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Biomedical subjects

B G Joyce

Publications and source records attributed to B G Joyce.

11 recordsLinked to original sources
PubMed1983

Plasma 17-hydroxyprogesterone concentrations in ill newborn infants.

Plasma 17-hydroxyprogesterone concentrations were determined in 47 preterm and term infants who were ill from a variety of causes. The results were compared with those in 53 healthy term infants. Mean plasma 17-hydroxyprogesterone values were appreciably higher in ill term and healthy preterm infants compared with healthy term infants, but the highest values were found in ill preterm infants. None of the infants had adrenal disease but some very ill infants had plasma 17-hydroxyprogesterone values approaching those seen in untreated infants with congenital adrenal hyperplasia. Interpretation of the results of plasma steroid measurements in newborn infants must take account of gestational age and the presence of stress related illness.

17-alpha-Hydroxyprogesterone↗
PubMed1982

Studies with steroid-fluorescein conjugates on oestrogen target tissues.

Steroid--fluorescein amine and steroid-BSA-fluorescein-isothiocyanate conjugates have been prepared and their ability to bind to oestrogen receptors assessed in competitive binding studies. The binding of all the fluorescent conjugates to uterine cytosol proteins was low when compared with either oestradiol or diethylstilboestrol. A comparative study was carried out to assess the relationship between oestrogen receptor content, determined biochemically, and histochemical localisation of the oestrogen binding components on thin sections of rat uteri, DMBA-induced mammary tumours and also human breast tumour tissue taken at mastectomy. The data indicate that in thin sections of tissue all of these conjugates appear to bind not to the classical oestrogen receptor moiety but to other oestrogen binding proteins.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1981

The immunocytochemical detection of protein hormones in human prostatic tissues.

The immunocytochemical detection of four pituitary protein hormones in tissue from 13 patients with benign prostatic hyperplasia has been described. There have been marked differences in the distribution and intensity of reaction product attributable to the various hormonal antisera. The intracellular presence of endogenous prolactin and FSH in the epithelial cytoplasm has been suggested together with the stromal localization of growth hormone and prolactin. Minimal diffuse staining over most cellular components was observed with the LH antiserum. This technique has provided an invaluable means of studying the potential involvement of pituitary protein hormones in the control of prostatic function and disease.

Cytoplasm↗
PubMed1981

A sensitive, specific, solid-phase enzymeimmunoassay for plasma progesterone.

A homologous enzymeimmunoassay (EIA) for plasma progesterone, using a horseradish peroxidase conjugate as enzyme label and an antiserum raised against a progesterone-11 kappa-hemisuccinyl/BSA conjugate, is described. The antiserum was covalently linked to microcrystalline cellulose to facilitate separation of bound and free steroid; this solid-phase antiserum was stable for at least nine months when stored at 4 degrees C. the freeze-dried enzyme label is also stable, having retained both enzymic and immunological activity for about four years. The EIA developed was specific and had the sensitivity (4.8 pg/tube) required for determining progesterone concentrations in in plasma samples collected at any time during the menstrual cycle. EIA of plasma samples provided results which were in good agreement with a well validated radioimmunoassay (RIA). The specificity and inter- and intra-assay coefficients of variation in the EIA were strictly comparable with those of the RIA. The method described has been in use for two years and has been assessed in external quality assurance programme established by the World Health organization and the United Kingdom Department of Health and Social Security.

Cross Reactions↗
PubMed1980

A sensitive enzymeimmunoassay with a fluorimetric end-point for the determination of testosterone in female plasma and saliva.

A fluorimetric enzymeimmunoassay has been developed having the sensitivity (500 fg/assay tube) required for determining testosterone concentrations in female plasma and saliva samples. The assay featured a solid-phase antiserum raised against an 11 alpha-hydroxytestosterone-11-hemisuccinate bovine serum albumin conjugate, an 11 alpha-hydroxytestosterone-11-hemisuccinate horseradish peroxidase conjugate as the "enzyme label", and p-hydroxyphenylacetic acid as the substrate for the development of fluorescence. Specificity was ensured by "extracting" testosterone from samples with a solid-phase anti testosterone-3-/0-carboxymethyl/-oxime serum. The assay was shown to satisfy accepted validation criteria providing results in good agreement with routine radioimmunoassay procedures in both plasma (r greater than 0.98, n=28) and saliva (r greater than 0.99, n=28). In saliva samples collected at 2 hourly intervals by normal healthy women (n=5) testosterone concentrations showed a well defined circadian rhythm: the mean testosterone concentration in early morning samples (174 pmol/litre) fell by 83% in late evening collections. In healthy female volunteers (n=7), mean daily throughout one complete cycle ranged from 50 to 218 pmol/litre. Following dexamethasone administration testosterone concentrations in plasma fell by approximately 50%, and salivary concentrations were undetectable after one hour. This enzymeimmunoassay may be useful in studies of female infertility.

Adult↗
PubMed1979

A sensitive solid phase enzymeimmunoassay for testosterone in plasma and saliva.

A sensitive, solid phase enzymeimmunoassay suitable for determining testosterone concentrations in samll aliquots of plasma (20 microliter) and saliva (200 microliter) has been developed. A solid phase antiserum raised against a testosterone-11 alpha-hemisuccinate/bovine serum albumin conjugate was prepared by coupling to cyanogen bromide activated cellulose. The "enzyme label" was a covalently linked testosterone/horseradish peroxidase conjugate. The assay had a lower limit of sensitivity of 4pg/assay tube and satisfied accepted criteria of specificity and precision. Testosterone concentrations determined by enzyme-immunoassay were in excellent agreement not only with a gas liquid chromatography/mass spectrometry procedure (r=0.96, n=12) but also with the radioimmunoassay in routine use (r=0.95, n=12). The EIA can therefore replace RIA in both the small clinical laboratory and high throughput service centres for determining plasma and salivary testosterone concentrations. In normal males salivary testosterone concentrations reflected circulating steroid levels and indicated the possibility of assaying saliva rather than plasma in clinical studies.

Antibody Specificity↗
PubMed1978

An improved enzyme immunoassay for progesterone in human plasma.

We describe an enzyme immunoassay for progesterone in which we use a progesterone-11alpha-hemisuccinyl-horseradish peroxidase conjugate as the "label" and an antiserum raised in rabbits to a progesterone-11alpha-hemisuccinyl-bovine serum albumin conjugate. In this assay, antibody-bound and free steroid are separated by using a second antibody precipitation procedure. The assay has a lower limit of sensitivity of 10 pg/assay tube and satisfies the usual criteria of specificity, precision, and accuracy. Results obtained with a comparison radioimmunoassay and our procedure agreed well (r = 0.98). Eighty samples can be assayed per day. It is not only well suited for surveys where accurate determination of progesterone concentrations in small plasma aliquots is required, but also for monitoring ovulation induction in patients attending infertility clinics.

Cross Reactions↗
PubMed1977

A specific enzymeimmunoassay for progesterone in human plasma.

An enzymeimmunoassay for plasma progesterone was established using progesterone covalently linked to the enzyme, horseradish peroxidase, as the 'label'. Separation of free and bound steroid was effected by Sepharose-coupled antiprogesterone-11alpha-hemisuccinyl bovine serum albumin antiserum (Sepharose-antisera). The enzymeimmunoassay satisfied the normal criteria of specificity, precision and accuracy. Comparison of assay results obtained by radioimmunoassay (with and without thin-layer chromatography) and enzyme-immunoassay (with and without thin-layer chromatography) showed excellent agreement of results in all cases (r greater than 0.98). This enzymeimmunoassay is particularly applicable to the routine determination of plasma progesterone in the smaller clinical laboratory.

Female↗
PubMed1975

Specific determination of testosterone in female plasma by radioimmunoassay: a rapid and reliable procedure for the routine clinical laboratory.

A rapid and reliable procedure for the specific determination of testosterone in female plasma is described. The assay entails a simple biphasic solvent partitioning of plasma extracts in order to remove cross-reacting steroids before quantitation of testosterone by radioimmunoassay using an antiserum raised against testosterone-11alpha-hemisuccinyl-bovine serum albumin. "Testosterone' values obtained in this way are in excellent agreeement with those obtained following thin-layer chromatographic purification of plasma extracts. However, the present procedure is easier, faster and cheaper to perform, and enables a single technician to assay 32 females plasma samples (in duplicate) in one working day.

Adrenal Glands↗