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D R Pledger

Publications and source records attributed to D R Pledger.

14 recordsLinked to original sources
PubMed1990

Parathyrin assay. An analytical evaluation of two commercial Immuno Radiometric Assay kits.

We have performed a comparative evaluation of two Immuno Radiometric Assay (IRMA) kits for parathyrin against an existing Radioimmuno Assay (RIA) technique for the measurement of intact parathyrin. The analytical evaluation which was performed in line with the ECCLS recommended kit evaluation protocol showed a marginal improvement in precision with the new assays. There was a substantial improvement in the theoretical limit of detection utilising the IRMA kits although it may prove difficult to realize this improvement in practice with individual samples because of differing protein matrices. The evaluation also demonstrated the degree of parallelism and range of linearity of both kits as well as inaccuracies when compared with the International Reference Preparation for parathyrin (IRP 79/500) as the accepted standard. The demonstration of lack of agreement between measured and kit assigned results for standards when cross-over studies between kits were performed may highlight a possible contributing factor to inaccuracy. Alternatively there may be a difference of antisera avidity within the kits for intact parathyrin. Whilst minor differences in sample stability were demonstrated between the kits, the sample stability was much improved compared to that for intact parathyrin measurement by RIA. The correlation studies showed a degree of correlation consistent with other comparisons similarly performed.

Dose-Response Relationship, Drug↗
PubMed1988

Onco-developmental protein concentrations in the sera of patients with ovarian cancer prior to treatment.

Eight onco-developmental proteins have been measured in the serum of women prior to their operation and treatment for ovarian cancer. Alpha-foetoprotein, CEA, hCG and PAPP-A were not often elevated whereas CPAP, SP1, CanAg 50 and CA 125 were. Many of our findings differed from those of previous workers, possibly due to differences in clinical material and analytical technique. We conclude that large profiles of tumour markers are no longer of use in the investigation of ovarian cancer. At the present time we think that CA 125 could prove the most useful marker in the investigation of ovarian cancer.

Adenocarcinoma↗
PubMed1987

Serum digoxin assays: investigation of use and abuse.

Digoxin requesting patterns were studied prospectively over a 6-month period. Clinicians were not forewarned that the study was being undertaken. Many samples received in the laboratory were taken at incorrect times after the drug had been given. This led to inappropriate action being taken in some cases. Appropriate action was taken on most patients who had toxic serum digoxin levels together with clinical signs. The role of subtherapeutic digoxin levels seems unclear as these elicit a wide variety of responses.

Digoxin↗
PubMed1986

The specificity of serum uridine 5'-phosphogalactose: glycoprotein galactosyl transferase activity in the diagnosis of ovarian cancer.

Serum galactosyl transferase activity was measured in patients with ovarian cancer, non-ovarian cancer, inflammation and infection, miscellaneous control patients and a normal group. Patients with cancer had widely dispersed results, high and low results being recorded. The majority of patients with inflammation and infection had elevated results. Differences in methodology and selection of clinical material make it difficult to compare results from different groups of workers. We conclude that it is not possible at present to decide on the usefulness of serum galactosyl transferase measurements in the investigation of ovarian cancer.

Breast Neoplasms↗
PubMed1985

Preliminary observations on the application of carcino-placental alkaline phosphatase to the investigation of patients with seminoma of the testes.

Suitable tumour markers for monitoring the treatment of seminoma of the testis have not yet been established in clinical practice. Carcino-placental alkaline phosphatase (CPAP) has been suggested for this purpose but it is difficult to detect and specifically analyse this enzyme. We have devised an immunoenzymatic method of analysis in which cross-reactions with liver type and intestinal alkaline phosphatase are minimal and we have applied this test to seven patients with histologically proven seminoma. CPAP was raised in 4 patients prior to treatment and chorionic gonadotrophin in two of these. Alpha-fetoprotein was normal in all cases. We conclude that the use of CPAP in monitoring treatment of testicular seminoma is worthy of further attention.

Adult↗
PubMed1985

Lack of comparability between CEA analyses using three different methods.

Three different methods for the assay of carcinoembryonic antigen were investigated--radioimmunoassay, enzyme-linked immunoassay, and a commercial immunoradiometric assay. Two standard preparations of CEA were used: the 1st British Standard (73/601) and a commercial preparation obtained as a component of the IRMA kit. Serum samples were assayed by each method against each standard material. Significant differences between results were obtained when the different methods were compared. When using the two standards in the same assay system no significant differences were found between results. A possible explanation and the implications of these findings for the routine assay of CEA are discussed.

Carcinoembryonic Antigen↗
PubMed1984

The predictive value of three pregnancy-associated proteins in the detection of the light-for-dates baby.

Three pregnancy-associated proteins, human placental lactogen, pregnancy-specific beta 1-glycoprotein and pregnancy-associated plasma protein-A have been measured in two groups of pregnant women. One group subsequently gave birth to children of normal birthweight, the other group were all delivered of a child with a birthweight less than the 10th centile. From the results obtained the values of the tests in predicting intrauterine growth retardation have been calculated. Human placental lactogen proved to be the most useful of the tests compared in predicting intrauterine growth retardation in the individual patient.

Female↗
PubMed1984

Abnormally elevated pregnancy specific beta 1 glycoprotein (SP1 beta) with very low placental lactogen (hPL) concentrations in a pregnancy with satisfactory outcome.

Pregnancies with very low maternal serum concentrations of placental function monitors, yet resulting in a normal outcome, have been reported occasionally before (4, 6). We report here a case in which maternal serum placental lactogen (hPL) concentrations were very low, urinary estrogen output assessed by estrogen/creatinine ratio was satisfactory, but maternal serum pregnancy specific beta 1 glycoprotein (SP1 beta) concentrations were grossly elevated. Ultrasound findings suggested impairment of growth. The outcome of the pregnancy was satisfactory, although the baby, apparently of 38-40 weeks' gestation, developed mild respiratory distress.

Adult↗
PubMed1983

The effect of excess antigen on the enzyme-linked immunosorbent assay of onco-placental proteins.

The time course of the antigen-antibody reaction between human chorionic gonadotrophin, pregnancy specific beta 1 glycoprotein and pregnancy associated plasma protein A and their respective immobilised antibodies has been investigated. All 3 antigens showed enhanced binding with increasing length of incubation up to a maximum value, followed by a decrease. It is suggested that the diminution in binding at high antigen concentration is caused by the solubilisation of the immobilised antigen-antibody complex and that this is promoted by the high concentration of antigen.

Animals↗
PubMed1983

An ELISA for pregnancy-associated plasma protein A.

An enzyme-linked immunoassay for pregnancy-associated plasma protein A is described. The assay is sensitive (7.6 IU/l) and precise (overall CV varied between 8.9% and 10.8%). Recovery was 100% over the working range. Parallel behaviour was observed between the International Reference Preparation 78/610 and pregnancy serum, thus allowing calibration of a laboratory standard pool against IRP 78/610.

Antigen-Antibody Complex↗