Comparison of a competitive protein binding method for serum thyroxine with a column technique for serum thyroxine iodine.
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Biomedical subjects
Publications and source records attributed to D Burnett.
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A method is described for the detection of methaqualone and its metabolites in the presence of large doses of other drugs.
beta 2-Microglobulin, which is associated with HLA class 1 antigens, was assayed in bile and serum from 19 patients following 22 liver transplants. Serum levels were elevated in all posttransplant patients irrespective of the presence of rejection. In contrast, biliary levels were significantly higher during episodes of acute rejection compared with posttransplant cholangitis (p less than 0.01), stable graft function (p less than 0.0001) and nontransplant samples (p less than 0.0001). When bile/serum ratios were studied, the difference between the rejection and the other groups was even more significant, and if a ratio of 0.2 was considered diagnostic of rejection, the test had a sensitivity of 96%, a specificity of 87% with an accuracy of 90%. Therefore, these results suggest that the measurement of bile/serum ratios of beta 2-microglobulin following liver transplantation may be useful in diagnosing acute rejection. When bile/serum ratios of beta 2-microglobulin were compared with those for other proteins, there was strong evidence to suggest that local release accounted for most of the increased biliary beta 2-microglobulin during rejection. These results provide further evidence that HLA class 1 antigens on the biliary epithelium may be important in liver allograft rejection.
A small series of granulocytic sarcomas (GS) or 'chloromas' has been studied by means of conventional histology and immunohistochemistry. The latter was found to be most useful in the diagnosis and characterization of these neoplasms, which are rare in Great Britain. Polytypic antisera to leukocyte elastase and cathepsin G have proved to be most useful, giving intense staining in all cases. These two markers are more specific than muramidase (lysozyme) and alpha 1-antitrypsin, since, unlike the latter two, they do not stain histiocytic cells. The results of staining with two monoclonal antisera, AGF 4.48 and AGF 4.36, are also described. In addition, the clinicopathological details of the seven cases are summarized and the literature is briefly surveyed.
The urinary excretion of the N-oxide and the glucuronides of five C-monohydroxy metabolizes of methaqualone has been studied in a group of young women aged 24-34 years and in a group of elderly women aged 85-87 years. The rate of appearance of the metabolites in the urine was slower in the elderly group but the relative importance of the six metabolites was the same in the two groups. There were differences in some metabolite ratios between the two groups, but only one difference approached statistical significance. The metabolite excretion in a 80 year old woman who had received methaqualone daily for over ten years was consistent with that of the elderly group. The results indicate that the ageing process per se and chronic weak hepatic enzyme induction in the elderly are not accompanied by changes in the relative importance of competitive metabolic pathways.
The Suess-Urey (S-U) mission has been proposed as a NASA Discovery mission to return samples of matter from the Sun to the Earth for isotopic and chemical analyses in terrestrial laboratories to provide a major improvement in our knowledge of the average chemical and isotopic composition of the solar system. The S-U spacecraft and sample return capsule will be placed in a halo orbit around the L1 Sun-Earth libration point for two years to collect solar wind ions which implant into large passive collectors made of ultra-pure materials. Constant Spacecraft-Sun-Earth geometries enable simple spin stabilized attitude control, simple passive thermal control, and a fixed medium gain antenna. Low data requirements and the safety of a Sun-pointed spinner, result in extremely low mission operations costs.
Currently, the frequency of granulocyte donation is limited by the prolonged circulation of hydroxyethyl starch (HES). We conducted a Phase I, uncontrolled, multicenter trial to evaluate both the efficacy and safety of a rapidly excreted low-molecular-weight analog of HES (LMW-HES). Seventy-five donors underwent 179 centrifugation leukapheresis procedures using LMW-HES as the red-cell-sedimenting agent. The efficacy of LMW-HES was established by harvesting adequate numbers of leukocytes. Most granulocyte concentrates contained at least 20 X 10(9) neutrophils when 8 l of blood was processed from donors optimally stimulated with steroids. The safety of LMW-HES was documented by the detection of almost no clinically significant adverse effects. In only 1.7 percent of procedures did donors require special attention, and only 1 of 179 procedures (0.6%) was permanently discontinued. Results of laboratory studies were usually normal or their values decreased transiently (approximately 15-25%) as a consequence of plasma volume expansion (dilution). Based on previous experience with HES, LMW-HES and HES perform comparably during leukapheresis. When commercially available, use of this new, rapidly excreted analog should permit more frequent leukapheresis donation.
Previously published work relating to quality control of drug assays has dealt mainly with interlaboratory comparisons. It is suggested that participants in external quality assessment schemes wil derive the maximum benefit from their participation if a suitable intralaboratory quality control scheme is established. Such a scheme should be capable of providing estimates of within- and between-batch imprecision over the concentration range for which the assay is used and give an indication of the development of systematic error (relative to previous performance). A scheme using serum pools at 3 concentrations, each to be analysed at least in duplicate, is recommended. Adaptations of this scheme, to be used when the number of patient samples per batch does not justify this number of control samples, are discussed in relation to various analytical situations. A ratio of 1 control sample to 10 patient samples is considered reasonable. The interpretation of results from external quality assessment schemes using performance indices, graphical assessment of 'bias' and standard deviation interval (SDI = bias divided by standard deviation) and the statistical evaluation of proportional and additive error by linear regression (least squares) analysis is discussed. In some cases it has been possible, from the results of interlaboratory studies, to show that a particular method will not generally give satisfactory results when compared either with other currently available methods, e.g. UV - spectrophotometric methods for phenobarbitone, phenytoin, carbamazepine and theophylline, or on the grounds of clinical requirements, e.g. doubling dilution broth techniques for gentamicin. Improvement in intralaboratory reproducibility would facilitate the identification of technical factors contributing to interlaboratory variation.