Abstract Aquaporins (AQPs) play a physiological role in several organs and tissues, and their alteration is associated with disorders of water regulation. The identification of molecular ...interactions, which are crucial in determining the rate of water flux through the channel, is of pivotal role for the discovery of molecules able to target those interactions and therefore to be used for pathologies ascribable to an altered AQP-dependent water balance. In the present study, a mutational screening of human aquaporin-4 (AQP4) gene was performed on subjects with variable degrees of hearing loss. One heterozygous missense mutation was identified in a Spanish sporadic case, leading to an Asp/Glu amino acid substitution at position 184 (D184E). A BLAST analysis revealed that the amino acid D184 is conserved across species, consistently with a crucial role in the structure/function of AQP4 water channels. The mutation induces a significant reduction in water permeability as measured by the Xenopus laevis oocytes swelling assay and by the use of mammalian cells by total internal reflection microscopy. By Western blot, immunofluorescence and 2D Blue Native/SDS-PAGE we show that the reduction in water permeability is not ascribable to a reduced expression of AQP4 mutant protein or to its incorrect plasma membrane targeting and aggregation into orthogonal arrays of particles. Molecular dynamics simulation provided a molecular explanation of the mechanism whereby the mutation induces a loss of function of the channel. Substituting glutamate for aspartate affects the mobility of the D loop, which acquires a higher propensity to equilibrate in a “closed conformation”, thus affecting the rate of water flux. We speculate that this mutation, combined with other genetic defects or concurrently with certain environmental stimuli, could confer a higher susceptibility to deafness.
Brivaracetam: review of its pharmacology and potential use as adjunctive therapy in patients with partial onset seizures CorrigendumMumoli L, Palleria C, Gasparini S, et al. Drug Des Devel Ther. ...2015;9:5719-5725. The authors advise several errors in the paper that are corrected in Corrigendum.View the original article by Mumoli et al.
Objective: To investigate cognitive and behavioural effects of bilateral lead implants for high frequency stimulation (HFS) of the subthalamic nucleus in patients with Parkinson’s disease; and to ...discriminate between HFS and the effects of surgical intervention on cognitive function by carrying out postoperative cognitive assessments with the stimulators turned on or off. Methods: Motor, cognitive, behavioural, and functional assessments were undertaken in 20 patients with Parkinson’s disease before implantation and then at three, six, and 12 months afterwards. Nine patients were also examined 18 months after surgery. Postoperative cognitive assessments were carried out with stimulators turned off at three and 18 months, and turned on at six and 12 months. Results: Cognitive assessment showed a significant postoperative decline in performance on tasks of letter verbal fluency (across all postoperative assessments, but more pronounced at three months) and episodic verbal memory (only at three months, with stimulators off). At three, six, and 12 months after surgery, there was a significant improvement in the mini-mental state examination and in a task of executive function (modified Wisconsin card sorting test). On all postoperative assessments, there was an improvement in parkinsonian motor symptoms, quality of life, and activities of daily living while off antiparkinsonian drugs. A significant postoperative decrease in depressive and anxiety symptoms was observed across all assessments. Similar results were seen in the subgroup of nine patients with an 18 month follow up. Following implantation, three patients developed transient manic symptoms and one showed persistent psychic akinesia. Conclusions: Bilateral HFS of the subthalamic nucleus is a relatively safe procedure with respect to long term cognitive and behavioural morbidity, although individual variability in postoperative cognitive and behavioural outcome invites caution. Stimulation of the subthalamic nucleus does not per se appear to impair cognitive performance in patients with Parkinson’s disease and may alleviate the postpoperative decline in verbal fluency.
Cardiac resynchronization therapy is beneficial in heart failure patients with LVEF ≤35% and electrical dyssynchrony. However, its effects among patients with less severe LV dysfunction have not been ...established. Recent post‐hoc analyses of landmark CRT trials suggest that CRT benefit may be present in patients with LVEF >35% and is associated with improvement in cardiac reverse remodelling, all‐cause mortality, and need for heart failure hospitalizations. This review summarizes the currently available literature regarding the potential impact of CRT in patients with more modest reductions in LVEF.
See Editorial by Maas, A.H. and Westenbrink, B. D
Since the introduction of the flexible fibreoptic bronchoscope in the late 1960s there have been relatively few technological advances for three decades, aside from the development of a white light ...video bronchoscope with a miniature charge-coupled device built in its tip replacing the fibreoptics. White light flexible videobronchoscopy with its ancillary devices (forceps biopsy, bronchial brushing, bronchoalveolar lavage, bronchial washings and transbronchial needle aspiration) has long been the only established diagnostic bronchoscopic technique. With the advances in microtechnology over the past two decades, recent technical developments such as autofluorescence bronchoscopy and endoscopic ultrasound allow better evaluation of endobronchial, mediastinal and parenchymal lesions.
Abstract Aim To assess the activity and safety of non-pegylated liposomal doxorubicin (Myocet®) in combination with docetaxel and trastuzumab as first-line treatment of patients with ...HER-2/neu-positive metastatic breast cancer (MBC). Patients and methods The maximum tolerated dose of the combination was defined in the phase I part of the study. In the phase II part, 45 HER-2/neu-positive MBC patients were enrolled to receive 6–8 cycles of Myocet® 50 mg/m2 (day 1), docetaxel 30 mg/m2 (days 2 and 9) plus trastuzumab (day 2, 4 mg/kg followed by 2 mg/kg/week) every 21 d until unacceptable toxicity or progression occurred. Objective response (primary end-point) and treatment tolerability were assessed according to World Health Organisation criteria. Cardiotoxicity was defined as signs and/or symptoms of congestive heart failure and/or a decrease in left ventricular ejection fraction (LVEF). Results The overall response rate was 55.6% (complete response 8.9%, partial response 46.7%), with a median time-to-progression of 10.9 months (C.I. 8.7–15.0). Median overall survival was not reached. The most frequent grade 3–4 adverse events were granulocytopaenia (60.0%), leukocytopenia (43.2%) and alopecia (35.6%). Grade 3–4 diarrhoea, pain, oral and skin toxicity (4.4%, each) and nausea/vomiting, thrombocytopenia and elevated alkaline phosphatase (2.2%, each) were also reported. In 2 patients LVEF fell to <50%, with a decrease from baseline >15%. LVEF median values remained stable from baseline to the end of the study (60%). Conclusions The combination of Myocet®, docetaxel and trastuzumab is safe and shows promising activity as first-line treatment of HER-2-positive MBC.
Juvenile or type 2 hemochromatosis (JH) is transmitted as a recessive trait that leads to severe iron overload and organ damage typically before age 30 years. Linkage to a locus on chromosome 1q has ...been found in most patients with JH. The recently identified causal gene encodes hemojuvelin, a protein with a proposed crucial role in iron metabolism. A second, rare type of JH, with clinical expression identical to the 1q-linked form, is due to inactivation of hepcidin, the key regulator of iron homeostasis. Here we report the spectrum of mutations of the hemojuvelin gene (HJV) in 34 patients who did not show hepcidin mutations. This represents the largest cohort of patients with JH collected worldwide. We identified 17 different (16 novel) mutations of HJV, both at the homozygous and at the compound heterozygous state. Mutations either generate premature termination codons or were missense substitutions, affecting highly conserved residues, relevant to the protein structure and/or function. (Blood. 2004;103:4317-4321)
Rhinoviruses are the major cause of the common cold and acute exacerbations of asthma and chronic obstructive pulmonary disease. We previously reported rapid rhinovirus induction of intracellular ...superoxide anion, resulting in NF-κB activation and pro-inflammatory molecule production. The mechanisms of rhinovirus superoxide induction are poorly understood. Here we found that the proteolytic activation of the xanthine dehydrogenase/xanthine oxidase (XD/XO) system was required because pretreatment with serine protease inhibitors abolished rhinovirus-induced superoxide generation in primary bronchial and A549 respiratory epithelial cells. These findings were confirmed by Western blotting analysis and by silencing experiments. Rhinovirus infection induced intracellular depletion of reduced glutathione (GSH) that was abolished by pretreatment with either XO inhibitor oxypurinol or serine protease inhibitors. Increasing intracellular GSH with exogenous H2S or GSH prevented both rhinovirus-mediated intracellular GSH depletion and rhinovirus-induced superoxide production. We propose that rhinovirus infection proteolytically activates XO initiating a pro-inflammatory vicious circle driven by virus-induced depletion of intracellular reducing power. Inhibition of these pathways has therapeutic potential.
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