Biomedical subjects

Angela Rogers

Publications and source records attributed to Angela Rogers.

5 recordsLinked to original sources

PubMed2005

Circulating osteoprotegerin and receptor activator for nuclear factor kappaB ligand: clinical utility in metabolic bone disease assessment.

CONTEXT: The discovery of the receptor activator for nuclear factor kappaB (RANK) ligand (RANKL)/RANK signaling pathway has marked a major advance in our understanding of the mechanisms controlling osteoclastogenesis. RANKL, expressed by preosteoblasts and stromal cells, binds to RANK, expressed by cells of the osteoclast lineage, inducing a signaling cascade leading to the differentiation and fusion of osteoclast precursor cells and stimulating the activity of the mature osteoclast. The effects of RANKL are counteracted by osteoprotegerin (OPG), a soluble neutralizing decoy receptor. EVIDENCE: This paper reviews the literature surrounding the use of circulating OPG and soluble RANKL (sRANKL) measurements and assesses their potential as markers of bone disease. Original clinical and basic research articles and reviews were identified using a Pubmed search strategy (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi) and cover the time period up until January 2005. Search terms osteoprotegerin, OPG, RANK, RANKL, and RANK ligand were used alone and in combination with bone, osteoporosis, and disease. EVIDENCE SYNTHESIS: Assays for detecting OPG and sRANKL in the circulation in humans have been developed, and differences in the circulating concentrations of OPG and sRANKL have been observed in different disease states. There are, however, some inconsistencies in study outcome. These may relate to differences in study design, methodology, and other unknown factors influencing the variability of these measurements. CONCLUSIONS: The clinical utility of serum OPG and sRANKL measurements as markers of disease activity requires additional investigation. In particular, rigorous testing of assays and identification of the sources of measurement variability are required.

Bone Diseases, Metabolic↗

PubMed2005

Knowledge, attitudes, behaviors, and perceptions of risk related to HIV/AIDS among Chinese university students in Hunan, China.

The purpose of this paper is to describe HIV/AIDS knowledge, attitudes, and perceptions and identify personal risk behaviors among undergraduate students in China. A descriptive, cross-sectional survey of 1326 students between ages 17 through 28 was conducted in 2002. Results indicated that students held considerable misconceptions about HIV transmission by casual contact and needle sharing as well as stigmatizing attitudes about injection drug use, homosexuality and HIV-positive women who bear children. Results indicated that 14% of Chinese university students are sexually active and risk behaviors tended to increase with age. Additionally, 24% of the students considered themselves to be at moderate to very high risk of contracting HIV and 40% of sexually active students never used condoms. Therefore, it is important to design HIV prevention strategies that target university students in China.

Acquired Immunodeficiency Syndrome↗

PubMed2005

Left ventricular function parameters obtained from gated myocardial perfusion SPECT imaging: a comparison of two data processing systems.

BACKGROUND AND AIM: The Cedars-Sinai Quantitative Gated Single Photon Emission Computed Tomography (SPECT) (QGS) program, used to quantify left ventricular function parameters from gated myocardial perfusion scintigraphy (MPS), has been extensively validated and compared with other methods of quantification. However, little is known about the reproducibility of QGS on different processing systems. This study compared the findings of QGS running on workstations provided by two different manufacturers. METHODS: Gated rest MPS studies of 50 patients were analysed retrospectively. Filtered back-projection (FBP) was performed using identical parameters on Philips Pegasys and Nuclear Diagnostics Hermes workstations to produce gated short-axis (SA) slices. In addition, the gated SA slices reconstructed on the Pegasys were transferred to the Hermes. QGS was used to calculate the end-diastolic volume (EDV), end-systolic volume (ESV) and left ventricular ejection fraction (LVEF) in each case. RESULTS: The mean+/-standard deviation differences between the Pegasys and Hermes function parameters were -7.06+/-3.91 ml (EDV), -5.54+/-3.21 ml (ESV) and +1.14%+/-1.43% (LVEF) when data were reconstructed on different systems, and -0.16+/-1.58 ml (EDV), -0.10+/-1.02 ml (ESV) and +0.14%+/-0.73% (LVEF) when data were reconstructed on the same system. Bland-Altman plots showed definite trends for EDV and ESV for data reconstructed on different systems, but no trends were seen for data reconstructed on the same system. CONCLUSIONS: When data were reconstructed on two separate systems, the difference between the function parameters obtained from Pegasys and Hermes could be ascribed to differences in the reconstruction process on each system despite the use of identical parameters (filters, etc). However, when the same reconstructed data were analysed on both systems, no significant difference in left ventricular function parameters was observed.

Aged↗

PubMed2003

Bone mineral density and biochemical markers of bone turnover in aseptic loosening after total hip arthroplasty.

The aims of this study were to determine whether subjects with aseptic loosening after total hip arthroplasty (THA) have regional differences in periprosthetic bone mineral density (BMD) and systemic biochemical markers of bone turnover compared to subjects with successful implants.Proximal femoral and pelvic BMD were measured by dual energy X-ray absorptiometry and bone turnover markers were assayed in 49 subjects 12.6+/-4.3 (mean+/-SD) years after cemented THA. Femoral BMD was lower in Gruen zones 2, 5, 6, and 7 in subjects with a loose femoral implant (n=17) compared to those (n=32) with fixed femoral implants (P<0.05 all comparisons). This BMD difference was greatest (-31%, P=0.02) in the proximal and medial region of the femur. Subjects with femoral loosening had higher levels of the bone resorption marker N-telopeptides of type-I collagen (P=0.02) than those with a fixed femoral implant. No differences in pelvic BMD or bone turnover markers were found between subjects with loose (n=18) versus fixed (n=31) pelvic implants. This study suggests that failure of femoral components after cemented THA is associated with region-specific decreases in BMD and an increase in urinary excretion of N-telopeptide cross-links of type-I collagen. These surrogate outcome markers may be of value in monitoring response to antiresorptive therapies used to treat periprosthetic osteolysis, although the diagnosis of aseptic loosening remains clinical and radiological.

Absorptiometry, Photon↗

PubMed2002

Is pathology examination useful after early surgical abortion?

OBJECTIVE: To study if the pathologist's examination of surgical abortion tissue offers more information than immediate fresh tissue examination by the surgeon. Immediate examination of the fresh tissue aspirate after surgical abortion helps reduce the risk of failed abortion and other complications. Regulations in some states also require a pathologist to analyze abortion specimens at added cost to providers. We conducted this study to evaluate the incremental clinical benefit of pathology examination after surgical abortion at less than 6 weeks' gestation. METHODS: As part of a prospective case series of women who had early surgical abortions at the Planned Parenthood League of Massachusetts during a 32-month period, we collected data on clinical outcomes and the results of postoperative tissue examinations. Using outcomes verified by in-person follow-up as the "gold standard," we calculated the validity of the tissue examinations by the surgeons and the outside pathologists. RESULTS: A total of 676 women had documented outcomes and complete tissue examination data. The sensitivity (ability of the examiner to detect an outcome other than complete abortion) was 57% (95% confidence interval [CI] 35, 76) for the surgeons' tissue inspections and 22% (95% CI 8, 44) for the pathologists' examinations. The predictive value of a positive (abnormal) tissue screen was 14% (95% CI 8, 24) and 7% (95% CI 3, 17) for the surgeons and pathologists, respectively. CONCLUSION: Routine pathology examination of the tissue aspirate after early surgical abortion confers no incremental clinical benefit. Although the surgeons' tissue inspections predicted abnormal outcomes poorly, the pathologists did no better. Our results challenge the rationale for state regulations requiring pathologic analysis of all surgical abortion specimens.

Abortion, Incomplete↗