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1.
Artigo em Inglês | MEDLINE | ID: mdl-39042155

RESUMO

The pharmacological treatment of epilepsy is often complex due to the lack of efficacy in many patients and profound side effects from current drugs, including sedation, motor impairment, and teratogenesis. In the quest for new antiepileptic drugs, animal venoms offer a valuable source of neuroactive molecules targeting ion channels and neurotransmitter receptors. This study investigates the antiepileptic potential of compounds isolated from the venom of the Parawixia bistriata spider. One compound, designated Parawixin-11, demonstrated significant anticonvulsant effects when injected into the cerebral ventricle in a dose-response manner. It effectively countered seizures induced by bicuculline (ED50 0.16 µg/animal), pentylenetetrazole (ED50 0.08 µg/animal), strychnine (ED50 0.05 µg/animal), pilocarpine (ED50 0.10 µg/animal), and NMDA (ED50 0.008 µg/animal). We also assessed whether intracerebroventricular administration of Parawixin-11 caused motor or cognitive impairments in rats using the open field, rotarod, and Morris water maze tests. No differences in exploration or movement were observed with doses of 0.3, 0.2, or 0.1 µg of Parawixin-11. Although there was an increased latency to find the platform during the acquisition phase of the Morris water maze test, no differences in spatial memory retention were noted. Given Parawixin-11's potency against NMDA-induced seizures, we hypothesize that it may modulate the glutamatergic system, aligning with the mechanisms of several spider-derived polyamines.

3.
Mikrochim Acta ; 190(9): 356, 2023 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-37594644

RESUMO

Herein, A microfluidic device is described, produced with a 3D-printed master mould that rapidly separates and concentrates Escherichia coli directly from whole blood samples, enabling a reduction in the turnaround time of bloodstream infections (BSIs) diagnosis. Moreover, it promotes the cleansing of the blood samples whose complexity frequently hampers bacterial detection. The device comprises a serpentine mixing channel with two inlets, one for blood samples (spiked with bacteria) and the other for magnetic nanoparticles (MNPs) functionalized with a (bacterio)phage receptor-binding protein (RBP) with high specificity for E. coli. After the magnetic labelling of bacteria throughout the serpentine, the microchannel ends with a trapping reservoir where bacteria-MNPs conjugates are concentrated using a permanent magnet. The optimized sample preparation device successfully recovered E. coli (on average, 66%) from tenfold diluted blood spiked within a wide range of bacterial load (102 CFU to 107 CFU mL-1). The non-specific trapping, tested with Staphylococcus aureus, was at a negligible level of 12%. The assay was performed in 30 min directly from diluted blood thus presenting an advantage over the conventional enrichment in blood cultures (BCs). The device is simple and cheap to fabricate and can be tailored for multiple bacterial separation from complex clinical samples by using RBPs targeting different species. Moreover, the possibility to integrate a biosensing element to detect bacteria on-site can provide a reliable, fast, and cost-effective point-of-care device.


Assuntos
Nanopartículas de Magnetita , Sepse , Humanos , Escherichia coli , Dispositivos Lab-On-A-Chip , Impressão Tridimensional
4.
Brain Behav Immun Health ; 31: 100654, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37449286

RESUMO

Sepsis is associated with numerous physiological and biochemical abnormalities that result in a life-threatening condition. The involvement of the Central Nervous System (CNS) during sepsis has received considerable attention, especially the hippocampus which plays a key role in the learning and memory processes. The increased interest in this limbic region during systemic inflammation (SI) is related to the number of sepsis survivor patients who have cognitive impairments. A single injection of lipopolysaccharide (LPS)-induced systemic inflammation is the most commonly used murine endotoxemia model because it replicates several pathophysiological changes observed in severe sepsis. Molecular hydrogen (H2) has been used as an anti-inflammatory therapeutic strategy to prevent neuroinflammation. However, the mechanisms by which inhaled H2 mitigate memory loss during SI remains unknown. To understand how H2 acts in the hippocampus, the current study focused on specific mechanisms that may be involved in reducing neuroinflammation in rats during SI. We hypothesized that inhaled H2 decreases LPS-induced hippocampal pro-inflammatory cytokines surges and this effect is associated with reduced memory loss. Using different and integrative approaches, i.e., from hippocampal cells electrophysiology to animal behavior, we report that inhaled H2 decreased LPS-induced peripheral and hippocampal inflammation, decreased microglial and astrocytic activation, lessen memory loss without affecting long-term potentiation (LTP). To our knowledge, this is the first evidence showing that inhaled H2 reduces hippocampal microglial and glial cells inflammation, which may be associated with a reduced memory impairment induced by SI.

5.
Int J Emerg Med ; 16(1): 36, 2023 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-37173632

RESUMO

BACKGROUND: The use of non-invasive positive pressure ventilation (NIPPV) in COVID-19 patients with hypoxaemia is still under debate. The aim was to evaluate the efficacy of NIPPV (CPAP, HELMET-CPAP or NIV) in COVID-19 patients treated in the dedicated COVID-19 Intermediate Care Unit of Coimbra Hospital and University Centre, Portugal, and to assess factors associated with NIPPV failure. METHODS: Patients admitted from December 1st 2020 to February 28th 2021, treated with NIPPV due to COVID-19 were included. Failure was defined as orotracheal intubation (OTI) or death during hospital stay. Factors associated with NIPPV failure were included in a univariate binary logistic regression analysis; those with a significance level of p < 0.001 entered a multivariate logistic regression model. RESULTS: A total of 163 patients were included, 64.4% were males (n = 105). The median age was 66 years (IQR 56-75). NIPPV failure was observed in 66 (40.5%) patients, 26 (39.4%) were intubated and 40 (60.6%) died during their hospital stay. The highest CRP (OR 1.164; 95%CI 1.036-1.308) and morphine use (OR 24.771; 95%CI 1.809-339.241) were identified as predictors of failure after applying multivariate logistic regression. Adherence to prone positioning (OR 0.109; 95%CI 0.017-0.700) and a higher value of the lowest platelet count during hospital stay (OR 0.977; 95%CI 0.960-0.994) were associated with a favorable outcome. CONCLUSIONS: NIPPV was successful in over half of patients. Highest CRP during hospital stay and morphine use were predictors of failure. Adherence to prone positioning and a higher value of the lowest platelet count during hospital stay were associated with a favourable outcome.

6.
Brain Commun ; 5(1): fcad016, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36844150

RESUMO

The ability of venom-derived peptides to disrupt physiological processes in mammals provides an exciting source for pharmacological development. Our research group has identified a new class of neuroactive peptides from the venom of a Brazilian social wasp, Polybia occidentalis, with the potential pharmacological profile to treat epilepsies. The study was divided into five phases: Phase 1 concerned the extraction, isolation and purification of Occidentalin-1202(n) from the crude venom, followed by the synthesis of an identical analogue peptide, named Occidentalin-1202(s). In Phase 2, we described the effects of both peptides in two acute models of epilepsy-kainic acid and pentylenetetrazole-induced model of seizures-and measured estimated ED50 and therapeutic index values, electroencephalographic studies and C-fos evaluation. Phase 3 was a compilation of advanced tests performed with Occidentalin-1202(s) only, reporting histopathological features and its performance in the pilocarpine-induced status epilepticus. After the determination of the antiepileptic activity of Occidentalin-1202(s), Phase 4 consisted of evaluating its potential adverse effects, after chronic administration, on motor coordination (Rotarod) and cognitive impairment (Morris water maze) tests. Finally, in Phase 5, we proposed a mechanism of action using computational models with kainate receptors. The new peptide was able to cross the blood-brain barrier and showed potent antiseizure effects in acute (kainic acid and pentylenetetrazole) and chronic (temporal lobe epilepsy model induced by pilocarpine) models. Motor and cognitive behaviour were not adversely affected, and a potential neuroprotective effect was observed. Occidentalin-1202 can be a potent blocker of the kainate receptor, as assessed by computational analysis, preventing glutamate and kainic acid from binding to the receptor's active site. Occidentalin-1202 is a peptide with promising applicability to treat epilepsy and can be considered an interesting drug model for the development of new medicines.

7.
Crit Rev Biotechnol ; 43(5): 787-804, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35848817

RESUMO

Bacterial pathogens are leading causes of infections with high mortality worldwide having a great impact on healthcare systems and the food industry. Gold standard methods for bacterial detection mainly rely on culture-based technologies and biochemical tests which are laborious and time-consuming. Regardless of several developments in existing methods, the goal of achieving high sensitivity and specificity, as well as a low detection limit, remains unaccomplished. In past years, various biorecognition elements, such as antibodies, enzymes, aptamers, or nucleic acids, have been widely used, being crucial for the pathogens detection in different complex matrices. However, these molecules are usually associated with high detection limits, demand laborious and costly production, and usually present cross-reactivity. (Bacterio)phage-encoded proteins, especially the receptor binding proteins (RBPs) and cell-wall binding domains (CBDs) of endolysins, are responsible for the phage binding to the bacterial surface receptors in different stages of the phage lytic cycle. Due to their remarkable properties, such as high specificity, sensitivity, stability, and ability to be easily engineered, they are appointed as excellent candidates to replace conventional recognition molecules, thereby contributing to the improvement of the detection methods. Moreover, they offer several possibilities of application in a variety of detection systems, such as magnetic, optical, and electrochemical. Herein we provide a review of phage-derived bacterial binding proteins, namely the RBPs and CBDs, with the prospect to be employed as recognition elements for bacteria. Moreover, we summarize and discuss the various existing methods based on these proteins for the detection of nosocomial and foodborne pathogens.


Assuntos
Bacteriófagos , Proteínas/metabolismo
8.
J Pharm Pract ; 36(4): 817-829, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35325582

RESUMO

Background: There is no consensus for assessment and management of patients with serious mental illness (SMI) who are at risk for cardiac morbidity and mortality due to antipsychotic-associated QTc prolongation. Objective: The objective of this review was to assess methods for risk scoring, QT correction calculation, and clinical management in SMI patients with antipsychotic-associated QTc prolongation. Methods: A search was performed in PubMed for case reports that described QTc prolongation in adult patients with schizophrenia or bipolar disorder prescribed an antipsychotic. Reports published in North America between 2000 and 2020 were eligible. The Mayo, Tisdale, and RISQ-PATH scoring tools were applied to cases to categorize risk level. Results: Seventeen cases were included. Most patients were prescribed a second-generation antipsychotic for schizophrenia, with baseline and maximum QTc values of 429 milliseconds and 545 milliseconds, respectively. The Mayo scoring tool identified 17 (100%) cases as "high risk," Tisdale identified 9 (53%) cases as "moderate risk" and 7 (41%) cases as "low risk," while RISQ-PATH identified 9 (53%) cases as "not low risk" and 8 (47%) cases as "low risk." Three cases reported the QT correction formula utilized (18%). The most common intervention to address antipsychotic-associated QTc prolongation was switching to a different antipsychotic (35%). Approximately one third of patients experienced Torsades de Pointes. Conclusion: There is a lack of standardization for antipsychotic-associated QTc prolongation risk assessment and management in patients with SMI. This review provides real-world data representing actual clinical practice.


Assuntos
Antipsicóticos , Síndrome do QT Longo , Esquizofrenia , Torsades de Pointes , Adulto , Humanos , Antipsicóticos/efeitos adversos , Síndrome do QT Longo/induzido quimicamente , Síndrome do QT Longo/diagnóstico , Eletrocardiografia , Torsades de Pointes/induzido quimicamente , Esquizofrenia/tratamento farmacológico , Fatores de Risco
9.
Front Microbiol ; 13: 871855, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35722298

RESUMO

Escherichia coli is a problematic pathogen that causes life-threatening diseases, being a frequent causative agent of several nosocomial infections such as urinary tract and bloodstream infections. Proper and rapid bacterial identification is critical for allowing prompt and targeted antimicrobial therapy. (Bacterio)phage receptor-binding proteins (RBPs) display high specificity for bacterial surface epitopes and, therefore, are particularly attractive as biorecognition elements, potentially conferring high sensitivity and specificity in bacterial detection. In this study, we elucidated, for the first time, the potential of a recombinant RBP (Gp17) to recognize E. coli at different viability states, such as viable but not culturable cells, which are not detected by conventional techniques. Moreover, by using a diagnostic method in which we combined magnetic and spectrofluorimetric approaches, we demonstrated the ability of Gp17 to specifically detect E. coli in various human specimens (e.g., whole blood, feces, urine, and saliva) in about 1.5 h, without requiring complex sample processing.

10.
Sci Rep ; 12(1): 3186, 2022 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-35210456

RESUMO

Sexual differentiation of the brain is influenced by testosterone and its metabolites during the perinatal period, when many aspects of brain development, including the maturation of GABAergic transmission, occur. Whether and how testosterone signaling during the perinatal period affects GABAergic transmission is unclear. Here, we analyzed GABAergic circuit functional markers in male, female, testosterone-treated female, and testosterone-insensitive male rats after the first postnatal week and in young adults. In the hippocampus, mRNA levels of proteins associated with GABA signaling were not significantly affected at postnatal day (P) 7 or P40. Conversely, membrane protein levels of KCC2, which are critical for determining inhibition strength, were significantly higher in females compared to males and testosterone-treated females at P7. Further, female and testosterone-insensitive male rats at P7 showed higher levels of the neurotrophin BDNF, which is a powerful regulator of neuronal function, including GABAergic transmission. Finally, spontaneous GABAergic currents in hippocampal CA1 pyramidal cells were more frequent in females and testosterone-insensitive males at P40. Overall, these results show that perinatal testosterone levels modulate GABAergic circuit function, suggesting a critical role of perinatal sex hormones in regulating network excitability in the adult hippocampus.


Assuntos
Neurônios GABAérgicos/metabolismo , Hipocampo/metabolismo , Neurônios/metabolismo , Células Piramidais/metabolismo , Simportadores/metabolismo , Transmissão Sináptica/efeitos dos fármacos , Testosterona/farmacologia , Síndrome de Resistência a Andrógenos/genética , Animais , Animais Recém-Nascidos/metabolismo , Feminino , Neurônios GABAérgicos/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Masculino , Mutação , Neurônios/efeitos dos fármacos , Células Piramidais/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Receptores Androgênicos/metabolismo , Caracteres Sexuais
11.
Cancers (Basel) ; 13(21)2021 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-34771730

RESUMO

BACKGROUND: Colorectal cancer (CRC) is a major cause of cancer-related death worldwide. Cancer progression, including invasion and metastasis, is a major cause of death among CRC patients. Current methods for CRC screening commonly consist of a combination of faecal immunochemical test (FIT) for stool occult blood detection and invasive procedures such as colonoscopy. Considering the slow progression of CRC, and that symptoms usually emerge at advanced stages, its early diagnostic can limit cancer's spread and provide a successful treatment. Biomarkers have a high potential for the diagnosis of CRC in either blood or stool samples. METHODS: In this study, we analysed the diagnostic value of six different biomarkers in stool samples of patients with CRC, advanced adenomas, other lesions and healthy individuals. We have also assessed the overall performance of the combination of these biomarkers for CRC detection. RESULTS: The results indicate that haemoglobin (Hb) and M2-pyruvate kinase (M2-PK) levels were increased in CRC patients in comparison to the controls. Conversely, the concentrations of matrix metalloproteinase (MMP)-2, MMP-9, and tumour necrosis factor-alpha (TNF-α) were not significantly different between the tested groups. CONCLUSION: The combination of FIT-Hb with the M2-PK levels increased the specificity or sensitivity for CRC detection and thus present potential as faecal diagnostic biomarkers for CRC.

13.
Innov Pharm ; 12(1)2021.
Artigo em Inglês | MEDLINE | ID: mdl-34007680

RESUMO

BACKGROUND: While many public pharmacy schools have an adjoining health-system to accommodate their students, some pharmacy programs form partnerships with non-affiliated health-systems to precept students. These health-systems often afford students the opportunity to complete multiple rotations within a single organization, offering decreased onboarding time and more longitudinal experiences. INNOVATION: Two autonomous partnerships were developed with independent healthcare systems for concentrated learning experiences during the advanced pharmacy practice experiences year. Each program differs in student requirements and is overseen by the practice site, with participation by area faculty. KEY FINDINGS: A survey assessed professional skill set development, achievement of program goals during the experiential year, and student satisfaction of a concentrated learning experience. A comparison between programs was completed to assess for consistency in student experiences. Nineteen students (83%) responded to the survey. Students from both health-systems reported similarities in professional skill growth. Likewise, all students reported achievement of program goals and overall satisfaction with their experiential training. CONCLUSIONS: Independently managed concentrated learning experiences provided evidence of consistent growth in student professional development and achievement of programmatic goals. Partnerships with non-affiliated healthcare systems can provide a rich training ground for student learners.

14.
Biotechnol Bioeng ; 118(8): 3164-3174, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34037981

RESUMO

Nosocomial or hospital-acquired infections (HAIs) have a major impact on mortality worldwide. Enterococcus and Staphylococcus are among the leading causes of HAIs and thus are important pathogens to control mainly due to their increased antibiotic resistance. The gold-standard diagnostic methods for HAIs are time-consuming, which hinders timely and adequate treatment. Therefore, the development of fast and accurate diagnostic tools is an urgent demand. In this study, we combined the sensitivity of magnetoresistive (MR) sensors, the portability of a lab-on-chip platform, and the specificity of phage receptor binding proteins (RBPs) as probes for the rapid and multiplex detection of Enterococcus and Staphylococcus. For this, bacterial cells were firstly labelled with magnetic nanoparticles (MNPs) functionalized with RBPs and then measured on the MR sensors. The results indicate that the RBP-MNPS provided a specific individual and simultaneous capture of more than 70% of Enterococcus and Staphylococcus cells. Moreover, high signals from the MR sensors were obtained for these samples, providing the detection of both pathogens at low concentrations (10 CFU/ml) in less than 2 h. Overall, the lab-on-chip MR platform herein presented holds great potential to be used as a point-of-care for the rapid, sensitive and specific multiplex diagnosis of bacterial infections.


Assuntos
Bacteriófagos/química , Técnicas Biossensoriais , Enterococcus , Dispositivos Lab-On-A-Chip , Sistemas Automatizados de Assistência Junto ao Leito , Infecções Estafilocócicas/diagnóstico , Staphylococcus , Humanos
15.
Front Behav Neurosci ; 15: 611902, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33643007

RESUMO

Cannabinoids and Cannabis-derived compounds have been receiving especial attention in the epilepsy research scenario. Pharmacological modulation of endocannabinoid system's components, like cannabinoid type 1 receptors (CB1R) and their bindings, are associated with seizures in preclinical models. CB1R expression and functionality were altered in humans and preclinical models of seizures. Additionally, Cannabis-derived compounds, like cannabidiol (CBD), present anticonvulsant activity in humans and in a great variety of animal models. Audiogenic seizures (AS) are induced in genetically susceptible animals by high-intensity sound stimulation. Audiogenic strains, like the Genetically Epilepsy Prone Rats, Wistar Audiogenic Rats, and Krushinsky-Molodkina, are useful tools to study epilepsy. In audiogenic susceptible animals, acute acoustic stimulation induces brainstem-dependent wild running and tonic-clonic seizures. However, during the chronic protocol of AS, the audiogenic kindling (AuK), limbic and cortical structures are recruited, and the initially brainstem-dependent seizures give rise to limbic seizures. The present study reviewed the effects of pharmacological modulation of the endocannabinoid system in audiogenic seizure susceptibility and expression. The effects of Cannabis-derived compounds in audiogenic seizures were also reviewed, with especial attention to CBD. CB1R activation, as well Cannabis-derived compounds, induced anticonvulsant effects against audiogenic seizures, but the effects of cannabinoids modulation and Cannabis-derived compounds still need to be verified in chronic audiogenic seizures. The effects of cannabinoids and Cannabis-derived compounds should be further investigated not only in audiogenic seizures, but also in epilepsy related comorbidities present in audiogenic strains, like anxiety, and depression.

16.
Exp Physiol ; 106(4): 1038-1060, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33512049

RESUMO

NEW FINDINGS: What is the central question of this study? Does peripheral non-invasive focused ultrasound targeted to the celiac plexus improve inflammatory bowel disease? What is the main finding and its importance? Peripheral non-invasive focused ultrasound targeted to the celiac plexus in a rat model of ulcerative colitis improved stool consistency and reduced stool bloodiness, which coincided with a longer and healthier colon than in animals without focused ultrasound treatment. The findings suggest that this novel neuromodulatory technology could serve as a plausible therapeutic approach for improving symptoms of inflammatory bowel disease. ABSTRACT: Individuals suffering from inflammatory bowel disease (IBD) experience significantly diminished quality of life. Here, we aim to stimulate the celiac plexus with non-invasive peripheral focused ultrasound (FUS) to modulate the enteric cholinergic anti-inflammatory pathway. This approach may have clinical utility as an efficacious IBD treatment given the non-invasive and targeted nature of this therapy. We employed the dextran sodium sulfate (DSS) model of colitis, administering lower (5%) and higher (7%) doses to rats in drinking water. FUS on the celiac plexus administered twice a day for 12 consecutive days to rats with severe IBD improved stool consistency scores from 2.2 ± 1 to 1.0 ± 0.0 with peak efficacy on day 5 and maximum reduction in gross bleeding scores from 1.8 ± 0.8 to 0.8 ± 0.8 on day 6. Similar improvements were seen in animals in the low dose DSS group, who received FUS only once daily for 12 days. Moreover, animals in the high dose DSS group receiving FUS twice daily maintained colon length (17.7 ± 2.5 cm), while rats drinking DSS without FUS exhibited marked damage and shortening of the colon (13.8 ± 0.6 cm) as expected. Inflammatory cytokines such as interleukin (IL)-1ß, IL-6, IL-17, tumour necrosis factor-α and interferon-γ were reduced with DSS but coincided with control levels after FUS, which is plausibly due to a loss of colon crypts in the former and healthier crypts in the latter. Lastly, overall, these results suggest non-invasive FUS of peripheral ganglion can deliver precision therapy to improve IBD symptomology.


Assuntos
Plexo Celíaco , Colite , Doenças Inflamatórias Intestinais , Animais , Plexo Celíaco/metabolismo , Plexo Celíaco/patologia , Colite/tratamento farmacológico , Colite/metabolismo , Colite/patologia , Colo/metabolismo , Citocinas/metabolismo , Sulfato de Dextrana/metabolismo , Sulfato de Dextrana/uso terapêutico , Modelos Animais de Doenças , Doenças Inflamatórias Intestinais/metabolismo , Doenças Inflamatórias Intestinais/terapia , Ratos
17.
Cell Mol Neurobiol ; 41(4): 751-763, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-32445041

RESUMO

Exposure to noise produces cognitive and emotional disorders, and recent studies have shown that auditory stimulation or deprivation affects hippocampal function. Previously, we showed that exposure to high-intensity sound (110 dB, 1 min) strongly inhibits Schaffer-CA1 long-term potentiation (LTP). Here we investigated possible mechanisms involved in this effect. We found that exposure to 110 dB sound activates c-fos expression in hippocampal CA1 and CA3 neurons. Although sound stimulation did not affect glutamatergic or GABAergic neurotransmission in CA1, it did depress the level of brain-derived neurotrophic factor (BDNF), which is involved in promoting hippocampal synaptic plasticity. Moreover, perfusion of slices with BDNF rescued LTP in animals exposed to sound stimulation, whereas BDNF did not affect LTP in sham-stimulated rats. Furthermore, LM22A4, a TrkB receptor agonist, also rescued LTP from sound-stimulated animals. Our results indicate that depression of hippocampal BDNF mediates the inhibition of LTP produced by high-intensity sound stimulation.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/deficiência , Hipocampo/fisiologia , Potenciação de Longa Duração , Som , Animais , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Região CA1 Hipocampal/fisiologia , Ácido Glutâmico/metabolismo , Potenciação de Longa Duração/fisiologia , Masculino , Proteínas Proto-Oncogênicas c-fos/metabolismo , Células Piramidais/metabolismo , Ratos Wistar , Sinapses/fisiologia , Transmissão Sináptica , Ácido gama-Aminobutírico/metabolismo
18.
Eur J Pharmacol ; 885: 173390, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32735983

RESUMO

Erythrinian alkaloids ((+)-erythravine and (+)-11-α-hydroxy-erythravine) have been pointed as the main responsible agents for the anticonvulsant and anxiolytic properties of Erythrina mulungu Mart ex Benth. The present work provides a new set of information about the mode of action of these alkaloids by the use of a complementary approach of neurochemical and electrophysiological assays. We propose here that the antiepileptic and anxiolytic properties exhibited by both alkaloids appear not to be related to the inhibition of glutamate binding or GABA uptake, or even to the increase of glutamate uptake or GABA binding, as investigated here by the use of rat cortical synaptosomes. Similarly, and even in a high concentration, (+)-erythravine and (+)-11-α-hydroxy-erythravine did not modulate the main sodium and potassium channel isoforms checked by the use of voltage-clamp studies on Xenopus laevis oocytes. However, unlike (+)-11-α-hydroxy-erythravine, which presented a little effect, it was possible to observe that the (+)-erythravine alkaloid produced a significant inhibitory modulation on α4ß2, α4ß4 and α7 isoforms of nicotinic acetylcholine receptors also checked by the use of voltage-clamp studies, which could explain at least partially its anxiolytic and anticonvulsant properties. Since (+)-11-α-hydroxy-erythravine and (+)-erythravine modulated nicotinic acetylcholine receptors to different extents, it is possible to reinforce that small differences between the chemical structure of these alkaloids can affect the selectivity and affinity of target-ligand interactions, conferring distinct potency and/or pharmacological properties to them, as previously suggested by differential experimental comparison between different erythrinian alkaloids.


Assuntos
Ansiolíticos/farmacologia , Anticonvulsivantes/farmacologia , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Animais , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Erythrina/química , Ácido Glutâmico/metabolismo , Antagonistas Nicotínicos/farmacologia , Oócitos , Técnicas de Patch-Clamp , Potássio/metabolismo , Receptores Nicotínicos/efeitos dos fármacos , Canais de Sódio/metabolismo , Sinaptossomos/efeitos dos fármacos , Sinaptossomos/metabolismo , Xenopus laevis , Ácido gama-Aminobutírico/metabolismo
19.
Biotechnol Bioeng ; 117(11): 3286-3298, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32658303

RESUMO

Healthcare-associated infections (HCAIs) affect hundreds of millions of patients, representing a significant burden for public health. They are usually associated to multidrug resistant bacteria, which increases their incidence and severity. Bloodstream infections are among the most frequent and life-threatening HCAIs, with Enterococcus and Staphylococcus among the most common isolated pathogens. The correct and fast identification of the etiological agents is crucial for clinical decision-making, allowing to rapidly select the appropriate antimicrobial and to prevent from overuse and misuse of antibiotics and the consequent increase in antimicrobial resistance. Conventional culture methods are still the gold standard to identify these pathogens, however, are time-consuming and may lead to erroneous diagnosis, which compromises an efficient treatment. (Bacterio)phage receptor binding proteins (RBPs) are the structures responsible for the high specificity conferred to phages against bacteria and thus are very attractive biorecognition elements with high potential for specific detection and identification of pathogens. Taking into account all these facts, we have designed and developed a new, fast, accurate, reliable and unskilled diagnostic method based on newly identified phage RBPs and spectrofluorometric techniques that allows the multiplex detection of Enterococcus and Staphylococcus in blood samples in less than 1.5 hr after an enrichment step.


Assuntos
Bacteriemia , Bacteriófagos/genética , Enterococcus , Proteínas Recombinantes de Fusão , Staphylococcus , Proteínas Virais , Animais , Bacteriemia/sangue , Bacteriemia/diagnóstico , Receptores de Bacteriófagos/química , Receptores de Bacteriófagos/metabolismo , Enterococcus/química , Enterococcus/metabolismo , Cavalos , Limite de Detecção , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Staphylococcus/química , Staphylococcus/metabolismo , Proteínas Virais/química , Proteínas Virais/genética , Proteínas Virais/metabolismo
20.
J Biochem Mol Toxicol ; 34(11): e22578, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32666660

RESUMO

ß-Lactam antibiotics such as ceftriaxone, are potent stimulators of the expression of l-glutamate transporter GLT-1 and may exert neuroprotective effects when chronically used in rats and mice. In this study, we used two animal models to test the neurological effect of subchronic treatment with ceftriaxone: experimental acute glaucoma in Wistar rats and induction of acute seizures with pentylenetetrazole in mice. We also assessed the performance of mice in the rotarod to calculate therapeutic indexes and exploratory activity in the open field. Our results showed that subchronic use of ceftriaxone was neuroprotective in both models, reducing injury in acute ischemia and ischemia/reperfusion in specific layers of retina and leading to a decrease in the seizure severity score. In behavioral experiments, we observed that ceftriaxone increased hyperactivity followed by a decrease in exploratory behavior in the open field, and there was no motor impairment in the rotarod test. We conclude that ceftriaxone may be useful as a tool in the development of new neuroprotective drugs targeting diseases which present a possible dysfunction in the balance of glutamatergic neurotransmission.


Assuntos
Antibacterianos/administração & dosagem , Ceftriaxona/administração & dosagem , Convulsivantes/farmacologia , Glaucoma/fisiopatologia , Fármacos Neuroprotetores/administração & dosagem , Convulsões/prevenção & controle , Tetrazóis/farmacologia , Doença Aguda , Animais , Comportamento Animal/efeitos dos fármacos , Masculino , Camundongos , Ratos , Ratos Wistar
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