Attentional modulation of SSVEP power depends on the network tagged by the flicker frequency

Modulation of the steady-state visual evoked potential (SSVEP) by attention was studied in detail using 15 'tag' frequencies in the range of 2.5-20 Hz. The stimuli were two series of random disc search arrays superimposed on two concentric color-marked annuli respectively. Two series of arrays were updated independently; one updated at one fixed frequency (flicker) and the other updated randomly according to a white noise distribution (random broadband flicker, rbbf). On each trial, the observer was instructed to attend one annulus and to detect a target (a triangle) that occasionally appeared in a random disc array in the attended annulus. The SSVEP results show that the choice of flicker frequency selects which cortical network synchronizes to the flicker two distinct cortical networks showed different effects of attention. SSVEP power and the effects of attention on SSVEP power strongly depend on both flicker frequency and radial position of rbbf annulus. At flicker frequencies in the delta band (2-4 Hz), and in the upper alpha band (10-11 Hz), an occipital-frontal network appears to phase-lock to the flicker when attending to the flicker, increasing the magnitude of the SSVEP. At flicker frequencies in the lower alpha band (8-10 Hz), a global response to a peripheral flickering stimulus, that includes parietal cortex and posterior frontal cortex, has higher amplitude when attention is directed away from the flickering peripheral stimulus and towards a competing rbbf stimulus in the fovea. Increases in SSVEP power when attention is directed to peripheral flicker are always associated with increases in phase locking. By contrast, at frequencies in the lower alpha band, increases in SSVEP power when attention is directed away from the flicker and towards foveal stimuli are not associated with changes in phase-locking. Thus, whether attention to a flicker stimulus increases or decreases SSVEP amplitude and phase locking depends on which of two cortical networks, which have distinct spatial and dynamic properties, is selected by the flicker frequency.     

Does cardiac resynchronisation therapy improve survival and quality of life in patients with end-stage heart failure?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether bi-ventricular pacing, also referred to as cardiac resynchronisation therapy (CRT), improves survival and quality of life in patients with severe (NYHA III/IV) symptomatic heart failure. Cardiac pacing can be achieved by stimulation of the right ventricle, left ventricle (LV) or by bi-ventricular pacing. This best evidence topic considers only bi-ventricular pacing. This involves placement of pacing leads in the right ventricle, epicardially on the LV with a lead typically placed in a branch of the coronary sinus and, unless the patient is in permanent atrial fibrillation, in the right atrium. Bi-ventricular pacing allows the optimisation of atrio-ventricular timing and resynchronisation of septal and postero-lateral left ventricular contraction. Symptomatic heart failure has a high morbidity and a poor prognosis. Patients with dyspnoea at rest or on minimal exertion (NYHA III/IV) are at high risk of death due to progressive heart failure, while those with less severe symptoms are more likely to experience sudden cardiac death. Up to 50% of patients with NYHA class III/IV symptoms have a prolonged QRS duration (>120 ms) on 12-lead ECG (usually in a LBBB pattern). This intra-ventricular conduction delay is a surrogate marker of mechanical dyssynchrony (an uncoordinated regional contraction-relaxation pattern) and is associated with reduced cardiac output and increased mortality. Bi-ventricular pacing can reduce the delay in activation of the LV free wall found in many patients with LV systolic dysfunction, thereby improving mechanical synchrony and cardiac output. It may also reduce pre-systolic mitral regurgitation. Three hundred and fifty-six papers were identified using the search method outlined, nine randomised controlled trials and a meta-analysis in addition to published guidelines presented the best evidence to answer the clinical question. Current best available evidence suggests that in patients with left ventricular systolic dysfunction (LVEF or=120 ms), and NYHA class III or IV symptoms despite optimal pharmacological therapy, bi-ventricular pacing significantly reduces the number of hospitalisations from heart failure, improves functional status (NYHA class, peak oxygen uptake and exercise tolerance) and improves health related quality of life. The CARE-HF study also demonstrated a reduction in mortality from progressive heart failure and all-cause mortality.     

End-of-Skin Grafts in Syndactyly Release: Description of a New Flap for Web Space Resurfacing and Primary Closure of Finger Defects

Treatment of syndactyly necessitates creation of neo-web space and separation of fingers. Traditionally, this has been done by use of flaps taken from the dorsum; the resultant raw areas thus created have been managed by use of skin grafts. The classical teaching has been that the separated fingers will need skin graft as primary closure is not possible. The skin grafts have a tendency to contract and lead to finger flexion contractures and “creep” of the web space. We describe a flap based upon subcutaneous tissue in the web that is moved in a V–Y fashion to resurface the neo-web. The flap donor site can easily be closed primarily. The fingers are then separated; the subcutaneous fat is carefully removed from the finger flaps under magnification to allow primary closure of the finger defects. It has been possible to primarily close the donor site and fingers in all the patients. The procedure has been used in seven patients with 14 web releases. The age varied between 10 months to 3 years. The V–Y advancement flap based upon the subcutaneous pedicle in the region of the web allows adequate creation of a new web space. The careful de-fattening of skin flaps allows the separated fingers to be closed primarily.     

Giant cell tumour of talus--a case report

Giant cell tumour of the talus bone is rare and is usually seen in skeletally mature adults. Here a case of giant cell tumour of the talus in a skeletally immature boy of 15 years is reported. The patient presented with swelling and tenderness of the left ankle with an osteolytic lesion seen in the talus on x-ray. A trephine biopsy followed by left talar excision was done. Following the biopsy report the patient underwent arthotomy and joint clearance. There was no recurrence noted at six months follow-up.     

Possible role of glial cells in the onset and progression of Lyme neuroborreliosis

Background  

Lyme neuroborreliosis (LNB) may present as meningitis, cranial neuropathy, acute radiculoneuropathy or, rarely, as encephalomyelitis. We hypothesized that glia, upon exposure to Borrelia burgdorferi, the Lyme disease agent, produce inflammatory mediators that promote the acute cellular infiltration of early LNB. This inflammatory context could potentiate glial and neuronal apoptosis.     

Preparation and characterization of Antheraea assama silk fibroin based novel non‐woven scaffold for tissue engineering applications

The quest for novel materials as scaffolds with suitable micro‐architecture for supporting tissue neogenesis in tissue engineering and regenerative medicine (TERM) is continuing. In this paper we report an Antheraea assama silk‐based non‐woven fibroin scaffold for applications in TERM. The novel three‐dimensional scaffold is highly interconnected and porous, with a pore size of 150 µm, porosity of 90% and water uptake capacity of 85%. FTIR revealed a typical β‐sheet structure of fibroin. The scaffold has thermal and mechanical properties superior to those of Bombyx mori, as revealed by DSC, TGA and tensile tests. The scaffold exhibited satisfactory blood compatibility, as determined by thrombogenicity, haemolysis, platelet/leukocyte count, platelet adhesion and protein adsorption studies. The scaffold was found to be cytocompatible with human cell lines A549, KB, HepG2 and HeLa for a period of up to 4 weeks. SEM analysis revealed excellent attachment, spreading and migration of cells in the scaffold. MTT assay was performed to estimate the viability and growth of cells in the matrix. Quantification of collagen in cell–scaffold constructs was done by picro‐Sirius red assay. Ex ovo chorioallantoic membrane assay and nitric oxide estimations in spent culture medium showed the scaffold's ability to promote angiogenesis. Finally, the biodegradability of the scaffold was determined by the weight loss observed upon treatment with trypsin over a period of 4 weeks. The results reveal that the fibroin from A. assama is a promising candidate as a biocompatible, biomimetic and biodegradable biomaterial of natural origin for applications in TERM. Copyright © 2009 John Wiley & Sons, Ltd.     

Platelet glycoprotein IIb/IIIa inhibition using eptifibatide with primary coronary stenting for acute myocardial infarction: a 30-day follow-up study.

The results of primary coronary stenting for acute myocardial infarction (AMI) have been reported to improve significantly with the concomitant administration of platelet glycoprotein IIb/IIIa inhibitor abciximab. There are, however, no data available with the use of eptifibatide, a more cost-effective, small-molecule GP IIb/IIIa blocker with a shorter half-life. In a prospective multicenter feasibility and efficacy study, we assigned 55 consecutive patients with AMI being taken up for primary stenting to receive eptifibatide just before the procedure (two boluses of 180 microg/kg 10 min apart and a 24-hr infusion of 2 microg/kg/min). Clinical outcomes were evaluated at 30 days after the procedure. The angiographic patency of the vessel with TIMI flow rates, TIMI myocardial perfusion (TMP) grade, and corrected TIMI frame counts were assessed at the end of procedure and before hospital discharge. At 30 days, the primary endpoint, a composite of death, myocardial infarction, and urgent target vessel revascularization (TVR) was seen in 12.7% of patients. The TIMI 3 and TMP grade 3 flow, which was seen in 93% and 86% of patient, respectively, at the end of the procedure, declined to 86% and 78%, respectively (P < 0.05) before hospital discharge. Corrected TIMI frame counts also decreased from 25.7 +/- 7.2 to 22.9 +/- 6.8 (P < 0.05). There were five (9.1%) instances of subacute thrombosis (SAT) presenting as AMI, needing urgent TVR in all, within 3-5 days of the primary procedure. No excessive bleeding complication, directly attributable to the use of eptifibatide, was observed. The study was terminated prematurely because of an unacceptable SAT rate. Administration of eptifibatide along with primary stenting for AMI is associated with a high TIMI 3 and TMP grade 3 flow acutely. However, these flows decline significantly before hospital discharge and lead to a high rate of SAT. The dosage and duration of infusion of eptifibatide in this setting needs further evaluation.     

Is visfatin an adipokine or myokine? Evidence for greater visfatin expression in skeletal muscle than visceral fat in chickens

Visfatin, an adipokine hormone produced primarily by visceral adipose tissue in mammals, has been implicated in the immune system, cellular aging, and glucose metabolism. Increased visceral adiposity and hyperglycemia have been correlated with elevated plasma visfatin levels in humans. The present study investigated visfatin cDNA and protein expression as well as plasma visfatin levels in chickens that are selected for rapid growth and are naturally hyperglycemic relative to mammals. By RT-PCR, we detected visfatin cDNA in multiple tissues in the chicken. The deduced amino acid sequence of full-length chicken visfatin was 92-93% homologous to mammalian visfatin. Using real-time quantitative PCR and Western blotting, chicken skeletal muscle was found to contain 5- and 3-fold greater quantities of visfatin mRNA and protein than abdominal fat pad, respectively. Visfatin mRNA and protein quantities were not significantly different among sc and visceral adipose tissue depots. Skeletal muscle visfatin mRNA and protein quantities as well as plasma visfatin levels determined by enzyme immunoassay were significantly higher in 8-wk-old compared with 4-wk-old chickens, possibly due to rapid skeletal muscle growth and visceral fat accretion occurring in broiler chickens during this period. However, fasting and refeeding did not affect plasma visfatin levels in the chicken. Collectively, our results provide novel evidence that skeletal muscle, not the visceral adipose tissue, is the primary source of visfatin in chickens, thereby raising the possibility that visfatin may be acting as a myokine affecting skeletal muscle growth and metabolism.     

Cost effectiveness of decentralised care model for managing MDR-TB in India

Background

In India, multidrug-resistant tuberculosis (MDR-TB) patients are usually treated in hospitals. Decentralised care model, however, has been suggested as a possible alternative by the World Health Organization (WHO). In the “End TB Strategy”, the WHO highlights, as one of the key targets for 2035, that ‘no TB-affected families should face catastrophic hardship due to the tuberculosis’. Removal of financial barriers to health-care access and mitigation of catastrophic expenditures are therefore considered vital to achieve the universal health coverage (UHC) goal. Since forgoing healthcare due to the financial constraints is a known fact in India, decentralised care as an intervention choice (as against hospital-based care) might enhance equity provided it is an affordable choice. Thus, an economic evaluation was conducted, from the perspective of the national health system in India, to assess the cost-effectiveness of decentralised care compared to centralised care for MDR-TB.

Cardiovascular magnetic resonance left ventricular strain in end-stage renal disease patients after kidney transplantation

Background

Cardiovascular disease is a significant cause of morbidity and mortality in patients with end-stage renal disease (ESRD) and kidney transplant (KT) patients. Compared with left ventricular (LV) ejection fraction (LVEF), LV strain has emerged as an important marker of LV function as it is less load dependent. We sought to evaluate changes in LV strain using cardiovascular magnetic resonance imaging (CMR) in ESRD patients who received KT, to determine whether KT may improve LV function.

Methods

We conducted a prospective multi-centre longitudinal study of 79 ESRD patients (40 on dialysis, 39 underwent KT). CMR was performed at baseline and at 12?months after KT.

Results

Among 79 participants (mean age 55 years; 30% women), KT patients had significant improvement in global circumferential strain (GCS) (p?=?0.007) and global radial strain (GRS) (p?=?0.003), but a decline in global longitudinal strain (GLS) over 12?months (p?=?0.026), while no significant change in any LV strain was observed in the ongoing dialysis group. For KT patients, the improvement in LV strain paralleled improvement in LVEF (57.4?±?6.4% at baseline, 60.6%?±?6.9% at 12?months; p?=?0.001). For entire cohort, over 12?months, change in LVEF was significantly correlated with change in GCS (Spearman’s r?=???0.42, p?<?0.001), GRS (Spearman’s r?=?0.64, p?<?0.001), and GLS (Spearman’s r?=???0.34, p?=?0.002). Improvements in GCS and GRS over 12?months were significantly correlated with reductions in LV end-diastolic volume index and LV end-systolic volume index (all p?<?0.05), but not with change in blood pressure (all p?>?0.10).

Conclusions

Compared with continuation of dialysis, KT was associated with significant improvements in LV strain metrics of GCS and GRS after 12?months, which did not correlate with blood pressure change. This supports the notion that KT has favorable effects on LV function beyond volume and blood pessure control. Larger studies with longer follow-up are needed to confirm these findings.