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Biomedical subjects

D I Fish

Publications and source records attributed to D I Fish.

7 recordsLinked to original sources
PubMed1992

The accuracy and clinical interpretation of serum ferritin assays.

The accuracy of methods used to assay serum ferritin was determined in two ways. In one a serum, to which the UK ferritin standard had been added, was issued to the participants in an inter-regional quality assurance scheme. The overall recovery was close to that expected. For the second assessment a series of sera from individuals of known iron status were issued. Differences between assay results related to the method of assay though the immunoradiometric and ELISA methods gave results which were close to each other. The variation in clinical interpretation applied to assay results when ferritin concentrations around the upper and lower limits of normal were assayed was more than could be accounted for by method imprecision and indicates that inappropriate reference ranges are in common use. 'Indeterminate', a proper clinical interpretation when the imprecision of a technique should prevent a definite response, was inadequately used.

Adult↗
PubMed1989

Intrinsic factor antibody tests.

The sensitivity of methods to detect antibodies to intrinsic factor was assessed. Five sera of known antibody content were tested in 31 laboratories and 30 sera from patients with pernicious anaemia were tested in one laboratory. Five non-commercial methods and two kits for type I antibodies and one non-commercial method for types I and II antibodies are in current use. Differences in sensitivity of the non-commercial methods for type I antibodies related more to the antigen: antibody ratio in the test system than to the method itself. A radioimmune assay for types I and II antibodies showed the best sensitivity but that of an enzyme linked immunosorbent assay (ELISA) method was poor.

Anemia, Pernicious↗
PubMed1987

Laboratory diagnosis of megaloblastic anaemia: current methods assessed by external quality assurance trials.

The results of an Interregional quality assurance scheme for tests in the diagnosis of megaloblastic anaemia were reviewed to assess the methods used. Serum folate assays showed great variation between methods, partly due to limitations in assessment by external quality assurance. Red cell folate assays yielded widely different results and much imprecision due both to the differences in preparation of the haemolysate and to the problems inherent in radioassay of a mixture of folate compounds. Intrinsic factor antibody tests showed appreciable variation in sensitivity. There was considerable inconsistency in the detection of polymorph nuclear hypersegmentation.

Anemia, Macrocytic↗
PubMed1983

Comparison of methods used in commercial kits for the assay of serum vitamin B12.

Fourteen commercial kits for serum vitamin B12 assay have been assessed. The analytical performance and clinical correlation were used to rank the methods employed for the extraction of the vitamin from its binders and for the separation of 'bound' from 'unbound' counts. The introduction of extraction without boiling and the separation by attachment of the vitamin B12 binder to a solid matrix have not been shown to be generally better or worse than conventional methods.

Anemia, Pernicious↗
PubMed1981

Vitamin B12 quality control trials.

The results of regional quality control trials of vitamin B12 assays are reported. Consideration is given to the materials suitable for such trials. The technical and clinical performance of the participants are assessed together with the methods used. The introduction of a target coefficient of variation has produced better identification of good and bad performance and the use of a reference serum has permitted comparison of assays of different methods. The linearity of most methods is suspect and indicates the need for reference sera of varying concentration. Introduction of kits has not generally improved precision and variation between laboratories shows the use of kits can be improved.

England↗
PubMed1980

An evaluation of commercial radioisotope methods for the determination of folate and vitamin B12.

Five commercial kits for the determination of folate and six kits for the determination of vitamin B12 were investigated. Their performance has been compared with microbiological methods for the two vitamins and with a non-commercial radioisotopic method for B12. The results show the importance of the determination of the reference range for an individual laboratory for each method. The precision of the kits varied appreciably, as did their performance using specimens from patients with different haematological disorders. In particular, certain kits failed to detect all patients with pernicious anaemia. The relative accuracy of the kits was assessed. Various factors which should be taken into account in the final selection of a satisfactory kit are discussed.

Anemia, Pernicious↗