Effectiveness of citrate buffer-fluoride mixture in Terumo tubes as an inhibitor of in vitro glycolysis

Introduction

Glycolysis affects glucose determination in vitro. The placement of sample tubes in ice-water slurry with plasma separation within 30 minutes is recommended, or alternatively the use of a glycolysis inhibitor. The aim of our two-steps study was to evaluate which Terumo tube is best for glucose determination in routine clinical setting.

Materials and methods

In the first study, blood from 100 volunteers was collected into lithium heparin (LH), NaF/Na heparin (FH) and NaF/citrate buffer/Na₂EDTA (FC-Mixture) tubes. LH sample was treated as recommended and considered as reference, while FH and FC-Mixture samples were aliquoted, maintained at room temperature (RT) for 1, 2 and 4 hours; centrifuged and plasma analysed in triplicate. In the second study, samples from 375 volunteers were collected in LH, FH and FC-Mixture tubes and held at RT before centrifugation from 10 to 340 minutes, depending on each laboratory practice. Samples were analysed in one analytical run.

Results

In the first study, FH glucose concentrations were 5.15 ± 0.66 mmol/L, 5.05 ± 0.65 mmol/L and 5.00 ± 0.65 mmol/L (P < 0.001) in tubes stored at RT for 1, 2 and 4 hours, respectively. Mean biases in all time points exceeded the analytical goal for desirable bias based on biological variation criteria. FC-Mixture glucose concentrations were 5.48 ± 0.65 mmol/L, 5.46 ± 0.6 mmol/L and 5.46 ± 0.64 mmol/L in tubes stored at RT for 1, 2 and 4 hours, respectively. Mean biases for FC-Mixture glucose in all time points reached optimal analytical goals. In the second study, the biases for LH and FH glucose compared to reference FC-Mixture glucose exceeded the preset analytical goals, regardless of the blood collection to centrifugation time interval.

Conclusions

FC-mixture tubes glucose concentrations were preserved up to 4h storage at RT. We confirmed that NaF alone does not allow immediate glycolysis inhibition in real life pre-centrifugation storage conditions (up to 340 minutes). FC-Mixture should be used exclusively for glucose determination in laboratories unable to implement the recommended blood samples’ treatment.Key words: glucose, pre-analytical phase, sodium fluoride, citrate acidification, stability     

Homocysteine status and acute myocardial infarction among Tamilians

Myocardial infarction is a major consequence of coronary artery disease. Apart from the traditional risk factors of myocardial infarction, recently many reports have suggested that hyperhomocysteinemia plays important role in myocardial infarction. Plasma homocysteine level was determined in 60 myocardial infarction patients and in 35 age matched healthy individuals. Statistically significant differences (p<0.01) were observed in the mean of plasma homocysteine concentrations between the acute myocardial infarction patients (24.59±6.14 mM/L) and in normal healthy individuals (13.73 ±3.54 mM/L). The level of homocysteine in myocardial infarction patients is significantly high (p <0.01) among myocardial infarction patients when compared to that of the controls. The the present study indicates a strong association between plasma homocysteine and acute myocardial infarction among Tamilians, thus implying plasma homocysteine as a possible risk factor for myocardial infarction.     

Providing transparency and credibility: the selection of international students for Australian universities. An examination of the relationship between scores in the International Student Admissions Test (ISAT), final year academic programs and an Australian university’s foundation program

Throughout 2003–04 five cohorts of students in their final year of school studies in various Malaysian colleges and a group of students completing an Australian university foundation year in Malaysia sat the International Student Admissions Test (ISAT). The ISAT is a multiple‐choice test of general academic abilities developed for students whose first language is not English. Both sets of scores were examined to investigate the relationship between skills measured by the academic programs and the generic reasoning skills measured by the ISAT. The data were examined by looking at correlations and patterns of the ISAT scores, and the total academic program scores and individual subject scores. As well, multiple regression was used to examine if the ISAT could act as a predictor for academic program scores. Although the ISAT and measures of achievement in the academic programs are two completely different instruments, the study showed that: (i) the scores were positively and significantly correlated; (ii) patterns of co‐variation of the ISAT and academic program scores demonstrate a positive relationship; and (iii) there is evidence that achieving a high score in the academic programs requires high reasoning skills, as measured by the ISAT. The findings of this study indicate that the ISAT is a useful predictor of student ability for use in the university selection process for international applicants.     

Autistic spectrum disorders: a challenge and a model for inclusion in education

Rita Jordan, Professor in Autism Studies at the School of Education, University of Birmingham, gave last year's Gulliford Lecture at the University of Birmingham on 4 October 2007. This article is based upon that lecture. In it, Professor Jordan discusses the role of education in the lives of people with autistic spectrum disorders. She traces the growth in our knowledge about autistic spectrum disorders and the development of a variety of ways of responding to autism, from the highly specialised, and frequently strictly segregated, to the explicitly inclusive. She uses her analysis to draw distinctions between 'therapeutic' models of education and education as 'entitlement'– and identifies problems with either paradigm. Professor Jordan closes her article by setting out her vision for a future in which there is greater flexibility and diversity and in which specialisation has a key role to play in making inclusion a working reality. The challenge of teaching pupils with autistic spectrum disorders will, argues Professor Jordan, help us all to imagine a truly inclusive model for education in which equity is achieved by treating all learners differently.     

The role of context in learning and instructional design

Context is a pervasive and potent force in any learning event. Yet instructional design models contain little guidance about how to accommodate contextual elements to improve learning and transfer. This paper defines context, outlines its levels and types, specifies some pertinent contextual factors within these types, suggests methods for conducting a contextual analysis and utilizing its results for instructional design, and outlines future issues for context-based instructional design. The incorporation of a contextual approach to instruction will make our design models systemic as well as systematic.     

Secure Base Representations in Children With Asthma: Links With Symptoms,Family Asthma Management,and Cytokine Regulation

Children's perceptions of caregivers as a secure base have been linked with socioemotional outcomes, but little is known about connections to physical health. We examined whether secure base representations are associated with children's symptoms, family management strategies, and inflammatory processes in children with asthma. Participants included 308 children (ages 8–17) and one parent. Children completed a blood draw to measure asthma-related immune functions and reported on perceptions of their mothers as a secure base and their asthma symptoms. Dyads completed interviews about asthma management. Analyses revealed that children's secure base perceptions were associated with better family asthma management and lower Type 2 T-helper cell cytokine production. These findings suggest that secure base representations may be protective for children with asthma.     

Mentoring Within the Field of Counseling: A Preliminary Study of Multicultural Perspectives

Although the concept of mentoring is receiving increasing attention in the counseling field, the intersection between multiculturalism and mentoring has not been formally addressed. This article explores mentoring relationships between faculty and students within counselor education from a multicultural perspective. Semi-structured interviews were used to explore African American, Asian American and Latina/o American counselor education graduate students’ perspectives on mentoring. Three similar themes (trust/comfort/honesty; respect; and teacher/student/guide) emerged for all three racial/ethnic groups as important key elements in the mentoring relationship, but with some distinctive culturally relevant variations in emphasis. Also, all three groups to some degree reported that having a mentor who was culturally competent and sensitive was helpful, adding further weight to the view that cultural issues play a role in mentoring relationships. Implications of the findings are discussed.     

Children''s Beliefs about Listening: Is It Enough to Be Still and Quiet?

This study examined children's conception of listening and their performance as listeners, 7-, 9-, and 11-year-old children were interviewed for their conceptions of good listening, their beliefs about appropriate actions for confused listeners to take, their attributions of responsibility for a listener's confusion, their reports of how speakers and listeners feel during communication breakdown, and their ability to detect inconsistencies during a comprehension-monitoring task. Results indicated that older children relied less on behavioral orientation and more on attempts to comprehend and other criteria in their definitions of good listening. Children believed that appropriate listening responses depend on the situation, and there was a developmental increase in asking the speaker a question and listening more carefully. With age, children also tended to report more complex negative emotions for listeners and speakers experiencing a breakdown in understanding. Children recalled incongruent material more than congruent material on the comprehension-monitoring task.