N-Methyl-D-aspartic Acid (NMDA) in the nervous system of the amphioxus Branchiostoma lanceolatum

<p>Abstract</p> <p>Background</p> <p>NMDA (<it>N</it>-methyl-D-aspartic acid) is a widely known agonist for a class of glutamate receptors, the NMDA type. Synthetic NMDA elicits very strong activity for the induction of hypothalamic factors and hypophyseal hormones in mammals. Moreover, endogenous NMDA has been found in rat, where it has a role in the induction of GnRH (Gonadotropin Releasing Hormone) in the hypothalamus, and of LH (Luteinizing Hormone) and PRL (Prolactin) in the pituitary gland.</p> <p>Results</p> <p>In this study we show evidence for the occurrence of endogenous NMDA in the amphioxus <it>Branchiostoma lanceolatum</it>. A relatively high concentration of NMDA occurs in the nervous system of this species (3.08 ± 0.37 nmol/g tissue in the nerve cord and 10.52 ± 1.41 nmol/g tissue in the cephalic vesicle). As in rat, in amphioxus NMDA is also biosynthesized from D-aspartic acid (D-Asp) by a NMDA synthase (also called D-aspartate methyl transferase).</p> <p>Conclusion</p> <p>Given the simplicity of the amphioxus nervous and endocrine systems compared to mammalian, the discovery of NMDA in this protochordate is important to gain insights into the role of endogenous NMDA in the nervous and endocrine systems of metazoans and particularly in the chordate lineage.</p

Very Early PSA Response to Abiraterone in mCRPC Patients: A Novel Prognostic Factor Predicting Overall Survival

BACKGROUND Abiraterone Acetate (AA) is approved for the treatment of mCRPC after failure of androgen deprivation therapy in whom chemotherapy is not yet clinically indicated and for treatment of mCRPC progressed during or after docetaxel-based chemotherapy regimen. The aim of this study is to evaluate the role of early PSA decline for detection of therapy success or failure in mCRPC patients treated with AA in post chemotherapy setting.PATIENTS AND METHODS We retrospectively evaluated 87 patients with mCRPC treated with AA. Serum PSA levels were evaluated after 15, 90 days and then monthly. The PSA flare phenomenon was evaluated, according to a confirmation value at least one week apart. The primary endpoint was to demonstrate that an early PSA decline correlates with a longer progression free survival (PFS) and overall survival (OS). The secondary endpoind was to demonstrate a correlation between better outcome and demographic and clinical patient characteristics.RESULTS We have collected data of 87 patients between Sep 2011 and Sep 2014. Early PSA response (≥ 50% from baseline at 15 days) was found in 56% evaluated patients and confirmed in 29 patients after 90 days. The median progression free survival (PFS) was 5,5 months (4,6-6,5) and the median overall survival (OS) was 17,1 months (8,8-25,2). In early responders patients (PSA RR ≥ 50% at 15 days), we found a significant statistical advantage in terms of PFS at 1 year, HR 0.28, 95%CI 0.12-0.65, p=0.003, and OS, HR 0.21 95% CI 0.06-0.72, p=0.01. The results in PFS at 1 years and OS reached statistical significance also in the evaluation at 90 days.CONCLUSION A significant proportion (78.6%) of patients achieved a rapid response in terms of PSA decline. Early PSA RR (≥ 50% at 15 days after start of AA) can provide clinically meaningful information and can be considered a surrogate of longer PFS and OS

Assessing safety functionalities in the design and validation of driving automation

This paper aims to contribute to the comprehensive and systematic safety assessment of Automated Driving Systems (ADSs) by identifying unknown hazardous areas of operation. The current methodologies employed in this domain typically involve estimating the distributions of situational variables based on human-centered field test, crash databases, or expert knowledge of critical values. However, due to the lack of a-priori knowledge regarding the influential factors, their critical ranges, and their distributions, these approaches may not be entirely suitable for the assessment of emerging automated driving technologies. To deal with this challenging problem, here we propose a testing methodology incorporating realistic yet unobserved driving conditions, distinguished by numerous situational variables, so to encompass unknown unsafe conditions comprehensively. Our methodology utilizes stochastic simulation and uncertainty modeling techniques to account for the variability of realistic driving conditions and their impact on ADSs' performances. By doing so, we aim to identify unsafe operational regions and triggering conditions that can lead to hazardous behaviors, thus improving the development and safety of automated driving functions. For our purposes, the Latin Hypercube Sampling technique and the recently proposed PAWN density-based sensitivity analysis method are employed. We apply this methodology for the first time in the specific field of ADSs design and validation, using an exemplificative use case. We discuss and compare the results obtained from our approach with those obtained from a traditional approach

Transphyletic conservation of developmental regulatory state in animal evolution

Specific regulatory states, i.e., sets of expressed transcription factors, define the gene expression capabilities of cells in animal development. Here we explore the functional significance of an unprecedented example of regulatory state conservation from the cnidarian Nematostella to Drosophila, sea urchin, fish, and mammals. Our probe is a deeply conserved cis-regulatory DNA module of the SRY-box B2 (soxB2), recognizable at the sequence level across many phyla. Transphyletic cis-regulatory DNA transfer experiments reveal that the plesiomorphic control function of this module may have been to respond to a regulatory state associated with neuronal differentiation. By introducing expression constructs driven by this module from any phyletic source into the genomes of diverse developing animals, we discover that the regulatory state to which it responds is used at different levels of the neurogenic developmental process, including patterning and development of the vertebrate forebrain and neurogenesis in the Drosophila optic lobe and brain. The regulatory state recognized by the conserved DNA sequence may have been redeployed to different levels of the developmental regulatory program during evolution of complex central nervous systems

Individual differences and knockout in zebrafish reveal similar cognitive effects of BDNF between teleosts and mammals

The remarkable similarities in cognitive performance between teleosts and mammals suggest that the underlying cognitive mechanisms might also be similar in these two groups. We tested this hypothesis by assessing the effects of the brain-derived neurotrophic factor (BDNF), which is critical for mammalian cognitive functioning, on fish's cognitive abilities. We found that individual differences in zebrafish's learning abilities were positively correlated with bdnf expression. Moreover, a CRISPR/Cas9 mutant zebrafish line that lacks the BDNF gene (bdnf(-/-)) showed remarkable learning deficits. Half of the mutants failed a colour discrimination task, whereas the remaining mutants learned the task slowly, taking three times longer than control bdnf(+/+) zebrafish. The mutants also took twice as long to acquire a T-maze task compared to control zebrafish and showed difficulties exerting inhibitory control. An analysis of habituation learning revealed that cognitive impairment in mutants emerges early during development, but could be rescued with a synthetic BDNF agonist. Overall, our study indicates that BDNF has a similar activational effect on cognitive performance in zebrafish and in mammals, supporting the idea that its function is conserved in vertebrates

Zebrafish, a novel model system to study uremic toxins: The case for the sulfur amino acid lanthionine

The non-proteinogenic amino acid lanthionine is a byproduct of hydrogen sulfide biosynthesis: the third endogenous vasodilator gas, after nitric oxide and carbon monoxide. While hydrogen sulfide is decreased in uremic patients on hemodialysis, lanthionine is increased and has been proposed as a new uremic toxin, since it is able to impair hydrogen sulfide production in hepatoma cells. To characterize lanthionine as a uremic toxin, we explored its effects during the early development of the zebrafish (Danio rerio), a widely used model to study the organ and tissue alterations induced by xenobiotics. Lanthionine was employed at concentrations reproducing those previously detected in uremia. Light-induced visual motor response was also studied by means of the DanioVision system. Treatment of zebrafish embryos with lanthionine determined acute phenotypical alterations, on heart organogenesis (disproportion in cardiac chambers), increased heart beating, and arrhythmia. Lanthionine also induced locomotor alterations in zebrafish embryos. Some of these effects could be counteracted by glutathione. Lanthionine exerted acute effects on transsulfuration enzymes and the expression of genes involved in inflammation and metabolic regulation, and modified microRNA expression in a way comparable with some alterations detected in uremia. Lanthionine meets the criteria for classification as a uremic toxin. Zebrafish can be successfully used to explore uremic toxin effects

Induction of Cytotoxic Oxidative Stress by d-Alanine in Brain Tumor Cells Expressing Rhodotorula gracilis d-Amino Acid Oxidase: A Cancer Gene Therapy Strategy

Overview summary Gene-directed enzyme prodrug therapy (GDEPT) is an antineoplastic treatment strategy designed to overcome the systemic toxicity of chemotherapy by specifically expressing a foreign enzyme in malignant cells that converts a nontoxic prodrug into a cytotoxic metabolite. The relative inefficiency of current in situ gene transfer methodology suggests that enzyme/prodrug combinations that produce membrane permeable metabolites will elicit a more favorable therapeutic response. Ideally, the agent produced by the transduced cell “factories” would be cytotoxic toward both proliferating and quiescent cells. We describe a novel GDEPT approach using d-amino acid oxidase from the red yeast Rhodotorula gracilis and d-alanine as a substrate that generates hydrogen peroxide, a reactive metabolite of oxygen that has both these characteristics. We also demonstrate the ability to sensitize tumor cells to this GDEPT protocol by manipulating cellular antioxidant pathways.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63220/1/hum.1998.9.2-185.pd

Polymer co-crystalline films for photonics

Robust syndiotactic polystyrene (sPS) films exhibiting highly stable co-crystalline phases can be obtained with a large variety of low-molecular-mass chromophore guest molecules. In this report different aspects relative to the structure and the optical properties of these films are described. In particular, possible applications of these films as fluorescent materials, as optical memories (based on the co-crystallization of photoreactive guest molecules), as non-linear optical materials (with polar guests) and as chiro-optical memories (based on temporary co-crystals with chiral guest molecules) are presented

The Prepetrous Segment of the Internal Carotid Artery as a Neglected Site of Symptomatic Atherosclerosis: A Single-Center Series

(1) Background: Non-stenotic complicated plaques are a neglected cause of stroke, in particular in young patients. Atherosclerosis has some preferential sites in extracranial arteries and the prepetrous segment of the internal carotid artery has been rarely described as site of atheroma in general and of complicated atheroma in stroke patients. The aim of this study is to describe the rate of the prepetrous internal carotid artery’s (ICA) involvement in a single-center case series of young stroke patients. (2) Methods: All patients < 50 years old with acute ischemic stroke admitted to a single-center Stroke Unit during two time periods (the first one from 1 January 2018 to 31 December 2019, and the second one from 1 January 2021 to 30 June 2022), were prospectively investigated as part of a screening protocol of the Searching for Explanations for Cryptogenic Stroke in the Young: Revealing the Etiology, Triggers, and Outcome (SECRETO) study [ClinicalTrials.gov ID NCT01934725], including extracranial vascular examination by using computed tomography (CT) or magnetic resonance imaging (MRI). (3) Results: Two out of ninety-three consecutive patients (2.15%) had a complicated atheroma in the prepetrous ICA as the cause of stroke and both CT angiography and high-resolution vessel wall MRI were applied to document the main features of positive remodeling, cap rupture, ulceration, intraplaque hemorrhage, and a transient thrombus superimposed on the atheroma. The two patients had a different evolution of healing in the first case and a persisting ulceration at 12 months in the second case. (4) Conclusions: The prepetrous ICA is a rarely described location of complicated atheroma in stroke patients at all ages and it represents roughly 2% of causes of acute stroke in this single-center case series in young people

Brain Proteome and Behavioural Analysis in Wild Type, BDNF+/− and BDNF−/− Adult Zebrafish (Danio rerio) Exposed to Two Different Temperatures

Experimental evidence suggests that environmental stress conditions can alter the expression of BDNF and that the expression of this neurotrophin influences behavioural responses in mammalian models. It has been recently demonstrated that exposure to 34 degrees C for 21 days alters the brain proteome and behaviour in zebrafish. The aim of this work was to investigate the role of BDNF in the nervous system of adult zebrafish under control and heat treatment conditions. For this purpose, zebrafish from three different genotypes (wild type, heterozygous BDNF+/- and knock out BDNF-/-) were kept for 21 days at 26 degrees C or 34 degrees C and then euthanized for brain molecular analyses or subjected to behavioural tests (Y-maze test, novel tank test, light and dark test, social preference test, mirror biting test) for assessing behavioural aspects such as boldness, anxiety, social preference, aggressive behaviour, interest for the novel environment and exploration. qRT-PCR analysis showed the reduction of gene expression of BDNF and its receptors after heat treatment in wild type zebrafish. Moreover, proteomic analysis and behavioural tests showed genotype- and temperature-dependent effects on brain proteome and behavioural responding. Overall, the absent expression of BDNF in KO alters (1) the brain proteome by reducing the expression of proteins involved in synapse functioning and neurotransmitter-mediated transduction; (2) the behaviour, which can be interpreted as bolder and less anxious and (3) the cellular and behavioural response to thermal treatment