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A Wheeler

Publications and source records attributed to A Wheeler.

6 recordsLinked to original sources
PubMed1987

Fully automated antithrombin-III assays by synthetic substrate on the Multistat III.

Antithrombin-III assays are performed to assess response to heparin therapy and efficacy of antithrombin concentrate therapy and in diagnosing hereditary thrombophilia, deep venous thrombosis, pulmonary embolus, and disseminated intravascular coagulation. Synthetic substrate assays for antithrombin-III are the methods of choice; however, most existing assay systems are semiautomated. A fully automated, antithrombin-III assay using the Kabi Chromogenic Synthetic Substrate S-2238 COATEST on the MULTISTAT III has been developed. This assay was compared with the Dade Protopath fluorometric assay. The correlation (r-sq) between the two assay systems was 0.82. Additionally, a three-way assay comparison was also performed, incorporating a new fluorometric substrate for antithrombin-III. The three-way comparative assays revealed correlation as follows: MULTISTAT III fluorometric assay and the MULTISTAT III/Kabi COATEST assay r-sq = 0.90; MULTISTAT III fluorometric assay and the Dade fluorometric assay r-sq = 0.86; and the MULTISTAT III/Kabi COATEST assay and the Dade Protopath fluorometric assay r-sq = 0.95. These automated assays were extremely cost effective and were a fraction of the cost of performing other types of antithrombin-III assays.

Antithrombin III↗
PubMed1986

Nucleotide sequences of a feline leukemia virus subgroup A envelope gene and long terminal repeat and evidence for the recombinational origin of subgroup B viruses.

Molecular clones of the subgroup A feline leukemia virus FeLV-A/Glasgow-1 have been obtained. Nucleotide sequence analysis of the 3' end of the proviral genome and comparison with the published sequence of FeLV-B/Gardner-Arnstein showed that the most extensive differences are located within the 5' domain of the env gene. Within this domain, several divergent regions of env are separated by more conserved segments. The 3' end of env is highly conserved, with only a single amino acid coding difference in p15env. The proviral long terminal repeats are also highly conserved, differing by only eight base substitutions and one base insertion. Specific probes constructed from the FeLV-A or FeLV-B env genes were used to compare the env genes of various exogenous FeLV isolates and the endogenous FeLV-related proviruses of normal cat DNA. An FeLV-A-derived env probe showed no hybridization to normal cat DNA but detected all FeLV-A and FeLV-C isolates tested. In contrast, an FeLV-B env probe detected independent FeLV-B isolates and a family of endogenous FeLV-related proviruses. Our observations provide strong evidence to support the hypothesis that FeLV-B viruses have arisen by recombination between FeLV-A and endogenous proviral elements in cat DNA.

Antigens, Viral↗
PubMed1985

A comparative study of the DuPont antithrombin III and fibrinogen assay systems.

Antithrombin III (AT-III) levels are useful for diagnosing thrombosis and for assessing antithrombotic therapy. Fibrinogen levels also are useful in numerous thrombohemorrhagic disorders and for noting cessation of fibrinolysis after thrombolytic therapy. With the availability of these assays on the DuPont aca, a comparative study of AT-III and fibrinogen assays was performed. DuPont assays were compared to Dade Protopath (AT-III) and Auto-Fi (fibrinogen) assays. In 38 instances a third comparative AT-III assay also was used, namely the Kabi S-2238 method (COATEST). Poor correlation existed between the DuPont AT-III and Protopath AT-III, r - sq = 0.53 to 0.61. There also was poor correlation between the DuPont and S-2238 AT-III assay, r - sq = 0.59. Excellent correlation was noted with the Protopath and Kabi AT-III assays, r - sq = 0.90. There was poor correlation between DuPont and Dade fibrinogen levels, r - sq = 0.55. When comparing AT-III values, the DuPont level was consistently higher. DuPont fibrinogen levels also were consistently higher. The DuPont AT-III and fibrinogen levels correlate poorly with existing assays, and higher results than those noted with the other methods appear common. Spuriously high values noted with the DuPont system could misguide clinicians caring for patients with thrombohemorrhagic diseases where they would expect low levels of AT-III or fibrinogen.

Antithrombin III↗