185 research outputs found
Impaired sense of smell in a Drosophila Parkinson's model.
Parkinson’s disease (PD) is one of the most common neurodegenerative disease characterized by the clinical triad: tremor, akinesia and rigidity. Several studies have suggested that PD patients show disturbances in olfaction at the earliest onset of the disease. The fruit fly Drosophila melanogaster 32 is becoming a powerful model organism to study neurodegenerative diseases. We sought to use this system to explore olfactory dysfunction, if any, in PINK1 mutants, which is a model for PD. PINK1 mutants display many important diagnostic symptoms of the disease such as akinetic motor behavior. In the present study, we describe for the first time, to the best of our knowledge, neurophysiological and neuroanatomical results concerning the olfactory function in PINK1 mutant flies. Electroantennograms were recorded in response to synthetic and natural volatiles (essential oils) from groups of PINK1 mutant adults at three different time points in their life cycle: one from 3-5 day-old flies, from 15-20 and from 27-30 days. The results obtained were compared with the same age-groups of wild type flies. We found that mutant adults showed a decrease in the olfactory response to 1-hexanol, α-pinene and essential oil volatiles. This olfactory response in mutant adults decreased even more as the flies aged. Immunohistological analysis of the antennal lobes in these mutants revealed structural abnormalities, especially in the expression of Bruchpilot protein, a marker for synaptic active zones. The combination of electrophysiological and morphological results suggests that the altered synaptic organization may be due to a neurodegenerative process. Our results indicate that this model can be used as a tool for understanding PD pathogensis and pathophysiology. These results help to explore the potential of using olfaction as a means of monitoring PD progression and developing new treatments
Accuracy of respiratory muscle assessments to predict weaning outcomes: a systematic review and comparative meta-analysis
Background: Several bedside assessments are used to evaluate respiratory muscle function and to predict weaning from mechanical ventilation in patients on the intensive care unit. It remains unclear which assessments perform best in predicting weaning success. The primary aim of this systematic review and meta-analysis was to summarize and compare the accuracy of the following assessments to predict weaning success: maximal inspiratory (PImax) and expiratory pressures, diaphragm thickening fraction and excursion (DTF and DE), end-expiratory (Tdiee) and end-inspiratory (Tdiei) diaphragm thickness, airway occlusion pressure (P0.1), electrical activity of respiratory muscles, and volitional and non-volitional assessments of transdiaphragmatic and airway opening pressures. Methods: Medline (via Pubmed), EMBASE, Web of Science, Cochrane Library and CINAHL were comprehensively searched from inception to 04/05/2023. Studies including adult mechanically ventilated patients reporting data on predictive accuracy were included. Hierarchical summary receiver operating characteristic (HSROC) models were used to estimate the SROC curves of each assessment method. Meta-regression was used to compare SROC curves. Sensitivity analyses were conducted by excluding studies with high risk of bias, as assessed with QUADAS-2. Direct comparisons were performed using studies comparing each pair of assessments within the same sample of patients. Results: Ninety-four studies were identified of which 88 studies (n = 6296) reporting on either PImax, DTF, DE, Tdiee, Tdiei and P0.1 were included in the meta-analyses. The sensitivity to predict weaning success was 63% (95% CI 47–77%) for PImax, 75% (95% CI 67–82%) for DE, 77% (95% CI 61–87%) for DTF, 74% (95% CI 40–93%) for P0.1, 69% (95% CI 13–97%) for Tdiei, 37% (95% CI 13–70%) for Tdiee, at fixed 80% specificity. Accuracy of DE and DTF to predict weaning success was significantly higher when compared to PImax (p = 0.04 and p < 0.01, respectively). Sensitivity and direct comparisons analyses showed that the accuracy of DTF to predict weaning success was significantly higher when compared to DE (p < 0.01). Conclusions: DTF and DE are superior to PImax and DTF seems to have the highest accuracy among all included respiratory muscle assessments for predicting weaning success. Further studies aiming at identifying the optimal threshold of DTF to predict weaning success are warranted. Trial registration: PROSPERO CRD42020209295, October 15, 2020
Differential effects of phytotherapic preparations in the hSOD1 Drosophila melanogaster model of ALS
The present study was aimed at characterizing the effects of Withania somnifera (Wse) and Mucuna pruriens (Mpe) on a Drosophila melanogaster model for Amyotrophic Lateral Sclerosis (ALS). In particular, the effects of Wse and Mpe were assessed following feeding the flies selectively overexpressing the wild human copper, zinc-superoxide dismutase (hSOD1-gain-of-function) in Drosophila motoneurons. Although ALS-hSOD1 mutants showed no impairment in life span, with respect to GAL4 controls, the results revealed impairment of climbing behaviour, muscle electrophysiological parameters (latency and amplitude of ePSPs) as well as thoracic ganglia mitochondrial functions. Interestingly, Wse treatment significantly increased lifespan of hSDO1 while Mpe had not effect. Conversely, both Wse and Mpe significantly rescued climbing impairment, and also latency and amplitude of ePSPs as well as failure responses to high frequency DLM stimulation. Finally, mitochondrial alterations were any more present in Wse-but not in Mpe-Treated hSOD1 mutants. Hence, given the role of inflammation in the development of ALS, the high translational impact of the model, the known anti-inflammatory properties of these extracts, and the viability of their clinical use, these results suggest that the application of Wse and Mpe might represent a valuable pharmacological strategy to counteract the progression of ALS and related symptom
Mucuna pruriens (Velvet bean) Rescues Motor, Olfactory, Mitochondrial and Synaptic Impairment in PINK1(B9) Drosophila melanogaster Genetic Model of Parkinson's Disease
The fruit fly Drosophila melanogaster (Dm) mutant for PTEN-induced putative kinase 1 (PINK1B9) gene is a powerful tool to investigate physiopathology of Parkinson's disease (PD). Using PINK1B9 mutant Dm we sought to explore the effects of Mucuna pruriens methanolic extract (Mpe), a L-Dopa-containing herbal remedy of PD. The effects of Mpe on PINK1B9 mutants, supplied with standard diet to larvae and adults, were assayed on 3–6 (I), 10–15 (II) and 20–25 (III) days old flies. Mpe 0.1% significantly extended lifespan of PINK1B9 and fully rescued olfactory response to 1-hexanol and improved climbing behavior of PINK1B9 of all ages; in contrast, L-Dopa (0.01%, percentage at which it is present in Mpe 0.1%) ameliorated climbing of only PINK1B9 flies of age step II. Transmission electron microscopy analysis of antennal lobes and thoracic ganglia of PINK1B9 revealed that Mpe restored to wild type (WT) levels both T-bars and damaged mitochondria. Western blot analysis of whole brain showed that Mpe, but not L-Dopa on its own, restored bruchpilot (BRP) and tyrosine hydroxylase (TH) expression to age-matched WT control levels. These results highlight multiple sites of action of Mpe, suggesting that its effects cannot only depend upon its L-Dopa content and support the clinical observation of Mpe as an effective medication with intrinsic ability of delaying the onset of chronic L-Dopa-induced long-term motor complications. Overall, this study strengthens the relevance of using PINK1B9 Dm as a translational model to study the properties of Mucuna pruriens for PD treatment
(1)H-NMR analysis provides a metabolomic profile of patients with multiple sclerosis
OBJECTIVE: To investigate the metabolomic profiles of patients with multiple sclerosis (MS) and to define the metabolic pathways potentially related to MS pathogenesis.
METHODS: Plasma samples from 73 patients with MS (therapy-free for at least 90 days) and 88 healthy controls (HC) were analyzed by (1)H-NMR spectroscopy. Data analysis was conducted with principal components analysis followed by a supervised analysis (orthogonal partial least squares discriminant analysis [OPLS-DA]). The metabolites were identified and quantified using Chenomx software, and the receiver operating characteristic (ROC) curves were calculated.
RESULTS: The model obtained with the OPLS-DA identified predictive metabolic differences between the patients with MS and HC (R2X = 0.615, R2Y = 0.619, Q2 = 0.476; p < 0.001). The differential metabolites included glucose, 5-OH-tryptophan, and tryptophan, which were lower in the MS group, and 3-OH-butyrate, acetoacetate, acetone, alanine, and choline, which were higher in the MS group. The suitability of the model was evaluated using an external set of samples. The values returned by the model were used to build the corresponding ROC curve (area under the curve of 0.98).
CONCLUSION: NMR metabolomic analysis was able to discriminate different metabolic profiles in patients with MS compared with HC. With the exception of choline, the main metabolic changes could be connected to 2 different metabolic pathways: tryptophan metabolism and energy metabolism. Metabolomics appears to represent a promising noninvasive approach for the study of M
Functional and morphological correlates in the drosophila LRRK2 loss-of-function model of Parkinson's disease: drug effects of Withania somnifera (Dunal) administration
The common fruit fly Drosophila melanogaster (Dm) is a simple animal species that contributed significantly to the development of neurobiology whose leucine-rich repeat kinase 2 mutants (LRRK2) loss-of-function in the WD40 domain represent a very interesting tool to look into physiopathology of Parkinson's disease (PD). Accordingly, LRRK2 Dm have also the potential to contribute to reveal innovative therapeutic approaches to its treatment. Withania somnifera Dunal, a plant that grows spontaneously also in Mediterranean regions, is known in folk medicine for its anti-inflammatory and protective properties against neurodegeneration. The aim of this study was to evaluate the neuroprotective effects of its standardized root methanolic extract (Wse) on the LRRK2 loss-of-function Dm model of PD. To this end mutant and wild type (WT) flies were administered Wse, through diet, at different concentrations as larvae and adults (L+/A+) or as adults (L-/A+) only. LRRK2 mutants have a significantly reduced lifespan and compromised motor function and mitochondrial morphology compared toWT flies 1% Wse-enriched diet, administered to Dm LRRK2 as L-/A+and improved a) locomotor activity b) muscle electrophysiological response to stimuli and also c) protected against mitochondria degeneration. In contrast, the administration of Wse to Dm LRRK2 as L+/A+, no matter at which concentration, worsened lifespan and determined the appearance of increased endosomal activity in the thoracic ganglia. These results, while confirming that the LRRK2 loss-of-function in the WD40 domain represents a valid model of PD, reveal that under appropriate concentrations Wse can be usefully employed to counteract some deficits associated with the disease. However, a careful assessment of the risks, likely related to the impaired endosomal activity, is require
Sardinia Radio Telescope wide-band spectral-polarimetric observations of the galaxy cluster 3C 129
We present new observations of the galaxy cluster 3C 129 obtained with the
Sardinia Radio Telescope in the frequency range 6000-7200 MHz, with the aim to
image the large-angular-scale emission at high-frequency of the radio sources
located in this cluster of galaxies. The data were acquired using the
recently-commissioned ROACH2-based backend to produce full-Stokes image cubes
of an area of 1 deg x 1 deg centered on the radio source 3C 129. We modeled and
deconvolved the telescope beam pattern from the data. We also measured the
instrumental polarization beam patterns to correct the polarization images for
off-axis instrumental polarization. Total intensity images at an angular
resolution of 2.9 arcmin were obtained for the tailed radio galaxy 3C 129 and
for 13 more sources in the field, including 3C 129.1 at the galaxy cluster
center. These data were used, in combination with literature data at lower
frequencies, to derive the variation of the synchrotron spectrum of 3C 129
along the tail of the radio source. If the magnetic field is at the
equipartition value, we showed that the lifetimes of radiating electrons result
in a radiative age for 3C 129 of t_syn = 267 +/- 26 Myrs. Assuming a linear
projected length of 488 kpc for the tail, we deduced that 3C 129 is moving
supersonically with a Mach number of M=v_gal/c_s=1.47. Linearly polarized
emission was clearly detected for both 3C 129 and 3C 129.1. The linear
polarization measured for 3C 129 reaches levels as high as 70% in the faintest
region of the source where the magnetic field is aligned with the direction of
the tail.Comment: 19 pages, 17 figures, accepted for publication in MNRA
Porocheratosi in corso di GVHD cutanea cronica
La porocheratosi è un raro disordine della cheratinizzazione di cui esistono forme ereditarie ed acquisite. Clini-camente è caratterizzata da lesioni anulari ad estensione centrifuga con margini ipercheratosici o, più raramente, da placche ipercheratosiche lineari. L’insorgenza della porocheratosi nel contesto dell’immunosopressione iatrogena è stata descritta in letteratura, soprattutto in pazienti che hanno ricevuto un trapianto d’organo solido. Meno comune è la porocheratosi in pazienti sottoposti a terapia immunosoppressiva dopo trapianto di cellule staminali ematopoietiche.
Descriviamo un paziente di 16 anni affetto da leucemia mieloide acuta sottoposto a trapianto di midollo osseo che ha sviluppato porocheratosi due anni dopo il trapianto, in remissione ematologica e nel contesto di un quadro di malattia del trapianto contro l’ospite (Graft Versus Host Disease, GVHD) cronica sclerodermiforme. Le lesioni sono state trattate inizialmente con crioterapia ed escissione chirurgica; tuttavia considerate le numerose recidive è stata introdotta terapia con acitretina, con buoni risultati clinici dopo 8 settimane di terapia. Attualmente il paziente è in buone condizioni generali, con remissione completa della GVHD cronica e buon controllo delle lesioni cutanee di porocheratosi
A digital beamformer for the PHAROS2 phased array feed
PHased Arrays for Re°ector Observing Systems (PHAROS) is a C-band (4–8 GHz) Phased Array Feed
(PAF) receiver designed to operate from the primary focus of a large single-dish radio astronomy antenna.
It consists of an array of 220-element Vivaldi antennas (10 11 2 polarization), cryogenically cooled at
roughly 20K along with low noise ampli¯ers (LNAs), and of analogue beamformers cryogenically cooled at
roughly 80 K. PHAROS2, the upgrade of PHAROS, is a PAF demonstrator developed in the framework of
the Square Kilometer Array Advanced Instrumentation Program (SKA AIP) with the goal of investigating
the potential of the PAF technologies at high frequencies in view of their possible application on the SKA
dish telescopes. The PHAROS2 design includes new cryogenically cooled LNAs with state-of-the-art performance,
a digital beamformer capable of synthesizing four beams from a sub-array of 24 single-polarization
antenna elements, and a C-band multi-channel Warm Section receiver capable of analogue ¯ltering
and down-converting the signals from the antennas to a suitable frequency range at the input of the digital
backend, providing an instantaneous bandwidth of 275MHz for each signal. In this paper, we describe the
design and performance of the PHAROS2 digital backend/beamformer, based on the Italian Tile Processing
Module (ITPM) hardware, which was initially developed for the SKA Low Frequency Aperture
Array (LFAA). The backend was adapted to perform the beamforming for our PAF application. We
describe the implementation of the beamformer on the Field Programmable Gate Arrays (FPGAs) of the
ITPM and how the backend was successfully used to synthesize four independent beams, both in the
laboratory (across the entire 275MHz instantaneous bandwidth) and during on-¯eld observations at
the BEST-2 array (across 16MHz instantaneous bandwidth), which is a subset of the Northern Cross Radio
Telescope (located in the district of Bologna, Italy). The beamformer design allows re-scaling to a greater
number of beams and wider bandwidths.peer-reviewe
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