Congenital inclusion tumours in spinal dysraphism

Objective  

To review the presentation, diagnosis and management of children with spinal dysraphism and CIT.     

Feature extraction from light-scatter patterns of Listeria colonies for identification and classification

Bacterial contamination by Listeria monocytogenes not only puts the public at risk, but also is costly for the food-processing industry. Traditional biochemical methods for pathogen identification require complicated sample preparation for reliable results. Optical scattering technology has been used for identification of bacterial cells in suspension, but with only limited success. Therefore, to improve the efficacy of the identification process using our novel imaging approach, we analyze bacterial colonies grown on solid surfaces. The work presented here demonstrates an application of computer-vision and pattern-recognition techniques to classify scatter patterns formed by Listeria colonies. Bacterial colonies are analyzed with a laser scatterometer. Features of circular scatter patterns formed by bacterial colonies illuminated by laser light are characterized using Zernike moment invariants. Principal component analysis and hierarchical clustering are performed on the results of feature extraction. Classification using linear discriminant analysis, partial least squares, and neural networks is capable of separating different strains of Listeria with a low error rate. The demonstrated system is also able to determine automatically the pathogenicity of bacteria on the basis of colony scatter patterns. We conclude that the obtained results are encouraging, and strongly suggest the feasibility of image-based biodetection systems.     

OxLDL-dependent activation of arginase II is dependent on the LOX-1 receptor and downstream RhoA signaling

AimsArginase II regulates NOS activity by competing for the substrate l-arginine. Oxidized LDL (OxLDL) is a proatherogenic molecule that activates arginase II. We tested the hypotheses that OxLDL-dependent arginase II activation occurs through a specific receptor, and via a Rho GTPase effector mechanism that is inhibited by statins.Methods and resultsArginase II activation by OxLDL was attenuated following preincubation with the LOX-1 receptor-blocking antibody JTX92. This also prevented the dissociation of arginase II from microtubules. LOX-1^?/? mice failed to exhibit the increased arginase II activity seen in WT mice fed a high cholesterol diet. Furthermore, endothelium from LOX-1^?/? mice failed to demonstrate the diet-dependent reduction in NO and increase in ROS that were observed in WT mice. OxLDL induced Rho translocation to the membrane and Rho activation, and these effects were inhibited by pretreatment with JTX92 or statins. Transfection with siRNA for RhoA, or inhibition of ROCK both decreased OxLDL-stimulated arginase II activation. Preincubation with simvastatin or lovastatin blocked OxLDL-induced dissociation of arginase II from microtubules and prevented microtubule depolymerization.ConclusionsThis study provides a new focus for preventive therapy for atherosclerotic disease by delineating a clearer path from OxLDL through the endothelial cell LOX-1 receptor, RhoA, and ROCK, to the activation of arginase II, downregulation of NO, and vascular dysfunction.     

Adaptive noise cancellation to suppress electrocardiography artifacts during real-time interventional MRI

Purpose:

To develop a system for artifact suppression in electrocardiogram (ECG) recordings obtained during interventional real‐time magnetic resonance imaging (MRI).

Materials and Methods:

We characterized ECG artifacts due to radiofrequency pulses and gradient switching during MRI in terms of frequency content. A combination of analog filters and digital least mean squares adaptive filters were used to filter the ECG during in vivo experiments and the results were compared with those obtained with simple low‐pass filtering. The system performance was evaluated in terms of artifact suppression and ability to identify arrhythmias during real‐time MRI.

Results:

Analog filters were able to suppress artifacts from high‐frequency radiofrequency pulses and gradient switching. The remaining pulse artifacts caused by intermittent preparation sequences or spoiler gradients required adaptive filtering because their bandwidth overlapped with that of the ECG. Using analog and adaptive filtering, a mean improvement of 38 dB (n = 11, peak QRS signal to pulse artifact noise) was achieved. This filtering system was successful in removing pulse artifacts that obscured arrhythmias such as premature ventricular complexes and complete atrioventricular block.

Conclusion:

We have developed an online ECG monitoring system employing digital adaptive filters that enables the identification of cardiac arrhythmias during real‐time MRI‐guided interventions. J. Magn. Reson. Imaging 2011;33:1184–1193. © 2011 Wiley‐Liss, Inc.     

Hirschsprung Disease — Current Diagnosis and Management

Hirschsprung disease is a common cause of neonatal and infantile large gut obstruction. It is characterised by varying extent of contiguous aganglionosis extending from the anorectum proximally. Since its recognition, the diagnosis and management has continuously evolved with advances in histological evaluation and surgical techniques. This article summarizes the current modalities of investigation and optimal surgical management of Hirschsprung disease and concludes with a reference to the Indian scenario.     

CoMFA, CoMSIA, and docking studies on thiolactone-class of potent anti-malarials: identification of essential structural features modulating anti-malarial activity

The integrated ligand‐ and structure‐based drug design techniques have been applied on a homogeneous dataset of thiolactone‐class of potent anti‐malarials, to explore the essential structural features for the inhibition of Plasmodium falciparum. Developed CoMFA (q² = 0.716) and CoMSIA (q² = 0.632) models well explained structure–activity variation in both the training (CoMFA R² = 0.948 & CoMSIA R² = 0.849) and test set (CoMFA R²_pred = 0.789 & CoMSIA R²_pred = 0.733) compounds. The docking and scoring of the most active compound 10 into the active site of high‐resolution (2.35 Å) structure of FabB‐TLM binary complex (PDB‐ID: 1FJ4) indicated that thiolactone core of this compound forms bifurcated H‐bonding with two catalytic residues His298 and His333, and its saturated decyl side group is stabilized by hydrophobic interactions with the residues of a small hydrophobic groove, illustrating that the active site architecture, including two catalytic histidines and a small hydrophobic groove, is vital for protein–ligand interaction. In particular, the length and flexibility of the side group attached to the position 5 of thiolactone have been observed to play a significant role in the interaction with FabB enzyme. These results present scope for rational design of thiolactone‐class of compounds that could furnish improved anti‐malarial activity.     

Lingual thyroglossal duct cysts--a review

Objectives

Lingual thyroglossal duct cysts (TGDC) are rare and liable to be missed in a cursory clinical examination. This study aimed to report the details of lingual TGDC from the authors’ series and review existing literature on the entity.

Methods

A 12 year retrospective survey of all cases of thyroglossal duct anomalies managed at a tertiary teaching hospital was conducted to identify those with lingual TGDC. Their clinical presentation, investigations, diagnosis and management were analysed. Case series from anecdotal published English literature were critically reviewed with particular regard to diagnosis and management.

Results

Of 78 cases of thyroglossal duct anomalies, 3 were lingual TGDC. All were females. One neonate presented with feeding difficulty and was clinically misdiagnosed as a ranula. The two older children presented with a cyst at the foramen caecum. The varied imaging and diagnostic dilemma are presented. The older children had cysts abutting the hyoid and were managed with transoral excision and a Sistrunk procedure; the neonate was managed with transoral excision only. This report also reviews the sparse literature and discusses specific issues in their treatment. The differential diagnoses encompass a wide array of developmental and neoplastic entities. Specific anatomic imaging with USG/CT/MRI and functional evaluation with radionuclide thyroid scan are essential investigative modalities. Besides a classical Sistrunk procedure and simple transoral excision, newer less invasive treatment options including marsupialisation and alcohol ablation have been reported.

Conclusions

In conclusion, the diagnosis and management of lingual TGDC needs to be individualised depending on their presentation and anatomic location. The Sistrunk's procedure is ideal for those in close proximity to the hyoid; however complete cyst excision would suffice in the rest.