Rural Victorian Telestroke project

BACKGROUND

Intravenous thrombolysis improves functional outcomes in acute ischaemic stroke. However, many rural stroke patients are denied thrombolysis because of a rural neurologist shortage. 'Telestroke' facilitates thrombolysis by providing remote access to neurologists via videoconferencing systems.

AIMS

To develop a safe and feasible Telestroke system in a rural Victorian hospital that facilitates delivery of intravenous thrombolysis to acute ischaemic stroke patients.

METHODS

A pilot videoconferencing Telestroke system was set up between Royal Melbourne Hospital and Northeast Health Wangaratta. Acute stroke patients presenting within 4.5 h of symptom onset without intracranial haemorrhage were eligible for Telestroke. However, eligible patients were excluded from Telestroke if they had haemorrhagic risk factors. Data were collected from intervention (October 2009-September 2010) and control group (October 2008-September 2009) by medical file audit. Primary outcome measure was percentage of patients thrombolysed. Secondary outcome measures included incidence of symptomatic intracerebral haemorrhage and door-to-computed tomography time.

RESULTS

One hundred and forty-five acute stroke patients presented in control year and 130 patients in intervention year. Fifty-four patients in intervention and 36 patients in control group were eligible for thrombolysis. In intervention group, 24 patients had Telestroke activated and 8 patients underwent thrombolysis. There was no thrombolysis in the control group. There were neither symptomatic intracerebral haemorrhages nor deaths attributable to thrombolysis. Median door-to-computed tomography time did not significantly differ between eligible patients in control and intervention groups.

CONCLUSION

Telestroke has the potential to bridge the gap of rural-metropolitan inequality in acute stroke care. Our Telestroke system successfully introduced safe thrombolysis and early specialist review of acute stroke patients in rural Victoria.

Development of universal primers for isolating fragments of the LEAFY gene

LEAFY orthologs are found throughout land plants. Degenerate primers were designed for amplifying exon 3 region fragments of the LEAFY gene. Sixteen taxa from different plants were sampled, all of which were successfully isolated, which indicated that this set of primers is universally applicable for all land plants. With the use of this method, there may be potential for applying LEAFY exon 3 as a single-copy nuclear marker to resolve reticulate evolution at high taxonomic levels and to clarify the origin and evolutionary history of the LEAFY gene.

Fast Prediction of Injection Pressure and Minimal Front Temperature for Injection Moulding

Fast prediction of injection pressure and minimal front temperature can usually be used to optimize the process parameters for injection moulding. In this paper, a fast strip analysis (FSA) model was presented on the basis of a geometric approximation method, which simplifies an original part to a rectangular edge-gated strip. The dimensions of the rectangular strip were calculated through the original part's geometric mesh by using graph theory. Subsequently, a finite difference method was employed to simulate a non-isothermal and unidirectional flow in the strip. Numerical examples show that although FSA model is an approximation method, its results are approximately identical to that of detailed CAE software, while the running time of the proposed model is several magnitudes less than that of CAE software.

A new high intensity and short-pulse molecular beam valve

In this paper, we report on the design and performance of a new home-built pulsed gas valve, which we refer to as the Nijmegen Pulsed Valve (NPV). The main output characteristics include a short pulse width (as short as 20 μs) combined with operating rates up to 30 Hz. The operation principle of the NPV is based on the Lorentz force created by a pulsed current passing through an aluminum strip located within a magnetic field, which opens the nozzle periodically. The amplitude of displacement of the opening mechanism is sufficient to allow the use of nozzles with up to 1.0 mm diameter. To investigate the performance of the valve, several characterizations were performed with different experimental methods. First, a fast ionization gauge was used to measure the beam intensity of the free jet emanating from the NPV. We compare free jets from the NPV with those from several other pulsed valves in current use in our laboratory. Results showed that a high intensity and short pulse-length beam could be generated by the new valve. Second, the NPV was tested in combination with a skimmer, where resonance enhanced multiphoton ionization combined with velocity map imaging was used to show that the NPV was able to produce a pulsed molecular beam with short pulse duration (~20 μs using 0.1% NO/He at 6 bars) and low rotational temperature (~1 K using 0.5% NO/Ar at 6 bars). Third, a novel two-point pump-probe method was employed which we label double delay scan. This method allows a full kinematic characterization of the molecular beam, including accurate speed ratios at different temporal positions. It was found that the speed ratio was maximum (S = 50 using 0.1% NO/He at 3 bars) at the peak position of the molecular beam and decreased when it was on the leading or falling edge.

Clopidogrel hyper-response and bleeding risk in neurointerventional procedures

BACKGROUND AND PURPOSE

Antiplatelet therapy is associated with decreased ischemic events after neurointerventional procedures. Antiplatelet resistance negates the protective effects of antiplatelet medication, leading to a higher incidence of ischemic events. A possible link between antiplatelet hyper-response and increased hemorrhagic complications has been inadequately investigated. We aimed to examine the correlation between antiplatelet hyper-response and the risk of hemorrhagic complications.

MATERIALS AND METHODS

Patients who were treated with antiplatelet medications and underwent neurointerventional procedures were prospectively recruited. We collected the following data: demographics, vascular risk factors, antiplatelet and anticoagulation treatment, antiplatelet responsiveness, coagulation profile, and hemorrhagic complications. P2Y12 receptor-mediated platelet inhibition was tested by using the VerifyNow assay device. The primary end points were postprocedural major and minor hemorrhagic complications. Receiver operator characteristic analysis was used to evaluate the percentage of platelet inhibition as a diagnostic tool for bleeding events. The association between hemorrhage and percentage of platelet inhibition was investigated by using logistic regression modeling.

RESULTS

Forty-seven patients were enrolled. The mean age was 56±12 years, and 28% were men. Ten patients (21.3%) developed hemorrhagic complications. Clopidogrel response was higher in patients with a major bleeding complication compared with those with minor or no bleeding (median, 94% versus 24% platelet inhibition; P=.0084). Of the 7 patients (14.9%) defined as hyper-responders with ≥72% platelet inhibition, 42.8% had a major bleeding complication.

CONCLUSIONS

Hyper-response to clopidogrel is associated with increased risk of hemorrhagic complications. Larger studies are urgently needed to validate a clinically useful threshold to define clopidogrel hyper-response and to examine the clinical effects of antiplatelet dosage adjustment.

Anisotropic polarizability of ultracold polar 40K87Rb molecules

We report the measurement of the anisotropic ac polarizability of ultracold polar (40)K(87)Rb molecules in the ground and first rotationally excited states. Theoretical analysis of the polarizability agrees well with experimental findings. Although the polarizability can vary by more than 30%, a "magic" angle between the laser polarization and the quantization axis is found where the polarizability of the |N=0,m(N)=0> and the |N=1,m(N)=0> states match. At this angle, rotational decoherence due to the mismatch in trapping potentials is eliminated, and we observe a sharp increase in the coherence time. This paves the way for precise spectroscopic measurements and coherent manipulations of rotational states as a tool in the creation and probing of novel quantum many-body states of polar molecules.

The paradox of extreme high-altitude migration in bar-headed geese Anser indicus

Bar-headed geese are renowned for migratory flights at extremely high altitudes over the world's tallest mountains, the Himalayas, where partial pressure of oxygen is dramatically reduced while flight costs, in terms of rate of oxygen consumption, are greatly increased. Such a mismatch is paradoxical, and it is not clear why geese might fly higher than is absolutely necessary. In addition, direct empirical measurements of high-altitude flight are lacking. We test whether migrating bar-headed geese actually minimize flight altitude and make use of favourable winds to reduce flight costs. By tracking 91 geese, we show that these birds typically travel through the valleys of the Himalayas and not over the summits. We report maximum flight altitudes of 7290 m and 6540 m for southbound and northbound geese, respectively, but with 95 per cent of locations received from less than 5489 m. Geese travelled along a route that was 112 km longer than the great circle (shortest distance) route, with transit ground speeds suggesting that they rarely profited from tailwinds. Bar-headed geese from these eastern populations generally travel only as high as the terrain beneath them dictates and rarely in profitable winds. Nevertheless, their migration represents an enormous challenge in conditions where humans and other mammals are only able to operate at levels well below their sea-level maxima.

Is general anaesthesia preferable to conscious sedation in the treatment of acute ischaemic stroke with intra-arterial mechanical thrombectomy? A review of the literature

INTRODUCTION

Intra-arterial mechanical thrombectomy (IAMT) is an endovascular technique that allows for the acute retrieval of intravascular thrombi and is increasingly being used for the treatment of acute ischaemic stroke (AIS). There are currently two anaesthetic options during IAMT: general anaesthesia (GA) and conscious sedation (CS). The decision to use GA versus CS is the source of controversy, as it requires careful balance between patient pain, movement and airway protection whilst minimising time delay and haemodynamic fluctuations. This review examines and summarises the evidence for the use of GA versus CS in the treatment of AIS by IAMT.

METHODS

Studies were identified using systematic bibliographic searches. The five applicable studies were analysed with reference to overall outcomes and the key parameters that govern the decision to use GA or CS. The key parameters included the impact of GA and CS on pain, complication rates, time delays, airway protection and haemodynamic stability.

RESULTS

Several retrospective analyses have shown that the use of GA is associated with adverse outcomes.

CONCLUSION

Intra-arterial mechanical thrombectomy under general anaesthesia is associated with poor outcomes in observational studies. It is reasonable to offer conscious sedation as the preferred option where adverse patient factors such as agitation are lacking.

Binding of carbon nanotube to BMP receptor 2 enhances cell differentiation and inhibits apoptosis via regulating bHLH transcription factors

Biomaterials that can drive stem cells to an appropriate differentiation level and decrease apoptosis of transplanted cells are needed in regenerative medicine. Nanomaterials are promising novel materials for such applications. Here we reported that carboxylated multiwalled carbon nanotube (MWCNT 1) promotes myogenic differentiation of mouse myoblast cells and inhibits cell apoptosis under the differentiation conditions by regulating basic helix-loop-helix transcription factors. MWCNT 1 attenuates bone morphogenetic protein receptor (BMPR) signaling activity by binding to BMPR2 and attenuating the phosphorylation of BMPR1. This molecular understanding allowed us to tune stem cell differentiation to various levels by chemical modifications, demonstrating human control of biological activities of nanoparticles and opening an avenue for potential applications of nanomaterials in regenerative medicine.

S100A4 regulates motility and invasiveness of human esophageal squamous cell carcinoma through modulating the AKT/Slug signal pathway

The involvement of S100A4 in modulating invasiveness of esophageal squamous cell carcinoma (ESCC) cell lines was explored. It was shown that S100A4 expression is positively correlated with the degree of invasiveness in human ESCC cells. The S100A4-rich EC-1 cells displayed higher migratory and invasive cell behavior while ET-1 cells with low S100A4 expression levels displayed lower migratory and invasive cell behavior. S100A4 silencing by small interfering (siRNA) in EC-1 cells induced E-cadherin expression, and overexpression of S100A4 in a lowly invasive TE-1 cells suppressed E-cadherin expression. It is suggested that S100A4 silencing inhibit invasion via E-cadherin upregulation, and overexpression of S100A4 promote invasion via E-cadherin downregulation in ESCC cells. Compared with the vector-transfected cells, S100A4 silencing in EC-1 cells showed reduced ability of migration and invasiveness, and overexpression of S100A4 in TE-1 cells showed increased ability of migration and invasiveness via wound-healing and Transwell assay, and pseudometastatic model assay. Furthermore, re-expression of S100A4 could increase the invasive phenotypes in S100A4 siRNA transfected EC-1 cells, and S100A4 silencing could decrease the invasive phenotypes in S100A4 circular DNA (cDNA) transfected TE-1 cells. It was found that Slug is downregulated in S100A4 siRNA transfected EC-1 cells, and Slug is upregulated in S100A4 cDNA transfected TE-1 cells. It was also discovered S100A4 cDNA induced protein kinase B (AKT) phosphorylation at Serine-473(phospho-AKT [p-AKT]) levels, followed by the Slug upregulation, and S100A4 siRNA decreases the phospho-AKT levels, followed by the Slug downregulation. The data suggested that S100A4 could regulate migratory and invasive behavior of human ESCC cells through modulating AKT/Slug pathway.