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Biomedical subjects

P F Fottrell

Publications and source records attributed to P F Fottrell.

At least 37 records · Page 2Linked to original sources
PubMed1989

Solid-phase enzymoimmunoassay of estrone in saliva.

In this solid-phase enzymoimmunoassay for estrone in saliva, microtiter plates are used after extraction of the sample with diethyl ether. No chromatographic step is involved. The detection limit of the assay is 450 fg per well (33 pmol/L). Intra- and interassay coefficients of variation for the assay of low, medium, and high concentrations of estrone in saliva were respectively 4.2, 12.7; 5.2, 8.7; and 2.7, 5.8%. Using this assay, we found a highly significant correlation (P less than 0.001) between estrone concentrations in time-matched serum and saliva samples. The analytical procedure is rapid and relatively simple. One person can assay 50-60 saliva samples during a normal working day. We conclude that the assay is very suitable, even in small laboratories, for saliva estrone measurements, which, in facilitating serial sampling, enables dynamic observations of estrone concentrations and ovarian activity to be more easily made.

Adult↗
PubMed1989

Direct solid-phase enzymoimmunoassay of testosterone in saliva.

This competitive, solid-phase enzymoimmunoassay for testosterone in saliva is carried out on microtiter plates and involves no chromatographic or extraction steps. With an overnight incubation the detection limit of the assay is 230 fg per well (16.1 pmol/L). There was a good correlation (correlation coefficient 0.95) between testosterone concentrations measured with and without prior extraction of the saliva samples. Repeated assay of three control saliva samples containing a range of testosterone concentrations (200-1000 pmol/L) gave within- and between-assay coefficients of variation of 5.5-13.2%. The analytical procedure is simple and closely resembles already published procedures for the determination of progesterone and estrone (with extraction) in saliva. One person can assay 200 samples in 24 h and the assay is suitable for reproductive and sports medical applications, particularly for projects involving serial sampling and yielding large numbers of samples.

Adolescent↗
PubMed1989

Solid-phase enzymoimmunoassay for osteocalcin in human serum or plasma, with use of a monoclonal antibody.

In this solid-phase enzymoimmunoassay on microtiter plates for osteocalcin in serum or plasma, we use an osteocalcin-horseradish-peroxidase conjugate and a monoclonal antibody raised against bovine osteocalcin. We thoroughly standardized the assay for measurement of osteocalcin in both serum and plasma, demonstrating independence of sample volume, and determining the analytical recovery and within-and between-assay CVs. The detection limit was between 0.6 and 1.1 micrograms/L and the ED50 was 16 micrograms/L for a 5-microL sample volume. The intra-assay CV over the range 3 to 74 micrograms/L was less than or equal to 15%. The interassay CV over the range 3.6 to 46 micrograms/L was less than or equal to 16%. Results by this assay and by an in-house radioimmunoassay in which the same monoclonal antibody was used correlated well (r2 = 0.948). Osteocalcin concentrations in serum and plasma as measured with the present assay agreed well with published values.

Adult↗
PubMed1989

Radioimmunoassay of osteocalcin with polyclonal and monoclonal antibodies.

We have developed and thoroughly validated radioimmunoassays (RIAs) for osteocalcin in plasma and serum, demonstrating independence of volume and determining the recovery of added standard and within- and between-assay precision. Antibodies were raised in rabbits and mice by immunization with either osteocalcin adsorbed to polyvinylpyrrolidone or osteocalcin conjugated to bovine serum albumin. In both species, use of the conjugated osteocalcin was more efficacious. Correlation of the results obtained when groups of plasma or serum samples were analyzed by RIAs with different antibodies (two polyclonal and one monoclonal) indicated that the normal range observed for osteocalcin concentrations in serum depends on the antibody used. These findings may account for the wide range of "normal" osteocalcin values reported by different groups.

Adult↗
PubMed1988

Normal salivary progesterone levels throughout the ovarian cycle as determined by a direct enzyme immunoassay.

This study, which is concerned with establishing clinically relevant corridors defining normal progesterone (P) levels in saliva, has addressed some of the shortcomings associated with previous equivalent studies (e.g., limited data, inadequately monitored ovulations, inadequately defined subjects). A sensitive, direct, microtiter plate, enzymeimmunoassay (EIA) for progesterone developed in the authors' unit, was used to determine daily salivary progesterone concentrations over 41 menstrual cycles in 41 women. Each woman was without associated factors known to affect ovarian function and each cycle included was judged to be (single) ovulatory by serial pelvic ultrasound examinations. Daily salivary progesterone levels from these cycles were statistically analyzed and corridors of progesterone concentrations associated with normal luteal function were established.

Female↗
PubMed1988

Solid-phase enzymoimmunoassay of estrone in serum.

This rapid solid-phase enzymoimmunoassay for estrone in serum or plasma is done on microtiter plates after the serum is extracted with diethyl ether. No chromatographic or centrifugation steps are involved. The detection limit of the assay is 380 fg per well (28 pmol/L). Intra- and interassay coefficients of variation for the assay of low, medium, and high concentrations of estrone in plasma were respectively 4.4, 9.3; 2.3, 9.1; and 2.0, 6.3 percent. There was a good correlation (correlation coefficient 0.95) between estrone concentrations measured with this assay and with a commercial radioimmunoassay. The analytical procedure is simple, and one person can assay 80 serum samples per working day. We conclude that the assay is very suitable for serum estrone measurements and is more convenient than published radioimmunoassays.

Antibody Specificity↗
PubMed1988

Potential applications of salivary steroid immunoassays for investigations of cancer of reproductive tissues.

The potential applications of measuring reproductive steroids in saliva were examined for investigating the basis of the lower prevalence of breast cancer and cancers of the reproductive system among former college athletes compared to non-athletes. Daily salivary progesterone measurements during the menstrual cycle by a rapid cost effective enzyme-immunoassay provided a more accurate method than established procedures for detecting abnormal ovarian function such as luteal phase defects. These abnormalities are common in athletes who have a later menarche, a higher incidence of oligomenorrhoea and amenorrhoea than non-athletes. A control corridor was established of upper and lower limits for normality of daily salivary progesterone values during the complete menstrual cycle in 42 volunteers. It is concluded that salivary steroid assays provide an accurate and non-invasive procedure suitable for long term comparative studies on ovarian steroids in female athletes and non-athletes before and after menarche.

Circadian Rhythm↗
PubMed1987

Compliance with gluten free diet in coeliac disease.

Fifty two children in whom coeliac disease was confirmed by persistent enteropathy while they were taking gluten were monitored to assess the effects of compliance with a gluten free diet (GFD). Between the ages of 17.8 and 18.5 years height (in 45 patients followed up for a mean of 14.9 years) and weight (in 43 followed up for a mean of 15.2 years) were significantly lower in those complying poorly with a GFD compared with those complying well. Of the 37 patients still attending the clinic after a mean of 25 years, having been followed up for a mean of 18.4 years, 16 who had complied well with the diet had normal or only slightly abnormal mucosal morphology whereas all 10 who had not complied had abnormal morphology. In these 10 lactase, sucrase, and alkaline phosphatase activities were significantly less than values in those who complied well. Mucosal sucrase and alkaline phosphatase activities in those who complied well were no different from those in a control population, whereas lactase activity was significantly lower. It is concluded that failure to comply with a GFD during childhood results in decreased adult stature and in persisting active enteropathy with depressed brush border enzyme activity.

Body Height↗
PubMed1984

Intestinal lactase, sucrase, and alkaline phosphatase in 373 patients with coeliac disease.

Lactase, sucrase, and alkaline phosphatase activities were measured in 833 peroral small intestinal biopsies from 373 patients with coeliac disease. Enzyme activities decreased with increasing degrees of mucosal damage. Enzyme activities in mucosae of patients with coeliac disease in remission were lower than in control groups matched for age, sex, and site of biopsy. Enzyme activities were measured in 81 patients when the mucosa was severely damaged and later when considerable improvement had occurred. Lactase activity remained low in 13% of patients under the age of 18 and in 33% of those over 18 years. Sucrase activity usually improved with histological recovery, but alkaline phosphatase activity tended to remain depressed in patients in whom lactase activity failed to improve.

Adolescent↗
PubMed1984

Direct solid-phase enzyme immunoassay of progesterone in saliva.

We have developed a rapid enzyme immunoassay for progesterone in saliva. This solid-phase assay is carried out on microtitre plates with no extraction or centrifugation steps. The detection limit of the assay is 200 fg per well (3.2 pmol/L). Intra- and interassay coefficients of variation for low, medium, and high concentrations of progesterone were 7.5, 16.0; 9.1, 8.3; and 8.7, 6.7%, respectively. Correlation between total plasma progesterone (assayed by enzyme immunoassay with extraction) and salivary progesterone concentrations was good (r = 0.848, p less than 0.001, n = 56). We found the assay useful for monitoring ovarian function. The analytical procedure is convenient, and one person can assay more than 200 saliva samples per working day. The turnaround time for 36 samples is 2 h, including 1.5 h of incubation time, when previously coated plates are used. We conclude that such assays are very suitable for measuring progesterone in serial saliva samples and could become the preferred method for monitoring ovarian function.

Adult↗
PubMed1981

Early or pre-coeliac mucosa: development of gluten enteropathy.

Duodenal mucosa showed normal morphology, interepithelial lymphocytes, alkaline phosphatase, and sucrase in a girl with growth retardation and iron deficiency, but normal absorption of lactose and xylose after two years of abnormal stools. Mucosal lactase was low. Fourteen months later mucosal damage consistent with coeliac disease was evident, and gluten intolerance was subsequently confirmed by gluten challenge. It is probable that, in some children, the mucosal lesion occurs very gradually, so that at an early stage with normal morphology, suppression of lactase activity and possibly interference with iron absorption may be the only abnormalities.

Anemia, Hypochromic↗