, microscopic polyangiitis, Wegener's granulomatosis, and Churg-Strauss syndrome in a French urban multiethnic population in 2000: a capture-recapture estimate.

OBJECTIVE: To estimate the prevalences of polyarteritis nodosa (PAN), microscopic polyangiitis (MPA), Wegener's granulomatosis (WG), and Churg-Strauss syndrome (CSS). METHODS: Cases were collected in Seine-St. Denis County, a northeastern suburb of Paris, which has 1,093,515 adults (> or =15 years), 28% of whom are of non-European ancestry. The study period encompassed the entire calendar year 2000. Cases were identified by general practitioners, the departments of all the public hospitals and 2 large private clinics, and the National Health Insurance System. The Chapel Hill nomenclature was used to define MPA, and American College of Rheumatology criteria to define WG and CSS; PAN was diagnosed based on clinical laboratory, histological and/or angiographic findings. Three-source capture-recapture analysis was performed to correct for incomplete case ascertainment. RESULTS: A total of 75 cases were retained and capture-recapture analysis estimated that 23.8 cases had been missed by any 1 of the 3 sources. Accordingly, prevalences per 1,000,000 adults (95% confidence interval [95% CI]) were estimated to be 30.7 (95% CI 21-40) for PAN, 25.1 (95% CI 16-34) for MPA, 23.7 (95% CI 16-31) for WG, and 10.7 (95% CI 5-17) for CSS. The overall prevalence was 2.0 times higher for subjects of European ancestry than for non-Europeans (P = 0.01). CONCLUSIONS: This study provides the first prevalence estimates for these 4 vasculitides for a multiethnic, urban population. The significantly higher prevalence observed for Europeans may infer a genetic susceptibility of Caucasians. Compared with previous estimates based mostly on rural populations, the higher frequency of PAN and the lower frequency of WG might suggest specific environmental etiologic factors.

Adult↗

PubMed2004

Precipitation by polycation as capture step in purification of plasmid DNA from a clarified lysate.

The demand for highly purified plasmids in gene therapy and plasmid-based vaccines requires large-scale production of pharmaceutical-grade plasmid. Large-scale purification of plasmid DNA from bacterial cell culture normally includes one or several chromatographic steps. Prechromatographic steps include precipitation with solvents, salts, and polymers combined with enzymatic degradation of nucleic acids. No method alone has so far been able to selectively capture plasmid DNA directly from a clarified alkaline lysate. We present a method for selective precipitation of plasmid DNA from a clarified alkaline lysate using polycation poly(N, N'-dimethyldiallylammonium) chloride (PDMDAAC). The specific interaction between the polycation and the plasmid DNA resulted in the formation of a stoichiometric insoluble complex. Efficient removal of contaminants such as RNA, by far the major contaminant in a clarified lysate, and proteins as well as 20-fold plasmid concentration has been obtained with about 80% recovery. The method utilizes a inexpensive, commercially available polymer and thus provides a capture step suitable for large-scale production.

Absorption↗

PubMed1984

Bis(trifluoromethyl)aryl derivatives for drug analysis by gas chromatography electron capture negative ion chemical ionization mass spectrometry. Application to the measurement of low levels of clonidine in plasma.

A gas chromatographic mass spectrometric assay for clonidine in plasma with a detection limit of a few picograms per ml was required. The p-trifluoromethylbenzyl, pentafluorobenzyl and pentafluorobenzoyl derivatives of clonidine were synthesized and the electron capture negative ion chemical ionization mass spectra of these compounds show extensive fragmentation with prominent ions at m/z 35 and 37 due to the two chlorine atoms in the clonidine molecule. Selected ion monitoring of specific high mass ions in these mass spectra indicated that the required sensitivity could not be obtained with these derivatives. Several bis(trifluoromethyl)pyrimidines were synthesized and these compounds were found to give an intense negative ion current under conditions of resonance electron capture. Consequently, a derivative of clonidine containing a bis(trifluoromethyl)aryl group was synthesized by reacting the drug with 3,5-bis(trifluoromethyl)benzoyl chloride. The negative ion mass spectrum of the reaction product has a base peak at m/z 673 and, when this ion is specifically monitored, an amount of derivative equivalent to 1 picogram of clonidine can be detected. This allowed the development of an assay for clonidine in plasma with a precision of 8% (SD) at 50 pg ml-1, 22% (SD) at 20 pg ml-1 and a lower limit for quantitative determination of 10 pg ml-1. Plasma concentrations of clonidine in 10 subjects given a single 50 micrograms oral dose are reported.

Clonidine↗

PubMed1986

Combined capillary column gas chromatography/electron capture negative ion chemical ionization mass spectrometry of dihydropyridine calcium antagonists.

Several dihydropyridine calcium antagonists showed intense [M]-. ion peaks as the base peaks and a few fragment peaks in the electron capture negative ion chemical ionization mass spectra. The peak intensities of the [M]-. ion of these antagonists were about 100 times as high as those of the most abundant positive ion. The use of a capillary column connected directly to the ion source prevents the oxidation of these agents in the column and the transfer line. Furthermore, the presence of plasma extract decreases the oxidation of these agents in the injection port. The limits of sensitivity with this technique are 500 fg-5 pg on the column. Combined capillary column gas chromatography/electron capture negative ion chemical ionization mass spectrometry should be suitable for sensitive and specific assays of dihydropyridine calcium antagonists in biological fluids.

Body Fluids↗

PubMed1987

Analysis of phospholipid molecular species in rat lung as dinitrobenzoate diglycerides by electron capture negative chemical ionization mass spectrometry.

The use of electron capture negative ion desorption chemical ionization mass spectrometry was demonstrated in the analysis of phospholipid molecular species at the 1,3-dinitrobenzoate (DNB) diglyceride derivative. Modification of phosphatidylcholine (PC) or phosphatidylethanolamine (PE) by phospholipase C treatment and acylation of the resultant diglyceride with 3,5-dinitrobenzoylchloride afforded separation of the alkylacyl, alkenylacyl, and diacyl dinitrobenzoate subclasses by thin-layer chromatography (TLC). Separation of alkylacyl DNB into individual molecular species by reverse-phase high-performance liquid chromatography (RPHPLC) was demonstrated. Electron capture desorption chemical ionization of individual molecular species (10-25 ng) from a direct probe yielded a mass spectrum characterized by an intense molecular anion. This molecular anion was the base peak of the spectrum accounting for greater than 80% of the total ionization. From this molecular anion the total carbon number and degree of unsaturation of the fatty chains could be determined. Analysis of fatty acid content of the molecular species allowed unequivocal assignment of structure for the alkyl ether phospholipids. Using selected ion monitoring as little as 0.5 pmol of these species could be detected with a signal-to-noise ratio greater than or equal to 3. This technique was useful in the analysis of low picomolar amounts of molecular species of ether phospholipids in the rat lung. Given an appropriate internal standard, analysis of dynamic changes in turnover, metabolism and precursor product relationships could be undertaken.

Animals↗

PubMed1989

Indole derivatization procedures for electron capture negative chemical ionization mass spectrometry: identification of 1-methyl-1,2,3,4-tetrahydro-beta-carboline in rat brain and lung.

Procedures have been developed for the isolation of pharmacologically active indole compounds from biological samples and for the introduction of electron-capturing groups, pentafluorobenzyl and trifluoroacetyl, onto the indole nitrogen atom. The resulting derivatives have good gas chromatographic properties and strong electron affinities which make them highly suitable for detection by electron capture negative chemical ionization mass spectrometry. These procedures were used to identify 1-methyl-1,2,3,4-tetrahydro-beta-carboline as a component of rat brain and lung.

Animals↗

PubMed1991

Characterization of lipoxins by combined gas chromatography and electron-capture negative ion chemical ionization mass spectrometry: formation of lipoxin A4 by stimulated human whole blood.

The lipoxins are a recent addition to the family of bioactive products derived from arachidonic acid. Here, we have prepared pentafluorobenzyl ester, trimethylsilyl ether derivatives of lipoxin A4, lipoxin B4 and pentadeuterolipoxin A4 and have characterized these products by electron-capture negative ion chemical ionization gas chromatography/mass spectrometry (NICI GC/MS). Lipoxin A4 (5S,6R,15S-trihydroxy-7,9,13-trans-11-cis-eicosa-tetraenoic acid; LXA4) was quantified following extraction from whole blood by stable isotopic dilution utilizing deuterium-labeled LXA4 as internal standard and selected ion monitoring of the [M--pentafluorobenzyl] anions. Studies with a second tritiated internal standard (e.g. [11,12-3H]LXA4) also showed that the recovery of LXA4 was greater than 80% following solid-phase extraction from whole blood, and greater than 90% from isolated cells. In addition, neither isolated neutrophils nor platelets oxidatively metabolized [11,12-3H]LXA4 when incubated in the presence or absence of stimuli. Whole blood incubated with either the ionophore of divalent cations (A23187), thrombin, or thrombin plus the chemotactic peptide formylmethionyl-leucine-phenylalanine generated both LXA4 and thromboxane, which were quantified by stable isotope dilution. The ratio of thromboxane to LXA4 formed by stimulated whole blood ranged from approximately 2:1 to 20:1. These results indicate that the lipoxins display suitable characteristics as their respective pentafluorobenzyl ester, trimethylsilyl ether derivatives for quantification by electron-capture NICI GC/MS. Moreover, they provide evidence that LXA4 can be generated from endogenous sources in whole blood following exposure to physiologically relevant stimuli.

Adult↗

PubMed2007

The CAPTURE registry: results of carotid stenting with embolic protection in the post approval setting.

BACKGROUND: Pivotal study data examining carotid stenting with embolic protection as a less invasive alternative to endarterectomy for high surgical risk patients have been acquired under controlled conditions with highly selected physicians and hospitals. This report examines outcomes of carotid stenting post-approval after diffusion of this technology to a broader cross-section of physicians and hospitals. METHODS: The Carotid Acculink/Accunet Post-Approval Trial to Uncover Unanticipated or Rare Events (CAPTURE) is a prospective, multi-center registry to assess two important aspects of the post-IDE experience: the safety of carotid stenting by physicians with varying levels of experience as a measure of the adequacy of physician training, and the identification of rare/unexpected device-related complications. The primary endpoint was a composite of death, any stroke, or myocardial infarction within 30 days post-procedure. RESULTS: 3,500 patients were enrolled by 353 physicians at 144 sites. The 30-day primary endpoint event rate was 6.3% (95% CI: 5.5-7.1%) and did not differ among the three operator experience levels (5.3%, 6.0%, and 7.4%; P = 0.31) from most to least experienced, respectively. There were no differences in outcomes among physician specialties when adjusted for case mix. There were no unanticipated device related adverse events. CONCLUSIONS: The results of the CAPTURE study compare favorably to those achieved in the predicate pivotal investigations, and suggest that the post-approval transfer of this new therapy to the community practice setting via carotid stent training programs is effective in preparing physicians with varying experience levels and specialty training backgrounds.

Aged↗

PubMedDate not supplied

Focused antigen capture immunoassay.

A new approach is described to immunoblotting in which antigens after isoelectric focusing are capture on nitrocellulose membranes coated with a specific antibody. The method has been applied to the analysis of human IgA kappa and lambda from whole blood and serum without prior purification. The visualized bands were quantified by laser densitometry in four pI ranges. It is concluded that, under the conditions used, close to 100% of serum IgA is captured. The method has a coefficient of variation of 4.5-12.8%, mean 8.0%.

Antigen-Antibody Reactions↗

PubMed2004

Principal component analysis for selection of optimal SNP-sets that capture intragenic genetic variation.

Candidate gene association studies often utilize one single nucleotide polymorphism (SNP) for analysis, with an initial report typically not being replicated by subsequent studies. The failure to replicate may result from incomplete or poor identification of disease-related variants or haplotypes, possibly due to naive SNP selection. A method for identification of linkage disequilibrium (LD) groups and selection of SNPs that capture sufficient intra-genic genetic diversity is described. We assume all SNPs with minor allele frequency above a pre-determined frequency have been identified. Principal component analysis (PCA) is applied to evaluate multivariate SNP correlations to infer groups of SNPs in LD (LD-groups) and to establish an optimal set of group-tagging SNPs (gtSNPs) that provide the most comprehensive coverage of intra-genic diversity while minimizing the resources necessary to perform an informative association analysis. This PCA method differs from haplotype block (HB) and haplotype-tagging SNP (htSNP) methods, in that an LD-group of SNPs need not be a contiguous DNA fragment. Results of the PCA method compared well with existing htSNP methods while also providing advantages over those methods, including an indication of the optimal number of SNPs needed. Further, evaluation of the method over multiple replicates of simulated data indicated PCA to be a robust method for SNP selection. Our findings suggest that PCA may be a powerful tool for establishing an optimal SNP set that maximizes the amount of genetic variation captured for a candidate gene using a minimal number of SNPs.

Adult↗