Comparative Therapeutic Effects of Natural Compounds Against Saprolegnia spp. (Oomycota) and Amyloodinium ocellatum (Dinophyceae)

The fish parasites Saprolegnia spp. (Oomycota) and Amyloodinium ocellatum (Dinophyceae) cause important losses in freshwater and marine aquaculture industry, respectively. The possible adverse effects of compounds used to control these parasites in aquaculture resulted in increased interest on the search for natural products with antiparasitic activity. In this work, eighteen plant-derived compounds (2\u2032,4\u2032-Dihydroxychalcone; 7-Hydroxyflavone; Artemisinin; Camphor (1R); Diallyl sulfide; Esculetin; Eucalyptol; Garlicin 80%; Harmalol hydrochloride dihydrate; Palmatine chloride; Piperine; Plumbagin; Resveratrol; Rosmarinic acid; Sclareolide; Tomatine, Umbelliferone, and Usnic Acid) have been tested in vitro. Sixteen of these were used to determine their effects on the gill cell line G1B (ATCC\uaeCRL-2536TM) and on the motility of viable dinospores of Amyloodinium ocellatum, and thirteen were screened for inhibitory activity against Saprolegnia spp. The cytotoxicity results on G1B cells determined that only two compounds (2\u2032,4\u2032-Dihydroxychalcone and Tomatine) exhibited dose-dependent toxic effects. The highest surveyed concentrations (0.1 and 0.01mM) reduced cell viability by 80%. Upon lowering the compound concentration the percentage of dead cells was lower than 20%. The same two compounds revealed to be potential antiparasitics by reducing in a dose-dependent manner the motility of A. ocellatum dinospores up to 100%. With respect to Saprolegnia, a Minimum Inhibitory Concentration was found for Tomatine (0.1mM), Piperine and Plumbagin (0.25mM), while 2\u2032,4\u2032-Dihydroxychalcone considerably slowed downmycelial growth for 24 h at a concentration of 0.1mM. Therefore, this research allowed to identify two compounds, Tomatine and 2\u2032,4\u2032-Dihydroxychalcone, effective against both parasites. These compounds could represent promising candidates for the treatment of amyloodiniosis and saprolegniosis in aquaculture. Nevertheless, further in vitro and in vivo tests are required in order to determine concentrations that are effective against the considered pathogens but at the same time safe for hosts, environment and consumers

Development of Micro-Electrode Array Based Tests for Neurotoxicity: Assessment of Interlaboratory Reproducibility with Neuroactive Chemicals

Neuronal assemblies within the nervous system produce electrical activity that can be recorded in terms of action potential patterns. Such patterns provide a sensitive endpoint to detect effects of a variety of chemical and physical perturbations. They are a function of synaptic changes and do not necessarily involve structural alterations. In vitro neuronal networks (NNs) grown on micro-electrode arrays (MEAs) respond to neuroactive substances as well as the in vivo brain. As such, they constitute a valuable tool for investigating changes in the electrophysiological activity of the neurons in response to chemical exposures. However, the reproducibility of NN responses to chemical exposure has not been systematically documented. To this purpose six independent laboratories (in Europe and in USA) evaluated the response to the same pharmacological compounds (Fluoxetine, Muscimol, and Verapamil) in primary neuronal cultures. Common standardization principles and acceptance criteria for the quality of the cultures have been established to compare the obtained results. These studies involved more than 100 experiments before the final conclusions have been drawn that MEA technology has a potential for standard in vitro neurotoxicity/neuropharmacology evaluation. The obtained results show good intra- and inter-laboratory reproducibility of the responses. The consistent inhibitory effects of the compounds were observed in all the laboratories with the 50% Inhibiting Concentrations (IC50s) ranging from: (mean ± SEM, in μM) 1.53 ± 0.17 to 5.4 ± 0.7 (n = 35) for Fluoxetine, 0.16 ± 0.03 to 0.38 ± 0.16 μM (n = 35) for Muscimol, and 2.68 ± 0.32 to 5.23 ± 1.7 (n = 32) for Verapamil. The outcome of this study indicates that the MEA approach is a robust tool leading to reproducible results. The future direction will be to extend the set of testing compounds and to propose the MEA approach as a standard screen for identification and prioritization of chemicals with neurotoxicity potential

A Neuromorphic Prosthesis to Restore Communication in Neuronal Networks

Recent advances in bioelectronics and neural engineering allowed the development of brain machine interfaces and neuroprostheses, capable of facilitating or recovering functionality in people with neurological disability. To realize energy-efficient and real-time capable devices, neuromorphic computing systems are envisaged as the core of next-generation systems for brain repair. We demonstrate here a real-time hardware neuromorphic prosthesis to restore bidirectional interactions between two neuronal populations, even when one is damaged or missing. We used in vitro modular cell cultures to mimic the mutual interaction between neuronal assemblies and created a focal lesion to functionally disconnect the two populations. Then, we employed our neuromorphic prosthesis for bidirectional bridging to artificially reconnect two disconnected neuronal modules and for hybrid bidirectional bridging to replace the activity of one module with a real-time hardware neuromorphic Spiking Neural Network. Our neuroprosthetic system opens avenues for the exploitation of neuromorphic-based devices in bioelectrical therapeutics for health care

Effects of the dose of erythropoiesis stimulating agents on cardiovascular events, quality of life, and health-related costs in hemodialysis patients: the clinical evaluation of the dose of erythropoietins (C.E. DOSE) trial protocol

<p>Abstract</p> <p>Background</p> <p>Anemia is a risk factor for death, adverse cardiovascular outcomes and poor quality of life in patients with chronic kidney disease (CKD). Erythropoietin Stimulating Agents (ESA) are commonly used to increase hemoglobin levels in this population. In observational studies, higher hemoglobin levels (around 11-13 g/dL) are associated with improved survival and quality of life compared to hemoglobin levels around 9-10 g/dL. A systematic review of randomized trials found that targeting higher hemoglobin levels with ESA causes an increased risk of adverse vascular outcomes. It is possible, but has never been formally tested in a randomized trial, that ESA dose rather than targeted hemoglobin concentration itself mediates the increased risk of adverse vascular outcomes. The Clinical Evaluation of the DOSe of Erythropoietins (C.E. DOSE) trial will assess the benefits and harms of a high versus a low fixed ESA dose for the management of anemia in patients with end stage kidney disease.</p> <p>Methods/Design</p> <p>This is a randomized, prospective open label blinded end-point (PROBE) trial due to enrol 2204 hemodialysis patients in Italy. Patients will be randomized 1:1 to 4000 IU/week versus 18000 IU/week of intravenous epoietin alfa or beta, or any other ESA in equivalent doses. The dose will be adjusted only if hemoglobin levels fall outside the 9.5-12.5 g/dL range. The primary outcome will be a composite of all-cause mortality, non fatal stroke, non fatal myocardial infarction and hospitalization for cardiovascular causes. Quality of life and costs will also be assessed.</p> <p>Discussion</p> <p>The C.E.DOSE study will help inform the optimal therapeutic strategy for the management of anemia of hemodialysis patients, improving clinical outcomes, quality of life and costs, by ascertaining the potential benefits and harms of different fixed ESA doses.</p> <p>Trial registration</p> <p>Clinicaltrials.gov NCT00827021</p

Calpains participate in nerve terminal degeneration induced by spider and snake presynaptic neurotoxins

alpha-latrotoxin and snake presynaptic phospholipases A2 neurotoxins target the presynaptic membrane of axon terminals of the neuromuscular junction causing paralysis. These neurotoxins display different biochemical activities, but similarly alter the presynaptic membrane permeability causing Ca2+ overload within the nerve terminals, which in turn induces nerve degeneration. Using different methods, here we show that the calcium-activated proteases calpains are involved in the cytoskeletal rearrangements that we have previously documented in neurons exposed to ch-latrotoxin or to snake presynaptic phospholipases A2 neurotoxins. These results indicate that calpains, activated by the massive calcium influx from the extracellular medium, target fundamental components of neuronal cytoskeleton such as spectrin and neurofilaments, whose cleavage is functional to the ensuing nerve terminal fragmentation. (C) 2013 Elsevier Ltd. All rights reserved

Calcium overload in nerve terminals of cultured neurons intoxicated by alpha-latrotoxin and snake PLA2 neurotoxins.

Snake presynaptic neurotoxins with phospholipase A2 (PLA2) activity cause degeneration of the neuromuscular junction. They induce depletion of synaptic vesicles and increase the membrane permeability to Ca(2+) which fluxes from the outside into the nerve terminal. Moreover, several toxins were shown to enter the nerve terminals of cultured neurons, where they may display their PLA2 activity on internal membranes. The relative contribution of these different actions in nerve terminal degeneration remains to be established. To gather information on this point, we have compared the effects of beta-bungarotoxin, taipoxin, notexin and textilotoxin with those of alpha-latrotoxin on the basis of the notion that this latter toxin is well known to cause massive Ca(2+) influx and exocytosis of synaptic vesicles. All the parameters analysed here, including calcium imaging, are very similar for the two classes of neurotoxins. This indicates that Ca(2+) overloading plays a major role in the degeneration of nerve terminals induced by the snake presynaptic neurotoxins

The cerebellar role in attention

Background: Clinical and functional neuroimaging studies showed a cerebellar involvement in different attention tasks. Nevertheless, most studies have focused on single aspects of attention and it is still lacking a consensus regarding the overall cerebellar contribution to this function. Methods: A computerized battery (“Test-Battery of Attentional Performance”, TAP) was administered to cerebellar patients and healthy subjects well-matched for age and education, to analyze various components of attention. A one-way ancova was used to evaluate eventual differences between patients’ and controls’ performances. Simple tapping reaction time was used as covariate to exclude the influence of the motor component on the cognitive performance. Results: Cerebellar patients were significantly impaired in divided attention, flexibility and sustained attention tasks, while there were no differences between patients and control groups in go-nogo, working memory, spatial attention and ocular movements tasks. These results demonstrate that cerebellar damage produces deficits in attentional domain that may be the consequence of the existence of discrete parallel circuits that connect specific cerebellar portions with specific areas of the cerebral cortex.Background: Clinical and functional neuroimaging studies showed a cerebellar involvement in different attention tasks. Nevertheless, most studies have focused on single aspects of attention and it is still lacking a consensus regarding the overall cerebellar contribution to this function. Methods: A computerized battery (“Test-Battery of Attentional Performance”, TAP) was administered to cerebellar patients and healthy subjects well-matched for age and education, to analyze various components of attention. A one-way ancova was used to evaluate eventual differences between patients’ and controls’ performances. Simple tapping reaction time was used as covariate to exclude the influence of the motor component on the cognitive performance. Results: Cerebellar patients were significantly impaired in divided attention, flexibility and sustained attention tasks, while there were no differences between patients and control groups in go-nogo, working memory, spatial attention and ocular movem

The cerebellar cognitive profile

The cerebellar role in non-motor functions is supported by the clinical finding that lesions confined to cerebellum produce the cerebellar cognitive affective syndrome. Nevertheless, there is no consensus regarding the overall cerebellar contribution to cognition. Among other reasons, this deficiency might be attributed to the small sample sizes and narrow breadths of existing studies on lesions in cerebellar patients, which have focused primarily on a single cognitive domain. The aim of this study was to examine the expression of cerebellar cognitive affective syndrome with regard to lesion topography in a large group of subjects with cerebellar damage. We retrospectively analysed charts from patients in the Ataxia Lab of Santa Lucia Foundation between 1997 and 2007. Of 223 charts, 156 were included in the study, focusing on the importance of the cerebellum in cognition and the relevance of lesion topography in defining the cognitive domains that have been affected. Vascular topography and the involvement of deep cerebellar nuclei were the chief factors that determined the cognitive profile. Of the various cognitive domains, the ability to sequence was the most adversely affected in nearly all subjects, supporting the hypothesis that sequencing is a basic cerebellar operation.The cerebellar role in non-motor functions is supported by the clinical finding that lesions confined to cerebellum produce the cerebellar cognitive affective syndrome. Nevertheless, there is no consensus regarding the overall cerebellar contribution to cognition. Among other reasons, this deficiency might be attributed to the small sample sizes and narrow breadths of existing studies on lesions in cerebellar patients, which have focused primarily on a single cognitive domain. The aim of this study was to examine the expression of cerebellar cognitive affective syndrome with regard to lesion topography in a large group of subjects with cerebellar damage. We retrospectively analysed charts from patients in the Ataxia Lab of Santa Lucia Foundation between 1997 and 2007. Of 223 charts, 156 were included in the study, focusing on the importance of the cerebellum in cognition and the relevance of lesion topography in defining the cognitive domains that have been affected. Vascular topograp

A solid-state molecular capsule based on p-sulfonatocalix[7]arene and dicationic Diquat guest

An extended framework of molecular capsules based on p-sulfonatocalix[7] arene and a dicationic Diquat guest has been obtained. One Diquat guest molecule is encapsulated inside two trimeric -cone subunits of two different p-sulfonatocalix[7]arene caps. The molecular capsules are sealed electrostatically by means of interactions between anionic sulfonato groups and Ba 2+ cations. Interestingly, the extended capsular framework gives rise to cavities hosting water molecules

Recurrent and fatal diarrhea caused by Cystoisospora belli in a man with HIV infection

Cystoisospora belli causes intestinal infection in immunocompromised hosts, including human immunodeficiency viruses (HIV)-positive patients, especially from tropical and sub-tropical areas, with watery and recurrent diarrhea, leading in advanced cases to malabsorption and death. Microbiological diagnosis is limited by intermittent or low shedding of oocysts in stool; therefore, endoscopy may be necessary to identify the pathogen in histological samples. Trimethoprim-sulfamethoxazole (TMP-SMX) represents the treatment of choice, and alternative agents are used in recurrences, but limited efficacy is described. Here, we present recently observed case of severe and fatal infection due to C. belli in a HIV-positive 40-year-old man from Brazil, revealing several limitations in diagnosis and therapy, which need to be investigated further. In particular, it is still not clear how the infection persisted over time leading to malabsorption, kidney injury, and subsequent death, even if a reasonable immune reconstitution was demonstrated. Additionally, we investigated what mechanisms might cause, whether failure of recovery of the immune response specifically to C. belli, drug malabsorption, resistance to TMP-SMX, sequestration into lymphoid tissue, or co-presence of visceral untreated Kaposi sarcoma. Also, the appropriate dosage and way of administration of the best therapeutic regimen were examined, since there is a lack of literature on these issues. Globalization and wider use of immunosuppressive therapies underline the importance of maintaining adequate awareness, also in HIV-negative and non-immigrant populations