641 research outputs found
Investigational treatments for neurodegenerative diseases caused by inheritance of gene mutations: lessons from recent clinical trials
: We reviewed recent major clinical trials with investigational drugs for the treatment of subjects with neurodegenerative diseases caused by inheritance of gene mutations or associated with genetic risk factors. Specifically, we discussed randomized clinical trials in subjects with Alzheimer's disease, Huntington's disease and amyotrophic lateral sclerosis bearing pathogenic gene mutations, and glucocerebrosidase-associated Parkinson's disease. Learning potential lessons to improve future therapeutic approaches is the aim of this review. Two long-term, controlled trials on three anti-β-amyloid monoclonal antibodies (solanezumab, gantenerumab and crenezumab) in subjects carrying Alzheimer's disease-linked mutated genes encoding for amyloid precursor protein or presenilin 1 or presenilin 2 failed to show cognitive or functional benefits. A major trial on tominersen, an antisense oligonucleotide designed to reduce the production of the huntingtin protein in subjects with Huntington's disease, was prematurely interrupted because the drug failed to show higher efficacy than placebo and, at highest doses, led to worsened outcomes. A 28-week trial of tofersen, an antisense oligonucleotide for superoxide dismutase 1 in patients with amyotrophic lateral sclerosis with superoxide dismutase 1 gene mutations failed to show significant beneficial effects but the 1-year open label extension of this study indicated better clinical and functional outcomes in the group with early tofersen therapy. A trial of venglustat, a potent and brain-penetrant glucosylceramide synthase inhibitor, in Parkinson's disease subjects with heterozygous glucocerebrosidase gene mutations revealed worsened clinical and cognitive performance of patients on the enzyme inhibitor compared to placebo. We concluded that clinical trials in neurodegenerative diseases with a genetic basis should test monoclonal antibodies, antisense oligonucleotides or gene editing directed against the mutated enzyme or the mutated substrate without dramatically affecting physiological wild-type variants
Chiral QED in Terms of Chiral Boson with a Generalized Fadeevian Regularization
Chiral QED with a generalized Fadeevian regularization is considered.
Imposing a chiral constraint a gauged version of Floranini-Jackiw lagrangian is
constructed. The imposition of the chiral constarint has spoiled t he
manifestly Lorentz covariance of the theory. The phase space structure for this
theory has been det ermined. It is found that spectrum changes drastically but
it is Lorentz invariant. Chiral fermion di sappears from the spectra and the
photon anquire mass as well. Poincare algebra has been calculated to show
physicial Lorentz invariance explicitely.Comment: 11 page
Are NSAIDs Useful to Treat Alzheimer's Disease or Mild Cognitive Impairment?
Several epidemiological studies suggest that long-term use of non-steroidal anti-inflammatory drugs (NSAIDs) may protect subjects carrying one or more ε4 allele of the apolipoprotein E (APOE ε4) against the onset of Alzheimer's disease (AD). The biological mechanism of this protection is not completely understood and may involve the anti-inflammatory properties of NSAIDs or their ability of interfering with the β-amyloid (Aβ) cascade. Unfortunately, long-term, placebo-controlled clinical trials with both non-selective and cyclooxygenase-2 (COX-2) selective inhibitors in mild-to-moderate AD patients produced negative results. A secondary prevention study with rofecoxib, a COX-2 selective inhibitor, in patients with mild cognitive impairment was also negative. A primary prevention study (ADAPT trial) of naproxen (a non-selective COX inhibitor) and celecoxib (a COX-2 selective inhibitor) in cognitively normal elderly subjects with a family history of AD was prematurely interrupted for safety reasons after a median period of treatment of 2 years. Although both drugs did not reduce the incidence of dementia after 2 years of treatment, a 4-year follow-up assessment surprisingly revealed that subjects previously exposed to naproxen were protected from the onset of AD by 67% compared to placebo. Thus, it could be hypothesized that the chronic use of NSAIDs may be beneficial only in the very early stages of the AD process in coincidence of initial Aβ deposition, microglia activation and consequent release of pro-inflammatory mediators. When the Aβ deposition process is already started, NSAIDs are no longer effective and may even be detrimental because of their inhibitory activity on chronically activated microglia that on long-term may mediate Aβ clearance. The research community should conduct long-term trials with NSAIDs in cognitively normal APOE ε4 carriers
A new anomalous contribution to the central charge of the N=2 monopole
We calculate the one-loop corrections to the mass and central charge of the
BPS monopole in N=2 super-Yang-Mills theory in 3+1 dimensions using a
supersymmetry-preserving version of dimensional regularization adapted to
solitons. In the renormalization scheme where previous studies have indicated
vanishing quantum corrections, we find nontrivial corrections that we identify
as the 3+1 dimensional analogue of the anomaly in the conformal central charge
of the N=1 supersymmetric kink in 1+1 dimensions. As in the latter case, the
associated contribution to the ordinary central charge has exactly the required
magnitude to preserve BPS saturation at the one-loop level. It also restores
consistency of calculations involving sums over zero-point energies with the
low-energy effective action of Seiberg and Witten.Comment: 1+10 pages. v3: version to appear in Physics Letters B (more precise
title and abstract, additional explanations in the text concerning the nature
of the anomaly involved
Alternative pharmacological treatment options for agitation in Alzheimer's disease
In patients with dementia and Alzheimer's disease (AD), treatment of neuropsychiatric symptoms (NPS) is a major concern in the management of these devastating diseases. Among NPS in AD, agitation and aggression are common with earlier institutionalization, increased morbidity and mortality, and greater caregiver burden. Pharmacological treatments for AD-related agitation, specifically off-label use of atypical antipsychotics, showed only modest improvements, with increased side-effect burden and risk of mortality. Non-pharmacological treatment approaches have become the preferred firstline option. However, when such treatments fail, pharmacological options are often used. Therefore, there is an urgent need to identify effective and safe pharmacological treatments for agitation/aggression in AD and dementia. Unfortunately, progresses have been slow, with a small number of methodologically heterogeneous randomized controlled trials (RCTs), with disappointing results. However, evidence coming from recently completed RCTs on novel or repositioned drugs (mibampator, dextromethorphan/ quinidine, cannabinoids, and citalopram) showed some promise in treating agitation in AD, but still with safety concerns. Further evidence will come from ongoing Phase II and III trials on promising novel drugs for treating these distressing symptoms in patients with AD and dementia
A SURVEY ON THE FRAUDULENT USE OF ANABOLIC SUBSTANCES IN BOVINES SLAUGHTERED IN MOLISE
An investigation has been performed on the fraudulent use of anabolic substances in the Region of Molise. One hundred fourty-four bovines (12-24 months old, 123 males and 21 females) have been included in the survey. Ante-mortem assessment on their behaviour and clinical analysis on some target organs were carried out. After slaughtering, samples of prostate, bulbo-urethral glands, Bartholin's glands, mammary gland, ovaries, thymus and thyroid were collected and processed for an anatomo-histopathological evaluation, as suggested in the guidelines of the Italian National Plan for Residues (PNR) 2009. Overall, the 15% of the subjects analysed have been classified as "suspect", whereas the 44% as "uncertain" and the remaining 59% as "negative". The lesion most frequently found was a serious atrophy of the thymic parenchyma with fat infiltration (15% of males and 14% of females), suggesting a prevalence of an illegal use of cortisonic drugs
Chiral Bosons Through Linear Constraints
We study in detail the quantization of a model which apparently describes
chiral bosons. The model is based on the idea that the chiral condition could
be implemented through a linear constraint. We show that the space of states is
of indefinite metric. We cure this disease by introducing ghost fields in such
a way that a BRST symmetry is generated. A quartet algebra is seen to emerge.
The quartet mechanism, then, forces all physical states, but the vacuum, to
have zero norm.Comment: 9 page
Integrable flows in c=1 string theory
In these notes we review the method to construct integrable deformations of
the compactified c=1 bosonic string theory by primary fields (momentum or
winding modes), developed recently in collaboration with S. Alexandrov and V.
Kazakov. The method is based on the formulation of the string theory as a
matrix model. The flows generated by either momentum or winding modes (but not
both) are integrable and satisfy the Toda lattice hierarchy.Comment: sect.1 extended and typos correcte
Chiral bosons and improper constraints
We argue that a consistent quantization of the Floreanini-Jackiw model, as a
constrained system, should start by recognizing the improper nature of the
constraints. Then each boundary conditon defines a problem which must be
treated sparately. The model is settled on a compact domain which allows for a
discrete formulation of the dynamics; thus, avoiding the mixing of local with
collective coordinates. For periodic boundary conditions the model turns out to
be a gauge theory whose gauge invariant sector contains only chiral
excitations. For antiperiodoc boundary conditions, the mode is a second-class
theory where the excitations are also chiral. In both cases, the equal-time
algebra of the quantum energy-momentum densities is a Virasoro algebra. The
Poincar\'e symmetry holds for the finite as well as for the infinite domain.Comment: 13 pages, Revtex file, IF.UFRGS Preprin
Sound Waves in (2+1) Dimensional Holographic Magnetic Fluids
We use the AdS/CFT correspondence to study propagation of sound waves in
strongly coupled (2+1) dimensional conformal magnetic fluids. Our computation
provides a nontrivial consistency check of the viscous magneto-hydrodynamics of
Hartnoll-Kovtun-Muller-Sachdev to leading order in the external field.
Depending on the behavior of the magnetic field in the hydrodynamic limit, we
show that it can lead to further attenuation of sound waves in the (2+1)
dimensional conformal plasma, or reduce the speed of sound. We present both
field theory and dual supergravity descriptions of these phenomena. While to
the leading order in momenta the dispersion of the sound waves obtained from
the dual supergravity description agrees with the one predicted from field
theory, we find a discrepancy at higher order. This suggests that further
corrections to HKMS magneto-hydrodynamics are necessary.Comment: 32 pages, LaTeX; minor corrections, references added; an error in the
boundary conditions fixed, a slight change in the result
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