Multi-source feature learning for joint analysis of incomplete multiple heterogeneous neuroimaging data

Analysis of incomplete data is a big challenge when integrating large-scale brain imaging datasets from different imaging modalities. In the Alzheimer's Disease Neuroimaging Initiative (ADNI), for example, over half of the subjects lack cerebrospinal fluid (CSF) measurements; an independent half of the subjects do not have fluorodeoxyglucose positron emission tomography (FDG-PET) scans; many lack proteomics measurements. Traditionally, subjects with missing measures are discarded, resulting in a severe loss of available information. In this paper, we address this problem by proposing an incomplete Multi-Source Feature (iMSF) learning method where all the samples (with at least one available data source) can be used. To illustrate the proposed approach, we classify patients from the ADNI study into groups with Alzheimer's disease (AD), mild cognitive impairment (MCI) and normal controls, based on the multi-modality data. At baseline, ADNI's 780 participants (172AD, 397 MCI, 211 NC), have at least one of four data types: magnetic resonance imaging (MRI), FDG-PET, CSF and proteomics. These data are used to test our algorithm. Depending on the problem being solved, we divide our samples according to the availability of data sources, and we learn shared sets of features with state-of-the-art sparse learning methods. To build a practical and robust system, we construct a classifier ensemble by combining our method with four other methods for missing value estimation. Comprehensive experiments with various parameters show that our proposed iMSF method and the ensemble model yield stable and promising results.     

Impact of acute left ventricular apical thrombus on cardioversion for atrial fibrillation

Among patients undergoing cardioversion for atrial fibrillation, the presence of left ventricular thrombus is a relatively uncommon and challenging clinical dilemma. While left atrial appendage thrombus is a contraindication to cardioversion, there is paucity of data regarding the safety of cardioversion in with the presence of left ventricular apical thrombus. Also, thrombus characteristics such as protrusion and mobility on echocardiography are known risk factors for systemic embolism. In this article, we present a case highlighting the management of atrial fibrillation in the setting of left ventricular dysfunction, acute heart failure, and echocardiographic evidence of acute left ventricular apical thrombus.     

A Toolbox for Herpesvirus miRNA Research: Construction of a Complete Set of KSHV miRNA Deletion Mutants

Kaposi’s sarcoma-associated herpesvirus (KSHV) encodes 12 viral microRNAs (miRNAs) that are expressed during latency. Research into KSHV miRNA function has suffered from a lack of genetic systems to study viral miRNA mutations in the context of the viral genome. We used the Escherichia coli Red recombination system together with a new bacmid background, BAC16, to create mutants for all known KSHV miRNAs. The specific miRNA deletions or mutations and the integrity of the bacmids have been strictly quality controlled using PCR, restriction digestion, and sequencing. In addition, stable viral producer cell lines based on iSLK cells have been created for wildtype KSHV, for 12 individual miRNA knock-out mutants (ΔmiR-K12-1 through -12), and for mutants deleted for 10 of 12 (ΔmiR-cluster) or all 12 miRNAs (ΔmiR-all). NGS, in combination with SureSelect technology, was employed to sequence the entire latent genome within all producer cell lines. qPCR assays were used to verify the expression of the remaining viral miRNAs in a subset of mutants. Induction of the lytic cycle leads to efficient production of progeny viruses that have been used to infect endothelial cells. Wt BAC16 and miR mutant iSLK producer cell lines are now available to the research community.     

Multi-angle ratiometric approach to measure chemical exchange in amide proton transfer imaging

Amide proton transfer imaging, a specific form of chemical exchange saturation transfer imaging, has previously been applied to studies of acute ischemic acidosis, stroke, and cancer. However, interpreting the resulting contrast is complicated by its dependence on the exchange rate between amides and water, the amide concentration, amide and water relaxation, and macromolecular magnetization transfer. Hence, conventional chemical exchange saturation transfer contrast is not specific to changes such as reductions in pH due to tissue acidosis. In this article, a multi-angle ratiometric approach based on several pulsed-chemical exchange saturation transfer scans at different irradiation flip angles is proposed to specifically reflect exchange rates only. This separation of exchange effects in pulsed-chemical exchange saturation transfer experiments is based on isolating rotation vs. saturation contributions, and such methods form a new subclass of chemical exchange rotation transfer (CERT) experiments. Simulations and measurements of creatine/agar phantoms indicate that a newly proposed imaging metric isolates the effects of exchange rate changes, independent of other sample parameters.     

Functional reconstruction of complex tendo Achilles defect by free latissimus dorsi muscle flap

Managing the complex tendo Achilles defect involves reconstructing the Achilles tendon as well as providing soft tissue cover to the heel area. The advent of microsurgery has revolutionised the reconstruction of this difficult defect providing a number of options to the reconstructive surgeon. We present a case of complex tendo Achilles defect reconstructed by the latissimus dorsi free flap.KEY WORDS: Complex defect, reconstruction, tendo-Achille     

Benign Fibrous Histiocytoma: A Rare Case Report and Literature Review

Fibrous histiocytoma is a benign soft tissue tumour that may present as a fibrous mass anywhere in the human body. The involvement of the oral cavity is extremely rare and very few cases have been reported in literature till date. We here report a case of benign fibrous histiocytoma localized in the oral cavity. The clinical and histological features of the lesion are discussed precisely in the light of a literature review of this pathology in oral cavity.     

Modification of Heister Jaw Opener

Heister introduced a mouth gag of incentric pattern which is still being used. Heister jaw opener has narrow blades which rest on the occlusal surface of molar teeth. The force of mouth gag is not equally distributed on all the teeth, therefore there is great risk of tooth avulsion in periodontally compromised dentition and fracture of tooth while using standard Heister appliance. To overcome this modification of Heister mouth gag is done.     

Correction of pre-existing astigmatism by on-axis incision size modulation in manual small-incision cataract surgery

Purpose:To study the effect of wound size modulation on pre-existing astigmatism by on-axis placement of incision in manual small-incision cataract surgery (MSICS).Methods:In this prospective interventional study conducted at a tertiary care centre, 40 eyes of 40 consecutive senile cataract patients with 1.00–3.00 D corneal astigmatism were enrolled for the study. MSICS by modified Blumenthal’s technique was performed through 6.0, 6.5, and 7.0 mm on-axis incision in 1.0–1.49 D (group A), 1.50–1.99 D (group B), and 2.00–3.00 D (group C) astigmatism, respectively. Surgically induced astigmatism (SIA) was calculated by vector analysis and double angle plots (DAP) at 12 weeks postoperatively.Results:There were 22 males and 18 females with mean age of 58.12 ± 1.18 years. The mean SIA at 12 weeks was 0.85 ± 0.28 D in group A (17 eyes), 1.32 ± 0.65 D in group B (10 eyes), and 1.91 ± 0.69 D in group C (13 eyes). The overall median uncorrected visual acuity was 0.18 (IQR = 0 to 0.2). The mean astigmatism decreased from 1.95 ± 0.74 D to 1.04 + 0.57 D (P = 0.00) in superior incision and from 1.70 + 0.50 D to 0.92 ± 0.45 D (P = 0.00) in temporal incision group with central shift of centroid in all cases.Conclusion:The customization of on-axis external incision size can be used to manage pre-existing corneal astigmatism of less than 3.00 D using both temporal and superior incisions effectively.