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1.
Learn Behav ; 2024 Apr 26.
Article in English | MEDLINE | ID: mdl-38671293

ABSTRACT

To investigate the extent of adoption of more efficient coding strategies, pigeons learned, in three experiments, a symbolic matching-to-sample task that featured an asymmetric sample-comparison mapping. In all experiments, one comparison was correct following one of the samples (one-to-one mapping), and another comparison was correct following the remaining samples (many-to-one mapping). The experiments differed in sample number; Experiment 1 featured three samples, Experiment 2 five samples, and Experiment 3 seven samples. Our goal was to assess the adoption of a single-code/default coding strategy, which establishes two response rules: one rule specific to the sample mapped one-to-one (the single code), and another rule to be applied following any other sample (the default rule). Alternatively, the animals could establish more response rules, one per sample. Thus, the single-code/default strategy allows learning a task via a reduced number of response rules, and the more samples are mapped many-to-one, the greater the savings it allows. As such, the three experiments should progressively be more amenable to the adoption of this strategy. Overall, the adoption of a single-code/default strategy was not widespread. When taken together with previous results, the present study suggests that the amount of training may affect the coding strategy pigeons adopt. Additionally, our results underscore that individual differences are a fundamental aspect to consider when studying learning flexibility.

2.
Pharmaceuticals (Basel) ; 16(10)2023 Oct 03.
Article in English | MEDLINE | ID: mdl-37895870

ABSTRACT

A lack of control over blood loss can have catastrophic implications, including death. Although several hemostatic medications have been employed to reduce bleeding, a vast majority of them are ineffective, expensive, or pose health risks to the patient. To overcome these constraints, chitosan-polyethylene glycol (CS-PEG) hemostatic gels loaded with ethanolic extract of Jatropha mollissima sap (EES) were prepared and their hemostatic, physicochemical, and cytotoxic properties were evaluated. The gels were produced by mixing CS with PEG (an external plasticizer) and EES. The phytochemical analysis revealed a significant concentration of total polyphenols and tannins content in the extract and catechin was identified as one of the key compounds of EES. Infrared spectroscopy analysis revealed the presence of EES in the gels, as well as the chemical interaction between CS and PEG. The gels were thermally stable between 25 and 37 °C (ambient and human body temperature range), had pseudoplastic deformation behavior (rheological properties preserved after shearing), were simple to inject (compression force 30 N), and were biocompatible. In vivo experiments showed that both CS-PEG-EES gels exhibited greater hemostatic action in preventing tail hemorrhage in Wistar rats, with decreased bleeding time and blood weight compared with unloaded CS-PEG gels (control groups) and Hemostank, a commercial product. However, the gel prepared with acetic acid was more efficient in controlling bleeding. These findings reveal that CS-PEG-EES gels can reduce hemorrhages and are a potent, simple, and safe hemostatic agent.

3.
Article in English | MEDLINE | ID: mdl-37140989

ABSTRACT

Summary: We present an adolescent with X-linked hypophosphatemic rickets (XLH) with bone age advancement and its response to aromatase inhibitors (AIs). A male with XLH, confirmed with a deletion on the PHEX gene, received regular treatment since the first year of life with average growth velocity and height. He had bone age compatible with chronological age until 13 when he had a bone age advancement and a decrease in the predicted final height thought to be due to initiation of oral isotretinoin, which has been previously reported. Then, anastrozole was initiated and maintained concomitant to the rickets treatment for 2 years with bone age stabilization. He had no adverse effects or worsening of bone health markers. As a result, he maintained his height gain and improved his final height Z score compared with the predicted final height at initiating anastrozole. In conclusion, although AIs was a reasonable strategy to stabilize bone age and minimize height impairment, careful monitoring is mandatory to understand its benefits and effects on XLH patients. Learning points: Although X-linked hypophosphatemic rickets patients have normal puberty, they can be affected by metabolic and environmental factors that may advance their bone age and impair the predicted final height, similar to the general population. Isotretinoin may accelerate skeletal maturation during puberty in an adolescent with X-linked hypophosphatemic rickets. Aromatase inhibitors showed to be a reasonable strategy to stabilize bone age and minimize height impairment in an adolescent with X-linked hypophosphatemic rickets.

4.
Chemosphere ; 316: 137779, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36632955

ABSTRACT

Exposure to mercury can interfere with the expression of proteins and enzymes, compromise important pathways, such as apoptosis and glucose metabolism, and even induce the expression of metallothioneins. In this study, analytical techniques were used to determine the concentration of total mercury (THg) in muscle and liver tissue, protein pellets, and spots [using graphite furnace atomic absorption spectrometry (GFAAS)], and molecular techniques were used to identify metalloproteins present in mercury-associated protein spots. Thirty individuals from three different fish species, Cichla sp. (n = 10), Brachyplatystoma filamentosum (n = 10), and Semaprochilodus sp. (n = 10) from the Brazilian Amazon were used. Oxidative stress indicators [such as glutathione peroxidase (GSH-Px), catalase (CAT), superoxide dismutase (SOD), a marker of lipid peroxidation (LPO)] and the possible expression of metallothioneins in muscle and liver tissues were investigated. The two piscivorous species, Cichla sp. and B. filamentosum, presented the highest concentrations of mercury in their hepatic tissue, 1219 ± 15.00 and 1044 ± 13.6 µg kg-1, respectively, and in their muscle tissue, 101 ± 1.30 µg kg-1 and 87.4 ± 0.900 µg kg-1, respectively. The non-carnivorous species Semaprochilodus sp. had comparatively low concentrations of mercury in both its hepatic (852 ± 11.1 µg kg-1) and muscle (71.4 ± 0.930 µg kg-1) tissues. The presence of mercury was identified in 24 protein spots using GFAAS; concentrations ranged from 11.5 to 787 µg kg-1, and mass spectrometry identified 21 metal-binding proteins. The activities of GSH-Px, CAT, and SOD, related to oxidative stress, decreased proportionally as tissue Hg concentrations increased, while the levels of LPO markers increased, indicating the presence of stress. Our study results demonstrate possible mercury interference in oxidative stress markers (GSH-Px, CAT, SOD, and LPO), in addition to the identification of 21 metal-binding proteins as possible biomarkers of mercury exposure in fish.


Subject(s)
Characiformes , Cichlids , Mercury , Animals , Fishes/metabolism , Mercury/analysis , Characiformes/metabolism , Muscles/chemistry , Cichlids/metabolism , Superoxide Dismutase/metabolism , Glutathione Peroxidase/metabolism , Biomarkers/metabolism , Oxidative Stress , Liver/metabolism
5.
Article in English | MEDLINE | ID: mdl-36566682

ABSTRACT

Studies on the globin family are continuously revealing insights into the mechanisms of gene and protein evolution. The rise of a new globin gene type in Pelobatoidea and Neobatrachia (Amphibia:Anura) from an α-globin precursor provides the opportunity to investigate the genetic and physical mechanisms underlying the origin of new protein structural and functional properties. This amphibian-specific globin (globin A/GbA) discovered in the heart of Rana catesbeiana is a monomer. As the ancestral oligomeric state of α-globins is a homodimer, we inferred that the ancestral state was lost somewhere in the GbA lineage. Here, we combined computational molecular evolution with structural bioinformatics to determine the extent to which the loss of the homodimeric state is pervasive in the GbA clade. We also characterized the loci of GbA genes in Bufo bufo. We found two GbA clades in Neobatrachia. One was deleted in Ranidae, but retained and expanded to yield a new globin cluster in Bufonidae species. Loss of the ancestral oligomeric state seems to be pervasive in the GbA clade. However, a taxonomic sampling that includes more Pelobatoidea, as well as early Neobatrachia, lineages would be necessary to determine the oligomeric state of the last common ancestor of all GbA. The evidence presented here points out a possible loss of oligomerization in Pelobatoidea GbA as a result of amino acid substitutions that weaken the homodimeric state. In contrast, the loss of oligomerization in both Neobatrachia GbA clades was linked to independent deletions that disrupted many packing contacts at the homodimer interface.


Subject(s)
Evolution, Molecular , Globins , Animals , Globins/genetics , Phylogeny , Amphibians/genetics
6.
Trab. Educ. Saúde (Online) ; 21: e02158224, 2023.
Article in Portuguese | LILACS | ID: biblio-1515613

ABSTRACT

RESUMO: Trata-se de um estudo cartográfico que buscou analisar a atuação de médicos(as) de família e comunidade na Atenção Primária da saúde suplementar, realizado por meio de diários e entrevistas cartográficas entre março de 2021 e janeiro de 2022, processados semanalmente em reuniões de pesquisa. Tal estudo se deu com base nos analisadores: 'território', 'família' e 'comunidade'. Notou-se que a territorialização e a abordagem familiar ganham outros contornos na Medicina de Família e Comunidade praticada na saúde suplementar. Além disso, verificou-se que algumas das ferramentas típicas da Atenção Básica - como visita domiciliar, educação em saúde, genograma, ecomapa e vigilância em saúde - não eram utilizadas na atenção suplementar ou tiveram outras aplicabilidades dissonantes do modelo preconizado. Concluiu-se que a Medicina de Família e Comunidade na saúde suplementar se aproxima de uma atuação mais clínica, com perda da potência das linhas de força que constituem tal especialidade, tendendo a uma medicina menos familiar e comunitária.


RESUMEN: Se trata de un estudio cartográfico que buscó analizar el desempeño de los médicos de familia y comunidad en atención primaria de salud complementaria, realizado a través de diarios y entrevistas cartográficas entre marzo de 2021 y enero de 2022, que fueron procesados semanalmente en reuniones de investigación. Este estudio se basó en los analizadores: 'territorio', 'familia' y 'comunidad'. Se observó que la territorialización y el enfoque familiar adquieren otros contornos en la Medicina Familiar y Comunitaria practicada en salud complementaria. Además, se encontró que algunas de las herramientas típicas de la atención básica, como las visitas domiciliarias, la educación sanitaria, el genograma, el ecomap y la vigilancia sanitaria, no se utilizaron en la atención complementaria o tenían otra aplicabilidad disonante del modelo recomendado. Se concluyó que la Medicina Familiar y Comunitaria en salud complementaria se aproxima a una práctica más clínica, con pérdida de potencia de las líneas eléctricas que constituyen dicha especialidad, tendiendo a una medicina menos familiar y comunitaria.


ABSTRACT: This is a cartographic study that sought to analyze the performance of family and community physicians in primary care of supplementary health, carried out through diaries and cartographic interviews between March 2021 and January 2022, which were weekly processed in research meetings. This study was based on the analyzers: 'territory', 'family' and 'community'. It was noticed that territorialization and family approach gain other contours in Family and Community Medicine practiced in supplementary health. In addition, it was found that some of the typical tools of basic care - such as home visits, health education, genogram, ecomap and health surveillance - were not used in supplementary care or had other dissonant applicabilities of the recommended model. It was concluded that Family and Community Medicine in supplementary health approaches a more clinical practice, with loss of power from the power lines that constitute such specialty, tending to a less familiar and community medicine.


Subject(s)
Humans , Male , Female , Adult , Physicians, Family/organization & administration , Primary Health Care/organization & administration , Prepaid Health Plans/organization & administration , Brazil , Interviews as Topic , Qualitative Research , Geographic Mapping , Territorialization in Primary Health Care
7.
Int J Mol Sci ; 23(20)2022 Oct 14.
Article in English | MEDLINE | ID: mdl-36293152

ABSTRACT

Catechol-O-methyltransferase (COMT) has been involved in a number of medical conditions including catechol-estrogen-induced cancers and a great range of cardiovascular and neurodegenerative diseases such as Parkinson's disease. Currently, Parkinson's disease treatment relies on a triple prophylaxis, involving dopamine replacement by levodopa, the use of aromatic L-amino acid decarboxylase inhibitors, and the use of COMT inhibitors. Typically, COMT is highly thermolabile, and its soluble isoform (SCOMT) loses biological activity within a short time span preventing further structural and functional trials. Herein, we characterized the thermal stability profile of lysate cells from Komagataella pastoris containing human recombinant SCOMT (hSCOMT) and enzyme-purified fractions (by Immobilized Metal Affinity Chromatography-IMAC) upon interaction with several buffers and additives by Thermal Shift Assay (TSA) and a biological activity assessment. Based on the obtained results, potential conditions able to increase the thermal stability of hSCOMT have been found through the analysis of melting temperature (Tm) variations. Moreover, the use of the ionic liquid 1-butyl-3-methylimidazolium chloride [C4mim]Cl (along with cysteine, trehalose, and glycerol) ensures complete protein solubilization as well as an increment in the protein Tm of approximately 10 °C. Thus, the developed formulation enhances hSCOMT stability with an increment in the percentage of activity recovery of 200% and 70% when the protein was stored at 4 °C and -80 °C, respectively, for 12 h. The formation of metanephrine over time confirmed that the enzyme showed twice the productivity in the presence of the additive. These outstanding achievements might pave the way for the development of future hSCOMT structural and biophysical studies, which are fundamental for the design of novel therapeutic molecules.


Subject(s)
Carboxy-Lyases , Ionic Liquids , Parkinson Disease , Humans , Catechol O-Methyltransferase/genetics , Catechol O-Methyltransferase/metabolism , Levodopa/therapeutic use , Parkinson Disease/drug therapy , Dopamine/therapeutic use , Cysteine , Metanephrine , Glycerol/therapeutic use , Trehalose/therapeutic use , Ionic Liquids/therapeutic use , Catechols/pharmacology , Catechols/chemistry , Estrogens/therapeutic use
8.
Environ Monit Assess ; 194(10): 705, 2022 Aug 23.
Article in English | MEDLINE | ID: mdl-35999477

ABSTRACT

Metalloproteomics is an innovative methodology for identifying of protein-associated mercury. Thus, we analyzed the muscle proteome of Arapaima gigas (pirarucu), collected in the Madeira River of the Brazilian Amazon, to identify protein-associated mercury, with the aim of identifying possible mercury biomarkers in fish muscle tissue. After obtaining the protein pellet, we conducted two-dimensional electrophoresis (2D PAGE) to fractionate the muscle proteome. Total mercury in muscle tissue and protein pellets and mapping of mercury content in protein spots of the 2D PAGE gels was determined using graphite furnace atomic absorption spectrometry (GFAAS). The protein-associated mercury identification was performed using liquid chromatography coupled with sequence mass spectrometry (LC‒MS/MS). Total mercury determinations by GFAAS indicated concentrations on the order of 153 ± 1.90 mg kg-1 and 142 ± 1.50 mg kg-1 (total precipitation of protein fraction) and 139 ± 1.45 mg kg-1 (fractional precipitation of protein fraction) in muscle tissue and protein pellets, respectively. Mercury concentrations in the range of 48 ± 0.90 to 165 ± 3.00 mg kg-1 were found in twelve protein spots. Among the 2D PAGE protein spots, eleven Hg-binding proteins were identified using LC‒MS/MS, which showed characteristics of mercury exposure biomarkers for important metabolic functions, such as five parvalbumin isoforms, triosephosphate isomerase, cofilin 2 (muscle), and fructose-bisphosphate aldolases.


Subject(s)
Mercury , Water Pollutants, Chemical , Animals , Biomarkers/metabolism , Brazil , Chromatography, Liquid , Environmental Monitoring , Fishes/metabolism , Mercury/analysis , Muscles/chemistry , Proteome , Tandem Mass Spectrometry , Water Pollutants, Chemical/analysis
9.
Int J Mol Sci ; 23(13)2022 Jun 30.
Article in English | MEDLINE | ID: mdl-35806268

ABSTRACT

Membrane-bound catechol-O-methyltransferase (MBCOMT), present in the brain and involved in the main pathway of the catechol neurotransmitter deactivation, is linked to several types of human dementia, which are relevant pharmacological targets for new potent and nontoxic inhibitors that have been developed, particularly for Parkinson's disease treatment. However, the inexistence of an MBCOMT 3D-structure presents a blockage in new drugs' design and clinical studies due to its instability. The enzyme has a clear tendency to lose its biological activity in a short period of time. To avoid the enzyme sequestering into a non-native state during the downstream processing, a multi-component buffer plays a major role, with the addition of additives such as cysteine, glycerol, and trehalose showing promising results towards minimizing hMBCOMT damage and enhancing its stability. In addition, ionic liquids, due to their virtually unlimited choices for cation/anion paring, are potential protein stabilizers for the process and storage buffers. Screening experiments were designed to evaluate the effect of distinct cation/anion ILs interaction in hMBCOMT enzymatic activity. The ionic liquids: choline glutamate [Ch][Glu], choline dihydrogen phosphate ([Ch][DHP]), choline chloride ([Ch]Cl), 1- dodecyl-3-methylimidazolium chloride ([C12mim]Cl), and 1-butyl-3-methylimidazolium chloride ([C4mim]Cl) were supplemented to hMBCOMT lysates in a concentration from 5 to 500 mM. A major potential stabilizing effect was obtained using [Ch][DHP] (10 and 50 mM). From the DoE 146% of hMBCOMT activity recovery was obtained with [Ch][DHP] optimal conditions (7.5 mM) at -80 °C during 32.4 h. These results are of crucial importance for further drug development once the enzyme can be stabilized for longer periods of time.


Subject(s)
Catechol O-Methyltransferase , Ionic Liquids , Anions , Catechol O-Methyltransferase/chemistry , Choline/chemistry , Enzyme Stability , Humans , Ionic Liquids/chemistry
10.
Drug Discov Today ; 27(10): 103328, 2022 10.
Article in English | MEDLINE | ID: mdl-35907613

ABSTRACT

Catechol-O-methyltransferase (COMT) is an enzyme responsible for the O-methylation of biologically active catechol-based molecules. It has been associated with several neurological disorders, especially Parkinson's disease (PD), because of its involvement in catecholamine metabolism, and has been considered an important therapeutic target for central nervous system disorders. In this review, we summarize the biophysical, structural, and therapeutical relevance of COMT; the medicinal chemistry behind the development of COMT inhibitors and the application of computer-aided design to support the design of novel molecules; current methodologies for the biosynthesis, isolation, and purification of COMT; and revise existing bioanalytical approaches for the assessment of enzymatic activity in several biological matrices.


Subject(s)
Catechol O-Methyltransferase Inhibitors , Central Nervous System Diseases , Catechol O-Methyltransferase/chemistry , Catechol O-Methyltransferase/metabolism , Catechol O-Methyltransferase Inhibitors/chemistry , Catechol O-Methyltransferase Inhibitors/pharmacology , Catechol O-Methyltransferase Inhibitors/therapeutic use , Catecholamines , Catechols/chemistry , Central Nervous System Diseases/drug therapy , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Humans
11.
Methods Mol Biol ; 2466: 135-144, 2022.
Article in English | MEDLINE | ID: mdl-35585316

ABSTRACT

Nucleic acid-based therapy has been emerging as a new strategy with great potential for the treatment of numerous diseases, especially those caused by gene defects. In this context, biotechnology plays a critical role on establishing suitable processes for biopharmaceuticals manufacturing, while the purification step still imposes a major burden. Affinity chromatography using amino acids as specific ligands has been successfully applied for plasmid DNA purification. In this protocol, we describe the process for nucleic acids production and extraction, as well as the chromatographic matrix synthesis for separation between DNA and RNA. This novel arginine-macroporous support presents excellent binding capacity and great robustness for nucleic acids isolation.


Subject(s)
Nucleic Acids , RNA , Arginine/chemistry , Chromatography, Affinity/methods , DNA/genetics , Plasmids/genetics , RNA/chemistry , RNA/genetics
12.
Surg Neurol Int ; 12: 316, 2021.
Article in English | MEDLINE | ID: mdl-34345457

ABSTRACT

BACKGROUND: Arachnoid webs (AWs) can cause cord compression and syringomyelia in the thoracic spine. Here, we describe two patients who underwent operative treatment for AW and reviewed the literature. CASE DESCRIPTION: Two patients underwent surgical treatment for thoracic AW. Both presented with spastic gait and numbness in the lower extremities. On MR, these lesions exhibited the "scalpel" sign (i.e. due to the accumulation of cerebrospinal fluid on the dorsal aspect of the spinal cord). Operative intervention, consisting of fenestration and web resection, resulted in symptom resolution. CONCLUSION: Thoracic AWs are rare lesions that should be considered among the differential diagnosis of spinal compressive syndromes. Surgical fenestration and resection of the AW correct the flow dynamics allowing for full symptoms resolution.

13.
Nanomedicine ; 36: 102429, 2021 08.
Article in English | MEDLINE | ID: mdl-34174419

ABSTRACT

Nanoparticles offer targeted delivery of drugs with minimal toxicity to surrounding healthy tissue and have great potential in the management of human papillomavirus (HPV)-related diseases. We synthesized lipid-modified AS1411 aptamers capable of forming nanoaggregates in solution containing Mg2+. The nanoaggregates presented suitable properties for pharmaceutical applications such as small size (100 nm), negative charge, and drug release. The nanoaggregates were loaded with acridine orange derivative C8 for its specific delivery into cervical cancer cell lines and HPV-positive tissue biopsies. This improved inhibition of HeLa proliferation and cell uptake without significantly affecting healthy cells. Finally, the nanoaggregates were incorporated in a gel formulation with promising tissue retention properties aiming at developing a local delivery strategy of the nanoaggregates in the female genital tract. Collectively, these findings suggest that the nanoformulation protocol has great potential for the delivery of both anticancer and antiviral agents, becoming a novel modality for cervical cancer management.


Subject(s)
Antineoplastic Agents , Antiviral Agents , Aptamers, Nucleotide , Cell Proliferation/drug effects , Drug Delivery Systems , Oligodeoxyribonucleotides , Uterine Cervical Neoplasms/drug therapy , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacokinetics , Antineoplastic Agents/pharmacology , Antiviral Agents/chemistry , Antiviral Agents/pharmacokinetics , Antiviral Agents/pharmacology , Aptamers, Nucleotide/chemistry , Aptamers, Nucleotide/pharmacokinetics , Aptamers, Nucleotide/pharmacology , Female , HeLa Cells , Humans , Oligodeoxyribonucleotides/chemistry , Oligodeoxyribonucleotides/pharmacokinetics , Oligodeoxyribonucleotides/pharmacology , Uterine Cervical Neoplasms/metabolism
14.
Neurosurgery ; 89(3): 450-459, 2021 08 16.
Article in English | MEDLINE | ID: mdl-34161592

ABSTRACT

BACKGROUND: Gait and balance disturbance are challenging symptoms in advanced Parkinson's disease (PD). Anatomic and clinical data suggest that the fields of Forel may be a potential surgical target to treat these symptoms. OBJECTIVE: To test whether bilateral stimulation centered at the fields of Forel improves levodopa unresponsive freezing of gait (FOG), balance problems, postural instability, and falls in PD. METHODS: A total of 13 patients with levodopa-unresponsive gait disturbance (Hoehn and Yahr stage ≥3) were included. Patients were evaluated before (on-medication condition) and 1 yr after surgery (on-medication-on-stimulation condition). Motor symptoms and quality of life were assessed with the Unified Parkinson's Disease Rating scale (UPDRS III) and Quality of Life scale (PDQ-39). Clinical and instrumented analyses assessed gait, balance, postural instability, and falls. RESULTS: Surgery improved balance by 43% (95% confidence interval [CI]: 21.2-36.4 to 35.2-47.1; P = .0012), reduced FOG by 35% (95% CI: 15.1-20.3 to 8.1-15.3; P = .0021), and the monthly number of falls by 82.2% (95% CI: 2.2-6.9 to -0.2-1.7; P = .0039). Anticipatory postural adjustments, velocity to turn, and postural sway measurements also improved 1 yr after deep brain stimulation (DBS). UPDRS III motor scores were reduced by 27.2% postoperatively (95% CI: 42.6-54.3 to 30.2-40.5; P < .0001). Quality of life improved 27.5% (95% CI: 34.6-48.8 to 22.4-37.9; P = .0100). CONCLUSION: Our results suggest that DBS of the fields of Forel improved motor symptoms in PD, as well as the FOG, falls, balance, postural instability, and quality of life.


Subject(s)
Deep Brain Stimulation , Gait Disorders, Neurologic , Parkinson Disease , Brain , Gait , Gait Disorders, Neurologic/drug therapy , Gait Disorders, Neurologic/etiology , Humans , Levodopa/therapeutic use , Parkinson Disease/complications , Parkinson Disease/drug therapy , Postural Balance , Quality of Life
15.
ACS Omega ; 6(11): 7959-7965, 2021 Mar 23.
Article in English | MEDLINE | ID: mdl-33778307

ABSTRACT

This work presents a new oscillating reaction based on chlorate and observed in a CSTR at room temperature. This can be the first member of a new family of oscillating reactions. In addition, it is also the first oscillating reaction to use nitrous acid as a reactant. Four different behaviors were observed: simple oscillations, mixed mode oscillations, bursts, and quasiperiodicity. The period of oscillations is very short, which is around 1 s. Together with the fact that it also shows fast bursts, it opens the possibility that it can be used to simulate fast biological events, like the neuron's communications signals.

16.
Biol Trace Elem Res ; 199(2): 712-720, 2021 Feb.
Article in English | MEDLINE | ID: mdl-32449008

ABSTRACT

This manuscript describes the results of a metalloproteomic study of mercury in samples of muscle and liver tissue of the species Serrasalmus rhombeus, popularly known as black piranha and characterised as the most voracious and aggressive predator in the Brazilian Amazon. The metalloproteomic study involved using two-dimensional electrophoresis (2D PAGE) to fractionate the proteome of the muscle and liver tissue samples, along with atomic absorption spectrometry in a graphite furnace (GFAAS) to identify mercury associated with protein SPOTs and mass spectrometry with electrospray ionisation (ESI-MS/MS) to characterise the mercury-binding proteins. The protein SPOTs characterised showed concentrations in the order of 156 mg kg-1, which ranks as the highest concentrations of mercury determined so far in metalloproteomic studies involving fish species in the Amazon region. Based on FASTA sequences of proteins characterised by ESI-MS/MS, bioinformatics studies were performed that allowed identifying nine proteins with characteristics of biomarkers of mercury exposure. Of those proteins, glutathione peroxidase stands out as an enzyme of great importance in the antioxidant defence of organisms subjected to oxidative stress caused by xenobiotics.


Subject(s)
Characiformes , Mercury , Animals , Biomarkers , Brazil , Mercury/analysis , Tandem Mass Spectrometry
17.
Methods Mol Biol ; 2197: 207-222, 2021.
Article in English | MEDLINE | ID: mdl-32827139

ABSTRACT

Human papillomavirus (HPV ) has been extensively associated with the development of cervical cancer due to the expression of oncoproteins like E7. This protein can interfere with pRB tumor suppressor activity, enabling the uncontrolled proliferation of abnormal cells. DNA vaccines are known as the third-generation vaccines, providing the ability of targeting viral infections such as HPV in a preventive and therapeutic way. Although current strategies make use of plasmid DNA (pDNA) as the vector of choice to be used as a DNA vaccine, minicircle DNA (mcDNA) has been proving its added value as a non-viral DNA vector by demonstrating higher expression efficiency and increased biosafety than the pDNA. However, due to its innovative profile, few methodologies have been explored and implemented for the manufacture of this molecule. This chapter describes the detailed procedures for the production, extraction, and purification of supercoiled E7-mcDNA vaccine, by using size-exclusion chromatography to obtain mcDNA with a purity degree which meets the regulatory agency criteria. Then, the assessment of E7 antigen expression through immunocytochemistry is also described.


Subject(s)
DNA, Circular/isolation & purification , Papillomavirus Vaccines/isolation & purification , Plasmids/isolation & purification , Vaccines, DNA/isolation & purification , Cell Culture Techniques , Chromatography, Gel , Escherichia coli/genetics , Fermentation , Gene Expression , Immunohistochemistry , Papillomavirus E7 Proteins/genetics , Papillomavirus E7 Proteins/immunology , Papillomavirus Vaccines/genetics , Papillomavirus Vaccines/immunology , Vaccines, DNA/genetics , Vaccines, DNA/immunology
18.
Methods Mol Biol ; 2197: 271-284, 2021.
Article in English | MEDLINE | ID: mdl-32827143

ABSTRACT

In DNA-based therapy research, the conception of a suitable vector to promote the target gene carriage, protection, and delivery to the cell is imperative. Exploring the interactions between polyethylenimine (PEI) and a plasmid DNA can give rise to the formation of suitable complexes for gene release and concomitant protein production. The nanosystems formulation method, based on coprecipitation, seems to be adequate for the conception of nanoparticles with suitable properties (morphology, size, surface charge, and pDNA complexation capacity) for intracellular applications. The developed systems are able of cell uptake, intracellular trafficking, and gene expression, in an extent depending on the ratio of nitrogen to phosphate groups (N/P). It comes that the transfection process can be tailored by this parameter and, therefore, also the therapeutic outcomes. This knowledge contributes for progresses in the development of suitable delivery systems with potential application in DNA vaccines field.


Subject(s)
Gene Transfer Techniques , Plasmids/administration & dosage , Plasmids/chemistry , Polyethyleneimine/chemistry , Vaccines, DNA/administration & dosage , Cations , Drug Delivery Systems , HeLa Cells , Humans , Nanoparticles , Spectroscopy, Fourier Transform Infrared , Vaccines, DNA/chemistry , Vaccines, DNA/genetics
19.
Pharmaceuticals (Basel) ; 15(1)2021 Dec 31.
Article in English | MEDLINE | ID: mdl-35056108

ABSTRACT

A pharmacophore-based virtual screening methodology was used to discover new catechol-O-methyltransferase (COMT) inhibitors with interest in Parkinson's disease therapy. To do so, pharmacophore models were constructed using the structure of known inhibitors and then they were used in a screening in the ZINCPharmer database to discover hit molecules with the desired structural moieties and drug-likeness properties. Following this, the 50 best ranked molecules were submitted to molecular docking to better understand their atomic interactions and binding poses with the COMT (PDB#6I3C) active site. Additionally, the hits' ADMET properties were also studied to improve the obtained results and to select the most promising compounds to advance for in-vitro studies. Then, the 10 compounds selected were purchased and studied regarding their in-vitro inhibitory potency on human recombinant membrane-bound COMT (MBCOMT), as well as their cytotoxicity in rat dopaminergic cells (N27) and human dermal fibroblasts (NHDF). Of these, the compound ZIN27985035 displayed the best results: For MBCOMT inhibition an IC50 of 17.6 nM was determined, and low cytotoxicity was observed in both cell lines (61.26 and 40.32 µM, respectively). Therefore, the promising results obtained, combined with the structure similarity with commercial COMT inhibitors, can allow for the future development of a potential new Parkinson's disease drug candidate with improved properties.

20.
Nucleic Acid Ther ; 31(1): 82-91, 2021 02.
Article in English | MEDLINE | ID: mdl-33252302

ABSTRACT

Minicircle DNA (mcDNA) has been suggested as a vanguard technology for gene therapy, consisting of a nonviral DNA vector devoid of prokaryotic sequences. Unlike conventional plasmid DNA (pDNA), this small vector is able to sustain high expression rates throughout time. Thus, this work describes the construction, production, and purification of mcDNA-p53 and its precursor parental plasmid (PP)-p53 for a comparative study of both DNA vectors in the growth suppression of human papillomavirus (HPV)-18-infected cervical cancer cells. First, live cell imaging and fluorescence microscopy studies allowed to understand that mcDNA-p53 vector was able to enter cell nuclei more rapidly than PP-p53 vector, leading to a transfection efficiency of 68% against 34%, respectively. Then, p53 transcripts and protein expression assessment revealed that both vectors were able to induce transcription and the target protein expression. However, the mcDNA-p53 vector performance stood out, by demonstrating higher p53 expression levels (91.65 ± 2.82 U/mL vs. 74.75 ± 4.44 U/mL). After assuring the safety of both vectors by viability studies, such potential was confirmed by proliferation and apoptosis assays. These studies confirmed the mcDNA-p53 vector function toward cell cycle arrest and apoptosis in HPV-18-infected cervical cancer cells. Altogether, these results suggest that the mcDNA vector has a more promising and efficient role as a DNA vector than conventional pDNA, opening new investigation lines for cervical cancer treatment in the future.


Subject(s)
Human papillomavirus 18/genetics , Papillomavirus Infections/therapy , Tumor Suppressor Protein p53/genetics , Uterine Cervical Neoplasms/therapy , Apoptosis/drug effects , Cell Cycle Checkpoints/drug effects , DNA, Kinetoplast/genetics , DNA, Kinetoplast/pharmacology , Female , Gene Transfer Techniques , Genetic Therapy/trends , Human papillomavirus 18/pathogenicity , Humans , Papillomavirus Infections/genetics , Papillomavirus Infections/pathology , Papillomavirus Infections/virology , Plasmids/genetics , Tumor Suppressor Protein p53/pharmacology , Uterine Cervical Neoplasms/genetics , Uterine Cervical Neoplasms/pathology , Uterine Cervical Neoplasms/virology
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