Determination of gamma-hydroxybutyric acid in dried blood spots using a simple GC-MS method with direct 'on spot' derivatization

The objective of this study was the development of an accurate and sensitive method for the determination of gamma-hydroxybutyric acid (GHB) in dried whole blood samples using a GC-MS method. The complete procedure was optimized, with special attention for the sample pre-treatment, and validated. Therefore, dried blood spots (DBS) of only 50 µl were prepared and, after addition of internal standard GHB-d6, directly derivatized using 100 µl of a freshly prepared mixture of trifluoroacetic acid anhydride (TFAA) and heptafluorobutanol (HFB-OH) (2:1). The derivatized extract was injected into a gas chromatograph coupled to a mass spectrometer (GC-MS), operating in the electron impact mode (EI), with a total run time of 12.3 min. Method validation included the evaluation of linearity, precision, accuracy, sensitivity, selectivity and stability. A weighting factor of 1/x2 was chosen and acceptable intra-batch precision, inter-batch precision and accuracy were seen. The linear calibration curve ranged from 2 to 100 µg/ml, with a limit of detection of 1 µg/ml. Our procedure, utilizing the novel approach of direct “on spot” derivatization, followed by analysis with GC-MS, proved to be reliable, fast and applicable in routine toxicology

Feasibility of following up gamma-hydroxybutyric acid concentrations in sodium oxybate (Xyrem®)-treated narcoleptic patients using dried blood spot sampling at home : an exploratory study

Background: Gamma-hydroxybutyric acid (GHB), well known as a party drug, especially in Europe, is also legally used (sodium oxybate, Xyrem (R)) to treat a rare sleep disorder, narcolepsy with cataplexy. This exploratory study was set up to measure GHB concentrations in dried blood spots (DBS) collected by narcoleptic patients treated with sodium oxybate. Intra- and inter-individual variation in clinical effects following sodium oxybate administration has been reported. The use of DBS as a sampling technique, which is stated to be easy and convenient, may provide a better insight into GHB concentrations following sodium oxybate intake in a real-life setting. Objective The aim was twofold: evaluation of the applicability of a recently developed DBS-based gas chromatography mass spectrometry (GC MS) method, and of the feasibility of the sampling technique in an ambulant setting. Methods: Seven narcoleptic patients being treated with sodium oxybate at the Department for Respiratory Diseases of Ghent University Hospital were asked to collect DBS approximately 20 min after the first sodium oxybate (Xyrem (R); UCB Pharma Ltd, Brussels, Belgium) intake on a maximum of 7 consecutive days. Using an automatic lancet, patients pricked their fingertip and, after wiping off the first drop of blood, subsequent drops were collected on a DBS card. The DBS cards were sent to the laboratory by regular mail and, before analysis, were visually inspected to record DBS quality (large enough, symmetrically spread on the filter paper with even colouration on both sides of the filter paper). Results: Of the seven patients, three patients succeeded to collect five series of DBS, one patient decided to cease participation because of nausea, one was lost during follow-up and two patients started falling asleep almost immediately after the intake of sodium oxybate. Analysing the DBS in duplicate resulted in acceptable within-DBS card precision. DBS with acceptable quality were obtained by patients without supervision. Conclusion: Our results demonstrate the acceptable precision of the complete procedure, from sampling at home to quantitative analysis in the laboratory. Given the intra-and inter-individual variability in clinical effects seen with sodium oxybate, the easy adaptation of DBS sampling opens the possibility of following up GHB concentrations in patients in real-life settings in future studies

Exploring the educational aspirations of rural youth: an image-based study using participant produced photographs

Department Head: Carole J. Makela.2010 Spring.Includes bibliographical references (pages 77-81).Education is an important variable in forming student aspirations in that it serves to help students become more knowledgeable about the world, more sensitive and understanding of their relationship to it, and more eager to contribute to the community. The purpose of this visual ethnography study was to explore how students in one rural ninth grade classroom perceive their home, school, and community environments as supporting and/or inhibiting their educational aspirations. The approach allowed students to describe their reality in a tangible visual manner by studying; what students do (behaviors), what they say (reporting on photographs), and what they make, (photographs). Cultural themes emerged from the three environments; school, community and home in which rural ninth grade students spend a majority of their time. This study was conducted in a rural area in the county of Colorado referred to as Steel County, located approximately ten miles east of the city. The community surrounding Steel County consists of residential areas, produce farms, and small businesses. The rural high school student body is comprised from sub-cities and transfer students from outside areas compiling a fifty mile parameter. The use of photography provided a unique lens at capturing multi-level relationships that impact rural educational aspirations. Student photographs successfully captured social relationships within the cultural, political-economic, socio-political and spatial context of a rural community, captured within the home, school and community setting

3000 steps in 30 minutes, five days per week yields metabolic improvements compared to 150 weekly minutes

The physical activity recommendation for U.S. adults is to engage in moderate-intensity exercise for at least 150 minutes per week. Pedometers have gained popularity as a tool for motivating and estimating daily physical activity. Recently it was suggested 3000 steps in 30 minutes may be equivalent to moderate-intensity walking. To date, this recommendation has yet to be examined over an extended period of time. PURPOSE: To evaluate changes in cardiorespiratory fitness, body composition, blood lipids, blood glucose, and CRP from 150 minutes of free living weekly exercise compared to pedometer measured 3000 steps in 30 minutes, five days per week. METHODS: Subjects were randomly divided into two interventions (free living and pedometer) for 12 weeks. A free living (FL) group (n=12) accumulated 150 minutes moderate-intensity physical activity per week. A pedometer (P) group (n=13) attended three 30-min supervised walking sessions and walked two 30-min sessions independently. Metabolic variables were measured pre- and post-intervention. RESULTS: Twenty-five subjects began the study and nineteen FL (n=8) and P (n=11) subjects completed the study. Adherence was 77.9% and 85.2% in FL and P groups, respectively. SBP (-8.24 ± 11.3; p \u3c 0.05) and glucose (-7.2 ±11.8mg/dl; p \u3c 0.05) were significantly lower in P pre/post. Mean changes in CRP (-1.6 mg/dl, p = 0.11), LM (0.14 kg, p = 0.19), and VO2max (1.6 mg/kg/min, p = 0.2) approached significance in P only. In contrast, FL pre/post measurements did not significantly differ in any parameter. HR, BP, GLU, LM, and BMD improved in both groups. CRP and VO2max improved in P only. CONCLUSION: Evidence suggests the general recommendation of 150 minutes per week does not successfully improve metabolic variables or promote adherence. Additionally, there is a dose response to 3000 steps in 30 minutes on metabolic variables compared with 150 minutes per week. This gives a practical application for the use of pedometers and metronomes to monitor intensity and motivate adherence. Further, results indicate walking 3000 steps in 30 minutes is an appropriate proxy for meeting the 150 minutes per week recommendation

Doctor of Philosophy

dissertationAnecdotal evidence exists for a stereotype of poor elderly driving performance but this stereotype has not been empirically documented despite possible detrimental effects through stereotype threat. Study 1, Experiment 1, measured implicit and explicit associations between aging and driving in older (>60) and younger (<31) adults. Individual differences in attentional control were measured using an operation span (OSPAN), working memory task. Associations between advanced age and impaired driving were found in both groups, and individual differences in attentional control correlated with implicit associations for older, but not younger adults. Study 1, Experiment 2, determined the extent to which attentional control moderates the stereotype's implicit expression in young adults. Younger adults in Experiment 2 took the implicit association test (IAT) twice. Half were asked to control the stereotype by responding as if they were an older adult the second time. In this latter condition, individual differences in attention control predicted young adults' change in IAT scores. Older adults from Study 1 also participated in Study 2. To test for the effects of stereotype threat, participants completed a car following scenario in a driving simulator, either under stereotype threat or control conditions. Dependent measures included brake reaction time, following distance, and collision occurrence. Compared to the control group, participants under stereotype threat were over six times more likely to collide with other vehicles. Further, under stereotype threat, participants lower in attentional control showed increased brake reaction times and following distances; a pattern often associated with distracted/impaired driving

Dried blood spots in toxicology : from the cradle to the grave?

About a century after its first described application by Ivar Bang, the potential of sampling via dried blood spots (DBS) as an alternative for classical venous blood sampling is increasingly recognized. Perhaps best known is the use of DBS in newborn screening programs, ignited by the hallmark paper by Guthrie and Susi half a century ago. However, it is only recently that both academia and industry have recognized the many advantages that DBS sampling may offer for bioanalytical purposes, as reflected by the strong increase in published reports during the last few years. Currently, major DBS applications include newborn screening for metabolic disorders, epidemiological surveys (e. g. HIV monitoring), therapeutic drug monitoring (TDM), as well as toxicology. In this review, we provide a comprehensive overview of the distinct subdisciplines of toxicology for which DBS sampling has been applied. DBS sampling for toxicological evaluation has been performed from birth until autopsy, aiming at the assessment of therapeutic drugs, drugs of abuse, environmental contaminants, toxins, as well as (trace) elements, with applications situated in fields as toxicokinetics, epidemiology and environmental and forensic toxicology. We discuss the strengths and limitations of DBS in the different subdisciplines and provide future prospects for the use of this promising sampling technique in toxicology

College Health Care Providers’ Student-Centered Care

Patient care in the university setting is indelibly connected to college health care providers. College health care providers adapt to a specific set of circumstances unique to the university context in their patient care roles. The authors therefore sought to investigate the patient care phenomenon from college health care providers’ lived experiences. The patient care phenomenon was explored via in-depth interviews with 11 college health care providers at universities in the Midwest and Northeast regions of the United States. The phenomenological theoretical framework of the study revealed five themes of patient care during data analysis: health education, behavioral health, student advocacy, relationship management, and reputation management. The authors designate the multi-dimensional nature of the patient care phenomenon “student-centered care” and consider practical implications for other providers who treat young university-age patients

Parenting the second time around: Voices from the Hispanic community on raising their grandchilden

This study explores the experiences of Hispanic grandmothers who are parenting a second time around. This study looked at the strengths, needs, services, within their kinship arrangements. Child welfare workers could gain an in-depth understanding in cultural context that could influence their practice and service delivery