Clinical surveillance of thrombotic microangiopathies in Scotland, 2003-2005

The prevalence, incidence and outcomes of haemolytic uraemic syndrome (HUS) and thrombotic thrombocytopaenic purpura (TTP) are not well established in adults or children from prospective studies. We sought to identify both outcomes and current management strategies using prospective, national surveillance of HUS and TTP, from 2003 to 2005 inclusive. We also investigated the links between these disorders and factors implicated in the aetiology of HUS and TTP including infections, chemotherapy, and immunosuppression. Most cases of HUS were caused by verocytotoxin-producing Escherichia coli (VTEC), of which serotype O157 predominated, although other serotypes were identified. The list of predisposing factors for TTP was more varied although use of immunosuppressive agents and severe sepsis, were the most frequent precipitants. The study demonstrates that while differentiating between HUS and TTP is sometimes difficult, in most cases the two syndromes have quite different predisposing factors and clinical parameters, enabling clinical and epidemiological profiling for these disorders

Selecting Socio-scientific Issues for Teaching: A Grounded Theory Study of How Science Teachers Collaboratively Design SSI-Based Curricula

Currently there is little guidance given to teachers in selecting focal issues for socio-scientific issues (SSI)-based teaching and learning. As a majority of teachers regularly collaborate with other teachers, understanding what factors influence collaborative SSI-based curriculum design is critical. We invited 18 secondary science teachers to participate in a professional development on SSI-based instruction and curriculum design. Through intentional design, we studied how these teachers formed curriculum design teams and how they selected focal issues for SSI-based curriculum units. We developed substantiative grounded theory to explain these processes. Key findings include how teachers' tensions and agential moves worked in tandem in the development of a safe and shared place to share discontentment and generate opportunities to form design teams and select issues. Teacher passion and existing resources are factors as influential as considerations for issue relevance. Implications for teacher professional development and research are included

Single versus multiple human-equivalent doses of C. parvum in mice: neutralization of the anti-metastatic effect.

The murine dose of i.v. C. parvum (466 microgram) was compared with a single, low, human-equivalent dose of 70 microgram and with repeated weekly low doses. All treatments increased the antibody titre against C. parvum (CP). However, repeated doses stimulated a much higher titre than single doses. In all treated animals spleen weight peaked at 2 weeks and then fell. A single low dose caused a 3-fold increase, a single high dose or multiple low doses a 6-fold increase. Liver weight changes followed a similar pattern. Hepatosplenomegaly was prolonged by multiple doses. The effects of these treatments on Lewis tumour metastases were studied. A single high dose and a single low dose on the day of tumour implantation (Day 0) were equally effective at inhibiting pulmonary metastases. Repeated low doses starting on Day 0 were no more effective than a single dose. The effect of CP on survival after primary-tumour excision on Day 10 was observed. Low dose CP on Day 7 doubled the harmonic mean of survival time. Repeated doses were no more effective than a single dose. Low-dose prophylaxis up to 2 weeks before tumour significantly inhibited metastases. However, when repeated low-dose prophylaxis was combined with a single low dose on Day 0, the anti-metastatic effect was abrogated. This neutralization of the anti-metastatic effect of CP given on Day 0 was found to persist after a 13-week treatment-free interval. Possible mechanisms for this phenomenon are discussed

What Powers the Compact Radio Emission in Nearby Elliptical and S0 Galaxies?

Many nearby early-type (elliptical and S0) galaxies contain weak (milli-Jansky level) nuclear radio sources on scales a few hundred parsecs or less. The origin of the radio emission, however, has remained unclear, especially in volume-limited samples that select intrinsically less luminous galaxies. Both active galactic nuclei and nuclear star formation have been suggested as possible mechanisms for producing the radio emission. This paper utilizes optical spectroscopic information to address this issue. A substantial fraction of the early-type galaxies surveyed with the Very Large Array by Wrobel & Heeschen (1991) exhibits detectable optical emission lines in their nuclei down to very sensitive limits. Comparison of the observed radio continuum power with that expected from the thermal gas traced by the optical emission lines implies that the bulk of the radio emission is nonthermal. Both the incidence and the strength of optical line emission correlate with the radio power. At a fixed line luminosity, ellipticals have stronger radio cores than S0s. The relation between radio power and line emission observed in this sample is consistent with the low-luminosity extension of similar relations seen in classical radio galaxies and luminous Seyfert nuclei. A plausible interpretation of this result is that the weak nuclear sources in nearby early-type galaxies are the low-luminosity counterparts of more powerful AGNs. The spectroscopic evidence supports this picture. Most of the emission-line objects are optically classified as Seyfert nuclei or low-ionization nuclear emission-line regions (LINERs), the majority of which are likely to be accretion-powered sources.Comment: LaTex, 16 pages including embedded figures. Accepted for publication in the Astrophysical Journa

Intravascular coagulation resulting from intravenous injection of C. parvum in mice.

In mice, i.v. C. parvum induces intravascular coagulation. This is a prolonged reaction lasting up to 7 days. It results in thrombosis in hepatic vessels with consequent hepatic necrosis, and thrombosis in pulmonary and splenic vessels. This may be important in the assessment of the tumour-inhibitory activity of C. parvum

The EMAIL test – measurement of integrated saccade latency and visual processing times without eye-tracking

INTRODUCTION: The acquisition and processing of visual information often involve eye-movements and motor responses. Visual processing times and oculomotor parameters are of interest since fatigue as well as temporary changes in alertness caused by common drugs can also affect task completion times and overall accuracy in visual search. Eye-trackers are useful in such studies, but expensive equipment is needed and accurate measurements require careful calibration. We propose a new method to measure integrated oculomotor response parameters that is simple to carry out and does not require eye-tracking equipment. The EMAIL (Eye Movement and Intrinsic Latency) test captures parameters that describe both the time course of eye-movement generation as well as the time needed to detect and process specific object attributes at the end of each saccade. METHODS: The test relies on measuring the time needed to detect peripheral targets, carry out an appropriate eyemovement and process some feature of the stimulus (such as colour, coherent motion, rapid flicker, spatial orientation or acuity). In this round of experiments, the stimulus was a Landolt ring flanked by distractors and presented at a randomly selected location on either side of fixation, 8o in the periphery. The measurement variable is the target presentation time, δT, needed to achieve ~ 73% correct response. The subject’s task is to saccade to the peripheral target, to register the gap in the central ring and to press one of four response buttons to indicate its correct orientation. Eye -tracking was added to this initial research study to separate the cortical processing time needed to detect the orientation of the gap in the Landolt ring from the integrated task completion time. RESULTS: The results obtained so far show a significant effect of age and fatigue. Under normal conditions, measured times are in the range 160 to 270 ms. In general, δT values are longer when vertical eye-movements are involved. The greatest changes are observed in saccade latency and the cortical processing times. DISCUSSION: The new EMAIL test provides a simple method to investigate how fatigue and other factors affect visual processing times. When combined with eye-tracking, the test makes it possible to measure changes in cortical processing times for specific stimulus attributes and may also turn out to be a useful tool to assess the severity of loss in traumatic brain injury studies