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Ruth Allen

Publications and source records attributed to Ruth Allen.

7 recordsLinked to original sources
PubMed2006

Presentation of a structurally diverse and commercially available drug data set for correlation and benchmarking studies.

A multivariate analysis of drugs on the Swedish market was the basis for the selection of a small, physicochemically diverse set of 24 drug compounds. Factors such as structural diversity, commercial availability, price, and a suitable analytical technique for quantification were considered in the selection. Lipophilicity, pKa, solubility, and permeability across human Caco-2 cell monolayers were measured for the compiled data set. The results show that, by use of a physicochemically diverse data set, experimental responses over a wide range were obtained. The paper also shows how experimental difficulties due to the diversity of the data set can be overcome. We anticipate that this data set can serve as a benchmark set for validation of new experimental techniques or in silico models. It can also be used as a diverse starting data set for the development of new computational models.

Caco-2 Cells↗
PubMed2005

Concentrations of selective metabolites of organophosphorus pesticides in the United States population.

We report population-based concentrations (stratified by age, sex, and composite race/ethnicity variables) of selective metabolites of chlorpyrifos (3,5,6-trichloro-2-pyridinol; TCPY), chlorpyrifos methyl (TCPY), malathion (malathion dicarboxylic acid; MDA), diazinon (2-isopropyl-4-methyl-6-hydroxypyrimidine; IMPY), methyl parathion (para-nitrophenol; PNP), and parathion (PNP). We measured the concentrations of TCPY, MDA, IMPY, and PNP in 1997 urine samples from participants, aged 6-59 years, of the National Health and Nutrition Examination Survey, 1999-2000. We detected TCPY in more than 96% of the samples tested. Other organophosphorus pesticide metabolites were detected less frequently: MDA, 52%; IMPY, 29%; and PNP, 22%. The geometric means for TCPY were 1.77 microg/L and 1.58 microg/g creatinine. The 95th percentiles for TCPY were 9.9 microg/L and 8.42 microg/g creatinine. The 95th percentiles for MDA were 1.6 microg/L and 1.8 microg/g creatinine. The 95th percentiles for IMPY and PNP were 3.7 microg/L (3.4 microg/g creatinine) and 5.0 microg/L (4.2 microg/g creatinine), respectively. Multivariate analyses showed that children aged 6-11 years had significantly higher concentrations of TCPY than adults and adolescents. Similarly, adolescents had significantly higher TCPY concentrations than adults. Although the concentrations between sexes and among composite racial/ethnic groups varied, no significant differences were observed.

Adolescent↗
PubMed2004

Professionally indicated short-term risk-taking in the treatment of borderline personality disorder.

OBJECTIVE: To define and explore the rationale for professionally indicated short-term risk-taking in treating adults with borderline personality disorder, and discuss prerequisites for the approach, clinical implementation and medicolegal contexts. CONCLUSION: When prerequisites are met and clinical and medicolegal practice is sound and thorough, taking short-term risk, as part of a comprehensive treatment, is a legitimate professional consideration in working with some adults with borderline personality disorder.

Adaptation, Psychological↗
PubMed2003

High-throughput measurement of pKa values in a mixed-buffer linear pH gradient system.

A procedure is described for measuring pKa values in a short time, e.g., 4 min/assay. Samples, as 10 mM solutions, are prepared in DMSO in 96-well plates. A flowing pH gradient is produced by mixing two buffer solutions containing mixtures of weak acids and bases that do not absorb significantly in the UV above 250 nm. The sample solution is diluted with water and then injected directly into the flowing gradient, which then passes through a diode array spectrophotometer measuring in the UV wavelength range. The buffer has been formulated so that its acid-base titration curve is linear over a wide pH range, such that the pH of the gradient is a linear function of time. The solution pH in the measurement flow cell is therefore proportional to the time elapsed since the start of gradient generation. The sample's pKa values are calculated from the change in UV absorbance at multiple wavelengths as a function of pH. The pKa values of 71 drugs have been measured, and results compare well with values measured by pH-metric or traditional UV methods. Rules are suggested for the rapid inspection of data and the choice of method for the calculation of pKa from the data.

Journal Article↗
PubMed1998

Surveying Students' Attitudes During the OSCE.

This study assessed students' attitudes, students' level of confidence and the importance of faculty feedback during an Objective Structured Clinical Examination (OSCE). A survey was administered as one of 15 OSCE stations to 138 sophomore medical students. Eight of the twelve survey items were Likert type items with a follow-up open-ended question. The remaining four items required only an open-ended response. The five surveyors participated in the design of the questionnaire and in training to insure reliable information acquisition and recording. The OSCE was given in five identical tracks in a single day. Each surveyor interviewed either 27 or 28 students during the four-hour period of the track. The Likert responses to the eight items were analyzed and statistical comparisons made for each question. The open-ended responses were analyzed using qualitative summary techniques and compared to the Likert responses.Statistical analyses of the Likert based items showed students had high levels of confidence in their ability to conduct physical examinations and histories, found faculty feedback helpful and informative, but were nervous throughout the examination. The qualitative analysis provided additional information regarding students' feelings about the OSCE, their levels of confidence, their stress levels and the importance of faculty feedback during the examination.Results of the survey suggest curricular changes which could be made in preparation for the OSCE and for a new Introduction to Clinical Medicine course currently in its first year in the College of Medicine.

Journal Article↗