Nascent Aß42 Fibrillization in Synaptic Endosomes Precedes Plaque Formation in a Mouse Model of Alzheimer's-like ß-Amyloidosis.

Accumulation of amyloid-ß peptide (Aß) aggregates in synapses may contribute to the profound synaptic loss characteristic of Alzheimer's disease (AD). The origin of synaptic Aß aggregates remains elusive, but loss of endosomal proteostasis may trigger their formation. In this study, we identified the synaptic compartments where Aß accumulates, and performed a longitudinal analysis of synaptosomes isolated from brains of TgCRND8 APP transgenic mice of either sex. To evaluate the specific contribution of Aß-degrading protease endothelin-converting enzyme (ECE-1) to synaptic/endosomal Aß homeostasis, we analyzed the effect of partial Ece1 KO in brain and complete ECE1 KO in SH-SY5Y cells. Global inhibition of ECE family members was used to further assess their role in preventing synaptic Aß accumulation. Results showed that, before extracellular amyloid deposition, synapses were burdened with detergent-soluble Aß monomers, oligomers, and fibrils. Levels of all soluble Aß species declined thereafter, as Aß42 turned progressively insoluble and accumulated in Aß-producing synaptic endosomal vesicles with characteristics of multivesicular bodies. Accordingly, fibrillar Aß was detected in brain exosomes. ECE-1-deficient mice had significantly increased endogenous synaptosomal Aß42 levels, and protease inhibitor experiments showed that, in TgCRND8 mice, synaptic Aß42 became nearly resistant to degradation by ECE-related proteases. Our study supports that Aß accumulating in synapses is produced locally, within endosomes, and does not require the presence of amyloid plaques. ECE-1 is a determinant factor controlling the accumulation and fibrillization of nascent Aß in endosomes and, in TgCRND8 mice, Aß overproduction causes rapid loss of Aß42 solubility that curtails ECE-mediated degradation.SIGNIFICANCE STATEMENT Deposition of aggregated Aß in extracellular plaques is a defining feature of AD. Aß aggregates also accumulate in synapses and may contribute to the profound synaptic loss and cognitive dysfunction typical of the disease. However, it is not clear whether synaptotoxic Aß is mainly derived from plaques or if it is produced and aggregated locally, within affected synaptic compartments. Filling this knowledge gap is important for the development of an effective treatment for AD, as extracellular and intrasynaptic pools of Aß may not be equally modulated by immunotherapies or other therapeutic approaches. In this manuscript, we provide evidence that Aß aggregates building up in synapses are formed locally, within synaptic endosomes, because of disruptions in nascent Aß proteostasis.

Cutin-derived oligomers induce hallmark plant immune responses.

The cuticle constitutes the outermost defensive barrier of most land plants. It comprises a polymeric matrix-cutin, surrounded by soluble waxes. Moreover, the cuticle constitutes the first line of defense against pathogen invasion, while also protecting the plant from many abiotic stresses. Aliphatic monomers in cutin have been suggested to act as immune elicitors in plants. This study analyses the potential of cutin oligomers to activate rapid signaling outputs reminiscent of pattern-triggered immunity in the model plant Arabidopsis. Cutin oligomeric mixtures led to Ca2+ influx and mitogen-activated protein kinase activation. Comparable responses were measured for cutin, which was also able to induce a reactive oxygen species burst. Furthermore, cutin oligomer treatment resulted in a unique transcriptional reprogramming profile, having many archetypal features of pattern-triggered immunity. Targeted spectroscopic and spectrometric analyses of the cutin oligomers suggest that the elicitor compounds consist mostly of two up to three 10,16-dihydroxyhexadecanoic acid monomers linked together through ester bonds. This study demonstrates that cutin breakdown products can act as inducers of early plant immune responses. Further investigation is needed to understand how cutin breakdowns are perceived and to explore their potential use in agriculture.

Characterization and quantification of epilepsy patients with hospital episodes in Portugal: A multicenter retrospective study from Liga Portuguesa Contra a Epilepsia.

INTRODUCTION: Epilepsy affects around 50 million people worldwide and is associated with lower quality of life scores, an increased risk of premature death, and significant socio-economic implications. The lack of updated evidence on current epidemiology and patient characterization creates considerable uncertainty regarding the epilepsy burden in Portugal. The study aims to characterize and quantify the epilepsy patients who have been hospitalized, with medical or surgical procedures involved, and to analyze their associated comorbidities and mortality rates. METHODS: A multicenter retrospective study was conducted using hospital production data of epilepsy patients. The study included all patients diagnosed with epilepsy-related International Classification of Diseases-9/10 codes between 2015 and 2018 in 57 Portuguese National Health Service (NHS) hospitals (n = 57 institutions). Patient characterization and quantification were done for all patients with an epilepsy diagnosis, with specific analyses focusing on those whose primary diagnosis was epilepsy. Baseline, demographic, and clinical characteristics were analyzed using descriptive statistics. RESULTS: Between 2015 and 2018, a total of 80,494 hospital episodes (i.e., patient visit that generates hospitalization and procedures) were recorded, with 18 % to 19 % directly related to epilepsy. Among these epilepsy-related hospital episodes, 13.0 % led to short term hospitalizations (less than 24 h). Additionally, the average length of stay for all these epilepsy-related episodes was 8 days. A total of 49,481 patients were identified with epilepsy based on ICD-9/10 codes. The median age of patients was 64 years (min: 0; max: 104), with a distribution of 4.8 patients per 1,000 inhabitants. From the total of deaths (9,606) between 2015 and 2018, 14% were associated with patients whose primary diagnosis was epilepsy, with 545 of these being epilepsy-related deaths. Among patients with a primary diagnosis of epilepsy, the most common comorbidities were hypertension (24%) and psychiatric-related or similar comorbidities (15%), such as alcohol dependance, depressive and major depressive disorders, dementia and other convulsions. CONCLUSION: This study showed similar results to other European countries. However, due to methodological limitations, a prospective epidemiological study is needed to support this observation. Furthermore, the present study provides a comprehensive picture of hospitalized epilepsy patients in Portugal, their comorbidities, mortality, and hospital procedures.

A new class of monoclonal Aß antibodies selectively targets and triggers deposition of Aß protofibrils.

Aggregation and accumulation of amyloid-ß peptide (Aß) are a critical trigger for the onset of Alzheimer's disease (AD). While the plaques are the most outstanding Aß pathological feature, much of the recent research emphasis has been on soluble Aß species because of their diffusible, proinflammatory, and toxic properties. The focus on soluble aggregated Aß species has also increased the interest in antibodies that are selective for different Aß conformations. In the current study, we developed and characterized a new class of monoclonal antibodies (referred to as mAbSL) that are selective for Aß protofibrils. Cloning and sequencing of the heavy and light chain variable regions for multiple antibodies identified sequence characteristics that may impart the conformational selectivity by the antibodies. Transfection of FreeStyle 293F cells with the plasmids permitted in-house expression and purification of mAbSL antibodies along with non-conformation-selective Aß monoclonal antibodies (Aß mAbs). Several of the purified mAbSL antibodies demonstrated significant affinity and selectivity for Aß42 protofibrils compared with Aß42 monomers and Aß42 fibrils. Competition ELISA assays assessing the best overall antibody, mAbSL 113, yielded affinity constants of 7 nM for the antibody-Aß42 protofibril interaction, while the affinity for either Aß42 monomers or Aß42 fibrils was roughly 80 times higher. mAbSL 113 significantly inhibited Aß42 monomer aggregation by a unique mechanism compared with the inhibition displayed by Aß mAb 513. Aß42 protofibril dynamics were also markedly altered in the presence of mAbSL 113, whereby insoluble complex formation and protofibril deposition were stimulated by the antibody at low substoichiometric molar ratios. As the field contemplates the therapeutic effectiveness of Aß conformation-selective antibodies, the findings presented here demonstrate new information on a monoclonal antibody that selectively targets Aß protofibrils and impacts Aß dynamics.

Toward the Proactive Design of Sustainable Chemicals: Ionic Liquids as a Prime Example.

The tailorable and often unique properties of ionic liquids (ILs) drive their implementation into a broad variety of seminal technologies. The modular design of ILs allows in this context a proactive selection of structures that favor environmental sustainability─ideally without compromising their technological performance. To achieve this objective, the whole life cycle must be taken into account and various aspects considered simultaneously. In this review, we discuss how the structural design of ILs affects their environmental impacts throughout all stages of their life cycles and scrutinize the available data in order to point out knowledge gaps that need further research activities. The design of more sustainable ILs starts with the selection of the most beneficial precursors and synthesis routes, takes their technical properties and application specific performance into due account, and considers its environmental fate particularly in terms of their (eco)toxicity, biotic and abiotic degradability, mobility, and bioaccumulation potential. Special emphasis is placed on reported structure-activity relationships and suggested mechanisms on a molecular level that might rationalize the empirically found design criteria.

Cytogenomic Analysis of Long-Term Epilepsy-Associated Tumors Using an Array-Based CGH Strategy.

A palette of copy number changes in long-term epilepsy-associated tumors (LEATs) have been reported, but the data are heterogeneous. To better understand the molecular basis underlying the development of LEATs, we performed array-comparative genomic hybridization analysis to investigate chromosomal imbalances across the entire genome in 8 cases of LEATs. A high number of aberrations were found in 4 patients, among which deletions predominated. Both whole-chromosome and regional abnormalities were observed, including monosomy 19, deletion of 1p, deletions of 4p, 12p, and 22q, and gain of 20p. The common altered regions are located mainly on chromosomes 19 and 4p, identifying genes potentially involved in biological processes and cellular mechanisms related to tumorigenesis. Our study highlights new genomic alterations and reinforces others previously reported, offering new molecular insights that may help in diagnosis and therapeutic decision-making.

An Ionic Liquid Extraction That Preserves the Molecular Structure of Cutin Shown by Nuclear Magnetic Resonance.

The biopolyester cutin is ubiquitous in land plants, building the polymeric matrix of the plant's outermost defensive barrier, the cuticle. Cutin influences many biological processes in planta; however, due to its complexity and highly branched nature, the native structure remains partially unresolved. Our aim was to define an original workflow for the purification and systematic characterization of the molecular structure of cutin. To purify cutin we tested the ionic liquids cholinium hexanoate and 1-butyl-3-methyl-imidazolium acetate. The ensuing polymeric materials are highly esterified, amorphous, and have a typical monomeric composition as demonstrated by solid-state NMR, complemented by spectroscopic, thermal, and x-ray scattering analyses. We performed a systematic study by solution-state NMR of cryogenically milled cutins extracted from tomatoes (Solanum lycopersicum 'Micro-Tom'; the wild type and the GLYCEROL-3-PHOSPHATE ACYLTRANSFERASE [GPAT6] and CUTIN SYNTHASE [CUS1] mutants). We resolved their molecular structures, relative distribution of ester aliphatics, free acid end-groups and free hydroxyl groups, differentiating between those derived from primary and secondary esters. Our data demonstrate the existence of free hydroxyl groups in cutin and provide insight into how the mutations affect the esterification arrangement of cutin. The usage of ionic liquids for studying plant polyesters has advantages over conventional approaches, since simple modifications can be applied to recover a biopolymer carrying distinct types/degrees of modifications (e.g. preservation of esters or cuticular polysaccharides), which in combination with the solution NMR methodologies developed here, constitutes essential tools to fingerprint the multifunctionality and the structure of cutin in planta.

Ischemic Cerebellar Stroke in a 4-Year-Old Boy After Chickenpox: An Atypical Vascular Involvement.

Cerebrovascular events in pediatric population are very rare. Up to 30% may result from varicella zoster (VZV) arteriopathy, usually as a delayed complication of varicella primary infection. The most typical pattern includes involvement of anterior brain circulation arteries, probably by VZV migration from the trigeminal ganglia. Strokes related with VZV usually have a good prognosis, but risk of recurrence is greater when compared to other stroke etiologies in this age group. We report the case of a 4-year-old boy, immunocompetent, who presented a basilar artery stenosis and a cerebellar stroke, an extremely rare presentation of VZV arteriopathy. The investigation workup and treatment are detailed, as the clinical and imaging follow-up after one year.

Induced neuroprotection by remote ischemic perconditioning as a new paradigm in ischemic stroke at the acute phase, a systematic review.

BACKGROUND: Remote ischemic conditioning during cerebral ischemia (remote ischemic perconditioning, RIPerC) refers to the application of several cycles of brief ischemia and reperfusion (I/R) commonly to a limb, and it represents a new paradigm in neuroprotection with multiple mechanisms of action in ischemic stroke (IS) patients during acute phase. Some clinical trials just finished, and a few others are still ongoing; gather the current knowledge and pull it down to influence the present and future studies was the goal of this paper. METHODS: A systematic review of published research papers and/or registered clinical trials since 2000 was performed. RESULTS: Nineteen studies were identified and only four studies were completed. All of them have demonstrated that RIPerC is safe, feasible and well tolerated in IS patients. However, a high heterogeneity of clinical trial characteristics was observed: five (26.3%) randomized clinical trials (RCTs) included only thrombolytic-treated patients, three (15.8%) RCTs only thrombectomy-treated patients, and five (26.3%) RCTs required radiological confirmation of IS. Temporal inclusion criteria vary from 4 h to 48 h. Most of the clinical trials used 4 cycles of RIPerC in the upper non-affected limb. Interestingly, only three (16.7%) RCTs applied RIPerC during the transportation in the ambulance. Neuroimaging outputs were the main endpoints when endovascular therapy was applied; functional outcome is also the main endpoint in large-medium size studies. CONCLUSIONS: This review summarizes the completed and ongoing clinical trials on RIPerC in IS patients, where RIPerC has been used alone or in combination with recanalization therapies. Ongoing clinical trials will provide new information on the best RIPerC intervention strategy and potentially improve the functional outcome of IS patients; definition of new RIPerC strategies would ideally aim at enhancing tissue preservation, promoting neurological recovery, and stratify patients to improve treatment feasibility.

Unilateral Optic Neuritis in Children: Experience of a Tertiary Centre.

INTRODUCTION: Optic neuritis (ON) is an inflammation of the optic nerve that can be associated with a multitude of different systemic conditions and primary CNS disorders. In children, only around 25% of unilateral ON cases are considered idiopathic. Despite being considered a clinical diagnosis per se, neuroimaging plays a crucial role in the diagnostic pathway for these patients. METHODS: Demographic, clinical, and imaging data of all patients presenting with unilateral ON at a tertiary paediatric centre over 40 months (January 1, 2016, to April 30, 2019) were retrospectively analyzed. RESULTS: A total of 10 patients filled the inclusion criteria. The average age of presentation was 14.1 years. Patients in this series had ON associated with multiple sclerosis (n = 2), anti-MOG demyelinating disorders (n = 2), and neuromyelitis optica with anti-AQP4 antibodies (n = 1). ON was determined to be secondary to Toxocara canis infection in 1 case and a side effect of anti-TNFα therapy (adalimumab) in another. MR imaging showed T2 hyperintensity and/or gadolinium enhancement of one of the optic nerves in all but 3 patients, and coincidently these were the cases with monophasic idiopathic ON (average follow-up period of 2 years). Additional brain MR findings directly contributed to the final diagnosis in half of the cases. CONCLUSIONS: These cases are demonstrative of the wide range of possible causes of unilateral ON in the paediatric population. The absence of typical ON features in MR imaging was strongly suggestive of idiopathic ON in this cohort (p < 0.01).

Regulation of the cutinases expressed by Aspergillus nidulans and evaluation of their role in cutin degradation.

Four cutinase genes are encoded in the genome of the saprophytic fungus Aspergillus nidulans, but only two of them have proven to codify for active cutinases. However, their overall roles in cutin degradation are unknown, and there is scarce information on the regulatory effectors of their expression. In this work, the expression of the cutinase genes was assayed by multiplex qRT-PCR in cultures grown in media containing both inducer and repressor carbon sources. The genes ancut1 and ancut2 were induced by cutin and its monomers, while ancut3 was constitutively expressed. Besides, cutin induced ancut4 only under oxidative stress conditions. An in silico analysis of the upstream regulatory sequences suggested binding regions for the lipid metabolism transcription factors (TF) FarA for ancut1 and ancut2 while FarB for ancut3. For ancut4, the analysis suggested binding to NapA (the stress response TF). These binding possibilities were experimentally tested by transcriptional analysis using the A. nidulans mutants ANΔfarA, ANΔfarB, and ANΔnapA. Regarding cutin degradation, spectroscopic and chromatographic methods showed similar products from ANCUT1 and ANCUT3. In addition, ANCUT1 produced 9,10-dihydroxy hexadecanoic acid, suggesting an endo-cleavage action of this enzyme. Regarding ANCUT2 and ANCUT4, they produced omega fatty acids. Our results confirmed the cutinolytic activity of the four cutinases, allowed identification of their specific roles in the cutinolytic system and highlighted their differences in the regulatory mechanisms and affinity towards natural substrates. This information is expected to impact the cutinase production processes and broaden their current biotechnological applications.

Canine Mammary Tumors: Comparison of Classification and Grading Methods in a Survival Study.

Histopathology remains the cornerstone for diagnosing canine mammary tumors (CMTs). Recently, 2 classification systems (the World Health Organization [WHO] classification of 1999 and the proposal of 2011) and 2 grading methods based on the human Nottingham grade have been used by pathologists. Despite some evidence that the histological subtype and grade are prognostic factors, there is no comprehensive comparative study of these classification and grading systems in the same series of CMTs. In this study, the 2 classifications and the 2 grading methods were simultaneously applied to a cohort of 134 female dogs with CMTs. In 85 animals with malignant tumors, univariable and multivariable survival analyses were performed. Using the 2 systems, the proportion of benign (161/305, 53%) and malignant (144/305, 47%) tumors was similar and no significant differences existed in categorization of benign tumors. However, the 2011 classification subdivided malignant tumors in more categories-namely, those classified as complex, solid, and tubulopapillary carcinomas by the WHO system. Histological subtype according to both systems was significantly associated with survival. Carcinomas arising in benign tumors, complex carcinomas, and mixed carcinomas were associated with a better prognosis. In contrast, carcinosarcomas and comedocarcinomas had a high risk of tumor-related death. Slight differences existed between the 2 grading methods, and grade was related to survival only in univariable analysis. In this cohort, age, completeness of surgical margins, and 2 index formulas adapted from human breast cancer studies (including tumor size, grade, and vascular/lymph node invasion) were independent prognostic factors.

Efficacy of a socioemotional learning programme in a sample of children with intellectual disability.

Socioemotional learning (SEL) is the process of developing social and emotional competences through which the child learns to recognize and manage emotions, care for others, make good decisions, behave responsibly and ethically, develop positive relationships and avoid negative behaviours (Promoting social and emotional learning: Guidelines for educators, 1997). To promote the development of these competences, specific programmes are developed. This study aims to analyse the impact of a SEL programme among children with intellectual disability. Two groups were established, control and experimental, and the Test of Emotion Comprehension (TEC) (Test of emotion comprehension - TEC, 2000; Les émotions à l'école, émotions et apprentissage, 2004) was applied to both as pre- and post-test. The programme was implemented in the experimental group, based on simply illustrated stories alluding the basic emotions. The findings suggest that the programme is effective in the development of socioemotional competences (SEC) in subjects with intellectual disabilities, evidencing the positive effects that the intervention programme had with the experimental group.

Unveiling Concealed Functions of Endosymbiotic Bacteria Harbored in the Ascomycete Stachylidium bicolor.

Among the plethora of unusual secondary metabolites isolated from Stachylidium bicolor are the tetrapeptidic endolides A and B. Both tetrapeptides contain 3-(3-furyl)-alanine residues, previously proposed to originate from bacterial metabolism. Inspired by this observation, we aimed to identify the presence of endosymbiotic bacteria in S. bicolor and to discover the true producer of the endolides. The endobacterium Burkholderia contaminans was initially detected by 16S rRNA gene amplicon sequencing from the fungal metagenome and was subsequently isolated. It was confirmed that the tetrapeptides were produced by the axenic B. contaminans only when in latency. Fungal colonies unable to produce conidia and the tetrapeptides were isolated and confirmed to be free of B. contaminans A second endosymbiont identified as related to Sphingomonas leidyi was also isolated. In situ imaging of the mycelium supported an endosymbiotic relationship between S. bicolor and the two endobacteria. Besides the technical novelty, our in situ analyses revealed that the two endobacteria are compartmentalized in defined fungal cells, prevailing mostly in latency when in symbiosis. Within the emerging field of intracellular bacterial symbioses, fungi are the least studied eukaryotic hosts. Our study further supports the Fungi as a valuable model for understanding endobacterial symbioses in eukaryotes.IMPORTANCE The discovery of two bacterial endosymbionts harbored in Stachylidium bicolor mycelium, Burkholderia contaminans and Sphingomonas leidyi, is described here. Production of tetrapeptides inside the mycelium is ensured by B. contaminans, and fungal sporulation is influenced by the endosymbionts. Here, we illustrate the bacterial endosymbiotic origin of secondary metabolites in an Ascomycota host.

Comparative evaluation of 3 microbond strength tests using 4 adhesive systems: Mechanical, finite element, and failure analysis.

STATEMENT OF PROBLEM: Bond strength (BS) values from in vitro studies are useful when dentists are selecting an adhesive system, but there is no ideal measuring method. PURPOSE: The purpose of this in vitro study was to investigate the influence of the evaluation method in the BS between dentin and composite resin. MATERIAL AND METHODS: Molars with exposed superficial dentin (N=240) were divided into 3 groups according to the test: microtensile (µTBS), microshear (µSBS), and micropush-out (µPBS). Each one was subdivided into 4 groups according to the adhesive system: total etch, 3- and 2-step; and self-etch, 2- and 1-step). For the µPBS test, a conical cavity was prepared and restored with composite resin. An occlusal slice (1.5 mm in thickness) was obtained from each tooth. For the µSBS test, a composite resin cylinder (1 mm in diameter) was built on the dentin surface of each tooth. For the µTBS test, a 2-increment composite resin cylinder was built on the dentin surface, and beams with a sectional area of 0.5 mm2 were obtained. Each subgroup was divided into 2 (n=10) as the specimens were tested after 7 days and 1 year of water storage. The specimens were submitted to load, and the failure recorded in units of megapascals. Original BS values from the µTBS and µSBS tests were normalized for the area from µPBS specimens. Original and normalized results were submitted to a 3-way ANOVA (α=.05). The correlation among mechanical results, stress distribution, and failure pattern was investigated. RESULTS: Significant differences (P<.05) were found among the adhesive systems and methods within both the original and normalized data but not between the storage times (P>.05). Within the 7 days of storage, the original BS values from µTBS were significantly higher (P<.001) than those from µPBS and µSBS. After 1 year, µSBS presented significantly lower results (P<.001). However, after the normalization for area, the BS values of the µTBS and µPBS tests were similar, and both were higher (P<.001) than that of µSBS in both storage times. In the µSBS and µTBS specimens, cohesive and adhesive failures were observed, whereas µPBS presented 100% of adhesive failures. The failure modes were compatible with the stress distribution. CONCLUSIONS: The storage time did not affect the results, but differences were found among the adhesives and methods. For comparisons of bond strength from tests with different bonding areas, the normalization for area seemed essential. The microshear bond test should not be used for bond strength evaluation, and the microtensile test needs improvement to enable reliable results regarding stress concentration and failure mode. The micropush-out test may be considered more reliable than the microtensile in the bond strength investigation, as demonstrated by the uniform stress concentration and adhesive failure pattern.

Clinical, biochemical, molecular, and histological features of 65 Portuguese patients with mitochondrial disorders.

INTRODUCTION: Mitochondrial disorders display remarkable genetic and phenotypic heterogeneity. METHODS: We performed a retrospective analysis of the clinical, histological, biochemical, and genetic features of 65 patients with molecular diagnoses of mitochondrial disorders. RESULTS: The most common genetic diagnosis was a single large-scale mitochondrial DNA (mtDNA) deletion (41.5%), and the most frequent clinical phenotype was chronic progressive external ophthalmoplegia (CPEO). It occurred in 41.5% of all patients, primarily in those with mtDNA deletions. Histological signs of mitochondrial dysfunction were found in 73.8% of patients, and respiratory chain enzyme assay (RCEA) abnormalities were detected in 51.9%. CONCLUSIONS: This study confirms the high relative frequency of single large-scale deletions among mitochondrial disorders as well as its particular association with CPEO. Muscle histology seems to be particularly useful in older patients and those with mtDNA deletions, whereas RCEA might be more helpful in young children or individuals with mtDNA depletion. Muscle Nerve 56: 868-872, 2017.

Evaluation of biodegradable polymer conduits--poly(L-lactic acid)--for guiding sciatic nerve regeneration in mice.

Polymeric biomaterials are often used for stimulating nerve regeneration. Among different conduits, poly(lactide acid) - PLA polymer is considered to be a good substrate due to its biocompatibility and resorbable characteristics. This polymer is an aliphatic polyester which has been mostly used in biomedical application. It is an organic compound with low allergenic potential, low toxicity, high biocompatibility and predictable kinetics of degradation. In this study we fabricated and evaluated a PLA microporous hollow fiber as a conduit for its ability to bridge a nerve gap in a mouse sciatic nerve injury model. The PLA conduit was prepared from a polymer solution, throughout extrusion technique. The left sciatic nerve of C57BL/6 mouse was transected and the nerve stumps were placed into a resorbable PLA (PLA group) or a PCL conduit (PCL group), n=5 each group. We have also used another group in which the nerves were repaired by autograft (autograft group, n=5). Motor function was analyzed according to sciatic functional index (SFI). After 56days, the regenerated nerves were processed for light and electron microscopy and morphometric analyses were performed. A quantitative analysis of regenerated nerves showed significant increase in the number of myelinated fibers and blood vessels in animals that received PLA conduit. The PLA group exhibited better overall tissue organization compared to other groups. Presenting well-organized bundles, many regenerating clusters composed of preserved nerve fibers surrounded by layers of compacted perineurium-like cells. Also the SFI revealed a significant improvement in functional recovery. This work suggests that PLA conduits are suitable substrate for cell survival and it provides an effective strategy to be used to support axonal growth becoming a potential alternative to autograft.

Transcriptomic and metabolomic profiling of ionic liquid stimuli unveils enhanced secondary metabolism in Aspergillus nidulans.

BACKGROUND: The inherent potential of filamentous fungi, especially of Ascomycota, for producing diverse bioactive metabolites remains largely silent under standard laboratory culture conditions. Innumerable strategies have been described to trigger their production, one of the simplest being manipulation of the growth media composition. Supplementing media with ionic liquids surprisingly enhanced the diversity of extracellular metabolites generated by penicillia. This finding led us to evaluate the impact of ionic liquids' stimuli on the fungal metabolism in Aspergillus nidulans and how it reflects on the biosynthesis of secondary metabolites (SMs). RESULTS: Whole transcriptional profiling showed that exposure to 0.7 M cholinium chloride or 1-ethyl-3-methylimidazolium chloride dramatically affected expression of genes encoding both primary and secondary metabolism. Both ionic liquids apparently induced stress responses and detoxification mechanisms but response profiles to each stimulus were unique. Primary metabolism was up-regulated by choline, but down-regulated by 1-ethyl-3-methylimidazolium chloride; both stimulated production of acetyl-CoA (key precursor to numerous SMs) and non proteinogenic amino acids (building blocks of bioactive classes of SMs). In total, twenty one of the sixty six described backbone genes underwent up-regulation. Accordingly, differential analysis of the fungal metabolome showed that supplementing growth media with ionic liquids resulted in ca. 40 differentially accumulated ion masses compared to control conditions. In particular, it stimulated production of monodictyphenone and orsellinic acid, otherwise cryptic. Expression levels of genes encoding corresponding polyketide biosynthetic enzymes (i.e. backbone genes) increased compared to control conditions. The corresponding metabolite extracts showed increased cell polarity modulation potential in an ex vivo whole tissue assay (The lial Live Targeted Epithelia; theLiTE™). CONCLUSIONS: Ionic liquids, a diverse class of chemicals composed solely of ions, can provide an unexpected means to further resolve the diversity of natural compounds, guiding discovery of fungal metabolites with clinical potential.

Preservation of different fig cultivars (Ficus carica L.) under modified atmosphere packaging during cold storage.

BACKGROUND: The effect of modified atmosphere packaging (MAP) on the stability of 'Cuello Dama Blanco' (CDB), 'Cuello Dama Negro' (CDN) and 'San Antonio' (SA) figs during post-harvest cold storage was evaluated by using three different films with a diverse number of microperforations (diameter, ø = 100 µm): M10 (16 holes), M30 (five holes) and M50 (three holes). A macroperforated film was used as control (five holes, ø = 9 mm). Gas composition, weight loss, percentage disorder, microbial counts and physico-chemical parameters were monitored during cold storage for 21 days. Furthermore, sensory quality was also evaluated. RESULTS: MAP has allowed the extension of cold storage and distribution time for the three different cultivars of figs, minimising weight loss and delaying pathological disorders related to endosepsis, smut, and souring. Of the three cultivars, the M50 batch (one hole per 50 mm) showed the best efficiency in terms of physico-chemical quality and delay of post-harvest decay, although the M30 batch was also found to be suitable for delaying the post-harvest decay, especially for the CDB cultivar. CONCLUSION: MAP is a useful tool to extend the storability with optimal quality properties for CDN and SA during 21 days of cold storage and 14-17 days of cold storage for CDB.

Understanding fungal functional biodiversity during the mitigation of environmentally dispersed pentachlorophenol in cork oak forest soils.

Pentachlorophenol (PCP) is globally dispersed and contamination of soil with this biocide adversely affects its functional biodiversity, particularly of fungi - key colonizers. Their functional role as a community is poorly understood, although a few pathways have been already elucidated in pure cultures. This constitutes here our main challenge - elucidate how fungi influence the pollutant mitigation processes in forest soils. Circumstantial evidence exists that cork oak forests in N. W. Tunisia - economically critical managed forests are likely to be contaminated with PCP, but the scientific evidence has previously been lacking. Our data illustrate significant forest contamination through the detection of undefined active sources of PCP. By solving the taxonomic diversity and the PCP-derived metabolomes of both the cultivable fungi and the fungal community, we demonstrate here that most strains (predominantly penicillia) participate in the pollutant biotic degradation. They form an array of degradation intermediates and by-products, including several hydroquinone, resorcinol and catechol derivatives, either chlorinated or not. The degradation pathway of the fungal community includes uncharacterized derivatives, e.g. tetrachloroguaiacol isomers. Our study highlights fungi key role in the mineralization and short lifetime of PCP in forest soils and provide novel tools to monitor its degradation in other fungi dominated food webs.