35 research outputs found
Spectroscopy of very hot plasma in non-flaring parts of a solar limb active region: spatial and temporal properties
In this work we investigate the thermal structure of an off-limb active
region in various non-flaring areas, as it provides key information on the way
these structures are heated. In particular, we concentrate in the very hot
component (>3 MK) as it is a crucial element to discriminate between different
heating mechanisms. We present an analysis using Fe and Ca emission lines from
both SOHO/SUMER and HINODE/EIS. A dataset covering all ionization stages from
Fe X to Fe XIX has been used for the thermal analysis (both DEM and EM). Ca XIV
is used for the SUMER-EIS radiometric cross-calibration.
We show how the very hot plasma is present and persistent almost everywhere
in the core of the limb AR. The off-limb AR is clearly structured in Fe XVIII.
Almost everywhere, the EM analysis reveals plasma at 10 MK (visible in Fe XIX
emission) which is down to 0.1% of EM of the main 3 MK plasma. We estimate the
power law index of the hot tail of the EM to be between -8.5 and -4.4. However,
we leave an open question on the possible existence of a small minor peak at
around 10 MK. The absence in some part of the AR of Fe XIX and Fe XXIII lines
(which fall into our spectral range) enables us to determine an upper limit on
the EM at such temperatures. Our results include a new Ca XIV 943.59 \AA~
atomic model
Deciphering OPA1 mutations pathogenicity by combined analysis of human, mouse and yeast cell models
OPA1 is the major gene responsible for Dominant Optic Atrophy (DOA) and the syndromic form DOA “plus”. Over 370 OPA1 mutations have been identified so far, although their pathogenicity is not always clear. We have analyzed one novel and a set of known OPA1 mutations to investigate their impact on protein functions in primary skin fibroblasts and in two “ad hoc” generated cell systems: the MGM1/OPA1 chimera yeast model and the Opa1−/− MEFs model expressing the mutated human OPA1 isoform 1. The yeast model allowed us to confirm the deleterious effects of these mutations and to gain information on their dominance/recessivity. The MEFs model enhanced the phenotypic alteration caused by mutations, nicely correlating with the clinical severity observed in patients, and suggested that the DOA “plus” phenotype could be induced by the combinatorial effect of mitochondrial network fragmentation with variable degrees of mtDNA depletion. Overall, the two models proved to be valuable tools to functionally assess and define the deleterious mechanism and the pathogenicity of novel OPA1 mutations, and useful to testing new therapeutic interventions
The mitochondrial master regulator gene PGC1alpha in novel sporadic melanoma cell lines: correlations with BRAF mutational status
Deciphering OPA1 mutations pathogenicity by combined analysis of human, mouse and yeast cell models
OPA1 is the major gene responsible for Dominant Optic Atrophy (DOA) and the syndromic form DOA “plus”. Over 370 OPA1 mutations have been identified so far, although their pathogenicity is not always clear. We have analyzed one novel and a set of known OPA1 mutations to investigate their impact on protein functions in primary skin fibroblasts and in two “ad hoc” generated cell systems: the MGM1/OPA1 chimera yeast model and the Opa1−/− MEFs model expressing the mutated human OPA1 isoform 1. The yeast model allowed us to confirm the deleterious effects of these mutations and to gain information on their dominance/recessivity. The MEFs model enhanced the phenotypic alteration caused by mutations, nicely correlating with the clinical severity observed in patients, and suggested that the DOA “plus” phenotype could be induced by the combinatorial effect of mitochondrial network fragmentation with variable degrees of mtDNA depletion. Overall, the two models proved to be valuable tools to functionally assess and define the deleterious mechanism and the pathogenicity of novel OPA1 mutations, and useful to testing new therapeutic interventions
The First Flight of the Marshall Grazing Incidence X-ray Spectrometer (MaGIXS)
The Marshall Grazing Incidence X-ray Spectrometer (MaGIXS) sounding rocket
experiment launched on July 30, 2021 from the White Sands Missile Range in New
Mexico. MaGIXS is a unique solar observing telescope developed to capture X-ray
spectral images, in the 6 - 24 Angstrom wavelength range, of coronal active
regions. Its novel design takes advantage of recent technological advances
related to fabricating and optimizing X-ray optical systems as well as
breakthroughs in inversion methodologies necessary to create spectrally pure
maps from overlapping spectral images. MaGIXS is the first instrument of its
kind to provide spatially resolved soft X-ray spectra across a wide field of
view. The plasma diagnostics available in this spectral regime make this
instrument a powerful tool for probing solar coronal heating. This paper
presents details from the first MaGIXS flight, the captured observations, the
data processing and inversion techniques, and the first science results.Comment: 20 pages, 18 figure
Genome-wide expression profiling and functional characterization of SCA28 lymphoblastoid cell lines reveal impairment in cell growth and activation of apoptotic pathways
BACKGROUND:
SCA28 is an autosomal dominant ataxia associated with AFG3L2 gene mutations. We performed a whole genome expression profiling using lymphoblastoid cell lines (LCLs) from four SCA28 patients and six unrelated healthy controls matched for sex and age.
METHODS:
Gene expression was evaluated with the Affymetrix GeneChip Human Genome U133A 2.0 Arrays and data were validated by real-time PCR.
RESULTS:
We found 66 genes whose expression was statistically different in SCA28 LCLs, 35 of which were up-regulated and 31 down-regulated. The differentially expressed genes were clustered in five functional categories: (1) regulation of cell proliferation; (2) regulation of programmed cell death; (3) response to oxidative stress; (4) cell adhesion, and (5) chemical homeostasis. To validate these data, we performed functional experiments that proved an impaired SCA28 LCLs growth compared to controls (p\u2009<\u20090.005), an increased number of cells in the G0/G1 phase (p\u2009<\u20090.001), and an increased mortality because of apoptosis (p\u2009<\u20090.05). We also showed that respiratory chain activity and reactive oxygen species levels was not altered, although lipid peroxidation in SCA28 LCLs was increased in basal conditions (p\u2009<\u20090.05). We did not detect mitochondrial DNA large deletions. An increase of TFAM, a crucial protein for mtDNA maintenance, and of DRP1, a key regulator of mitochondrial dynamic mechanism, suggested an alteration of fission/fusion pathways.
CONCLUSIONS:
Whole genome expression profiling, performed on SCA28 LCLs, allowed us to identify five altered functional categories that characterize the SCA28 LCLs phenotype, the first reported in human cells to our knowledge. \ua9 2013 Mancini et al.; licensee BioMed Central Ltd
Off-label long acting injectable antipsychotics in real-world clinical practice: a cross-sectional analysis of prescriptive patterns from the STAR Network DEPOT study
Introduction Information on the off-label use of Long-Acting Injectable (LAI) antipsychotics in the real world is lacking. In this study, we aimed to identify the sociodemographic and clinical features of patients treated with on- vs off-label LAIs and predictors of off-label First- or Second-Generation Antipsychotic (FGA vs. SGA) LAI choice in everyday clinical practice. Method In a naturalistic national cohort of 449 patients who initiated LAI treatment in the STAR Network Depot Study, two groups were identified based on off- or on-label prescriptions. A multivariate logistic regression analysis was used to test several clinically relevant variables and identify those associated with the choice of FGA vs SGA prescription in the off-label group. Results SGA LAIs were more commonly prescribed in everyday practice, without significant differences in their on- and off-label use. Approximately 1 in 4 patients received an off-label prescription. In the off-label group, the most frequent diagnoses were bipolar disorder (67.5%) or any personality disorder (23.7%). FGA vs SGA LAI choice was significantly associated with BPRS thought disorder (OR = 1.22, CI95% 1.04 to 1.43, p = 0.015) and hostility/suspiciousness (OR = 0.83, CI95% 0.71 to 0.97, p = 0.017) dimensions. The likelihood of receiving an SGA LAI grew steadily with the increase of the BPRS thought disturbance score. Conversely, a preference towards prescribing an FGA was observed with higher scores at the BPRS hostility/suspiciousness subscale. Conclusion Our study is the first to identify predictors of FGA vs SGA choice in patients treated with off-label LAI antipsychotics. Demographic characteristics, i.e. age, sex, and substance/alcohol use co-morbidities did not appear to influence the choice towards FGAs or SGAs. Despite a lack of evidence, clinicians tend to favour FGA over SGA LAIs in bipolar or personality disorder patients with relevant hostility. Further research is needed to evaluate treatment adherence and clinical effectiveness of these prescriptive patterns
The Role of Attitudes Toward Medication and Treatment Adherence in the Clinical Response to LAIs: Findings From the STAR Network Depot Study
Background: Long-acting injectable (LAI) antipsychotics are efficacious in managing psychotic symptoms in people affected by severe mental disorders, such as schizophrenia and bipolar disorder. The present study aimed to investigate whether attitude toward treatment and treatment adherence represent predictors of symptoms changes over time. Methods: The STAR Network \u201cDepot Study\u201d was a naturalistic, multicenter, observational, prospective study that enrolled people initiating a LAI without restrictions on diagnosis, clinical severity or setting. Participants from 32 Italian centers were assessed at three time points: baseline, 6-month, and 12-month follow-up. Psychopathological symptoms, attitude toward medication and treatment adherence were measured using the Brief Psychiatric Rating Scale (BPRS), the Drug Attitude Inventory (DAI-10) and the Kemp's 7-point scale, respectively. Linear mixed-effects models were used to evaluate whether attitude toward medication and treatment adherence independently predicted symptoms changes over time. Analyses were conducted on the overall sample and then stratified according to the baseline severity (BPRS < 41 or BPRS 65 41). Results: We included 461 participants of which 276 were males. The majority of participants had received a primary diagnosis of a schizophrenia spectrum disorder (71.80%) and initiated a treatment with a second-generation LAI (69.63%). BPRS, DAI-10, and Kemp's scale scores improved over time. Six linear regressions\u2014conducted considering the outcome and predictors at baseline, 6-month, and 12-month follow-up independently\u2014showed that both DAI-10 and Kemp's scale negatively associated with BPRS scores at the three considered time points. Linear mixed-effects models conducted on the overall sample did not show any significant association between attitude toward medication or treatment adherence and changes in psychiatric symptoms over time. However, after stratification according to baseline severity, we found that both DAI-10 and Kemp's scale negatively predicted changes in BPRS scores at 12-month follow-up regardless of baseline severity. The association at 6-month follow-up was confirmed only in the group with moderate or severe symptoms at baseline. Conclusion: Our findings corroborate the importance of improving the quality of relationship between clinicians and patients. Shared decision making and thorough discussions about benefits and side effects may improve the outcome in patients with severe mental disorders