50 research outputs found
Alfvenic waves in polar spicules
Context. For investigating spicules from the photosphere to coronal heights,
the new Hinode/SOT long series of high resolution observations from Space taken
in CaII H line emission offers an improved way to look at their remarkable
dynamical behavior using images free of seeing effects. They should be put in
the context of the huge amount of already accumulated material from
ground-based instruments, including high- resolution spectra of off-limb
spicules. Results. The surge-like behavior of solar polar region spicules
supports the untwisting multi-component interpretation of spicules exhibiting
helical dynamics. Several tall spicules are found with (i) upward and downward
flows similar at lower and middle-levels, the rate of upward motion being
slightly higher at high levels; (ii) the left and right-hand velocities are
also increasing with height; (iii) a large number of multi-component spicules
show shearing motion of both left-handed and right-handed senses occurring
simultaneously, which might be understood as twisting (or untwisting) threads.
The number of turns depends on the overall diameter of the structure made of
components and changes from at least one turn for the smallest structure to at
most two or three turns for surge-like broad structures; the curvature along
the spicule corresponds to a low turn number similar to a transverse kink mode
oscillation along the threads.Comment: 8 pages, 10 figures, Accepted in Astronomy and Astrophysic
Hemodynamic effect of atrioventricular and interventricular dyssynchrony in patients with biventricular pacing: Implications for the pacemaker syndrome
Background/Objectives: Pacemaker syndrome was mainly described as the sequel of atrioventricular (AV) dyssynchrony. The role of interventricular (VV) dyssynchrony has not been studied yet. The aims of this study were to noninvasively assess the hemodynamic effects of different ventricular pacing sites with and without AV and VV dyssynchrony and to observe the patients for clinical symptoms of the pacemaker syndrome during the AV sequential and ventricular-only pacing modes. Materials and Methods: Between March 2009 and February 2010, 40 patients (28 men; mean age, 61 ± 15 years) with biventricular (BiV) device were enrolled. Mean systolic and diastolic blood pressures (BP) of 5 beats were measured 5 minutes after each mode change using fingertip plethysmography. The patients were also observed for the occurrence of symptoms suggestive of the pacemaker syndrome, including dyspnea, palpitations, dizziness, presyncope, and syncope. Results: There was no difference in mean systolic BP among different ventricular-only pacing modes (all P = NS). However, mean systolic BP was significantly higher in AV sequential biventricular pacing (DDD-BiV) compared with ventricular-only pacing modes (all P0.05). Conclusions: The present study showed that the non-AV sequential BiV and LV pacing may have no significant benefit compared with RV pacing in terms of systolic blood pressure. However, there was marked hemodynamic improvement following mode change to AV sequential BiV pacing. This study may have important implications for pathogenesis of pacemaker syndrome
Biallelic SQSTM1 mutations in early-onset, variably progressive neurodegeneration.
OBJECTIVE: To characterize clinically and molecularly an early-onset, variably progressive neurodegenerative disorder characterized by a cerebellar syndrome with severe ataxia, gaze palsy, dyskinesia, dystonia, and cognitive decline affecting 11 individuals from 3 consanguineous families. METHODS: We used whole-exome sequencing (WES) (families 1 and 2) and a combined approach based on homozygosity mapping and WES (family 3). We performed in vitro studies to explore the effect of the nontruncating SQSTM1 mutation on protein function and the effect of impaired SQSTM1 function on autophagy. We analyzed the consequences of sqstm1 down-modulation on the structural integrity of the cerebellum in vivo using zebrafish as a model. RESULTS: We identified 3 homozygous inactivating variants, including a splice site substitution (c.301+2T>A) causing aberrant transcript processing and accelerated degradation of a resulting protein lacking exon 2, as well as 2 truncating changes (c.875_876insT and c.934_936delinsTGA). We show that loss of SQSTM1 causes impaired production of ubiquitin-positive protein aggregates in response to misfolded protein stress and decelerated autophagic flux. The consequences of sqstm1 down-modulation on the structural integrity of the cerebellum in zebrafish documented a variable but reproducible phenotype characterized by cerebellum anomalies ranging from depletion of axonal connections to complete atrophy. We provide a detailed clinical characterization of the disorder; the natural history is reported for 2 siblings who have been followed up for >20 years. CONCLUSIONS: This study offers an accurate clinical characterization of this recently recognized neurodegenerative disorder caused by biallelic inactivating mutations in SQSTM1 and links this phenotype to defective selective autophagy
Gray Matter Changes in Parkinson's and Alzheimer's Disease and Relation to Cognition
Purpose of Review We summarize structural (s)MRI findings of gray matter (GM) atrophy related to cognitive impairment in Alzheimer's disease (AD) and Parkinson's disease (PD) in light of new analytical approaches and recent longitudinal studies results. Recent Findings The hippocampus-to-cortex ratio seems to be the best sMRI biomarker to discriminate between various AD subtypes, following the spatial distribution of tau pathology, and predict rate of cognitive decline. PD is clinically far more variable than AD, with heterogeneous underlying brain pathology. Novel multivariate approaches have been used to describe patterns of early subcortical and cortical changes that relate to more malignant courses of PD. New emerging analytical approaches that combine structural MRI data with clinical and other biomarker outcomes hold promise for detecting specific GM changes in the early stages of PD and preclinical AD that may predict mild cognitive impairment and dementia conversion
Phenotypic continuum of NFU1-related disorders.
Bi-allelic variants in Iron-Sulfur Cluster Scaffold (NFU1) have previously been associated with multiple mitochondrial dysfunctions syndrome 1 (MMDS1) characterized by early-onset rapidly fatal leukoencephalopathy. We report 19 affected individuals from 10 independent families with ultra-rare bi-allelic NFU1 missense variants associated with a spectrum of early-onset pure to complex hereditary spastic paraplegia (HSP) phenotype with a longer survival (16/19) on one end and neurodevelopmental delay with severe hypotonia (3/19) on the other. Reversible or irreversible neurological decompensation after a febrile illness was common in the cohort, and there were invariable white matter abnormalities on neuroimaging. The study suggests that MMDS1 and HSP could be the two ends of the NFU1-related phenotypic continuum
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Biallelic MED27 variants lead to variable ponto-cerebello-lental degeneration with movement disorders.
MED27 is a subunit of the Mediator multiprotein complex, which is involved in transcriptional regulation. Biallelic MED27 variants have recently been suggested to be responsible for an autosomal recessive neurodevelopmental disorder with spasticity, cataracts and cerebellar hypoplasia. We further delineate the clinical phenotype of MED27-related disease by characterizing the clinical and radiological features of 57 affected individuals from 30 unrelated families with biallelic MED27 variants. Using exome sequencing and extensive international genetic data sharing, 39 unpublished affected individuals from 18 independent families with biallelic missense variants in MED27 have been identified (29 females, mean age at last follow-up 17 ± 12.4 years, range 0.1-45). Follow-up and hitherto unreported clinical features were obtained from the published 12 families. Brain MRI scans from 34 cases were reviewed. MED27-related disease manifests as a broad phenotypic continuum ranging from developmental and epileptic-dyskinetic encephalopathy to variable neurodevelopmental disorder with movement abnormalities. It is characterized by mild to profound global developmental delay/intellectual disability (100%), bilateral cataracts (89%), infantile hypotonia (74%), microcephaly (62%), gait ataxia (63%), dystonia (61%), variably combined with epilepsy (50%), limb spasticity (51%), facial dysmorphism (38%) and death before reaching adulthood (16%). Brain MRI revealed cerebellar atrophy (100%), white matter volume loss (76.4%), pontine hypoplasia (47.2%) and basal ganglia atrophy with signal alterations (44.4%). Previously unreported 39 affected individuals had seven homozygous pathogenic missense MED27 variants, five of which were recurrent. An emerging genotype-phenotype correlation was observed. This study provides a comprehensive clinical-radiological description of MED27-related disease, establishes genotype-phenotype and clinical-radiological correlations and suggests a differential diagnosis with syndromes of cerebello-lental neurodegeneration and other subtypes of 'neuro-MEDopathies'
Explanation of parent gender difference on needs of children of parent with mental illness: a qualitative research
Background: Parents play an important role in a child's life. The roles of parents are impaired by mental illness and this issue affects the child’s needs and meets them.
Objective: This study was designed and conducted to explain gender differences of parents with mental illness on their children needs.
Methods: This study was conducted using the grounded theory. Semi structured interviews were conducted with 17 participants in Qazvin 2010, selected based on purposeful and theoretical
sampling. Participants included children of patients with mental disorders, their families and mental health professionals (nurses, clinical psychologist and counselor). Data were analyzed using
constant comparison method suggested by Strauss & Corbin 1998.
Findings: Economic and social outcomes are two major problems occur in father illness, But focus of outcomes of mother's illness is emotional. Although all participants believed except Parents
gender, their illness affected on children; but mother illness has serious outcomes.
Conclusion: With respect to children problems in parents' mental illness, a special place for children should be considered in the patient care plan, especially when the mother has mental illness
that this issue is more important
Side Effects of Intravenous Streptokinase in Different Age Groups Patients with Acute Myocardial Infarction
Abstract
Background & aim: Myocardial infarction is one of the most common cardiovascular diseases. Streptokinase is used in patients with myocardial infarction with ST-segment elevation. The aim of this study was to compare the side effects of intravenous streptokinase in acute myocardial infarction patients in different age groups.
Methods: In the present analytic descriptive study, the samples included 100 eligible patients which received intravenous streptokinase. The research instrument was a questionnaire consisting of two parts: the first part was used to measure the underlying data and the second part to evaluate the side effects of intravenous streptokinase,. Data were analyzed by chi-square statistical tests.
Results: There were no significant adverse events between intravenous streptokinase and different age groups ((P>0.05).). The most common side effects of this drug were cardiovascular complications in different age groups.
Conclusion: the use of streptokinase intravenous drug in different age groups is associated with risk of cardiovascular complications.
Key words: age, side effects, streptokinase, acute myocardial infarction, thrombolytic therapy, ST elevatio