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1.
Acad Med ; 99(7): 741-744, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38518101

ABSTRACT

PROBLEM: Although the practice of medicine is often emotionally challenging, medical curricula seldom systematically address the emotional development of medical students. To fill this gap, the authors developed and evaluated an innovative pedagogical activity based on music to nurture medical students' emotional development. The authors believe that the metaphoric nature of music offers an efficient venue for exploring emotion perception, expression, and regulation. APPROACH: The pedagogical activity Emotions in Medicine was carried out throughout 2020 and 2021 and consisted of 4 encounters to explore: (1) emotion perception, (2) emotion expression, (3) emotion regulation, and (4) the role of emotions in medical practice. During all encounters, the authors used music to evoke students' emotions and focused the discussions on the relevance of emotions for meaningful medical practice. Emotional intelligence before and after the workshop was tested using the Schutte Self-Report Emotional Intelligence Test (SSEIT), a validated psychometric scale. OUTCOMES: The workshop facilitated emotional connection among students and created a safe space to explore the role of emotions in medical practice. The mean total pretest SSEIT score was 110 (SD = 14.2); it increased to 116.8 (SD = 16.1) in the posttest ( P < .001). This increase was true across its 4 dimensions: (1) perception of emotions, (2) management of own emotions (3) management of others' emotions, and (4) use of emotions. NEXT STEPS: Music can be an active tool to explore the role of emotions in medical practice. It fosters students' capacity to identify and reflect on emotions while exploring their role in patient care. Further (qualitative) research is needed to explore the mechanisms by which music facilitates learning emotion perception, expression, and regulation.


Subject(s)
Curriculum , Emotional Intelligence , Emotions , Music , Students, Medical , Humans , Students, Medical/psychology , Music/psychology , Female , Male , Education, Medical, Undergraduate/methods , Adult
2.
Sci Total Environ ; 912: 168718, 2024 Feb 20.
Article in English | MEDLINE | ID: mdl-38007122

ABSTRACT

The effective communication of flood hazard and risk is a necessary step to foster preparedness and resilience, hence reducing the detrimental impacts of flooding events. Classical flood maps, which show flow depth and velocity, have often proved to be incomprehensible to the majority of people. Some recent studies used color maps to convey the spatial distribution of diverse hazard indexes that, accounting for both water depth and velocity, are intended to communicate the hazard degree in a more intelligible way. It is first shown that these hazard indexes have some inherent limitations, as for example the implicit assumption of a linear relationship between flood hazard and flow velocity. As an alternative, we propose to map the loss probability (LP) of pedestrians exposed to floodwaters, which is a physics-based and data-consistent risk index accounting for both hazard and vulnerability. LP can be easily computed and allows for a sounder estimation and a more effective communication of flood risk to the general public.

3.
Biomed Opt Express ; 14(8): 3988-4002, 2023 Aug 01.
Article in English | MEDLINE | ID: mdl-37799688

ABSTRACT

Fixation methods such as formalin are commonly used for the preservation of tissue with the aim of keeping their structure as close as possible to the native condition. However, fixatives chemically interact with tissue molecules, such as collagen in the extracellular matrix (ECM) or myosin, and may thus modify their structure. Taking advantage of the second- and third-harmonic generation (SHG and THG) emission capabilities of such components, we used nonlinear two-photon microscopy (NL2PM) to evaluate the effect that preservation methods, such as chemical fixatives, have on the nonlinear capabilities of protein components within mouse tissues. Our results show that depending on the preservation technique used, the nonlinear capabilities of collagen, lipid droplets and myosin microarchitecture are strongly affected. Parameters of collagen fibers, such as density and branch points, especially in collagen-sparse regions, e.g., in kidneys, were found to be altered upon formalin fixation. Moreover, cryo-freezing drastically reduced SHG signals from myosin. Our findings provide valuable information to select the best tissue fixation method for visualization and quantification of structural proteins, such as collagen and myosin by advanced NL2PM imaging techniques. This may advance the interpretation of the role these proteins play in disease.

5.
Membranes (Basel) ; 13(3)2023 Mar 21.
Article in English | MEDLINE | ID: mdl-36984748

ABSTRACT

Protein S-palmitoylation is a reversible post-translational lipidation in which palmitic acid (16:0) is added to protein cysteine residue by a covalent thioester bond. This modification plays an active role in membrane targeting of soluble proteins, protein-protein interaction, protein trafficking, and subcellular localization. Moreover, palmitoylation is related to different diseases, such as neurodegenerative pathologies, cancer, and developmental defects. The aim of this research is to provide a straightforward and sensitive procedure to detect protein palmitoylation based on Acyl Biotin Exchange (ABE) chemistry. Our protocol setup consists of co-immunoprecipitation of native proteins (i.e., CD63), followed by the direct detection of palmitoylation on proteins immobilized on polyvinylidene difluoride (PVDF) membranes. With respect to the conventional ABE-based protocol, we optimized and validated a rapid semi-quantitative assay that is shown to be significantly more sensitive and highly reproducible.

6.
Diabetol Metab Syndr ; 15(1): 42, 2023 Mar 11.
Article in English | MEDLINE | ID: mdl-36899434

ABSTRACT

BACKGROUND: Subclinical atherosclerosis is frequently observed in type 1 diabetes (T1D) although the mechanisms and markers involved in the evolution to established cardiovascular disease are not well known. High-density lipoprotein cholesterol in T1D is normal or even high, and changes in its functionality and proteomics are considered. Our aim was to evaluate the proteomics of HDL subfractions in T1D and control subjects and its association with clinical variables, subclinical atherosclerosis markers and HDL functionality. METHODS: A total of 50 individuals with T1D and 30 matched controls were included. Carotid-femoral pulse wave velocity (PWV), flow-mediated vasodilation (FMD), cardiovascular autonomic neuropathy (CAN), and ten-year cardiovascular risk (ASCVDR) were determined. Proteomics (parallel reaction monitoring) was determined in isolated HDL2 and HDL3 that were also utilized to measure cholesterol efflux from macrophages. RESULTS: Among 45 quantified proteins, 13 in HDL2 and 33 in HDL3 were differentially expressed in T1D and control subjects. Six proteins related to lipid metabolism, one to inflammatory acute phase, one to complement system and one to antioxidant response were more abundant in HDL2, while 14 lipid metabolism, three acute-phase, three antioxidants and one transport in HDL3 of T1D subjects. Three proteins (lipid metabolism, transport, and unknown function) were more abundant in HDL2; and ten (lipid metabolism, transport, protease inhibition), more abundant in HDL3 of controls. Individuals with T1D had higher PWV and ten-year ASCVDR, and lower FMD, Cholesterol efflux from macrophages was similar between T1D and controls. Proteins in HDL2 and HDL3, especially related to lipid metabolism, correlated with PWV, CAN, cholesterol efflux, HDLc, hypertension, glycemic control, ten-year ASCVDR, and statins use. CONCLUSION: HDL proteomics can be predictive of subclinical atherosclerosis in type 1 diabetes. Proteins that are not involved in reverse cholesterol transport may be associated with the protective role of HDL.

7.
Data Brief ; 46: 108799, 2023 Feb.
Article in English | MEDLINE | ID: mdl-36544569

ABSTRACT

The Semantic Coherence Dataset has been designed to experiment with semantic coherence metrics. More specifically, the dataset has been built to the ends of testing whether probabilistic measures, such as perplexity, provide stable scores to analyze spoken language. Perplexity, which was originally conceived as an information-theoretic measure to assess the probabilistic inference properties of language models, has recently been proven to be an appropriate tool to categorize speech transcripts based on semantic coherence accounts. More specifically, perplexity has been successfully employed to discriminate subjects suffering from Alzheimer Disease and healthy controls. Collected data include speech transcripts, intended to investigate semantic coherence at different levels: data are thus arranged into two classes, to investigate intra-subject semantic coherence, and inter-subject semantic coherence. In the former case transcripts from a single speaker can be employed to train and test language models and to explore whether the perplexity metric provides stable scores in assessing talks from that speaker, while allowing to distinguish between two different forms of speech, political rallies and interviews. In the latter case, models can be trained by employing transcripts from a given speaker, and then used to measure how stable the perplexity metric is when computed using the model from that user and transcripts from different users. Transcripts were extracted from talks lasting almost 13 hours (overall 12:45:17 and 120,326 tokens) for the former class; and almost 30 hours (29:47:34 and 252,270 tokens) for the latter one. Data herein can be reused to perform analyses on measures built on top of language models, and more in general on measures that are aimed at exploring the linguistic features of text documents.

8.
Artif Intell Med ; 134: 102393, 2022 12.
Article in English | MEDLINE | ID: mdl-36462890

ABSTRACT

Devising automatic tools to assist specialists in the early detection of mental disturbances and psychotic disorders is to date a challenging scientific problem and a practically relevant activity. In this work we explore how language models (that are probability distributions over text sequences) can be employed to analyze language and discriminate between mentally impaired and healthy subjects. We have preliminarily explored whether perplexity can be considered a reliable metrics to characterize an individual's language. Perplexity was originally conceived as an information-theoretic measure to assess how much a given language model is suited to predict a text sequence or, equivalently, how much a word sequence fits into a specific language model. We carried out an extensive experimentation with healthy subjects, and employed language models as diverse as N-grams - from 2-grams to 5-grams - and GPT-2, a transformer-based language model. Our experiments show that irrespective of the complexity of the employed language model, perplexity scores are stable and sufficiently consistent for analyzing the language of individual subjects, and at the same time sensitive enough to capture differences due to linguistic registers adopted by the same speaker, e.g., in interviews and political rallies. A second array of experiments was designed to investigate whether perplexity scores may be used to discriminate between the transcripts of healthy subjects and subjects suffering from Alzheimer Disease (AD). Our best performing models achieved full accuracy and F-score (1.00 in both precision/specificity and recall/sensitivity) in categorizing subjects from both the AD class, and control subjects. These results suggest that perplexity can be a valuable analytical metrics with potential application to supporting early diagnosis of symptoms of mental disorders.


Subject(s)
Alzheimer Disease , Semantics , Humans , Benchmarking , Biomarkers , Linguistics , Alzheimer Disease/diagnosis
9.
J Diabetes Metab Disord ; 21(2): 1661-1667, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36404814

ABSTRACT

Abstract: Diabetic gastroparesis (DGP) is an autonomic neuropathy resulting from long-standing poorly controlled diabetes, and it is also linked to fluctuations in glycemic control due to variability on nutrient absorption. Objectives: Considering the scarcity of information, the aim of this study was to identify the impact of modifications on diet consistency on post-prandial glucose variability using a continuous glucose monitoring (CGM) and its effect on the perception and severity of gastrointestinal symptoms. Methods: This proof-of-concept study was carried out in a cross-sectional cohort of six individuals with type 1 diabetes mellitus with confirmed diagnosis of DGP. Two types of diet were used to evaluate glycemic control and DGP symptoms, general consistency standard meal (SD) and modified consistency test diet (MD), associated with an application of rapid acting insulin at the time of food intake. Glycemic control was evaluated by CGM, and the Gastroparesis Cardinal Symptom Index (GCSI) was applied after meals. Results: The CGM curve was different for MD + insulin and SD + insulin. There was a smaller increment of interstitial glucose with 2 h after MD + insulin, returning almost to the basal level 4 h later. Patients scored significantly lower GCSI after MD + insulin compared to the same index after they received SD + insulin. Moreover, there was a decrease in important clinical scores present in the index, like: "Not able to finish meal", "Loss of appetite" and "Stomach or belly feels larger". Conclusion: This study showed that a modified diet can improve postprandial glycemic excursion and the perception and severity of gastroparesis symptoms. Supplementary Information: The online version contains supplementary material available at 10.1007/s40200-022-01117-w.

10.
Toxins (Basel) ; 14(8)2022 08 08.
Article in English | MEDLINE | ID: mdl-36006204

ABSTRACT

The evolution of snake venoms resulted in multigene toxin families that code for structurally similar isoforms eventually harboring distinct functions. PLA2s are dominant toxins in viper venoms, and little is known about the impact of their diversity on human envenomings and neutralization by antivenoms. Here, we show the isolation of three distinct PLA2s from B. atrox venom. FA1 is a Lys-49 homologue, and FA3 and FA4 are catalytic Asp-49 PLA2s. FA1 and FA3 are basic myotoxic proteins, while FA4 is an acid non-myotoxic PLA2. FA3 was the most potent toxin, inducing higher levels of edema, inflammatory nociception, indirect hemolysis, and anticoagulant activity on human, rat, and chicken plasmas. FA4 presented lower anticoagulant activity, and FA1 had only a slight effect on human and rat plasmas. PLA2s presented differential reactivities with antivenoms, with an emphasis on FA3, which was not recognized or neutralized by the antivenoms used in this study. Our findings reveal the functional and antigenic diversity among PLA2s from B. atrox venom, highlighting the importance of assessing venom variability for understanding human envenomations and treatment with antivenoms, particularly evident here as the antivenom fails to recognize FA3, the most active multifunctional toxin described.


Subject(s)
Bothrops , Crotalid Venoms , Snake Bites , Animals , Antivenins/therapeutic use , Bothrops/metabolism , Crotalid Venoms/toxicity , Humans , Phospholipases A2/toxicity , Rats , Snake Bites/drug therapy
11.
Cancers (Basel) ; 14(15)2022 Jul 29.
Article in English | MEDLINE | ID: mdl-35954365

ABSTRACT

Tumor growth and metastasis strongly rely on cell-cell communication. One of the mechanisms by which tumor cells communicate involves the release and uptake of lipid membrane encapsulated particles full of bioactive molecules, called extracellular vesicles (EVs). EV exchange between cancer cells may induce phenotype changes in the recipient cells. Our work investigated the effect of EVs released by teratocarcinoma cells on glioblastoma (GBM) cells. EVs were isolated by differential centrifugation and analyzed through Western blot, nanoparticle tracking analysis, and electron microscopy. The effect of large EVs on GBM cells was tested through cell migration, proliferation, and drug-sensitivity assays, and resulted in a specific impairment in cell migration with no effects on proliferation and drug-sensitivity. Noticeably, we found the presence of the EGF-CFC founder member CRIPTO on both small and large EVs, in the latter case implicated in the EV-mediated negative regulation of GBM cell migration. Our data let us propose a novel route and function for CRIPTO during tumorigenesis, highlighting a complex scenario regulating its effect, and paving the way to novel strategies to control cell migration, to ultimately improve the prognosis and quality of life of GBM patients.

12.
Sci Adv ; 8(13): eabm8446, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35363513

ABSTRACT

Coastal flooding prevention measures, such as storm-surge barriers, are being widely adopted globally because of the accelerating rise in sea levels. However, their impacts on the morphodynamics of shallow tidal embayments remain poorly understood. Here, we combine field data and modeling results from the microtidal Venice Lagoon (Italy) to identify short- and long-term consequences of flood regulation on lagoonal landforms. Artificial reduction of water levels enhances wave-induced sediment resuspension from tidal flats, promoting in-channel deposition, at the expense of salt marsh vertical accretion. In Venice, we estimate that the first 15 closures of the recently installed mobile floodgates operated between October 2020 and January 2021 contributed to a 12% reduction in marsh deposition, simultaneously promoting a generalized channel infilling. Therefore, suitable countermeasures need to be taken to offset these processes and prevent significant losses of geomorphic diversity due to repeated floodgate closures, whose frequency will increase as sea levels rise further.

13.
J Cancer Res Clin Oncol ; 148(1): 225-236, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34110489

ABSTRACT

PURPOSE: 177Lu-Dotatate is an emerging treatment modality for patients with unresectable or metastatic well-differentiated NETs. This study examines survival predictors in patients who received 177Lu-Dotatate. METHODS: A retrospective single-center review was conducted, examining 47 individuals with progressive well-differentiated NETs treated with 177Lu-Dotatate (four induction cycles of 5.5 GBq at 10-week intervals followed by eight maintenance cycles of 3.7 GBq at 6-month intervals). RESULTS: Median follow-up was 63.1 months with a median progression-free survival (PFS) of 34.1 months. However, median overall survival (OS) was not reached at the time of analysis. The presence of ≥ 5 bone metastases (hazard ratio HR 4.33; p = 0.015), non-gastroenteropancreatic (non-GEP) NETs (HR 3.22; p = 0.025) and development of interim ascites (HR 3.15; p = 0.047) independently predicted a worse OS. Patients with chromogranin A of ≥ 4 × upper limit of normal (ULN) had shorter OS (p < 0.001) and PFS (p = 0.004). Similarly, those with pre-existing ascites demonstrated a worse OS (p = 0.009) and PFS (p = 0.026). Liver metastases involving greater than 50% liver volume and the existence of unusual metastatic locations had a negative impact on OS (p = 0.033) and PFS (p = 0.026), respectively. CONCLUSION: High burden of skeletal and hepatic metastases, non-GEP-NETs, chromogranin A of ≥ 4 × ULN, unusual metastatic sites, pre-existing and interim ascites are predictors of poor outcomes in patients treated with 177Lu-Dotatate. These common indicators can be used for the risk stratification and identification of patients most likely to benefit from PRRT. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02236910, Retrospectively registered on September, 2014.


Subject(s)
Bone Neoplasms/secondary , Liver Neoplasms/secondary , Neuroendocrine Tumors/mortality , Neuroendocrine Tumors/radiotherapy , Octreotide/analogs & derivatives , Organometallic Compounds/therapeutic use , Adult , Aged , Aged, 80 and over , Antiemetics/therapeutic use , Ascites/mortality , Ascites/pathology , Biomarkers, Tumor/analysis , Bone Neoplasms/mortality , Chromogranin A/analysis , Endoderm/pathology , Female , Humans , Liver Neoplasms/mortality , Male , Middle Aged , Neural Crest/pathology , Neuroendocrine Tumors/pathology , Octreotide/adverse effects , Octreotide/therapeutic use , Organometallic Compounds/adverse effects , Progression-Free Survival , Radiopharmaceuticals/adverse effects , Radiopharmaceuticals/therapeutic use , Retrospective Studies
14.
Curr Diabetes Rev ; 18(4): e270821195908, 2022.
Article in English | MEDLINE | ID: mdl-34455961

ABSTRACT

BACKGROUND: Cardiovascular autonomic neuropathy (CAN) is a common complication of type 2 Diabetes mellitus (T2D), and prevalence varies according to the methodology used. CAN should be diagnosed in the subclinical stage when an intensive treatment of T2D could avoid the progression to irreversible phases. OBJECTIVE: Determine the prevalence of early involvement (EI) of CAN in T2D individuals comparing two methodologies. METHODS: This was a cross-sectional study that included 183 T2D individuals who were monitored in a Tertiary centre. The diagnosis of CAN was based on the results of four cardiovascular autonomic reflex tests (CARTs: expiration-inspiration index, Valsalva maneuver, orthostatic test, and changes in blood pressure after standing) and of seven heart rate variability (7HRV) indices (CARTs plus the spectral analysis). The findings were validated in an independent cohort comprised of 562 T2D individuals followed in a Primary care setting. RESULTS: With the use of 7HRV, 30.6% and 77.8% of individuals in the Tertiary and in the Primary centers, respectively, were classified as without CAN; 25.1% and 15.3% as EI and 44.3% and 6.9% as definitive CAN, respectively. The use of CARTs decreased the proportion of individuals without CAN in both centers (7.1% and 47%) and increased the frequency of EI (30.6% and 36.6%) and definitive CAN (62.3% and 16.4%), respectively. The concordance between both evaluated methodologies was weak. CONCLUSION: Higher proportions of T2D individuals were diagnosed with EI and with definitive CAN with the use of CARTs.


Subject(s)
Autonomic Nervous System Diseases , Diabetes Mellitus, Type 2 , Diabetic Neuropathies , Autonomic Nervous System Diseases/diagnosis , Autonomic Nervous System Diseases/etiology , Cross-Sectional Studies , Diabetes Mellitus, Type 2/epidemiology , Diabetic Neuropathies/complications , Early Diagnosis , Heart Rate/physiology , Humans , Reflex
15.
Int J Mol Sci ; 22(20)2021 Oct 09.
Article in English | MEDLINE | ID: mdl-34681561

ABSTRACT

Chagas disease is a human infectious disease caused by Trypanosoma cruzi and can be transmitted by triatomine vectors, such as Rhodnius prolixus. One limiting factor for T. cruzi development is the composition of the bacterial gut microbiota in the triatomine. Herein, we analyzed the humoral immune responses of R. prolixus nymphs treated with antibiotics and subsequently recolonized with either Serratia marcescens or Rhodococcus rhodnii. The treatment with antibiotics reduced the bacterial load in the digestive tract, and the recolonization with each bacterium was successfully detected seven days after treatment. The antibiotic-treated insects, recolonized with S. marcescens, presented reduced antibacterial activity against Staphylococcus aureus and phenoloxidase activity in hemolymph, and lower nitric oxide synthase (NOS) and higher defensin C gene (DefC) gene expression in the fat body. These insects also presented a higher expression of DefC, lower prolixicin (Prol), and lower NOS levels in the anterior midgut. However, the antibiotic-treated insects recolonized with R. rhodnii had increased antibacterial activity against Escherichia coli and lower activity against S. aureus, higher phenoloxidase activity in hemolymph, and lower NOS expression in the fat body. In the anterior midgut, these insects presented higher NOS, defensin A (DefA) and DefC expression, and lower Prol expression. The R. prolixus immune modulation by these two bacteria was observed not only in the midgut, but also systemically in the fat body, and may be crucial for the development and transmission of the parasites Trypanosoma cruzi and Trypanosoma rangeli.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Rhodnius/microbiology , Rhodococcus/immunology , Serratia marcescens/immunology , Animals , Anti-Bacterial Agents/pharmacology , Defensins/metabolism , Fat Body/metabolism , Gastrointestinal Microbiome/drug effects , Gene Expression Regulation/drug effects , Immunity, Humoral , Insect Proteins/metabolism , Monophenol Monooxygenase/metabolism , Nitric Oxide Synthase/metabolism , Rhodnius/drug effects , Rhodnius/immunology , Rhodnius/metabolism , Staphylococcus aureus/physiology
16.
Brain Res Bull ; 176: 142-150, 2021 11.
Article in English | MEDLINE | ID: mdl-34500037

ABSTRACT

Psychological stress and occlusal alterations are contributing etiologic factors for temporomandibular and muscular disorders in the orofacial area. The neural modulation recruited for this relationship, however, is not elucidated. The aim of this study was to investigate potential central mechanisms involved in the exodontia-induced occlusal instability associated with unpredictable chronic stress (UCS). Male adult Wistar rats were submitted to occlusal instability (unilateral molar teeth extraction) and/or to a UCS protocol and treated with diazepam or vehicle. The anxiety-like behavior was evaluated by elevated plus maze (EPM) and open field (OF) tests. Limbic structures such as the central nucleus of the amygdala (CeA), paraventricular nucleus of the hypothalamus (PVN), dorsal periaqueductal gray matter (dPAG) and nucleus accumbens core (NAc) were analyzed for expression of FosB/ΔFosB (immediate early genes) by immunohistochemistry. Exodontia and/or UCS decreased the time spent in the open arms at the EPM and the distance travelled at the OF, and increased the immobility time at the OF, suggesting anxiety-like behavior. In addition, exodontia induction resulted in an upregulation of FosB/ΔFosB in the CeA, PVN and dPAG, while UCS and exodontia + UCS upregulate FosB/ΔFosB immunoreactivity in the CeA, PVN, dPAG and NAc. Treatment with diazepam decreased the expression of FosB/ΔFosB in all analyzed structures of animals subject to UCS and exodontia + UCS, while promoted a reduction in the FosB/ΔFosB expression in the CeA, PVN and dPAG in animals subject to exodontia. Our findings showed an anxiogenic effect of exodontia and UCS, which is correlated with intranuclear neuron activation of limbic structures in a spatially dependent manner and that is prevented by the administration of diazepam.


Subject(s)
Limbic System/metabolism , Neurons/metabolism , Proto-Oncogene Proteins c-fos/metabolism , Stress, Psychological/metabolism , Tooth Extraction , Animals , Anti-Anxiety Agents/pharmacology , Diazepam/pharmacology , Immunohistochemistry , Limbic System/drug effects , Male , Neurons/drug effects , Rats , Rats, Wistar , Up-Regulation
17.
An Acad Bras Cienc ; 93(3): e20191402, 2021.
Article in English | MEDLINE | ID: mdl-34378638

ABSTRACT

Beta-1,3-glucanases are enzymes that hydrolyze beta-1,3-glucans, and they are essential for the metabolism of seaweed, plants and fungi. These enzymes also participate in the digestion of herbivore and fungivore animals. Because of the importance of these enzymes in insects, beta-1,3-glucanase inhibitors may be used for the development of new control strategies against agricultural pests and disease vectors. Beta-1,3-glucanase inhibitors have been described in the brown seaweed Laminaria cichorioides, but were never recorded in Brazilian seaweed species. We evaluated the presence of beta-1,3-glucanase inhibitors in samples of Padina gymnospora, Dictyota sp., Colpomenia sinuosa, and Lobophora sp., collected in Arraial d'Ajuda (Bahia). Ethanolic or buffer extracts were used in inhibition tests against the beta-1,3-glucanase of Trichoderma sp. Extracts in buffer showed no inhibition, but ethanolic extracts from all species showed different extents of inhibition. Samples from Dictyota sp. and P. gymnospora showed inhibitions above 75% (absolute ethanol) or 50% (ethanol 50%). In summary, extraction with absolute ethanol resulted in better inhibitions, and P. gymnospora showed the higher inhibitions. Brazilian seaweed may be good sources of beta-1,3-glucanase inhibitors for biochemical and physiological studies of these enzymes. Besides that, these molecules show potential for the development of new biotechnological tools for insect control.


Subject(s)
Seaweed , Animals , Brazil , Fungi , Vegetables
18.
J Extracell Vesicles ; 10(6): e12081, 2021 04.
Article in English | MEDLINE | ID: mdl-33936568

ABSTRACT

Cellular, inter-organismal and cross kingdom communication via extracellular vesicles (EVs) is intensively studied in basic science with high expectation for a large variety of bio-technological applications. EVs intrinsically possess many attributes of a drug delivery vehicle. Beyond the implications for basic cell biology, academic and industrial interests in EVs have increased in the last few years. Microalgae constitute sustainable and renewable sources of bioactive compounds with a range of sectoral applications, including the formulation of health supplements, cosmetic products and food ingredients. Here we describe a newly discovered subtype of EVs derived from microalgae, which we named nanoalgosomes. We isolated these extracellular nano-objects from cultures of microalgal strains, including the marine photosynthetic chlorophyte Tetraselmis chuii, using differential ultracentrifugation or tangential flow fractionation and focusing on the nanosized small EVs (sEVs). We explore different biochemical and physical properties and we show that nanoalgosomes are efficiently taken up by mammalian cell lines, confirming the cross kingdom communication potential of EVs. This is the first detailed description of such membranous nanovesicles from microalgae. With respect to EVs isolated from other organisms, nanoalgosomes present several advantages in that microalgae are a renewable and sustainable natural source, which could easily be scalable in terms of nanoalgosome production.


Subject(s)
Drug Delivery Systems/methods , Extracellular Vesicles/chemistry , Microalgae/metabolism , Extracellular Vesicles/metabolism , Extracellular Vesicles/physiology , Microalgae/genetics , Ultracentrifugation/methods
19.
Biomater Sci ; 9(8): 2917-2930, 2021 Apr 21.
Article in English | MEDLINE | ID: mdl-33620041

ABSTRACT

Safe, efficient and specific nano-delivery systems are essential for current and emerging therapeutics, precision medicine and other biotechnology sectors. Novel bio-based nanotechnologies have recently arisen, which are based on the exploitation of extracellular vesicles (EVs). In this context, it has become essential to identify suitable organisms or cellular types to act as reliable sources of EVs and to develop their pilot- to large-scale production. The discovery of new biosources and the optimisation of related bioprocesses for the isolation and functionalisation of nano-delivery vehicles are fundamental to further develop therapeutic and biotechnological applications. Microalgae constitute sustainable sources of bioactive compounds with a range of sectorial applications including for example the formulation of health supplements, cosmetic products or food ingredients. In this study, we demonstrate that microalgae are promising producers of EVs. By analysing the nanosized extracellular nano-objects produced by eighteen microalgal species, we identified seven promising EV-producing strains belonging to distinct lineages, suggesting that the production of EVs in microalgae is an evolutionary conserved trait. Here we report the selection process and focus on one of this seven species, the glaucophyte Cyanophora paradoxa, which returned a protein yield in the small EV fraction of 1 µg of EV proteins per mg of dry weight of microalgal biomass (corresponding to 109 particles per mg of dried biomass) and EVs with a diameter of 130 nm (mode), as determined by the micro bicinchoninic acid assay, nanoparticle tracking and dynamic light scattering analyses. Moreover, the extracellular nanostructures isolated from the conditioned media of microalgae species returned positive immunoblot signals for some commonly used EV-biomarkers such as Alix, Enolase, HSP70, and ß-actin. Overall, this work establishes a platform for the efficient production of EVs from a sustainable bioresource and highlights the potential of microalgal EVs as novel biogenic nanovehicles.


Subject(s)
Extracellular Vesicles , Microalgae , Biomarkers , Biotechnology , Dynamic Light Scattering
20.
Alcohol Clin Exp Res ; 45(1): 64-68, 2021 01.
Article in English | MEDLINE | ID: mdl-33190281

ABSTRACT

BACKGROUND: To investigate epigenetic mechanisms potentially involved in the cognitive decline associated with chronic alcohol intake, we evaluated the expressions of three micro-RNAs (miR-34a, -34b, and -34c) highly expressed in the hippocampus and involved in neuronal physiology and pathology. MiR-34a participates in functioning and survival of mature neurons; miR-34b is associated with Alzheimer-like disorders; and miR-34c is implicated in the memory impairment of Alzheimer disease in rodents and humans. METHODS: A total of 69 cases were selected from the Biobank for Aging Studies and categorized according to the absence (n = 50) or presence (n = 19) of alcohol use disorder (AUD). Cases presenting with neuropathological diagnoses of dementias were excluded. Total RNA was extracted from hippocampal paraffinized slices, complementary DNA was synthesized from miRs, and RT-qPCR was performed with TaqMan® assays. RESULTS: Higher expressions of miR-34a and miR-34c, but not of miR-34b, were found in the group with AUD in comparison with the group without AUD after adjustment for potential confounders (age, sex, body mass index, presence of hypertension, diabetes mellitus, smoking, and physical inactivity). CONCLUSIONS: Hippocampal upregulation of miR-34a and miR-34c may be involved in the cognitive decline associated with chronic alcohol consumption.


Subject(s)
Alcoholism/metabolism , Cognitive Dysfunction/chemically induced , Hippocampus/metabolism , MicroRNAs/metabolism , Aged , Central Nervous System Depressants/adverse effects , Cognitive Dysfunction/metabolism , Epigenesis, Genetic , Ethanol/adverse effects , Female , Hippocampus/drug effects , Humans , Male , Middle Aged
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