Biomedical subjects

J Percival

Publications and source records attributed to J Percival.

At least 19 recordsLinked to original sources

PubMed1999

The role of serum TGF-beta isoforms as potential markers of osteoporosis.

Osteoporosis is a major public health problem characterized by low bone mineral density (BMD) that presently has no biochemical test useful for its diagnosis. The cytokine TGF-beta has been postulated to play a role in controlling bone density by regulating the fine balance between bone matrix deposition by osteoblasts and its resorption by osteoclasts. We explored whether measurement of serum levels of different TGF-beta isoforms could be useful as a clinical tool in osteoporosis. We measured the concentration of TGF-beta1 antigen using the BDA19 capture sandwich enzyme-linked immunosorbent assay (ELISA), TGF-beta2 antigen concentration using a Quantikine sandwich ELISA kit and TGF-beta3 antigen concentration using a modified version of the TGF-beta1 Quantikine sandwich ELISA kit. Subjects were 41 women with osteoporosis (with nontraumatic vertebral fracture or lumbar spine BMD Z-score <-1.5 SD) and a total of 199 control women from different sources. Serum concentrations of TGF-beta1 and TGF-beta2 were similar in all groups. However, detectable levels of TGF-beta3 (>0.2 ng/ml) were found in 35 of 41 patients with osteoporosis (median 7.2 (5.2-8.9) ng/ml) compared with 11 of 36 controls or 24 of 89 healthy women of unknown bone density. Differences among the groups could not be accounted for by age, weight, medications, use of hormone replacement therapy or the presence of osteoarthritis. Using the optimal cut-off of >/=2 ng/ml, the test was able to detect an individual with low spine BMD (Z-score <-1.5) with a sensitivity of 84% and a specificity of 53%, with similar results for the femoral neck. The odds ratio for osteoporosis associated with a positive test at this level was 5.93 (95% CI 2.41-11.59), and 4.1 (95% CI 1.66-10.11) using the WHO cut-off of T-score <-2.5. Serum TGF-beta3 concentration is raised in osteoporotic women and the test appears to have potential as a marker for osteoporosis. The underlying mechanisms and the relationships between TGF-beta3 and bone turnover and fractures remain to be explored.

Analysis of Variance↗

PubMed1998

Observer variability in the measurement of the size of intracranial aneurysms using power TCD.

This study assessed the observer variability for measurement of intracranial aneurysmal size visualized on color "power" Transcranial Doppler Ultrasound (TCD). Patients with recent subarachnoid hemorrhage underwent color "power" TCD blind to angiography. Identified aneurysms were measured from the frozen image (in real time or from video tape) using the trackball function. Two observers measured the maximum (systolic) and minimum (end diastolic) area of each aneurysm, and an adjacent reference artery. Each observer was blind to the other's results. Interobserver variability was assessed using the Bland and Altman technique. Thirty-nine aneurysms were identified in 32 patients in 10 months. The maximum cross-sectional area of the aneurysm was 38:41 mm2 (observer 1:observer 2), and the mean difference was -3 mm2 (95% confidence interval [CI] of the difference -5.4-1.46 mm2). The maximum cross-sectional area of the reference artery was 26:28 mm2 (observer 1:observer 2), and the mean difference was -2 mm2 (95% CI -5.7-1.2 mm2). Neither difference was significant. Intraobserver reliability also was good. The measurement of intracranial aneurysm and artery size with power TCD is reliable sufficiently for use in longitudinal studies of changes in aneurysm size.

Adult↗

PubMed1997

Packing it in.

Explore the source record for details and available documents.

Health Promotion↗

PubMed1997

Two families with an autosomal dominant inheritance pattern for papillary carcinoma of the thyroid.

BACKGROUND: Papillary carcinoma of the thyroid (PTC) is the most prevalent malignancy of the thyroid gland. Although the majority of lesions are sporadic tumors, an established relationship exists between familial adenomatous polyposis (FAP) and PTC. Moreover, some authors postulate the existence of familial PTC as a distinct entity. Evidence for this is limited, however, there being few well characterized descriptions of pedigrees with high prevalence of PTC. AIMS: The objective of the present study was to examine an apparent heritable predisposition to PTC occurring in two Tasmanian families in which PTC occurs commonly. METHODS: Pedigree charts were constructed for both families and the medical records of the members reviewed. RESULTS: In Pedigree I, 7 of 25 members had PTC (6 of these had coexisting multinodular goiter (MNG), and 11 others had MNG. In Pedigree II, identical male twins and their daughters had PTC. CONCLUSIONS: In both families there is evidence of autosomal dominant inheritance of PTC. The association of PTC with MNG suggests a possible role for MNG in tumor pathogenesis in hereditary PTC. The majority of the patients were diagnosed with PTC before commencement of prospective screening, indicating clinically relevant disease in the families described.

Adult↗

PubMed1996