AQP4-MOG Double-Positive Neuromyelitis Optica Spectrum Disorder: Case Report with Central and Peripheral Nervous System Involvement and Review of Literature

(1) The co-occurrence of AQP4 and myelin oligodendrocyte glycoprotein (MOG) antibodies in patients with demyelinating disorders is extremely rare. In addition, a concomitant involvement of the peripheral nervous system (PNS) has been described either in association with AQP4 antibodies-positive neuromyelitis optica spectrum disorder (NMOSD), or MOG-associated disease. We report on a case of NMOSD with co-occurrence of AQP4 and MOG antibodies and concomitant central and peripheral nervous system involvement. We also reviewed available cases of AQP4-MOG double-positive patients. (2) Brain and spine MRI, cerebrospinal fluid studies, and electrophysiological test were performed. Serum AQP4 and MOG positivity was assessed with live cell-based assay. (3) A 62-year-old woman presented with recurrent optic neuritis, myelitis, and radiculitis, tested positive for AQP4 and MOG antibodies, and was treated successfully with rituximab. (4) Although few cases of AQP4-MOG double-positive patients were already described mostly affecting females with a concomitant spinal cord and optical nerve involvement, we describe the first case of double-positive NMOSD with the peculiar involvement of both central and peripheral nervous system.     

Diet and Proteinuria: State of Art

Proteinuria is a broad term used to describe the pathological presence of proteins, including albumin, globulin, Bence-Jones protein, and mucoprotein in the urine. When persistent, proteinuria is a marker of kidney damage and represents a reliable predictor of the risk of progression of renal failure. Medical nutrition therapy is imperative for patients with proteinuria because it may slow the progression of renal disease. The aim of this review is to explore different nutritional approaches in the management of proteinuria and their influence on pathophysiological processes. As such, protein restriction is the main dietary intervention. Indeed, other management approaches are frequently used to reduce it regarding micro and macronutrients, but also the dietary style. Among these, the nutritional approach represents one of the most used and controversial interventions and the studies rarely take the form of randomized and controlled trials. With this work we aspire to analyze current clinical knowledge of how nutrition could influence proteinuria, potentially representing a useful tool in the management of proteinuric nephropathy.     

Microglial Activation and Priming in Alzheimer’s Disease: State of the Art and Future Perspectives

Alzheimer’s Disease (AD) is the most common cause of dementia, having a remarkable social and healthcare burden worldwide. Amyloid β (Aβ) and protein Tau aggregates are disease hallmarks and key players in AD pathogenesis. However, it has been hypothesized that microglia can contribute to AD pathophysiology, as well. Microglia are CNS-resident immune cells belonging to the myeloid lineage of the innate arm of immunity. Under physiological conditions, microglia are in constant motion in order to carry on their housekeeping function, and they maintain an anti-inflammatory, quiescent state, with low expression of cytokines and no phagocytic activity. Upon various stimuli (debris, ATP, misfolded proteins, aggregates and pathogens), microglia acquire a phagocytic function and overexpress cytokine gene modules. This process is generally regarded as microglia activation and implies that the production of pro-inflammatory cytokines is counterbalanced by the synthesis and the release of anti-inflammatory molecules. This mechanism avoids excessive inflammatory response and inappropriate microglial activation, which causes tissue damage and brain homeostasis impairment. Once the pathogenic stimulus has been cleared, activated microglia return to the naïve, anti-inflammatory state. Upon repeated stimuli (as in the case of Aβ deposition in the early stage of AD), activated microglia shift toward a less protective, neurotoxic phenotype, known as “primed” microglia. The main characteristic of primed microglia is their lower capability to turn back toward the naïve, anti-inflammatory state, which makes these cells prone to chronic activation and favours chronic inflammation in the brain. Primed microglia have impaired defence capacity against injury and detrimental effects on the brain microenvironment. Additionally, priming has been associated with AD onset and progression and can represent a promising target for AD treatment strategies. Many factors (genetics, environmental factors, baseline inflammatory status of microglia, ageing) generate an aberrantly activated phenotype that undergoes priming easier and earlier than normally activated microglia do. Novel, promising targets for therapeutic strategies for AD have been sought in the field of microglia activation and, importantly, among those factors influencing the baseline status of these cells. The CX3CL1 pathway could be a valuable target treatment approach in AD, although preliminary findings from the studies in this field are controversial. The current review aims to summarize state of the art on the role of microglia dysfunction in AD pathogenesis and proposes biochemical pathways with possible targets for AD treatment.     

Percutaneous mechanical revascularization of chronic iliac artery occlusion with "first intention" stent placement

The selective inactivation of genes, in a tissue-specific or temporally controlled manner, is now an important requirement for the analysis of nervous system development and function. Hammerhead ribozymes--catalytic RNA enzymes that specifically bind to and then cleave target RNAs--may provide a way to meet this requirement, particularly for organisms in which gene inactivation by homologous recombination is not feasible. However, ribozyme application has to some extent been hampered by limited knowledge as to the base-pairing accessibility of RNA target sites in vivo. In an attempt to circumvent this limitation, we have used a computer program based on free energy minimization to predict secondary structures for 128 RNA sequences for which corresponding ribozymes or antisense oligonucleotides have been synthesized, tested, and reported in the literature. A comparative analysis of the predicted structures of these targets with the reported efficacy of their corresponding antisense reagents has allowed us to formulate a set of rules for the rational choice of hammerhead ribozyme flanking arms and cleavage sites.     

Analysis of flow instabilities in convex and concave floating zones heated by an equatorial ring under microgravity conditions

This analysis deals with advances in models concerning the floating zone technique as well as with novel results on the relative importance of various parameters in the crystal-growth process. The attention is focused in particular on microgravity fluid-dynamic aspects and on the effect of the volume of the liquid melt since the cylindrical configuration is expected to be only a very special case under microgravity conditions. The instability of Marangoni flow is investigated by direct three-dimensional and time-dependent simulation of the problem and parallel computations. Body-fitted curvilinear co-ordinates are adopted to handle the non-cylindrical shape. A novel realistic distribution is considered to model the surface heat flux generated by a ring heater positioned around the equatorial plane at a fixed distance from the axis of the liquid (full) zone.The fluid-dynamic environment that occurs inside the melt is very sensitive to the geometrical aspect ratio A_F (length/diameter) of the floating zone and to the volume factor S (ratio of the volume of the liquid zone and the volume of the corresponding cylindrical configuration: convex S>1, concave S<1). The role played by the geometrical constraints and degrees of freedom of the Marangoni toroidal rolls in determining the azimuthal structure and the stability of the flow field is discussed.     

Niobium pentoxide as promoter in the mixed MgH<Subscript>2</Subscript>/Nb<Subscript>2</Subscript>O<Subscript>5</Subscript> system for hydrogen storage: a multitechnique investigation of the H<Subscript>2</Subscript> uptake

Nb₂O₅ is known as good promoter for adsorption/desorption kinetics of hydrogen in magnesium hydride. In this article the interaction with hydrogen of bare Nb₂O₅, the oxidic component of the mixed MgH₂/Nb₂O₅ system, is investigated in various conditions (i.e. employing atomic, molecular and nascent hydrogen). The state of the hydrogen-Nb₂O₅ system was monitored using various techniques including: X-ray Diffraction, Electron Paramagnetic Resonance, Diffuse Reflectance UV-Vis Spectroscopy, Thermal Desorption Spectroscopy -Mass Spectrometry, Differential Scanning Calorimetry and Thermal Programmed Desorption. Niobium (V) oxide is not at all inert while interacting with hydrogen. This oxide is partially reduced by hydrogen, which is incorporated in the solid and released as both molecular hydrogen and water. This peculiar behaviour, reminiscent of some properties of the bronze family, suggests an active chemical role played by Nb₂O₅ in the mixed MgH₂/Nb₂O₅ system.     

Composition,preparation procedure and physical properties of linear homogeneous polyurethanes for membranes

Linear polyurethanes (PUs) were prepared in solution in two steps. In the first step, toluene‐diisocyanate (TDI) 80:20 (T) was reacted with a short‐chain poly(oxypropylene) diol (V) to obtain prepolymers characterized by various ratios of R = [T]°/[V]°. In the second step, the prepolymers were reacted with the extender 1,4‐cyclohexanedimethanol (E) with various extension ratios R_E = (R ? 1)[V]°/[E]°. The PU properties were analyzed by various techniques. In particular, the molecular weights determined by gel permeation chromatography (GPC), the thermal properties such as glass transition temperature T_g and specific heat variation ΔC_p measured by differential scanning calorimetry (DSC), the chemical composition of the PUs and the various types of hydrogen bonds present in the polymers evidenced by Fourier‐transform infrared (FTIR) spectroscopy, the monophasic structure evidenced by small‐angle X‐ray scattering (SAXS), and the existence of only one T_g confirmed that these PUs were linear, amorphous and monophasic. Positron annihilation lifetime spectroscopy (PALS) analysis showed that the mean volume of the nanoholes increased with increasing temperature, but was not dependent on the composition, as expected for a monophasic system. A stoichiometric semi‐empirical model was proposed that relates the PU blocks' micro‐composition to the R and R_E macro‐parameters, chosen for the synthesis. The polymer assumes various expressions of the general formula X? [(TV)_k? (TE)_n]_m? X for different values of the R and R_E ratios. The micro‐parameters k and m have a direct connection with the experimental mean molecular weights of the prepolymer and the polymer, respectively: n depends only on R. The model could foresee the density of hydrogen bonds and distinguished the bonds connected to either V or E, which could be shown by FTIR analysis. This paper shows that, when using stereo‐irregular diols and blends of 2,4‐ and 2,6‐TDI, non‐stereoregular PUs are obtained. If low‐molecular‐weight diols are used and R < 3.3, it is quite improbable that the PU blocks separate into macrophases and therefore monophasic amorphous PUs are obtained. Monophasic PUs can be useful for applications such as in the field of membrane gas and vapour separation. Copyright © 2005 Society of Chemical Industry     

Curvature Ratio Effect on Two-Phase Pressure Drops in Horizontal Return Bends: Experimental Data for R134a

This article presents 154 pressure drop data points measured during two-phase flow of R-134a in horizontal return bends. The tube diameter is constant at 10.85 mm and the curvature ratio is either 7.74 or 5.53. Saturation temperature varies from 15 to 20°C, vapor quality from 0.05 and 0.95, and mass velocity ranges from 300 to 600 kg m^?2 s^?1. Return bend pressure drops are calculated by subtracting the straight tube pressure drop from the total measured pressure drop along the bend. The perturbations induced up- and downstream of the singularity are taken into account in the measurements. The comparison of the pressure drops for the two configurations (curvature ratio of 5.53 and 7.74) showed that they are greater (about 10%) for the larger curvature ratio. This can be attributed to the effect of the developed length on the pressure drop; on the other side the pressure gradients are larger for the lower curvature ratio, which can be explained by the effect of the centrifugal force and the perturbations up- and downstream of the return bend. The experimental data are compared against four prediction methods available in the literature. The Domanski and Hermès correlation is the best at predicting the present data.