Neutrophil counts in leptospirosis patients infected with different serovars

In leptospirosis patients, haematological abnormalities have been reported. The aim of this study was to determine if neutrophil counts were different between patients known to be infected with a range of leptospiral serovars. The study retrospectively compared the neutrophil counts from the first blood samples taken from 210 leptospirosis patients at first presentation to a Queensland Health hospital. Significant differences (p <0.001) were observed in neutrophil counts across the 11 different infecting serovars. These findings suggest that neutrophil counts may be useful in the development of an algorithm determining the infecting serovar in suspected leptospirosis patients. Further studies are required to delineate host cytokine responses which may suggest the underlying aetiology of the observed differences in neutrophil counts. Such studies would also provide valuable therapeutic insights into treating the disease.

Increased generation of platelet-derived microparticles following percutaneous transluminal coronary angioplasty

Platelet-derived microparticles (PMPs) which are produced during platelet activation contribute to coagulation1 and bind to traumatized endothelium in an animal model2. Such endothelial injury occurs during percutaneous transluminal coronary angioplasty (PTCA), a procedure which restores the diameter of occluded coronary arteries using balloon inflations. However, re-occlusions subsequently develop in 20-25% of patients3, although this is limited by treatment with anti-platelet glycoprotein IIb/IIIa receptor drugs such as abciximab4. However, abciximab only partially decreases the need for revascularisation5, and therefore other mechanisms appear to be involved. As platelet activation occurs during PTCA, it is likely that PMPs may be produced and contribute to restenosis. This study population consisted of 113 PTCA patients, of whom 38 received abciximab. Paired peripheral arterial blood samples were obtained from the PTCA sheath: 1) following heparinisation (baseline); and 2) subsequent to all vessel manipulation (post-PTCA). Blood was prepared with an anti-CD61 (glycoprotein IIIa) fluorescence conjugated antibody to identify PMPs using flow cytometry, and PMP results expressed as a percentage of all CD61 events. The level of PMPs increased significantly from baseline following PTCA in the without abciximab group (paired t test, P=0.019). However, there was no significant change in the level of PMPs following PTCA in patients who received abciximab. Baseline clinical characteristics between patient groups were similar, although patients administered abciximab had more complex PTCA procedures, such as increased balloon inflation pressures (ANOVA, P=0.0219). In this study, we have clearly demonstrated that the level of CD61-positive PMPs increased during PTCA. This trend has been demonstrated previously, although a low sample size prevented statistical significance being attained6. The results of our work also demonstrate that there was no increase in PMPs after PTCA with abiciximab treatment. The increased PMPs may adhere to traumatized endothelium, contributing to re-occlusion of the arteries, but this remains to be determined. References: (1) Holme PA, Brosstad F, Solum NO. Blood Coagulation and Fibrinolysis. 1995;6:302-310. (2) Merten M, Pakala R, Thiagarajan P, Benedict CR. Circulation. 1999;99:2577-2582. (3) Califf RM. American Heart Journal.1995;130:680-684. (4) Coller BS, Scudder LE. Blood. 1985;66:1456-1459. (5) Topol EJ, Califf RM, Weisman HF, Ellis SG, Tcheng JE, Worley S, Ivanhoe R, George BS, Fintel D, Weston M, Sigmon K, Anderson KM, Lee KL, Willerson JT on behalf of the EPIC investigators. Lancet. 1994;343:881-886. (6) Scharf RE, Tomer A, Marzec UM, Teirstein PS, Ruggeri ZM, Harker LA. Arteriosclerosis and Thrombosis. 1992;12:1475-87.

Comparison of 3 accelerometer data reduction approaches, step counts, and 2 self-report measures for estimating physical activity in free-living adults

Background Accelerometers have become one of the most common methods of measuring physical activity (PA). Thus, validity of accelerometer data reduction approaches remains an important research area. Yet, few studies directly compare data reduction approaches and other PA measures in free-living samples. Objective To compare PA estimates provided by 3 accelerometer data reduction approaches, steps, and 2 self-reported estimates: Crouter's 2-regression model, Crouter's refined 2-regression model, the weighted cut-point method adopted in the National Health and Nutrition Examination Survey (NHANES; 2003-2004 and 2005-2006 cycles), steps, IPAQ, and 7-day PA recall. Methods A worksite sample (N = 87) completed online-surveys and wore ActiGraph GT1M accelerometers and pedometers (SW-200) during waking hours for 7 consecutive days. Daily time spent in sedentary, light, moderate, and vigorous intensity activity and percentage of participants meeting PA recommendations were calculated and compared. Results Crouter's 2-regression (161.8 +/- 52.3 minutes/day) and refined 2-regression (137.6 +/- 40.3 minutes/day) models provided significantly higher estimates of moderate and vigorous PA and proportions of those meeting PA recommendations (91% and 92%, respectively) as compared with the NHANES weighted cut-point method (39.5 +/- 20.2 minutes/day, 18%). Differences between other measures were also significant. Conclusions When comparing 3 accelerometer cut-point methods, steps, and self-report measures, estimates of PA participation vary substantially.

Every step counts : promoting activity among obese adolescents

In separate articles, two projects are described. The first describes a community project in Rockhampton to encourage people to walk more often and the second, a project to encourage more walking in obese adolescents

Literacy assessment that counts : mediating, interpreting and contesting translocal policy in a primary school

In Australia, as in many western education systems over the last two decades, discourses of accountability and performativity have reshaped education policy that has in turn reorganised the work of school leaders and teachers. One of the effects of this reorganisation is increased attention to the production, analysis and display of student achievement data. In this paper we examine in detail a sequence of the production and reading of literacy assessment data in a small Catholic school. Our analysis uses institutional ethnography’s concept of the ‘active text’, the text as occurring in a specific place and time even as it is articulated to social relations beyond its immediate context. Through this process we learn from those involved how their everyday work brings into being formalised, textually authorised processes in a local site that ensure the school meets accountability requirements while enabling teachers to resist standardisation of literacy teaching and assessment.

Plasma-assisted self-sharpening of platelet-structured single-crystalline carbon nanocones

A mechanism and model for the vertical growth of platelet-structured vertically aligned single-crystalline carbon nanostructures by the formation of graphene layers on a flat top surface are proposed and verified experimentally. It is demonstrated that plasma-related effects lead to self-sharpening of tapered nanocones to form needlelike nanostructures, in a good agreement with the predicted dependence of the radius of a nanocone's flat top on the incoming ion flux and surface temperature. The growth mechanism is relevant to a broad class of nanostructures including nanotips, nanoneedles, and nanowires and can be used to improve the predictability of nanofabrication processes. © 2007 American Institute of Physics.

Increased platelet-derived microparticles in the coronary circulation of percutaneous transluminal coronary angioplasty patients

Platelet-derived microparticles that are produced during platelet activation are capable of adhesion and aggregation. Endothelial trauma that occurs during percutaneous transluminal coronary angioplasty (PTCA) may support platelet-derived microparticle adhesion and contribute to development of restenosis. We have previously reported an increase in platelet-derived microparticles in peripheral arterial blood with angioplasty. This finding raised concerns regarding the role of plateletderived microparticles in restenosis, and therefore the aim of this study was to monitor levels in the coronary circulation. The study population consisted of 19 angioplasty patients. Paired coronary artery and sinus samples were obtained following heparinization, following contrast administration, and subsequent to all vessel manipulation. Platelet-derived microparticles were identified with an anti-CD61 (glycoprotein IIIa) fluorescence-conjugated antibody using flow cytometry. There was a significant decrease in arterial platelet-derived microparticles from heparinization to contrast administration (P 0.001), followed by a significant increase to the end of angioplasty (P 0.004). However, there was no significant change throughout the venous samples. These results indicate that the higher level of platelet-derived microparticles after angioplasty in arterial blood remained in the coronary circulation. Interestingly, levels of thrombin–antithrombin complexes did not rise during PTCA. This may have implications for the development of coronary restenosis post-PTCA, although this remains to be determined.

Increased generation of platelet-derived microparticles following percutaneous transluminal coronary angioplasty

Platelet-derived microparticles that are produced during platelet activation bind to traumatized endothelium. Such endothelial injury occurs during percutaneous transluminal coronary angioplasty. Approximately 20% of these patients subsequently develop restenosis, although this is improved by treatment with the anti-platelet glycoprotein IIb/IIIa receptor drug abciximab. As platelet activation occurs during angioplasty, it is likely that platelet-derived microparticles may be produced and hence contribute to restenosis. This study population consisted of 113 angioplasty patients, of whom 38 received abciximab. Paired peripheral arterial blood samples were obtained following heparinization and subsequent to all vessel manipulation. Platelet-derived microparticles were identified using an anti-CD61 (glycoprotein IIIa) fluorescence-conjugated antibody and flow cytometry. Baseline clinical characteristics between patient groups were similar. The level of platelet-derived microparticles increased significantly following angioplasty in the group without abciximab (paired t test, P 0.019). However, there was no significant change in the level of platelet-derived microparticles following angioplasty in patients who received abciximab, despite requiring more complex angioplasty procedures. In this study, we have demonstrated that the level of platelet-derived microparticles increased during percutaneous transluminal coronary angioplasty, with no such increase with abciximab treatment. The increased platelet-derived microparticles may adhere to traumatized endothelium, contributing to re-occlusion of the arteries, but this remains to be determined.

A comparison of lungworm faecal larval counts and trichostrongyloid faecal egg counts between Red Deer (Cervus elaphus) and Red DeerXWapiti F1 hybrids.

To determine if breed differences in susceptibility to trichostrongyloid and lungworm infection exist, two groups of weaner deer containing seven red deer and red deer X wapiti F1 hybrids were compared using faecal egg counts and faecal larval counts. All animals were run on the same pasture at the same time and treated with the same anthelmintics at the same time. Results indicated that there were significant differences between red deer and red deer X wapiti hybrids, with red deer having higher faecal lungworm counts and red deer X wapiti hybrids having significantly higher faecal egg counts. It is likely that these differences were due to breed. Differences in the efficacy of anthelmintic treatments were also noted between the two groups, with oral oxfendazole being less effective at reducing faecal lungworm counts in red deer X wapiti hybrids than red deer.

Estimating link-dependent origin-destination matrices from sample trajectories and traffic counts

In transport networks, Origin-Destination matrices (ODM) are classically estimated from road traffic counts whereas recent technologies grant also access to sample car trajectories. One example is the deployment in cities of Bluetooth scanners that measure the trajectories of Bluetooth equipped cars. Exploiting such sample trajectory information, the classical ODM estimation problem is here extended into a link-dependent ODM (LODM) one. This much larger size estimation problem is formulated here in a variational form as an inverse problem. We develop a convex optimization resolution algorithm that incorporates network constraints. We study the result of the proposed algorithm on simulated network traffic.

Numeracy counts in the statistical reasoning equation

The relationship between mathematics and statistical reasoning frequently receives comment (Vere-Jones 1995, Moore 1997); however most of the research into the area tends to focus on maths anxiety. Gnaldi (Gnaldi 2003) showed that in a statistics course for psychologists, the statistical understanding of students at the end of the course depended on students’ basic numeracy, rather than the number or level of previous mathematics courses the student had undertaken. As part of a study into the development of statistical thinking at the interface between secondary and tertiary education, students enrolled in an introductory data analysis subject were assessed regarding their statistical reasoning ability, basic numeracy skills and attitudes towards statistics. This work reports on the relationships between these factors and in particular the importance of numeracy to statistical reasoning.

Focusing on what counts: Using exploratory focus groups to enhance the development of an electronic survey in a mixed-methods research design

This paper describes the use of exploratory focus groups to inform the development of a survey instrument in a sequential phase mixed methods study investigating differences in secondary students’ career choice capability. Five focus groups were conducted with 23 year 10 students in the state of New South Wales (NSW), Australia. Analysis of the focus group data informed the design of the instrument for the second phase of the research project: a large-scale cross-sectional survey. In this paper, we discuss the benefits of using sequential phase mixed method approaches when inquiring into complex phenomena such as human capability.

Estimating link-dependent origin-destination matrices from sample trajectories and traffic counts

Origin-Destination matrices (ODM) estimation can benefits of the availability of sample trajectories which can be measured thanks to recent technologies. This paper focus on the case of transport networks where traffic counts are measured by magnetic loops and sample trajectories available. An example of such network is the city of Brisbane, where Bluetooth detectors are now operating. This additional data source is used to extend the classical ODM estimation to a link-specific ODM (LODM) one using a convex optimisation resolution that incorporates networks constraints as well. The proposed algorithm is assessed on a simulated network.

Soluble mediators in platelet concentrates modulate dendritic cell inflammatory responses in an experimental model of transfusion

The transfusion of platelet concentrates (PCs) is widely used to treat thrombocytopenia and severe trauma. Ex vivo storage of PCs is associated with a storage lesion characterized by partial platelet activation and the release of soluble mediators, such as soluble CD40 ligand (sCD40L), RANTES, and interleukin (IL)-8. An in vitro whole blood culture transfusion model was employed to assess whether mediators present in PC supernatants (PC-SNs) modulated dendritic cell (DC)-specific inflammatory responses (intracellular staining) and the overall inflammatory response (cytometric bead array). Lipopolysaccharide (LPS) was included in parallel cultures to model the impact of PC-SNs on cell responses following toll-like receptor-mediated pathogen recognition. The impact of both the PC dose (10%, 25%) and ex vivo storage period was investigated [day 2 (D2), day 5 (D5), day 7 (D7)]. PC-SNs alone had minimal impact on DC-specific inflammatory responses and the overall inflammatory response. However, in the presence of LPS, exposure to PC-SNs resulted in a significant dose associated suppression of the production of DC IL-12, IL-6, IL-1a, tumor necrosis factor-a (TNF-a), and macrophage inflammatory protein (MIP)-1b and storage-associated suppression of the production of DC IL-10, TNF-a, and IL-8. For the overall inflammatory response, IL-6, TNF-a, MIP-1a, MIP-1b, and inflammatory protein (IP)-10 were significantly suppressed and IL-8, IL-10, and IL-1b significantly increased following exposure to PC-SNs in the presence of LPS. These data suggest that soluble mediators present in PCs significantly suppress DC function and modulate the overall inflammatory response, particularly in the presence of an infectious stimulus. Given the central role of DCs in the initiation and regulation of the immune response, these results suggest that modulation of the DC inflammatory profile is a probable mechanism contributing to transfusion-related complications.