Comparison of high-resolution magnification narrow-band imaging and white-light endoscopy in the prediction of histology in Barrett's oesophagus

OBJECTIVE: To evaluate whether there is any appreciable difference in imaging characteristics between high-resolution magnification white-light endoscopy (WLE-Z) and narrow-band imaging (NBI-Z) in Barrett's oesophagus (BE) and if this translates into superior prediction of histology. MATERIAL AND METHODS: This was a prospective single-centre study involving 21 patients (75 areas, corresponding NBI-Z and WLE-Z images) with BE. Mucosal patterns (pit pattern and microvascular morphology) were evaluated for their image quality on a visual analogue scale (VAS) of 1-10 by five expert endoscopists. The endoscopists then predicted mucosal morphology based on four subtypes which can be visualized in BE. Type A: round pits, regular microvasculature; type B: villous/ridge pits, regular microvasculature; type C: absent pits, regular microvasculature; type D: distorted pits, irregular microvasculature. The sensitivity (Sn), specificity (Sp), positive predictive value (PPV), negative predictive value (NPV) and accuracy (Acc) were then compared with the final histopathological analysis and the interobserver variability calculated. RESULTS: The overall pit and microvasculature quality was significantly higher for NBI-Z, pit: NBI-Z=6, WLE-Z=4.5, p < 0.001; microvasculature: NBI-Z=7.3, WLE-Z=4.9, p < 0.001. This translated into a superior prediction of histology (Sn: NBI-Z: 88.9, WLE-Z: 71.9, p < 0.001). For the prediction of dysplasia, NBI-Z was superior to WLE-Z (chi(2)=10.3, p < 0.05). The overall kappa agreement among the five endoscopists for NBI-Z and WLE-Z, respectively, was 0.59 and 0.31 (p < 0.001). CONCLUSIONS: NBI-Z is superior to WLE-Z in the prediction of histology in BE, with good reproducibility. This novel imaging modality could be an important tool for surveillance of patients with BE.     

Comparison of Vascular Smooth Muscle Cell Apoptosis and Fibrous Cap Morphology in Symptomatic and Asymptomatic Carotid Artery Disease

The biological cascades that lead to carotid plaque disruptions and symptoms are largely unknown. Certain cellular events within the plaque might be responsible for destabilizing the plaque, though the popular belief is that the plaque size is directly related to symptoms. The aim of our study was to assess the morphology of the fibrous cap and apoptosis in the plaque and compare these two pathological features in symptomatic and asymptomatic carotid artery disease. Our work was carried out in plaques obtained following carotid endarterectomy performed for symptomatic disease (including hemispheric transient ischemic attacks, amaurosis fugax, or stroke) or asymptomatic high-grade severe stenosis. Scion images of Gomori's stained sections were used to measure fibrous cap thickness and area. TUNEL assay was performed to assess the extent of apoptosis. The results indicated that the area of the fibrous cap did not significantly correlate with the presence of symptoms. There was a higher percentage of apoptotic nuclei and the thinner fibrous cap in symptomatic plaques than in asymptomatic plaques. This finding suggests that these factors might be involved in destabilizing plaque, causing rupture and leading to symptomatic carotid disease.     

Rapid response team calls to patients with a pre-existing not for resuscitation order

Objective

Compare and contrast rapid response team (RRT) calls to patients with, and those without, a pre-existing not for resuscitation (NFR) order.

Methods

Retrospective medical record and database review of adult inpatients with a hospital stay greater than 24 h.

Results

198 (15.7%) of 1258 patients with a RRT call, had a pre-existing NFR order. Patients with, compared to those without a pre-existing NFR, were older (median years, 81 vs 70, p < 0.01), similar gender (males, 56.6% vs 54.3%, p = 0.55), the trigger be the worried criterion (48.5% vs 33.9%, p < 0.01) and have had a prior RRT call (30.8% vs 18.0%, p < 0.01).At time of RRT attendance, NFR patients had a higher respiratory rate (24 vs 20, p < 0.01), lower SaO2 (93% vs 97%, p = 0.02) and just as likely to receive a critical care (24.2% vs 25.8%, p = 0.63) or ward type (88.9% vs 90.1%, p = 0.61) intervention. NFR patients were less likely to be admitted to an ICU (2.0% vs 9.4%, p < 0.01), more likely to be left on the ward (92.4% vs 80.3%, p < 0.01), and be documented not for further RRT calls (2.5% vs 0.9%, p = 0.06), but have a similar mortality (5.6% vs 3.5%, p = 0.16), at time of RRT call.

Conclusions

RRT calls to patients with pre-existing NFR orders are not uncommon. The worried criterion is more often the trigger, they have abnormal respiratory observations at time of call, a similar level of intervention, less likely to be admitted to the ICU and more likely to be documented not for further RRT calls.     

Modulation of the human mirror neuron system during cognitive activity

In this experiment we examined the relationship between the mirror neuron system and increased attention caused by task demands. Whole head MEG recordings were made from 13 participants who were asked to passively observe finger movement sequences, observe these sequences with the knowledge they would later have to perform the sequence presented, and finally, to perform a nonmotor mathematics task based on the finger-movement sequences. Beta-band (15-35 Hz) sensorimotor desynchronization was found in overlapping areas during passive observation and in a separate motor execution condition, indicating the activity of the human mirror neuron system. The beta desynchronization in these areas was enhanced relative to passive viewing when participants had to watch the stimuli to later imitate and when they performed the mathematics task, indicating that mirror neuron system activity can be modulated by attention.     

Induced and evoked neural correlates of orientation selectivity in human visual cortex

Orientation discrimination is much better for patterns oriented along the horizontal or vertical (cardinal) axes than for patterns oriented obliquely, but the neural basis for this is not known. Previous animal neurophysiology and human neuroimaging studies have demonstrated only a moderate bias for cardinal versus oblique orientations, with fMRI showing a larger response to cardinals in primary visual cortex (V1) and EEG demonstrating both increased magnitudes and reduced latencies of transient evoked responses. Here, using MEG, we localised and characterised induced gamma and transient evoked responses to stationary circular grating patches of three orientations (0, 45, and 90° from vertical). Surprisingly, we found that the sustained gamma response was larger for oblique, compared to cardinal, stimuli. This "inverse oblique effect" was also observed in the earliest (80 ms) evoked response, whereas later responses (120 ms) showed a trend towards the reverse, "classic", oblique response. Source localisation demonstrated that the sustained gamma and early evoked responses were localised to medial visual cortex, whilst the later evoked responses came from both this early visual area and a source in a more inferolateral extrastriate region. These results suggest that (1) the early evoked and sustained gamma responses manifest the initial tuning of V1 neurons, with the stronger response to oblique stimuli possibly reflecting increased tuning widths for these orientations, and (2) the classic behavioural oblique effect is mediated by an extrastriate cortical area and may also implicate feedback from extrastriate to primary visual cortex.     

Reduced movement-related beta desynchronisation in juvenile myoclonic epilepsy: A MEG study of task specific cortical modulation

Objective

We investigated differences in task induced responses in occipital and sensorimotor cortex between patients with juvenile myclonic epilepsy (JME) and healthy controls .

Methods

Twelve patients with JME and 12 age-matched non-epilepsy volunteers performed visual and motor tasks during MEG. We used synthetic aperture magnetometry to localise areas of task-related oscillatory modulations, performed time–frequency analyses on the locations of peak task related power changes and compared power and frequency modulation at these locations between patients and controls.

Results

Patients with JME had significantly reduced pre-movement beta event-related desynchronisation in the motor task compared to controls. No significant differences were seen in other motor-related responses, or visual oscillatory responses.

Conclusions

Altered beta event-related desynchronisation may represent network specific dysfunction in JME possibly through GABAergic dysfunction.

Significance

Characterising task specific cortical responses in epilepsy offers the potential to understand the patho-physiological basis of seizures and provide a window on disease and treatment effects.     

The Role of Frailty in Failure to Rescue After Cardiovascular Surgery

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