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Biomedical subjects

Scott Young

Publications and source records attributed to Scott Young.

7 recordsLinked to original sources
PubMed2006

A survey of physician practices on prophylactic pancreatic stents.

BACKGROUND: Several prospective studies confirm that prophylactic stent placement in the pancreatic duct (PD) during high-risk ERCP procedures decreases the risk of post-ERCP pancreatitis. Inconsistencies exist regarding the indications for prophylactic PD stent placement, the type of stent used, and stent follow-up. OBJECTIVE: To assess the current practice patterns of expert biliary endoscopists regarding prophylactic pancreatic duct stents. DESIGN: An anonymous survey was mailed to 54 expert biliary endoscopists, assessing volume of procedures, stent indications, method of placement, and follow-up. RESULTS: A total of 91% (49/54) of surveys were returned and analyzed. Prophylactic PD stents were used by 96% of respondents. Stent use was universal during ampullectomy and pancreatic sphincterotomy. Most also used stents for minor papillotomy (93%) and sphincter of Oddi dysfunction (SOD) confirmed by manometry (82%). Endoscopists disagreed on the following: pre-cut sphincterotomy (71%), prior post-ERCP pancreatitis (64%), suspected SOD (58-69%), and traumatic sphincterotomy (44%). Endoscopists used straight stents (33%), pigtail stents (30%), or a combination (33%). Internal flanges were always used by 14%, never used by 54%, and sometimes used by 32%. Stent size and length varied widely, as did the time stents were left in place, and the retrieval method. CONCLUSIONS: Expert biliary endoscopists agree that prophylactic PD stenting is indicated during ERCP in high-risk patients. Wide variation exists in patient selection and stent placement technique.

Cholangiopancreatography, Endoscopic Retrograde↗
PubMed2005

Preclinical evaluation of transcriptional targeting strategies for carcinoma of the breast in a tissue slice model system.

INTRODUCTION: In view of the limited success of available treatment modalities for metastatic breast cancer, alternative and complementary strategies need to be developed. Adenoviral vector mediated strategies for breast cancer gene therapy and virotherapy are a promising novel therapeutic platform for the treatment of breast cancer. However, the promiscuous tropism of adenoviruses (Ads) is a major concern. Employing tissue specific promoters (TSPs) to restrict transgene expression or viral replication is an effective way to increase specificity towards tumor tissues and to reduce adverse effects in non-target tissues such as the liver. In this regard, candidate breast cancer TSPs include promoters of the genes for the epithelial glycoprotein 2 (EGP-2), cyclooxygenase-2 (Cox-2), alpha-chemokine SDF-1 receptor (stromal-cell-derived factor, CXCR4), secretory leukoprotease inhibitor (SLPI) and survivin. METHODS: We employed E1-deleted Ads that express the reporter gene luciferase under the control of the promoters of interest. We evaluated this class of vectors in various established breast cancer cell lines, primary breast cancer cells and finally in the most stringent preclinical available substrate system, constituted by precision cut tissue slices of human breast cancer and liver. RESULTS: Overall, the CXCR4 promoter exhibited the highest luciferase activity in breast cancer cell lines, primary breast cancer cells and breast cancer tissue slices. Importantly, the CXCR4 promoter displayed a very low activity in human primary fibroblasts and human liver tissue slices. Interestingly, gene expression profiles correlated with the promoter activities both in breast cancer cell lines and primary breast cancer cells. CONCLUSION: These data suggest that the CXCR4 promoter has an ideal 'breast cancer-on/liver-off' profile, and could, therefore, be a powerful tool in Ad vector based gene therapy or virotherapy of the carcinoma of the breast.

Adenoviridae↗
PubMed2005

Managing variability in the summary and comparison of gait data.

Variability in quantitative gait data arises from many potential sources, including natural temporal dynamics of neuromotor control, pathologies of the neurological or musculoskeletal systems, the effects of aging, as well as variations in the external environment, assistive devices, instrumentation or data collection methodologies. In light of this variability, unidimensional, cycle-based gait variables such as stride period should be viewed as random variables and prototypical single-cycle kinematic or kinetic curves ought to be considered as random functions of time. Within this framework, we exemplify some practical solutions to a number of commonly encountered analytical challenges in dealing with gait variability. On the topic of univariate gait variables, robust estimation is proposed as a means of coping with contaminated gait data, and the summary of non-normally distributed gait data is demonstrated by way of empirical examples. On the summary of gait curves, we discuss methods to manage undesirable phase variation and non-robust spread estimates. To overcome the limitations of conventional comparisons among curve landmarks or parameters, we propose as a viable alternative, the combination of curve registration, robust estimation, and formal statistical testing of curves as coherent units. On the basis of these discussions, we provide heuristic guidelines for the summary of gait variables and the comparison of gait curves.

Journal Article↗
PubMed2004

Weekly epoetin alfa maintains hemoglobin, improves quality of life, and reduces transfusion in breast cancer patients receiving chemotherapy.

PURPOSE: Epoetin alfa administered at 40,000 U once weekly (qw) to anemic cancer patients receiving chemotherapy increases hemoglobin levels, improves quality of life (QOL), and reduces transfusions. The benefit of epoetin alfa in maintaining hemoglobin levels in cancer patients with hemoglobin less than 12 g/dL has not been evaluated. METHODS: Breast cancer patients (N = 354) receiving chemotherapy were randomly assigned in 1:1 ratio to epoetin alfa (40,000 U qw) or standard of care (SOC). QOL was assessed at baseline and week 12. Hemoglobin responses, transfusion requirements, and prognostic factors for responses were measured. RESULTS: At week 12, Functional Assessment of Cancer Therapy-Anemia (FACT-An; mean, 2.16 +/- 12.84 for epoetin alfa v -4.43 +/- 13.42 for SOC) and FACT-An fatigue (mean, 1.85 +/- 10.52 for epoetin alfa v -3.55 +/- 11.14 for SOC) change scores were significantly higher in the epoetin alfa group (P < .0001). Hemoglobin responses defined as mean hemoglobin > or = 12 g/dL or a > or = 2 g/dL increase compared with baseline were significantly higher in the epoetin alfa group versus SOC: 52.0% v 5.1% and 65.7% v 6.3%, respectively (P < .0001 for both comparisons). Percentage transfused was significantly lower in the epoetin alfa group compared with SOC (8.6% v 22.9%). More than 90% of patients did not require a dose increase and 28.7% had a dose reduction. CONCLUSION: Epoetin alfa administered at 40,000 U qw is effective in improving QOL, maintaining hemoglobin level, and reducing transfusion requirements in breast cancer patients. The high effectiveness observed could be attributed in part to early treatment with epoetin alfa.

Adult↗
PubMed2002

Measurement and dynamic modeling of trace metal mobilization in soils using DGT and DIFS.

The technique of diffusive gradients in thin-films (DGT) accumulates metals on a Chelex resin after their diffusive transport through a hydrogel. It lowers metal concentrations in soil solution adjacent to the device and induces resupply of metal associated with the solid phase. DGT devices were deployed in an alluvial gley soil for 21 different time periods between 4 h and 19.5 d. The accumulated masses of Cu, Cd, Ni, and Zn were used to calculate the distribution coefficient for labile metal, Kdl, and adsorption and desorption rate constants. Calculations were performed using a dynamic numerical model of DGT-induced fluxes in soils (DIFS). It assumes first-order exchange between solid phase and solution and diffusional transport in both the soil solution and the hydrogel. The DIFS model fitted changes in accumulated mass with time very well. Values of Kdl calculated from DIFS of 100 (Cd), 250 (Cu), 150 (Ni), and 150 (Zn) were larger than values of distribution coefficients estimated by exchange with Ca(NO3)2 but similar to those estimated by isotopic exchange (Cd and Zn only). These results suggest that the solid-phase pool of metal affected by the removal of labile metal by DGT, which operates on a time scale of minutes, is similar to the solid-phase pool of metal that can isotopically exchange with solution on a time scale of 2 d. Response times of minutes were consistent with interaction rates with surfaces, and desorption rate constants agreed with other reported values. An appraisal of the DIFS model demonstrated the importance of the labile pool size in the solid phase for controlling supply to a sink, such as DGT or a plant. As values of Kdl and kinetic parameters are obtained using DGT with minimal soil disturbance and by a similar mechanism to that involved in plant uptake, they may be pertinent to bioavailability studies.

Diffusion↗
PubMedDate not supplied

The adoption gap: health information technology in small physician practices. Understanding office workflow can help realize the promise of technology.

Health information technology (HIT) can promote higher quality, lower costs, and increased patient and clinician satisfaction. Yet small practice settings (where the vast majority of patient care is provided) have been slow to adopt HIT products and services. Successful adoption requires close attention to office workflow, or how tasks are organized and resources used to achieve outcomes. HIT improvements in the small physician office setting are achieved through strong leadership, strategic planning, process reengineering, change management, and customizing IT systems to match and support desired office workflows and health care outcomes.

Diffusion of Innovation↗