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Biomedical subjects

J DeVries

Publications and source records attributed to J DeVries.

8 recordsLinked to original sources
PubMed2001

Matching reference materials with AOAC International methods of analysis.

Proper implementation and use of validated analytical methodology with use of appropriate reference materials (RM) is a preferred means of helping to ensure equivalent analytical method performance in diverse laboratories. Choice of an appropriate RM that not only matches the analyte and matrix of the required determination, but also has been demonstrated to be within the applicability of a specific analytical method, are key factors. In response to numerous requests since its founding in 1993, the Technical Division on Reference Materials (TDRM), AOAC International is implementing a program for recognizing the matching of specific reference materials to specific AOAC methods of analysis. This recognition is accomplished by means of a thorough peer-reviewed selection system, under the auspices of the AOAC official methods board and the executive committee of the TDRM. Potential RM/method matching (RM/MM) proposals will be submitted to an RM/MM committee. After technical review of the suitability of the proposed RM by the RM/MM committee, acceptable matches are recommended for review by the current AOAC process responsible for review and recognition of new methods and modifications to existing AOAC methods of analysis. Several trial matches have been used to develop and test this system. The end product of this effort will ultimately be made available as either a stand-alone document, a section of the AOAC Official Methods of Analysis, or a site within the AOAC web site listing recognized matches.

Journal Article↗
PubMed1998

Reversal of "no reflow" during vein graft stenting using high velocity boluses of intracoronary adenosine.

Slow or no reflow is a serious problem complicating catheter-based revascularization of degenerated saphenous vein bypass grafts. We examined the efficacy of rapidly delivered, high-velocity injections of intracoronary adenosine to reverse 11 slow-flow events complicating stenting of diseased bypass grafts. Ten of 11 events were rapidly improved to TIMI 3 flow by this technique within 3.8+/-1.6 min of the initial adenosine injection. In an ex vivo model, 3-ml syringes created higher peak pressures and velocities than 10- and 20-ml syringes. We conclude that rapid and repeated high-velocity intragraft administration of adenosine is a promising new approach to promptly reverse no-reflow events complicating PTCA and stenting of diseased saphenous vein grafts. Ex vivo studies demonstrate a potentially important mechanical advantage with the use of small syringes for injection. Further randomized studies will be required to better define the mechanism(s) and efficacy of this approach for treating no reflow, including its use in native vessels.

Adenosine↗
PubMed1990

Detection of mouse hepatitis virus nonstructural proteins using antisera directed against bacterial viral fusion proteins.

Mouse hepatitis virus, strain A59 cDNAs were inserted into the procaryotic fusion vector pGE374. RecA/viral/LacZ tripartite fusion proteins were synthesized from these plasmids and purified from E. coli. Antisera were raised in rabbits against these fusion proteins. Viral nonstructural proteins were detected in infected murine fibroblasts and glial cells. The anti-gene B, ORF1 sera detect a 30K cytoplasmic protein while the anti-gene E, ORF2 sera detect a 9.6K protein. Sera raised against proteins encoded in cDNAs from 5' portions of gene A immunoprecipitate the 200-250K polypeptides synthesized in vitro from genome RNA. Antisera raised against proteins encoded in both 5' and 3' portions of gene A immunoprecipitate membrane associated polypeptides of 150K and greater than 600K from MHV infected cells.

Animals↗
PubMed1989

Epithelioid sarcoma or malignant rhabdoid tumor of soft tissue? Epithelioid immunophenotype and rhabdoid karyotype.

Two children and one young adult with extremity sarcomas demonstrating an aggressive clinical behavior are described. Histologically, all three tumors displayed features compatible with a deep-seated epithelioid sarcoma or with a malignant rhabdoid tumor of soft tissue. Immunohistologically, both vimentin and epithelial antigens were demonstrated; however, no desmin was detectable. In all three cases, the DNA profile was diploid. In one case, a trisomy of chromosome 2 was found in the tumor cells, a phenomenon also observed in embryonal rhabdomyosarcomas. It is concluded that, although the immunohistologic findings support the epithelioid character of the tumors, this chromosomal finding suggests a relationship with rhabdomyosarcomas and justifies the designation of rhabdoid.

Adult↗
PubMed1971

Invitro formation of assimilatory reduced nicotinamide adenine dinucleotide phosphate: nitrate reductase from a Neurospora mutant and a component of molybdenum-enzymes.

An active Neurospora-like assimilatory NADPH-nitrate reductase (EC 1.6.6.2), which can be formed in vitro by incubation of extracts of nitrate-induced Neurospora crassa mutant nit-1 with extracts of (a) certain other nonallelic nitrate reductase mutants, (b) uninduced wild type, or (c) xanthine oxidizing and liver aldehyde-oxidase systems was also formed by combination of the nit-1 extract with other acid-treated enzymes known to contain molybdenum. These molybdenum enzymes included (a) nitrogenase, or its molybdenum-iron protein, from Clostridium, Azotobacter, and soybeannodule bacteroids, (b) bovine liver sulfite oxidase, (c) respiratory formate-nitrate reductase from Escherichia coli, (d) NADH-nitrate reductase from foxtail grass (Setaria faberii), and (e) FADH(2)- and reduced methyl viologennitrate reductase preparations from certain Neurospora mutants. Several molybdenum-amino-acid complexes, as possible catalytic models of nitrogenase, were inactive (as were some previously tested 20 nonmolybdenum enzymes) in place of the acid-treated molybdenum-containing enzymes. The results imply the existence of a molybdenum-containing component shared by the known molybdenum-enzymes.

Animals↗