Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 227
Filtrar
2.
J Nat Prod ; 2024 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-38900961

RESUMEN

The adaptation of amphibians to diverse environments is closely related to the characteristics of their skin. The complex glandular system of frog skin plays a pivotal role in enabling these animals to thrive in both aquatic and terrestrial habitats and consists of crucial functions such as respiration and water balance as well as serving as a defensive barrier due to the secretion of bioactive compounds. We herein report the first investigation on the skin secretion of Odontophrynus americanus, as a potential source of bioactive peptides and also as an indicator of its evolutionary adaptations to changing environments. Americanin-1 was isolated and identified as a neutral peptide exhibiting moderate antibacterial activity against E. coli. Its amphipathic sequence including 19 amino acids and showing a propensity for α-helix structure is discussed. Comparisons of the histomorphology of the skin of O. americanus with other previously documented species within the same genus revealed distinctive features in the Patagonian specimen, differing from conspecifics from other Argentine provinces. The presence of the Eberth-Katschenko layer, a prevalence of iridophores, and the existence of glycoconjugates in its serous glands suggest that the integument is adapted to retain skin moisture. This adaptation is consistent with the prevailing aridity of its native habitat.

3.
Primates ; 2024 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-38884897

RESUMEN

Friction ridges are important and unique biometric features that have been studied in fingerprint science since antiquity and used for human identification. This study aimed to analyze palmprints and soleprints of Callithrix penicillata, including the description of flexion creases, regions, minutiae classification, and delta counting, in order to evaluate the uniqueness of these data and feasibility of using this information as an identification method. Palmprints and footprints were collected using commercial fingerprint ink on A4 size paper. Following image digitalization using the GIMP (2.10.14) image editing program, regions and flexion creases were identified. A total of 600 minutiae were classified in females (288 palms and 312 soles) and 732 in males (360 palms and 372 soles), and all deltas were counted. It was possible to identify three main inconstant flexion creases, in both palmprints and soleprints, with different distribution and orientation when compared to those in humans. Less variety in the types of minutiae and differences in the distribution of deltas were found when compared to human studies. In addition, the hypothesis of non-coincident characteristics in each sample was confirmed.

4.
J Pediatr (Rio J) ; 2024 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-38823785

RESUMEN

OBJECTIVE: This study aimed to investigate the prevalence of autism spectrum disorder and its possible correlations with clinical characteristics in patients with infantile epileptic spasms syndrome in a single center in Brazil. METHODS: This retrospective cross-sectional study examined 53 children with the diagnosis of infantile epileptic spasms syndrome prior to an autism spectrum disorder assessment. Participants were divided into two groups based on the presence or absence of autism spectrum disorder. Available variables (sex, medications, median age at onset of infantile epileptic spasms syndrome, and presence of comorbidities) were compared using Mann-Whitney U or chi-square tests. RESULTS: Among the included patients, 12 (23 %) were diagnosed with autism spectrum disorder, corresponding to a relative risk of 0.29 (95 % confidence interval 0.174-0.492). The age at the first seizure ranged from 3 to 15 months, with a mean of 6.65 months. This age significantly differed between participants with autism spectrum disorder (10.58 months) and those without (5.43 months), p<0.001. CONCLUSION: Children with infantile epileptic spasms syndrome have a higher risk of being diagnosed with autism spectrum disorder. Later age of onset and period of spasm occurrence might be predisposing risk factors.

5.
Acta Biomater ; 181: 98-116, 2024 06.
Artículo en Inglés | MEDLINE | ID: mdl-38697382

RESUMEN

The emergence of antibiotic-resistant bacteria is a serious threat to public health. Antimicrobial peptides (AMP) are a powerful alternative to antibiotics due to their low propensity to induce bacterial resistance. However, cytotoxicity and short half-lives have limited their clinical translation. To overcome these problems, AMP conjugation has gained relevance in the biomaterials field. Nevertheless, few studies describe the influence of conjugation on enzymatic protection, mechanism of action and antimicrobial efficacy. This review addresses this gap by providing a detailed comparison between conjugated and soluble AMP. Additionally, commonly employed chemical reactions and factors to consider when promoting AMP conjugation are reviewed. The overall results suggested that AMP conjugated onto biomaterials are specifically protected from degradation by trypsin and/or pepsin. However, sometimes, their antimicrobial efficacy was reduced. Due to limited conformational freedom in conjugated AMP, compared to their soluble forms, they appear to act initially by creating small protuberances on bacterial membranes that may lead to the alteration of membrane potential and/or formation of holes, triggering cell death. Overall, AMP conjugation onto biomaterials is a promising strategy to fight infection, particularly associated to the use of medical devices. Nonetheless, some details need to be addressed before conjugated AMP reach clinical practice. STATEMENT OF SIGNIFICANCE: Covalent conjugation of antimicrobial peptides (AMP) has been one of the most widely used strategies by bioengineers, in an attempt to not only protect AMP from proteolytic degradation, but also to prolong their residence time at the target tissue. However, an explanation for the mode of action of conjugated AMP is still lacking. This review extensively gathers works on AMP conjugation and puts forward a mechanism of action for AMP when conjugated onto biomaterials. The implications of AMP conjugation on antimicrobial activity, cytotoxicity and resistance to proteases are all discussed. A thorough review of commonly employed chemical reactions for this conjugation is also provided. Finally, details that need to be addressed for conjugated AMP to reach clinical practice are discussed.


Asunto(s)
Péptidos Antimicrobianos , Bacterias , Materiales Biocompatibles , Materiales Biocompatibles/farmacología , Materiales Biocompatibles/química , Péptidos Antimicrobianos/química , Péptidos Antimicrobianos/farmacología , Bacterias/efectos de los fármacos , Humanos , Animales , Antibacterianos/farmacología , Antibacterianos/química , Péptidos Catiónicos Antimicrobianos/farmacología , Péptidos Catiónicos Antimicrobianos/química
6.
Bioorg Med Chem ; 104: 117714, 2024 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-38582046

RESUMEN

4,9-diaminoacridines with reported antiplasmodial activity were coupled to different trans-cinnamic acids, delivering a new series of conjugates inspired by the covalent bitherapy concept. The new compounds were more potent than primaquine against hepatic stages of Plasmodium berghei, although this was accompanied by cytotoxic effects on Huh-7 hepatocytes. Relevantly, the conjugates displayed nanomolar activities against blood stage P. falciparum parasites, with no evidence of hemolytic effects below 100 µM. Moreover, the new compounds were at least 25-fold more potent than primaquine against P. falciparum gametocytes. Thus, the new antiplasmodial hits disclosed herein emerge as valuable templates for the development of multi-stage antiplasmodial drug candidates.


Asunto(s)
Antimaláricos , Cinamatos , Malaria Falciparum , Humanos , Antimaláricos/farmacología , Antimaláricos/uso terapéutico , Primaquina/farmacología , Revelación , Plasmodium falciparum , Malaria Falciparum/tratamiento farmacológico , Plasmodium berghei
7.
J Telemed Telecare ; : 1357633X241245160, 2024 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-38659374

RESUMEN

INTRODUCTION: Using standardized scales to assess motor development via telemedicine can increase access for low-income populations. Our aim was to verify the agreement and feasibility between remotely and synchronously applying the Alberta Infant Motor Scale (AIMS) and the in-person format. METHODS: This was a concordance study, with 77 typical infants aged 4-18 months (mean = 13 months). The AIMS was applied remote via video calls and face-to-face. We applied a questionnaire to caregivers to verify feasibility. RESULTS: There was a high level of agreement between the remote and in-person assessments, with intraclass correlation coefficients above 0.98 and low standard error measure values (<1 item for each posture, <2 items for the total raw score, and =5% for the normative score). The smallest detectable change was between 1.67 and 2.45 for each posture, 3 for the total raw score, and 6% for the normative score. The Bland-Altman analysis showed low bias with the mean difference close to zero (<0.80) and low error with little dispersion of the difference points around the mean. Caregivers' perspectives on the synchronous remote assessment were positive, with good quality, clear information during the assessment, and comfort with the method. DISCUSSION: The synchronous remote application of the AIMS may be an alternative for families without access to in-person services that assess motor development.

8.
ACS Appl Mater Interfaces ; 16(12): 14533-14547, 2024 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-38482690

RESUMEN

Surface bioconjugation of antimicrobial peptides (AMP) onto nanoparticles (AMP-NP) is a complex, multistep, and time-consuming task. Herein, a microfluidic system for the one-pot production of AMP-NP was developed. Norbornene-modified chitosan was used for NP production (NorChit-NP), and thiolated-AMP was grafted on their surface via thiol-norbornene "photoclick" chemistry over exposure of two parallel UV LEDs. The MSI-78A was the AMP selected due to its high activity against a high priority (level 2) antibiotic-resistant gastric pathogen: Helicobacter pylori (H. pylori). AMP-NP (113 ± 43 nm; zeta potential 14.3 ± 7 mV) were stable in gastric settings without a cross-linker (up to 5 days in pH 1.2) and bactericidal against two highly pathogenic H. pylori strains (1011 NP/mL with 96 µg/mL MSI-78A). Eradication was faster for H. pylori 26695 (30 min) than for H. pylori J99 (24 h), which was explained by the lower minimum bactericidal concentration of soluble MSI-78A for H. pylori 26695 (32 µg/mL) than for H. pylori J99 (128 µg/mL). AMP-NP was bactericidal by inducing H. pylori cell membrane alterations, intracellular reorganization, generation of extracellular vesicles, and leakage of cytoplasmic contents (transmission electron microscopy). Moreover, NP were not cytotoxic against two gastric cell lines (AGS and MKN74, ATCC) at bactericidal concentrations. Overall, the designed microfluidic setup is a greener, simpler, and faster approach than the conventional methods to obtain AMP-NP. This technology can be further explored for the bioconjugation of other thiolated-compounds.


Asunto(s)
Quitosano , Helicobacter pylori , Nanopartículas , Quitosano/farmacología , Quitosano/química , Microfluídica , Antibacterianos/farmacología , Antibacterianos/química , Nanopartículas/química , Norbornanos , Péptidos Antimicrobianos
9.
Braz J Microbiol ; 55(1): 933-941, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38305952

RESUMEN

Infectious diseases are one of the most concerning threats to maned wolves (Chrysocyon brachyurus) due to the potential impact on free-ranging populations. The species is currently classified as vulnerable according to the national list of threatened species and occurs mainly in open habitats, such as the Cerrado, a tropical savannah, which comprises its main distribution area in Brazil. In the northeastern region, it occurs in the Cerrado of Bahia, Piauí, Maranhão, and Tocantins states. Therefore, this study aimed to investigate the occurrence of infectious agents in Chrysocyon brachyurus through an epidemiological assessment of free-ranging individuals in western Bahia, specifically in the Barreiras microregion, a Cerrado area intensely fragmented and anthropized by agricultural activity. Eleven specimens were evaluated for serological titration, antigen research, and genetic material research for canine distemper virus (CDV), canine parvovirus (CPV), adenovirus-canine-type 1 (CAdV-1), canine coronavirus (CCoV), Leptospira interrogans and Toxoplasma gondii from 2020 to 2022. In addition to maned wolves, domestic dogs were also evaluated and tested. All maned wolves (100%) evaluated by the dot-ELISA technique exhibited immunoglobulin M (IgM) and seven (64%) exhibited immunoglobulin G (IgG) against CDV and CPV, while 100% exhibited IgG against CDV when using the immunochromatographic technique. Regarding CAdV-1, 90% were seropositive for IgG, while 64% exhibited IgG against T. gondii. Nine dogs from the region were also sampled, and all (100%) exhibited IgM and IgG against CDV and CPV. For IgG against T. gondii and against CAdV-1, 90% of the animals were seropositive. Molecular evaluation yielded negative results for all maned wolves and dogs assessed for CAdV-1, CDV, and T. gondii, as well as the CCoV antigen. These data indicate the occurrence of viral agents and Toxoplasma gondii in maned wolves and dogs, suggesting circulation in both populations.


Asunto(s)
Canidae , Virus del Moquillo Canino , Parvovirus Canino , Toxoplasma , Lobos , Animales , Perros , Brasil/epidemiología , Inmunoglobulina G , Toxoplasma/genética , Inmunoglobulina M
10.
RSC Adv ; 14(9): 6253-6261, 2024 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-38375018

RESUMEN

Acridines are one of the most important nitrogen-containing heterocycle systems and have many applications in the therapeutic field. However, the synthesis of acridine-based scaffolds is not always straightforward. Herein, we report the optimization of two multi-step synthetic routes towards 4,9-diaminoacridines and 4-aminoacridines, which have shown promising antiplasmodial properties. The improved synthesis pathways make use of greener, simpler, and more efficient methods, with less reaction steps and increased overall yields, which were doubled in some cases. These are impactful results towards future approaches to the chemical synthesis of acridine-based compounds.

11.
J Appl Physiol (1985) ; 136(1): 189-198, 2024 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-38059293

RESUMEN

Aging is accompanied by considerable deterioration of homeostatic systems, such as autonomic imbalance characterized by heightened sympathetic activity, lower parasympathetic tone, and depressed heart rate (HR) variability, which are aggravated by hypertension. Here, we hypothesized that these age-related deficits in aged hypertensive rats can be ameliorated by exercise training, with benefits to the cardiovascular system. Therefore, male 22-mo-old spontaneously hypertensive rats (SHRs) and age-matched Wistar Kyoto (WKY) submitted to moderate-intensity exercise training (T) or kept sedentary (S) for 8 wk were evaluated for hemodynamic/autonomic parameters, baroreflex sensitivity, cardiac sympathetic/parasympathetic tone and analysis of dopamine ß-hydroxylase (DBH+) and oxytocin (OT+) pathways of autonomic brain nuclei. Aged SHR-S versus WKY-S exhibited elevated mean arterial pressure (MAP: +51%) and HR (+20%), augmented pressure/HR variability, no cardiac vagal tone, and depressed reflex control of the heart (HR range, -28%; gain, -49%). SHR-T exhibited a lower resting HR, a partial reduction in the MAP (-14%), in the pressure/HR variabilities, and restored parasympathetic modulation, with improvement of baroreceptor reflex control when compared with SHR-S. Exercise training increased the ascending DBH+ projections conveying peripheral information to the paraventricular nucleus of hypothalamus (PVN), augmented the expression of OT+ neurons, and reduced the density of DBH+ neurons in the rostral ventrolateral medulla (RVLM) of SHR-T. Data indicate that exercise training induces beneficial neuroplasticity in brain autonomic circuitry, and it is highly effective to restore the parasympathetic tone, and attenuation of age-related autonomic imbalance and baroreflex dysfunction, thus conferring long-term benefits for cardiovascular control in aged hypertensive individuals.NEW & NOTEWORTHY Exercise training reduces high blood pressure and cardiovascular autonomic modulation in aged hypertensive rats. The dysfunction in the baroreflex sensitivity and impaired parasympathetic tone to the heart of aged hypertensive rats are restored by exercise training. Exercise induces beneficial neuroplasticity in the brain nuclei involved with autonomic control of cardiovascular function of aged hypertensive rats.


Asunto(s)
Barorreflejo , Hipertensión , Ratas , Masculino , Animales , Barorreflejo/fisiología , Presión Sanguínea/fisiología , Ratas Endogámicas WKY , Ratas Endogámicas SHR , Frecuencia Cardíaca/fisiología , Plasticidad Neuronal
12.
J Bras Pneumol ; 49(5): e20230036, 2023.
Artículo en Inglés, Portugués | MEDLINE | ID: mdl-37909550

RESUMEN

OBJECTIVE: To compare patients with chronic hypersensitivity pneumonitis (cHP) and controls with normal spirometry in terms of their sleep characteristics, as well as to establish the prevalence of obstructive sleep apnea (OSA) and nocturnal hypoxemia. Secondary objectives were to identify factors associated with OSA and nocturnal hypoxemia; to correlate nocturnal hypoxemia with the apnea-hypopnea index (AHI) and lung function, as well as with resting SpO2, awake SpO2, and SpO2 during exercise; and to evaluate the discriminatory power of sleep questionnaires to predict OSA. METHODS: A total of 40 patients with cHP (cases) were matched for sex, age, and BMI with 80 controls, the ratio of controls to cases therefore being = 2:1. The STOP-Bang questionnaire, the Epworth Sleepiness Scale (ESS), the Pittsburgh Sleep Quality Index, the Berlin questionnaire and the Neck circumference, obesity, Snoring, Age, and Sex (NoSAS) score were applied to all cases, and both groups underwent full-night polysomnography. RESULTS: The patients with cHP had longer sleep latency, lower sleep efficiency, a lower AHI, a lower respiratory disturbance index, fewer central apneas, fewer mixed apneas, and fewer hypopneas than did the controls. The patients with cHP had significantly lower nocturnal SpO2 values, the percentage of total sleep time spent below an SpO2 of 90% being higher than in controls (median = 4.2; IQR, 0.4-32.1 vs. median = 1.0; IQR, 0.1-5.8; p = 0.01). There were no significant differences between cases with and without OSA regarding the STOP-Bang questionnaire, NoSAS, and ESS scores. CONCLUSIONS: The prevalence of OSA in cHP patients (cases) was high, although not higher than that in controls with normal spirometry. In addition, cases had more hypoxemia during sleep than did controls. Our results suggest that sleep questionnaires do not have sufficient discriminatory power to identify OSA in cHP patients.


Asunto(s)
Alveolitis Alérgica Extrínseca , Apnea Obstructiva del Sueño , Humanos , Estudios de Casos y Controles , Sueño , Apnea Obstructiva del Sueño/epidemiología , Apnea Obstructiva del Sueño/complicaciones , Encuestas y Cuestionarios , Hipoxia , Alveolitis Alérgica Extrínseca/epidemiología
13.
Biotechnol Adv ; 68: 108223, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37536466

RESUMEN

Agricultural systems are in need of low-cost, safe antibiotics to protect crops from pests and diseases. Peptaibiotics, a family of linear, membrane-active, amphipathic polypeptides, have been shown to exhibit antibacterial, antifungal, and antiviral activity, and to be inducers of plant resistance against a wide range of phytopathogens. Peptaibiotics belong to the new generation of alternatives to agrochemicals, aligned with the United Nations Sustainable Development Goals and the One Health approach toward ensuring global food security and safety. Despite that, these fungi-derived, non-ribosomal peptides remain surprisingly understudied, especially in agriculture, where only a small number has been tested against a reduced number of phytopathogens. This lack of adoption stems from peptaibiotics' poor water solubility and the difficulty to synthesize and purify them in vitro, which compromises their delivery and inclusion in formulations. In this review, we offer a comprehensive analysis of peptaibiotics' classification, biosynthesis, relevance to plant protection, and mode of action against phytopathogens, along with the techniques enabling researchers to extract, purify, and elucidate their structure, and the databases holding such valuable data. It is also discussed how chemical synthesis and ionic liquids could increase their solubility, how genetic engineering and epigenetics could boost in vitro production, and how omics can reduce screenings' workload through in silico selection of the best candidates. These strategies could turn peptaibiotics into effective, ultra-specific, biodegradable tools for phytopathogen control.


Asunto(s)
Antibacterianos , Péptidos , Péptidos/farmacología , Antibacterianos/farmacología , Proteínas Fúngicas , Productos Agrícolas
14.
Zoo Biol ; 42(6): 789-796, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37466265

RESUMEN

The global population of Dicotyles tajacu (Linnaeus, 1758) (Cetartiodactyla: Tayassuidae), commonly known as the collared peccary and distributed in the Neotropics, is currently in decline due to anthropogenic pressures. In this study, five microsatellite loci were used to genetically characterize a group of 20 captive-born collared peccaries intended for reintroduction. This study aimed to evaluate the genetic diversity and relatedness of captive individuals using microsatellite markers. The genetic data generated were used to evaluate the viability of the reintroduction and to propose measures for the management and conservation of this species. In this study, we found relatively high genetic diversity indices, indicating that the group was genetically diverse. Inbreeding coefficients with negative values were observed, indicating an excess of alleles in heterozygosis and an absence of inbreeding. One locus showed deviation from Hardy-Weinberg equilibrium, which may have been caused by the mixing of individuals from different origins. Relatedness analysis indicated that some individuals were highly related, with coefficients indicating they may be first-degree relatives. Our findings indicate that the studied group has enough genetic diversity to be released into nature, but the high individual relatedness found would require the adoption of strategies after the release of animals in the wild to ensure their persistence.


Asunto(s)
Animales de Zoológico , Artiodáctilos , Animales , Genotipo , Animales de Zoológico/genética , Artiodáctilos/genética , Repeticiones de Microsatélite/genética , Secuenciación de Nucleótidos de Alto Rendimiento , Variación Genética
15.
16.
Eur J Med Chem ; 258: 115575, 2023 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-37390511

RESUMEN

A novel family of 4-aminoacridine derivatives was obtained by linking this heteroaromatic core to different trans-cinnamic acids. The 4-(N-cinnamoylbutyl)aminoacridines obtained exhibited in vitro activity in the low- or sub-micromolar range against (i) hepatic stages of Plasmodium berghei, (ii) erythrocytic forms of Plasmodium falciparum, and (iii) early and mature gametocytes of Plasmodium falciparum. The most active compound, having a meta-fluorocinnamoyl group linked to the acridine core, was 20- and 120-fold more potent, respectively, against the hepatic and gametocyte stages of Plasmodium infection than the reference drug, primaquine. Moreover, no cytotoxicity towards mammalian and red blood cells at the concentrations tested was observed for any of the compounds under investigation. These novel conjugates represent promising leads for the development of new multi-target antiplasmodials.


Asunto(s)
Aminoacridinas , Antimaláricos , Animales , Aminacrina , Antimaláricos/farmacología , Mamíferos , Plasmodium berghei , Plasmodium falciparum , Primaquina
17.
Int J Hyperthermia ; 40(1): 2222941, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37344380

RESUMEN

BACKGROUND: Neuroblastoma (NB) is the most common extracranial solid tumor of childhood, and high-risk disease is resistant to intensive treatment. Histotripsy is a focused ultrasound therapy under development for tissue ablation via bubble activity. The goal of this study was to assess outcomes of histotripsy ablation in a xenograft model of high-risk NB. METHODS: Female NCr nude mice received NGP-luciferase cells intrarenally. Under ultrasound image guidance, histotripsy pulses were applied over a distance of 4-6 mm within the tumors. Bioluminescence indicative of tumor viability was quantified before, immediately after, and 24 h after histotripsy exposure. Tumors were immunostained to assess apoptosis (TUNEL), endothelium (endomucin), pericytes (αSMA), hypoxia (pimonidazole), vascular endothelial growth factor A (VEGFA), and platelet-derived growth factor-B (PDGF-B). The apoptotic cytokine TNFα and its downstream effector cleaved caspase-3 (c-casp-3) were assessed with SDS-PAGE. RESULTS: Histotripsy induced a 50% reduction in bioluminescence compared to untreated controls, with an absence of nuclei in the treatment core surrounded by a dense rim of TUNEL-positive cells. Tumor regions not targeted by histotripsy also showed an increase in TUNEL staining density. Increased apoptosis in histotripsy samples was consistent with increases in TNFα and c-casp-3 relative to controls. Treated tumors exhibited a decrease in hypoxia, VEGF, PDGF-B, and pericyte coverage of vasculature compared to control samples. Further, increases in vasodilation were found in histotripsy-treated specimens. CONCLUSIONS: In addition to ablative effects, histotripsy was found to drive tumor apoptosis through intrinsic pathways, altering blood vessel architecture, and reducing hypoxia.


Asunto(s)
Ultrasonido Enfocado de Alta Intensidad de Ablación , Neuroblastoma , Animales , Ratones , Humanos , Femenino , Factor A de Crecimiento Endotelial Vascular , Factor de Necrosis Tumoral alfa , Xenoinjertos , Ratones Desnudos , Neuroblastoma/terapia , Hipoxia , Apoptosis , Ultrasonido Enfocado de Alta Intensidad de Ablación/métodos
18.
Insects ; 14(6)2023 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-37367349

RESUMEN

The spotted-wing drosophila (Drosophila suzukii) is a polyphagous pest that causes severe damage and economic losses to soft-skinned fruit production. Current control methods are dominated by inefficient cultural practices and broad-spectrum insecticides that, in addition to having toxic effects on non-target organisms, are becoming less effective due to acquired resistance. The increasing awareness of the real impact of insecticides on health and the environment has promoted the exploration of new insecticidal compounds, addressing novel molecular targets. This study explores the efficacy of two orally delivered spider venom peptides (SVPs), J-atracotoxin-Hv1c (Hv1c) and µ-theraphotoxin-Hhn2b (TRTX), to manage D. suzukii, through survival assays and the evaluation of gene expression associated with detoxification pathways. Treatment with TRTX at 111.5 µM for 48 h enhanced fly longevity compared with the control group. Gene expression analysis suggests that detoxification and stress-related mechanisms, such as expression of P450 proteins and apoptotic stimuli signaling, are triggered in D. suzukii flies in response to these treatments. Our results highlight the potential interest of SVPs to control this pest, shedding light on how to ultimately develop improved target-specific formulations.

19.
Pharmaceutics ; 15(5)2023 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-37242752

RESUMEN

It is key to fight bacterial adhesion to prevent biofilm establishment on biomaterials. Surface immobilization of antimicrobial peptides (AMP) is a promising strategy to avoid bacterial colonization. This work aimed to investigate whether the direct surface immobilization of Dhvar5, an AMP with head-to-tail amphipathicity, would improve the antimicrobial activity of chitosan ultrathin coatings. The peptide was grafted by copper-catalyzed azide-alkyne cycloaddition (CuAAC) chemistry by either its C- or N- terminus to assess the influence of peptide orientation on surface properties and antimicrobial activity. These features were compared with those of coatings fabricated using previously described Dhvar5-chitosan conjugates (immobilized in bulk). The peptide was chemoselectively immobilized onto the coating by both termini. Moreover, the covalent immobilization of Dhvar5 by either terminus enhanced the antimicrobial effect of the chitosan coating by decreasing colonization by both Gram-positive (Staphylococcus aureus, Staphylococcus epidermidis) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacteria. Relevantly, the antimicrobial performance of the surface on Gram-positive bacteria depended on how Dhvar5-chitosan coatings were produced. An antiadhesive effect was observed when the peptide was grafted onto prefabricated chitosan coatings (film), and a bactericidal effect was exhibited when coatings were prepared from Dhvar5-chitosan conjugates (bulk). This antiadhesive effect was not due to changes in surface wettability or protein adsorption but rather depended on variations in peptide concentration, exposure, and surface roughness. Results reported in this study show that the antibacterial potency and effect of immobilized AMP vary greatly with the immobilization procedure. Overall, independently of the fabrication protocol and mechanism of action, Dhvar5-chitosan coatings are a promising strategy for the development of antimicrobial medical devices, either as an antiadhesive or contact-killing surface.

20.
Int J Biol Macromol ; 242(Pt 2): 124745, 2023 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-37150376

RESUMEN

Malaria, leishmaniasis and Chagas disease are vector-borne protozoal infections with a disproportionately high impact on the most fragile societies in the world, and despite malaria-focused research gained momentum in the past two decades, both trypanosomiases and leishmaniases remain neglected tropical diseases. Affordable effective drugs remain the mainstay of tackling this burden, but toxicicty, inneficiency against later stage disease, and drug resistance issues are serious shortcomings. One strategy to overcome these hurdles is to get new therapeutics or inspiration in nature. Indeed, snake venoms have been recognized as valuable sources of biomacromolecules, like peptides and proteins, with antiprotozoal activity. This review highlights major snake venom components active against at least one of the three aforementioned diseases, which include phospholipases A2, metalloproteases, L-amino acid oxidases, lectins, and oligopeptides. The relevance of this repertoire of biomacromolecules and the bottlenecks in their clinical translation are discussed considering approaches that should increase the success rate in this arduous task. Overall, this review underlines how venom-derived biomacromolecules could lead to pioneering antiprotozoal treatments and how the drug landscape for neglected diseases may be revolutionized by a closer look at venoms. Further investigations on poorly studied venoms is needed and could add new therapeutics to the pipeline.


Asunto(s)
Enfermedad de Chagas , Leishmaniasis , Malaria , Humanos , Venenos de Serpiente/química , Péptidos/farmacología , Enfermedad de Chagas/tratamiento farmacológico , Leishmaniasis/tratamiento farmacológico
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...