Chest MRI Using Multivane-XD,a Novel T2-Weighted Free Breathing MR Sequence

ObjectiveTo compare image quality of free-breathing T2-weighted MultiVane-XD (MVXD) sequence (non-Cartesian k-space filling using radial rectangular blades) with conventional MR sequences (short tau inversion recovery [STIR],balanced true field echo [BTFE], T1 in phase fast field echo [T1 FFE], and T1-fat saturated postgadolinium [T1PG]) in MR imaging of chest.Materials and MethodsTwenty-one patients (10 men and 11 women) underwent chest MRI including T2W MVXD, STIR, BTFE (18/21), T1 FFE, T1PG (10/21) sequences at 1.5 T. Two reviewers (A.S.B and M.J. with 20 and 10 years of experience in pulmonary imaging, respectively) evaluated each sequence with respect to overall image quality, image sharpness, definition of mediastinal vessels including the aorta, pulmonary arteries, superior vena cava, intrapulmonary vessels; trachea, main bronchi, intrapulmonary airways; lung-mediastinal interface, pulmonary lesion detection, and artefacts in the upper, middle, and lower third of chest using 5-point scales. No sedation was given. Pairwise comparisons between T2W MVXD and the 4 conventional sequences were made using unpaired student's t test.ResultsMean age of patients was 30.67 years (range: 6-60 years). T2 MVXD showed significantly better overall image quality and sharpness than STIR, T1 FFE, and T1PG (P < 0.01) while it was comparable to BTFE. Mediastinal vessels were significantly better visualized on T2 MVXD as compared to STIR and T1 (P < 0.003). However, BTFE and T1PG were superior to T2 MVXD for visualization of great vessels, SVC, and intrapulmonary vessels (P < 0.01). Visualization of trachea, major bronchi, intrapulmonary airways as well as intrapulmonary lesion detection was significantly better on T2 MVXD images in comparison to any of the other 4 sequences (P < 0.03). Intrapulmonary artifacts were significantly lesser in BTFE images as compared to T2 MVXD (P < 0.01). No significant difference was found between the severity of intrapulmonary artifacts in other MR sequences as compared to T2 MVXD.ConclusionsBy virtue of its better overall image quality, sharpness, superior visualization of mediastinal airways, and lesion detection, T2 MultiVane-XD promises to be a robust addition in the armamentarium of thoracic radiologists.     

Brain activation during the voiding phase of micturition in healthy adults: A meta‐analysis of neuroimaging studies

Several studies have used a variety of neuroimaging techniques to measure brain activity during the voiding phase of micturition. However, there is a lack of consensus on which regions of the brain are activated during voiding. The aim of this meta‐analysis is to identify the brain regions that are consistently activated during voiding in healthy adults across different studies. We searched the literature for neuroimaging studies that reported brain co‐ordinates that were activated during voiding. We excluded studies that reported co‐ordinates only for bladder filling, during pelvic floor contraction only, and studies that focused on abnormal bladder states such as the neurogenic bladder. We used the activation‐likelihood estimation (ALE) approach to create a statistical map of the brain and identify the brain co‐ordinates that were activated across different studies. We identified nine studies that reported brain activation during the task of voiding in 91 healthy subjects. Together, these studies reported 117 foci for ALE analysis. Our ALE map yielded six clusters of activation in the pons, cerebellum, insula, anterior cingulate cortex (ACC), thalamus, and the inferior frontal gyrus. Regions of the brain involved in executive control (frontal cortex), interoception (ACC, insula), motor control (cerebellum, thalamus), and brainstem (pons) are involved in micturition. This analysis provides insight into the supraspinal control of voiding in healthy adults and provides a framework to understand dysfunctional voiding. Clin. Anat., 2018. © 2018 Wiley Periodicals, Inc.     

Decoration of Zinc Oxide Nanorods into the Surface of Activated Carbon Obtained from Agricultural Waste for Effective Removal of Methylene Blue Dye

Zinc oxide (ZnO) nanorods incorporated activated carbon (AC) composite photocatalyst was synthesized using a hydrothermal process. The AC was prepared from lapsi (Choerospondias axillaris) seed stone, an agricultural waste product, found in Nepal by the chemical activation method. An aqueous suspension of AC with ZnO precursor was subjected to the hydrothermal treatment at 140 °C for 2 h to decorate ZnO rods into the surface of AC. As-obtained ZnO nanorods decorated activated carbon (ZnO/AC) photocatalyst was characterized by various techniques, such as scanning electron microscopy (SEM), X-ray diffraction (XRD), and photoluminescence (PL) spectroscopy. Results showed that highly crystalline hexagonal ZnO nanorods were effectively grown on the surface of porous AC. The photocatalytic property of the as-prepared ZnO/AC composite was studied by degrading methylene blue (MB) dye under UV-light irradiation. The ZnO/AC composite showed better photocatalytic property than that of the pristine ZnO nanorods. The enhanced photocatalytic performance in the case of the ZnO/AC composite is attributed to the combined effects of ZnO nanorods and AC.     

Leminorella sepsis in very low birth weight neonate as cause of neonatal mortality

Leminorella is a member of Enterobacteriaceae family and was known previously as Enteric Group 57. Based upon genetic differences using DNA hybridization, it has three taxa: Leminorella grimontii, Leminorella richardii, and Leminorella sp. strain 3. The third one is similar biochemically to the L. grimontii strains. The generic name has been derived on the name of a French microbiologist, Leon Le Minor. The biochemical properties includes being facultative anaerobes, growth on sheep blood, TSI, and MacConkey agar; hydrogen sulfide producer, l-arabinose fermenter, and tyrosine hydrolyzer; and are negative for d-mannose fermentation, urea, and lipase. They usually infect in adulthood and result in urinary tract infection, surgical site infection, bacteremia, peritonitis, respiratory tract infection, and soft tissue infection. We report the first case of L. grimontii sepsis in a very low birth weight neonate that died because of neonatal sepsis.     

Phosphoproteomic Analysis Reveals Regulatory Mechanisms at the Kidney Filtration Barrier

Diseases of the kidney filtration barrier are a leading cause of ESRD. Most disorders affect the podocytes, polarized cells with a limited capacity for self-renewal that require tightly controlled signaling to maintain their integrity, viability, and function. Here, we provide an atlas of in vivo phosphorylated, glomerulus-expressed proteins, including podocyte-specific gene products, identified in an unbiased tandem mass spectrometry–based approach. We discovered 2449 phosphorylated proteins corresponding to 4079 identified high-confidence phosphorylated residues and performed a systematic bioinformatics analysis of this dataset. We discovered 146 phosphorylation sites on proteins abundantly expressed in podocytes. The prohibitin homology domain of the slit diaphragm protein podocin contained one such site, threonine 234 (T234), located within a phosphorylation motif that is mutated in human genetic forms of proteinuria. The T234 site resides at the interface of podocin dimers. Free energy calculation through molecular dynamic simulations revealed a role for T234 in regulating podocin dimerization. We show that phosphorylation critically regulates formation of high molecular weight complexes and that this may represent a general principle for the assembly of proteins containing prohibitin homology domains.The kidney filter consists of three layers: fenestrated endothelial cells, the glomerular basement membrane, and podocytes.¹ Damage to any of these compartments becomes clinically evident as proteinuria and the development of kidney disease.² Of particular importance for the regulation of podocyte biology through signaling is the slit diaphragm, a specialized intercellular junction that bridges the 40-nm gap in between foot processes of neighboring podocytes. It also serves as a signaling platform regulating podocyte function. Mutations in genes encoding for components of the slit diaphragm, such as nephrin,³ podocin,⁴ CD2AP,⁵ and TRPC6,^6,7 are important causes of genetic forms of proteinuria. Alteration of these proteins results in defective signaling causing podocyte dysfunction, progressive glomerulosclerosis, and kidney failure. The slit diaphragm protein complex is a lipid-multiprotein supercomplex.⁸ Of central importance to the integrity and function of the protein complex is the prohibitin homology (PHB) domain protein podocin,⁹ which forms multimeric complexes and is required to control signal transduction through associated transmembrane proteins.^10,11Signaling processes governing podocyte function, integrity, and survival largely depend on signaling processes involving phosphorylation.^12,13 Comprehensive analyses of the signaling events in podocytes in vivo have been hampered by the fact that interference with these signaling cascades by genetic deletion often results in massively disrupted and dysfunctional podocytes. One of the primary aims of this study was to use phosphoproteomics to analyze thousands of phosphorylation sites in native murine glomeruli within single samples. Within this study, we show that this approach allows the introduction of new concepts into signaling processes at the kidney filtration barrier.     

Antimicrobial susceptibility and serotypes of Neisseria meningitidis and Streptococcus pneumoniae in Sri Lanka: Experience from the National Reference Laboratory

Objective: To determine the antimicrobial susceptibility and serotypes of Neisseria (N.) meningitidis and Streptococcus (S.) pneumoniae in Sri Lankan patients. ...     

Characterization of knockdown resistance in DDT- and pyrethroid-resistant Culex quinquefasciatus populations from Sri Lanka

DDT and pyrethroid resistance in Culex quinquefasciatus have been previously reported in Sri Lanka, but the mechanisms involved have yet to be characterized. We report the presence of two mutant alleles of the sodium channel gene, the target site for both DDT and pyrethroid insecticides. Both mutations resulted in classic knockdown resistance (kdr) L1014F mutation because of either an A-to-T substitution or an A-to-C substitution. We developed two alternative assays to distinguish between the two mutations and used these to screen 214 individuals from nine geographic locations throughout Sri Lanka. Very high levels of kdr mutations were found throughout the country. A predominance of the A-to-C mutation was observed over the A-to-T with an average allele frequency of 50% and 2%, respectively. In addition to these non-synonymous kdr substitutions, we also found an indel (TCACA) in the intron downstream of the kdr mutation. After genotyping this indel in 136 individuals, we found no evident correlation between kdr genotypes and intronic indel. The presence of two alternative kdr mutations has implications for the reliance on single molecular diagnostics for detection of resistance in field populations. Furthermore, the high levels of these kdr mutations in C. quinquefasciatus populations throughout Sri Lanka are of concern for the future of pyrethroid-based control programmes on this island.     

mTORC2 regulates renal tubule sodium uptake by promoting ENaC activity

The epithelial Na⁺ channel (ENaC) is essential for Na⁺ homeostasis, and dysregulation of this channel underlies many forms of hypertension. Recent studies suggest that mTOR regulates phosphorylation and activation of serum/glucocorticoid regulated kinase 1 (SGK1), which is known to inhibit ENaC internalization and degradation; however, it is not clear whether mTOR contributes to the regulation of renal tubule ion transport. Here, we evaluated the effect of selective mTOR inhibitors on kidney tubule Na⁺ and K⁺ transport in WT and Sgk1^–/– mice, as well as in isolated collecting tubules. We found that 2 structurally distinct competitive inhibitors (PP242 and AZD8055), both of which prevent all mTOR-dependent phosphorylation, including that of SGK1, caused substantial natriuresis, but not kaliuresis, in WT mice, which indicates that mTOR preferentially influences ENaC function. PP242 also substantially inhibited Na⁺ currents in isolated perfused cortical collecting tubules. Accordingly, patch clamp studies on cortical tubule apical membranes revealed that mTOR inhibition markedly reduces ENaC activity, but does not alter activity of K⁺ inwardly rectifying channels (ROMK channels). Together, these results demonstrate that mTOR regulates kidney tubule ion handling and suggest that mTOR regulates Na⁺ homeostasis through SGK1-dependent modulation of ENaC activity.