We report on a 9-years-old patient with mild intellectual disability, facial dimorphisms, bilateral semicircular canal dysplasia, periventricular nodular heterotopias, bilateral hippocampal malrotation and abnormal cerebellar foliation, who developed mild motor impairment and gait disorder due to a pilocytic astrocytoma of the spinal cord. Array-CGH analysis revealed two paternal inherited chromosomal events: a 484.3 Kb duplication on chromosome 15q26.3 and a 247 Kb deletion on 22q11.23. Further, a second de novo 1.5 Mb deletion on 22q11.21 occurred. Chromosome 22 at q11.2 and chromosome 15 at q24q26 are considered unstable regions subjected to copy number variations, i.e. structural alterations of genome, mediated by low copy repeat sequences or segmental duplications. The link between some structural CNVs, which compromise fundamental processes controlling DNA stability, and genomic disorders suggest a plausible scenario for cancer predisposition.
Evaluation of the genes at the breakpoints cannot account simultaneously for the phenotype and tumour development in this patient. The two paternal inherited CNVs arguably are not pathogenic and do not contribute to the clinical manifestations. Similarly, although the de novo large deletion at 22q11.21 overlaps with the Di George (DGS) critical region and results in haploinsufficiency of genes compromising critical processes for DNA stability, this case lacks several hallmarks of DGS.
Pilocytic astrocytoma; Spinal cord; Semicircular canal dysplasia; 15q duplication; 22q11.2 deletion
Recent epidemiological data suggest that non-alcoholic fatty liver disease (NAFLD) is closely associated with aortic valve sclerosis (AVS), an emerging risk factor for adverse cardiovascular outcomes, in nondiabetic and type 2 diabetic individuals. To date, nobody has investigated the association between NAFLD and AVS in people with type 2 diabetes, a group of individuals in which the prevalence of these two diseases is high.
Methods and Results
We recruited 180 consecutive type 2 diabetic patients without ischemic heart disease, valvular heart disease, hepatic diseases or excessive alcohol consumption. NAFLD was diagnosed by liver ultrasonography whereas AVS was determined by conventional echocardiography in all participants. In the whole sample, 120 (66.7%) patients had NAFLD and 53 (29.4%) had AVS. No patients had aortic stenosis. NAFLD was strongly associated with an increased risk of prevalent AVS (odds ratio [OR] 2.79, 95% CI 1.3–6.1, p<0.01). Adjustments for age, sex, duration of diabetes, diabetes treatment, body mass index, smoking, alcohol consumption, hypertension, dyslipidemia, hemoglobin A1c and estimated glomerular filtration rate did not attenuate the strong association between NAFLD and risk of prevalent AVS (adjusted-OR 3.04, 95% CI 1.3–7.3, p = 0.01).
Our results provide the first demonstration of a positive and independent association between NAFLD and AVS in patients with type 2 diabetes mellitus.
Motivation: Structural characterization of protein interactions is necessary for understanding and modulating biological processes. On one hand, X-ray crystallography or NMR spectroscopy provide atomic resolution structures but the data collection process is typically long and the success rate is low. On the other hand, computational methods for modeling assembly structures from individual components frequently suffer from high false-positive rate, rarely resulting in a unique solution.
Results: Here, we present a combined approach that computationally integrates data from a variety of fast and accessible experimental techniques for rapid and accurate structure determination of protein–protein complexes. The integrative method uses atomistic models of two interacting proteins and one or more datasets from five accessible experimental techniques: a small-angle X-ray scattering (SAXS) profile, 2D class average images from negative-stain electron microscopy micrographs (EM), a 3D density map from single-particle negative-stain EM, residue type content of the protein–protein interface from NMR spectroscopy and chemical cross-linking detected by mass spectrometry. The method is tested on a docking benchmark consisting of 176 known complex structures and simulated experimental data. The near-native model is the top scoring one for up to 61% of benchmark cases depending on the included experimental datasets; in comparison to 10% for standard computational docking. We also collected SAXS, 2D class average images and 3D density map from negative-stain EM to model the PCSK9 antigen–J16 Fab antibody complex, followed by validation of the model by a subsequently available X-ray crystallographic structure.
email@example.com or firstname.lastname@example.org
Supplementary data are available at Bioinformatics online.
Neuromyelitis optica (NMO) is thought to be caused by immunoglobulin G autoantibodies (NMO-IgG) against astrocyte water channel aquaporin-4 (AQP4). A recent study (Hinson et al. (2012) Proc Natl Acad Sci USA 109:1245- 1250) reported that NMO-IgG inhibits AQP4 water permeability directly and causes rapid cellular internalization of the M1 but not M23 isoform of AQP4, resulting in AQP4 clustering, enhanced complement-dependent cytotoxicity, and tissue swelling. Here, we report evidence challenging this proposed mechanism of NMO-IgG-mediated pathology. We measured osmotic water permeability by stopped-flow light scattering on plasma membrane vesicles isolated from AQP4-expressing CHO cells, an approach that can detect changes in water permeability as small as 5% and is not confounded by internalization effects. We found similar single- molecule water permeability for M1-AQP4 tetramers and M23-AQP4 clusters (orthogonal arrays of particles, OAPs). Exposure of AQP4 to high concentrations of NMOIgG from six seropositive NMO patients, and to high-affinity recombinant monoclonal NMO antibodies, did not reduce AQP4 water permeability. Also, NMO-IgG did not reduce water permeability in AQP4-reconstituted proteoliposomes. In transfected cells expressing M1- or M23-AQP4 individually, NMO-IgG caused more rapid internalization of M23- than M1-AQP4. In cells coexpressing both isoforms, M1- and M23-AQP4 comingled in OAPs that were internalized together in response to NMO-IgG. Super-resolution imaging and native gel electrophoresis showed that the size of AQP4 OAPs was not altered by NMO sera or recombinant NMO antibodies. We conclude that NMO-IgG does not: (i) inhibit AQP4 water permeability, (ii) cause preferential internalization of M1-AQP4, or (iii) cause intramembrane AQP4 clustering.
AQP4; aquaporin; OAP; NMO; astrocyte
Patients with lymphoma who have experienced a first relapse or progression and have disease deemed sensitive to salvage chemotherapy nevertheless have a high likelihood of having a second relapse. To decrease the likelihood of a second relapse after high-dose therapy (HDT) and autologous stem cell transplantation (ASCT), interferon (IFN) α-2b was given in a prospective randomized international trial.
In this trial, 221 patients with varying histologic diagnoses (8 small lymphocytic, 37 follicular, 9 mantle, 90 diffuse large B-cell, 20 peripheral T-cell, 3 high-grade B-cell non-Hodgkin lymphoma, and 54 Hodgkin lymphoma) were randomly assigned to receive no further treatment (arm A: 117 patients) or IFNα-2b, 3 MU three times weekly, for 18 months (arm B: 104 patients).
In arm B, 21 patients (20%) did not receive IFNα-2b because of early progression or absence of hematologic recovery, 29 patients (28%) completed the 18 months of treatment, and 54 patients (52%) interrupted treatment because of progression (23%) or toxicity (29%). Event-free survival and overall survival were not different between the two arms on an intent-to-treat analysis and also if analysis was restricted to patients who were alive and had not experienced disease progression three months after transplantation. The study was not sufficiently powered to evaluate effects in histologic subtypes.
In this trial, post-autograft IFNα-2b did not improve outcomes in a heterogeneous group of patients with lymphoma.
To examine the association of aortic valve sclerosis (AVS) and mitral annulus calcification (MAC) with all-cause and cardiovascular mortality in type 2 diabetic individuals.
RESEARCH DESIGN AND METHODS
We retrospectively analyzed the data from 902 type 2 diabetic outpatients, who had undergone a transthoracic echocardiography for clinical reasons during the years 1992–2007. AVS and MAC were diagnosed by echocardiography, and a heart valve calcium (HVC) score was calculated by summing up the AVS and MAC variables. The study outcomes were all-cause and cardiovascular mortality.
At baseline, 477 (52.9%) patients had no heart valves affected (HVC-0), 304 (33.7%) had one valve affected (HVC-1), and 121 (13.4%) had both valves affected (HVC-2). During a mean follow-up of 9 years, 137 (15.2%) patients died, 78 of them from cardiovascular causes. Compared with patients with HVC-0, those with HVC-2 had the highest risk of all-cause and cardiovascular mortality, whereas those with HVC-1 had an intermediate risk (P < 0.0001 by the log-rank test). After adjustment for sex, age, BMI, systolic blood pressure, diabetes duration, A1C, LDL cholesterol, estimated glomerular filtration rate, smoking, history of myocardial infarction, and use of antihypertensive and lipid-lowering drugs, the hazard ratio of all-cause mortality was 2.3 (95% CI 1.1–4.9; P < 0.01) for patients with HVC-1 and 9.3 (3.9–17.4; P < 0.001) for those with HVC-2. Similar results were found for cardiovascular mortality.
Our findings indicate that AVS and MAC, singly or in combination, are independently associated with all-cause and cardiovascular mortality in type 2 diabetic patients.
At present there is no cure for chronic obstructive pulmonary disease (COPD). However, some nonpharmacologic treatments, such as rehabilitation and lung volume reduction surgery, as well as pharmacologic intervention, can relieve some of the patient’s symptoms and improve quality of life, while also reducing the rate of exacerbations and hospitalizations. There needs to be a paradigm shift away from the unjustified nihilistic approach to COPD towards considering it a preventable and treatable disease. After patients quit smoking and start to lead healthier lifestyles, long-acting bronchodilators, such as long-acting beta-adrenergic agents (LABA) and long-acting antimuscarinic agents (LAMA), are recommended as the cornerstone of treatment for COPD, either as monotherapy or in combination. COPD is characterized by a reduced maximum expiratory flow and slow forced emptying of the lungs, which progress over time and are not completely reversible. In this condition, gas gets trapped in the lungs and pulmonary hyperinflation occurs. LABA and LAMA improve airway patency and deflate the lungs. Indacaterol is the first once-daily LABA approved for treatment of COPD, and is administered by inhalation through the Breezhaler® device. The speed of bronchodilation is similar to that with salbutamol (ie, about five minutes) and longer (ie, 24 hours) than that with traditional LABA, with the same 12-hour effect as salmeterol and formoterol, both of which require twice-daily administration. This is why indacaterol has been called the “ultra-LABA”. On the one hand, the fast onset of action provides immediate relief of symptoms, and on the other, its constant 24-hour bronchodilation provides “pharmacologic stenting” which facilitates lung emptying, thereby decreasing trapped gas and pulmonary hyperinflation. Once-daily administration of a fast and long-acting bronchodilator can improve patient adherence with therapy, which is known to be a major problem for many medical treatments. Dose-finding trials have shown that 75 μg is the minimum dose needed to achieve clinically important improvement. However, indacaterol 150 μg and 300 μg achieve an even greater improvement in lung function and patient-oriented outcomes. Further, these two doses of indacaterol significantly reduce pulmonary hyperinflation, thereby improving exercise tolerance and ability to perform day-to-day activities. It is more effective on lung volumes at the 300 μg dose than formoterol, and better than salmeterol and tiotropium at the 150 μg dose, at least in the acute setting. It is noteworthy that few studies document these results in patients with COPD and moderate airflow obstruction. These are exactly the kind of patients our research should be concentrating on, in view of the accelerated decay in forced expiratory volume in one second at this stage of the disease. Finally, all the relevant studies show that indacaterol is consistently well tolerated by patients with COPD at every stage, and that it has a high safety profile.
indacaterol; chronic obstructive pulmonary disease
In spite of its recent achievements, the technique of single particle electron cryomicroscopy (cryoEM) has not been widely used to study proteins smaller than 100kDa, although it is a highly desirable application of this technique. One fundamental limitation is that images of small proteins embedded in vitreous ice do not contain adequate features for accurate image alignment. We describe a general strategy to overcome this limitation by selecting a fragment antigen binding (Fab) to form a stable and rigid complex with a target protein, thus providing a defined feature for accurate image alignment. Using this approach, we determined a three-dimensional structure of a ~65 kDa protein by single particle cryoEM. Because Fabs can be readily generated against a wide range of proteins by phage display, this approach is generally applicable to study many small proteins by single particle cryoEM.
Aquaporin-4 (AQP4) is a water-selective transporter expressed in astrocytes throughout the central nervous system, as well as in kidney, lung, stomach and skeletal muscle. The two AQP4 isoforms produced by alternative spicing, M1 and M23 AQP4, form heterotetramers that assemble in cell plasma membranes in supramolecular structures called orthogonal arrays of particles (OAPs). Phenotype analysis of AQP4-null mice indicates the involvement of AQP4 in brain and spinal cord water balance, astrocyte migration, neural signal transduction and neuroinflammation. AQP4-null mice manifest reduced brain swelling in cytotoxic cerebral edema, but increased brain swelling in vasogenic edema and hydrocephalus. AQP4 deficiency also increases seizure duration, impairs glial scarring, and reduces the severity of autoimmune neuroinflammation. Each of these phenotypes is likely explicable on the basis of reduced astrocyte water permeability in AQP4 deficiency. AQP4 is also involved in the neuroinflammatory demyelinating disease neuromyelitis optica (NMO), where autoantibodies (NMO-IgG) targeting AQP4 produce astrocyte damage and inflammation. Mice administered NMO-IgG and human complement by intracerebral injection develop characteristic NMO lesions with neuroinflammation, demyelination, perivascular complement deposition and loss of glial fibrillary acidic protein and AQP4 immunoreactivity. Our findings suggest the potential utility of AQP4-based therapeutics, including small-molecule modulators of AQP4 water transport function for therapy of brain swelling, injury and epilepsy, as well as small-molecule or monoclonal antibody blockers of NMO-IgG binding to AQP4 for therapy of NMO.
AQP4; water transport; transgenic mice; brain edema; astrocyte migration; neuroexcitation; neuroinflammation; epilepsy; neuromyelitis optica
Pathogenic autoantibodies target aquaporin-4 (AQP4) water channels in individuals with neuromyelitis optica (NMO). Recently, allelic mutations were reported at residue 19 of AQP4 in three cases of NMO, and it was suggested that polymorphisms may influence disease by altering AQP4 supramolecular assembly into orthogonal arrays of particles (OAPs). We analyzed the determinants of OAP formation by human AQP4 to investigate the possible role of polymorphisms in NMO pathogenesis. NMO-associated mutations R19I and R19T in AQP4 did not affect OAP assembly, palmitoylation-dependent regulation of assembly, or NMO autoantibody binding. Residue-19 polymorphisms in AQP4 are thus unlikely to be disease relevant.
NMO; AQP4; Water channel; Neuroinflammation
Aquaporin-4 (AQP4) is a water channel expressed in astrocytes throughout the central nervous system, as well as in epithelial cells in various peripheral organs. AQP4 is involved in brain water balance, neuroexcitation, astrocyte migration, and neuroinflammation and is the target of pathogenic autoantibodies in neuromyelitis optica. Two AQP4 isoforms produced by alternative splicing, M1 and M23 AQP4, form heterotetramers that assemble in cell plasma membranes in supramolecular aggregates called orthogonal arrays of particles (OAPs). OAPs have been studied morphologically, by freeze-fracture electron microscopy, and biochemically, by native gel electrophoresis. We have applied single-molecule and high-resolution fluorescence microscopy methods to visualize AQP4 and OAPs in live cells. Quantum dot single particle tracking of fluorescently labeled AQP4 has quantified AQP4 diffusion in membranes, and has elucidated the molecular determinants and regulation of OAP formation. The composition, structure, and kinetics of OAPs containing fluorescent protein-AQP4 chimeras have been studied utilizing total internal reflection fluorescence microscopy, single-molecule photobleaching, and super-resolution imaging methods. The biophysical data afforded by live-cell imaging of AQP4 and OAPs has provided new insights in the roles of AQP4 in organ physiology and neurological disease.
The supramolecular assembly of aquaporin-4 (AQP4) in orthogonal arrays of particles (OAPs) involves N-terminus interactions of the M23-AQP4 isoform. We found AQP4 OAPs in cell plasma membranes but not in endoplasmic reticulum (ER) or Golgi, as shown by: (i) native gel electrophoresis of brain and AQP4-transfected cells; (ii) photobleaching recovery of GFP-AQP4 chimeras in live cells; and (iii) freeze-fracture electron microscopy (FFEM). We found that AQP4 OAP formation in plasma membranes but not Golgi was not related to AQP4 density, pH, membrane lipid composition, C-terminal PDZ-domain interactions or α-syntrophin expression. Remarkably, however, fusion of AQP4-containing Golgi vesicles with (AQP4-free) plasma membrane vesicles produced OAPs, suggesting the involvement of plasma membrane factor(s) in AQP4 OAP formation. In investigating additional possible determinants of OAP assembly we discovered membrane curvature-dependent OAP assembly, in which OAPs were disrupted by extrusion of plasma membrane vesicles to ~110 nm diameter, but not to ~220 nm diameter. We conclude that AQP4 supramolecular assembly in OAPs is a post-Golgi phenomenon involving plasma membrane-specific factor(s). Post-Golgi and membrane curvature-dependent OAP assembly may be important for vesicle transport of AQP4 in the secretory pathway and AQP4-facilitated astrocyte migration, and suggests a novel therapeutic approach for neuromyelitis optica (NMO).
AQP4; OAP; NMO; Golgi
Neural tube defects (NTDs) are severe malformations of the central nervous system, affecting 1 of 1,000 live births. Mouse models were instrumental in defining the signaling pathways defective in NTDs, including the planar cell polarity (PCP), also called noncanonical Frizzled/Disheveled pathway. Based on the highly penetrant occurrence of NTDs in double Fzd3/Fzd6−/− mutant mice, we investigated the role of the human orthologues, FZD3 and FZD6, by resequencing a cohort of 473 NTDs patients and 639 ethnically matched controls. While we could not demonstrate a significant contribution of FZD3 gene, we identified five rare FZD6 variants that were absent in all controls and predicted to have a functional effect by computational analysis: one de novo frameshift mutation (c.1843_1844insA), three missense changes (p.Arg405Gln, p.Arg511Cys p.Arg511His), and one substitution (c.*20C>T) affecting the 3′-untranslated region (UTR) of the gene. The overall rate of predicted deleterious variants of FZD6 was 5.1-fold higher in cases compared to controls, resulting in a significantly increased NTDs mutation burden. This study demonstrates that rare nonsynonymous variants in FZD6 may contribute to NTDs in humans and enlarges the spectrum of mutations that link PCP pathway to NTDs. Hum Mutat 33:384–390, 2012. © 2011 Wiley Periodicals, Inc.
neural tube defects (NTD); planar cell polarity pathway; FZD6
Deletions and duplications of the PAFAH1B1 and YWHAE genes in 17p13.3 are associated with different clinical phenotypes. In particular, deletion of PAFAH1B1 causes isolated lissencephaly while deletions involving both PAFAH1B1 and YWHAE cause Miller-Dieker syndrome. Isolated duplications of PAFAH1B1 have been associated with mild developmental delay and hypotonia, while isolated duplications of YWHAE have been associated with autism. In particular, different dysmorphic features associated with PAFAH1B1 or YWHAE duplication have suggested the need to classify the patient clinical features in two groups according to which gene is involved in the chromosomal duplication.
We analyze the proband and his family by classical cytogenetic and array-CGH analyses. The putative rearrangement was confirmed by fluorescence in situ hybridization.
We have identified a family segregating a 17p13.3 duplication extending 329.5 kilobases by FISH and array-CGH involving the YWHAE gene, but not PAFAH1B1, affected by a mild dysmorphic phenotype with associated autism and mental retardation. We propose that BHLHA9, YWHAE, and CRK genes contribute to the phenotype of our patient. The small chromosomal duplication was inherited from his mother who was affected by a bipolar and borderline disorder and was alcohol addicted.
We report an additional familial case of small 17p13.3 chromosomal duplication including only BHLHA9, YWHAE, and CRK genes. Our observation and further cases with similar microduplications are expected to be diagnosed, and will help better characterise the clinical spectrum of phenotypes associated with 17p13.3 microduplications.
Familial 17p13.3 duplication syndrome; PAFAH1B1 and YWHAE genes; Array-CGH
Three-dimensional submicrometric structures and biomolecular patterns have been fabricated on a porous silicon film by an electron beam-based functionalization method. The immobilized proteins act as a passivation layer against material corrosion in aqueous solutions. The effects' dependence on the main parameters of the process (i.e., the electron beam dose, the biomolecule concentration, and the incubation time) has been demonstrated.
Porous silicon; Electron beam; Lithography; Micromachining; Biomolecules; 87.85.Va
A new species of the genus Euscorpius Thorell, 1876is described based on specimens collected from Dilek Peninsula (Davutlar, Aydın) in Turkey. It is characterized by an oligotrichous trichobothrial pattern (Pv= 7, et= 5/6, eb= 4) and small size. Euscorpius (Euscorpius) avcii
sp. n. is the first named species of the subgenus Euscorpius from Turkey.
Scorpion; Euscorpius; new species; Turkey
Current guidelines suggest specific criteria for oral or long-acting injectable antipsychotic drugs (LAIs). This review aims to describe the demographic and clinical characteristics of the ideal profile of the patient with schizophrenia treated with LAIs, through the analysis of nonrandomized studies.
A systematic review of nonrandomized studies in English was performed attempting to analyze the factors related to the choice and use of LAIs in daily practice. The contents were outlined using the Cochrane methods for nonrandomized studies and the variables included demographic as well as clinical characteristics. The available literature did not allow any statistical analysis that could be used to identify the ideal profile of patients with schizophrenia to be treated with LAIs.
Eighty publications were selected and reviewed. Prevalence of LAI use ranged from 4.8% to 66%. The only demographic characteristics that were consistently assessed through retrieved studies were age (38.5 years in the 1970’s, 35.8 years in the 1980’s, 39.3 years in the 1990’s, to 39.5 years in the 2000’s) and gender (male > female).
Efficacy was assessed through the use of various symptom scales and other indirect measurements; safety was assessed through extrapyramidal symptoms and the use of anticholinergic drugs, but these data were inconsistent and impossible to pool. Efficacy and safety results reported in the different studies yielded a good therapeutic profile with a maximum of 74% decrease in hospital admissions and the prevalence of extrapyramidal symptoms with LAIs consistently increased at 6, 12, 18, and 24 months (35.4%, 37.1%, 36.9%, and 41.3%, respectively).
This analysis of the available literature strongly suggests that further observational studies on patients with schizophrenia treated with LAIs are needed to systematically assess their demographic and clinical characteristics and the relationships between them and patient outcome.
Besides the good efficacy and safety profile of LAIs, health care staff must also take into account the importance of establishing a therapeutic alliance with the patient and his/her relatives when selecting the most appropriate treatment. LAIs seem to be a good choice not only because of their good safety and efficacy profile, but also because they improve compliance, a key factor to improving adherence and to establishing a therapeutic alliance between patients with schizophrenia, their relatives, and their health care providers.
Delayed-action preparations; Antipsychotic agents; Schizophrenia; Patients; Review
Modulation of host responses is an important strategy by which parasites ensure successful establishment and persistence. Host counteraction against this modulation may be required for the host to develop resistance to infection. In this pilot study, intestinal infection of dogs with E. granulosus induced a strong polarization of the cytokine response towards a Th2 phenotype. Consecutive rounds of infection and cure induced resistance to infection resulting in a dramatically lower parasite burden. Repeatedly-infected resistant dogs also lost immune polarization and developed a balanced Th1/Th2 response. No major differences were observed in the production of regulatory cytokines (IL-10, TGF-β) between dogs with high parasite load and dogs with only few intestinal parasites. These results suggest that E. granulosus-driven immunomodulation contributes to successful infection in the definitive host. This information might be relevant for the development of more effective vaccines against this stage of the parasite.
Echinococcus granulosus; dog; cytokines; immunomodulation; cestodes
To identify risk factors for suicide using data from a large, 3-year, multinational follow-up study of schizophrenia (SOHO study).
Baseline characteristics of 8,871 adult patients with schizophrenia were included in a logistic regression post-hoc analysis comparing patients who attempted and/or committed suicide during the study with those who did not.
384 (4.3%) patients attempted or committed suicide. Completed suicides were 27 (0.3%). The significant risk factors for suicide behaviors were previous suicidality, depressive symptoms, prolactin-related adverse events, male gender and history of hospitalization for schizophrenia.
In view of the observational design of the study and the post-hoc nature of the analysis, the identified risk factors should be confirmed by ad-hoc specifically designed studies.
Suicide; Schizophrenia; Observational study
Previous cross-sectional studies demonstrate positive associations of fat-free mass and negative associations of centrally distributed fat deposits with respiratory function in older adults. Few studies have evaluated whether greater losses of muscle and increases in fat are associated with more rapid decline in respiratory function in aging.
Nine hundred and fifty-seven men and 1,024 women aged, respectively, 73.6 ± 2.8 years and 73.2 ± 2.8 years at baseline were followed for 5 years. Body weight, waist circumference, bone mineral density, fat-free mass, fat mass and fat mass percentage as measured by DXA, abdominal subcutaneous and visceral adipose tissue, thigh muscle area, thigh intermuscular fat by CT and forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) were evaluated at baseline and after 5-years follow-up.
Cross-sectional analyses showed that height and thigh muscle area were positively and visceral adipose tissue negatively related to FEV1 and FVC. Increase in fat mass over five years was associated with concurrent FEV1 and FVC decline. In analyses stratified by weight-change categories, men and women who gained weight (vs stable/lost weight) had more rapid declines in FEV1 and FVC.
In this well-functioning cohort, less muscle and greater abdominal fat were each associated with poorer lung spirometry cross-sectionally, whereas increase in fat mass over 5 years was associated with concurrent FEV1 and FVC decline. Weight gain and accompanying fat deposition may accelerate age-related declines in respiratory function.
Aging; Lung function; Body composition
Aquaporins (AQPs) have a broad range of cellular and organ functions; however, nontoxic inhibitors of AQP water transport are not available. Here, we applied chromophore-assisted light inactivation (CALI) to inhibit the water permeability of AQP1, and of two AQP4 isoforms (M1 and M23), one of which (M23) forms aggregates at the cell plasma membrane. Chimeras containing Killer Red (KR) and AQPs were generated with linkers of different lengths. Osmotic water permeability of cells expressing KR/AQP chimeras was measured from osmotic swelling–induced dilution of cytoplasmic chloride, which was detected using a genetically encoded chloride-sensing fluorescent protein. KR-AQP1 red fluorescence was bleached rapidly (∼10% per second) by wide-field epifluorescence microscopy. After KR bleaching, KR-AQP1 water permeability was reduced by up to 80% for the chimera with the shortest linker. Remarkably, CALI-induced reduction in AQP4-KR water permeability was approximately twice as efficient for the aggregate-forming M23 isoform; this suggests intermolecular CALI, which was confirmed by native gel electrophoresis on cells coexpressing M23-AQP4-KR and myc-tagged M23-AQP4. CALI also disrupted the interaction of AQP4 with a neuromyelitis optica autoantibody directed against an extracellular epitope on AQP4. CALI thus permits rapid, spatially targeted and irreversible reduction in AQP water permeability and interactions in live cells. Our data also support the utility of CALI to study protein–protein interactions as well as other membrane transporters and receptors.
Water channel aquaporin-4 (AQP4) is expressed in astrocytes throughout brain and spinal cord. Two major AQP4 isoforms are expressed, M1 and M23, having different translation initiation sites. A longer isoform (Mz) has been reported in rat with translation initiation 126-bp upstream from that of M1. By immunoblot analysis of SDS and native gels probed with a C-terminus anti-AQP4 antibody, Mz was detected in rat brain as a distinct band of size ~39 kDa. Mz was absent in human and mouse brain because of in-frame stop codons. The ability of rat Mz to form orthogonal arrays of particles (OAPs) was investigated by single particle tracking and native gel electrophoresis. We found that Mz, like M1, diffused rapidly in the cell plasma membrane and did not form OAPs. However, when coexpressed with M23, Mz associated in OAPs by forming heterotetramers with M23. Unexpectedly, Mz-expressing cells bound neuromyelitis optica autoantibodies (NMO-IgG) poorly, <5-fold compared to M1-expressing cells. Truncation analysis suggested that the poor NMO-IgG binding to Mz involves residues 31–41 upstream of Met-1. We conclude that Mz AQP4 is: (a) present at low level in rat but not human or mouse brain; (b) unable to form OAPs on its own but able to associate with M23 AQP4 in heterotetramers; and (c) largely unable to bind NMO-IgG because of N-terminus effects on the structure of the AQP4 / NMO-IgG binding site.
AQP4; water channel; astrocyte; NMO; orthogonal arrays of particles
Asthma guidelines suggest that therapy can be reduced once asthma is controlled. Despite these recommendations, asthmatic patients are seldom stepped down in clinical practice, and questions remain about when and how to reduce asthma therapy. The purpose of the present study was to evaluate lung function and asthma control in patients who were stepped down from the highest recommended dose of inhaled corticosteroid/long acting β2 agonist combination therapy.
This was a prospective, randomised, controlled, two-arm parallel group study. Asthmatic patients who were fully controlled with a high daily dose (1000/100 μg) of fluticasone/salmeterol were randomly assigned to 6 months of open-label treatment with either 500/100 μg fluticasone/salmeterol Diskus daily or 400/24 μg extrafine beclomethasone/formoterol pMDI daily. The primary outcome was the change in morning peak expiratory flow (PEF) values between baseline and the end of treatment. The secondary outcomes included asthma control and exacerbation frequency.
Four hundred twenty-two patients were included in the analysis. The PEF values remained above 95% of the predicted values throughout the study. The end-study morning PEF rates showed equivalence between the groups (difference between means, 2.49 L/min; 95% CI, -13.43 to 18.42). No changes from baseline were detected in PEF and forced expiratory volume in 1 second measured at the clinics, in the symptom scores or in the use of rescue medication. Asthma control was maintained in 95.2% of the patients at 6 months. No significant differences between the groups were detected in any other parameter, including exacerbation frequency and adverse events.
Stepping down patients whose asthma is controlled with the highest recommended dose of fluticasone/salmeterol to either 500/100 μg fluticasone/salmeterol daily or 400/24 μg extra-fine beclomethasone/formoterol daily provides comparable maintenance of lung function and asthma control.
Beclomethasone; Extrafine; Fluticasone; Formoterol; Salmeterol
New paradigms have been recently proposed in the pathogenesis of both chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF), evidencing surprising similarities between these deadly diseases, despite their obvious clinical, radiological and pathologic differences. There is growing evidence supporting a "double hit" pathogenic model where in both COPD and IPF the cumulative action of an accelerated senescence of pulmonary parenchyma (determined by either telomere dysfunction and/or a variety of genetic predisposing factors), and the noxious activity of cigarette smoke-induced oxidative damage are able to severely compromise the regenerative potential of two pulmonary precursor cell compartments (alveolar epithelial precursors in IPF, mesenchymal precursor cells in COPD/emphysema). The consequent divergent derangement of signalling pathways involved in lung tissue renewal (mainly Wnt and Notch), can eventually lead to the distinct abnormal tissue remodelling and functional impairment that characterise the alveolar parenchyma in these diseases (irreversible fibrosis and bronchiolar honeycombing in IPF, emphysema and airway chronic inflammation in COPD).
COPD; IPF; precursor cell senescence; telomere dysfunction; Wnt; Notch; Caveolin-1
Chronic right ventricular (RV) apical pacing may lead to left ventricular (LV) dyssynchrony and LV dysfunction. In heart failure due to RV pacing, upgrading to biventricular stimulation (CRT) can improve NYHA Class and LV function. A proportion of patients do not respond to upgrading. Aim was to assess whether etiology of LV dysfunction accounts for responses to CRT in RV-paced patients.
Sixty-two patients treated by CRT, under RV pacing from 50.2 ± 5.4 months, were studied. Cause of LV dysfunction was non-ischemic (NIC) in 28 and ischemic cardiomyopathy (IC) in 34 patients. Clinical and conventional echocardiographic parameters were available within 1 month before RV pacing, within 1 month before CRT and at 12 ± 2 months of follow-up (FU).
Decreased LVEF (from 37.0 ± 8.8 to 25.6 ± 6.1%, p <0.001), increased LV end-systolic dimensions (LVESD) (from 48.1 ± 8.6 to 55.2 ± 7.9 mm, p <0.001) and worsened NYHA Class (from 1.9 ± 1.1 to 3.2 ± .6, p < 0.005) were found before CRT, compared to pre RV-pacing. After CRT, 44/62 patients showed a ≥ 1 NYHA Class improvement; >10% decrease in LVESD was observed in 24 patients: 5 with IC, 19 with NIC (p < .0.001). The association between cause of LV dysfunction with >10% decrease in LVESD remained highly significant (p < 0.001) adjusting for pre-CRT QRS duration, NYHA Class, LVEF, LVESD, treatment or RV pacing duration.
CRT improves functional class even after long-lasting pacing. Reverse remodeling is evident in a small population, more likely with NIC.
congestive heart failure; biventricular stimulation; non-ischemic cardiomyopathy; ischemic cardiomyopathy