Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 127
Filtrar
1.
Rev Bras Ortop (Sao Paulo) ; 59(Suppl 1): e43-e48, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39027176

RESUMO

Ischiofemoral impingement (IFI), although infrequent, should be thought of as one of the causes of deep gluteal pain syndrome. Difficulty in establishing a diagnosis and inaccurate clinical examination can be associated with the small number of case reports in the literature. The initial IFI treatment uses conservative measures, and surgical treatment is infrequent. The following is a case report of four adult patients, all female, diagnosed with IFI, with unsuccessful conservative treatments, in whom endoscopic resection of the smaller trochanter was performed with good results.

2.
Vet Immunol Immunopathol ; 274: 110793, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38943998

RESUMO

Mastitis, an inflammation of the mammary gland affecting milk production and quality in dairy herds, is often associated with Staphylococcus spp. in goats. Neutrophils are crucial in combating infections by migrating into milk and deploying various defense strategies, including the release of neutrophil extracellular traps (NETs) composed of DNA, histones, and bactericidal proteins. This study investigated whether NETs are released by goat neutrophils stimulated in vitro by Staphylococcus aureus and Staphylococcus warneri, two common pathogens of goat mastitis. PMNs were isolated from blood from healthy adult goats. We evaluated goat NET formation by stimulating cells with: phorbol 12-myristate 13-acetate (PMA) as a positive control, cytochalasin for inhibition of actin polymerization, S. aureus, and S. warneri. NET formation was observed in response to chemical stimulation and bacterial presence, effectively trapping pathogens. Variations in NET formation between S. aureus and S. warneri suggest pathogen-specific responses. These findings suggest that the formation of NETs may be an important complementary mechanism in the defense against mastitis in goats. In conclusion, this study unveils a novel defense mechanism in goats, indicating the role of NETs against S. aureus and S. warneri in mastitis.


Assuntos
Armadilhas Extracelulares , Doenças das Cabras , Cabras , Mastite , Neutrófilos , Infecções Estafilocócicas , Staphylococcus aureus , Animais , Cabras/imunologia , Armadilhas Extracelulares/imunologia , Feminino , Mastite/veterinária , Mastite/imunologia , Mastite/microbiologia , Doenças das Cabras/imunologia , Doenças das Cabras/microbiologia , Neutrófilos/imunologia , Staphylococcus aureus/imunologia , Infecções Estafilocócicas/veterinária , Infecções Estafilocócicas/imunologia , Staphylococcus/imunologia
3.
Bioresour Technol ; 402: 130763, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38692377

RESUMO

The fungus Thermothelomyces thermophilus is a thermotolerant microorganism that has been explored as a reservoir for enzymes (hydrolytic enzymes and oxidoreductases). The functional analysis of a recombinant cellobiose dehydrogenase (MtCDHB) from T. thermophilus demonstrated a thermophilic behavior, an optimal pH in alkaline conditions for inter-domain electron transfer, and catalytic activity on cellooligosaccharides with different degree of polymerization. Its applicability was evaluated to the sustainable production of cellobionic acid (CBA), a potential pharmaceutical and cosmetic ingredient rarely commercialized. Dissolving pulp was used as a disaccharide source for MtCDHB. Initially, recombinant exoglucanases (MtCBHI and MtCBHII) from T. thermophilus hydrolyzed the dissolving pulp, resulting in 87% cellobiose yield, which was subsequently converted into CBA by MtCDHB, achieving a 66% CBA yield after 24 h. These findings highlight the potential of MtCDHB as a novel approach to obtaining CBA through the bioconversion of a plant-based source.


Assuntos
Desidrogenases de Carboidrato , Proteínas Recombinantes , Desidrogenases de Carboidrato/metabolismo , Proteínas Recombinantes/metabolismo , Concentração de Íons de Hidrogênio , Dissacarídeos/biossíntese , Dissacarídeos/metabolismo , Temperatura , Celobiose/metabolismo , Sordariales/enzimologia , Hidrólise , Eurotiales/enzimologia
4.
Molecules ; 29(7)2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38611856

RESUMO

SARS-CoV-2 is the virus responsible for a respiratory disease called COVID-19 that devastated global public health. Since 2020, there has been an intense effort by the scientific community to develop safe and effective prophylactic and therapeutic agents against this disease. In this context, peptides have emerged as an alternative for inhibiting the causative agent. However, designing peptides that bind efficiently is still an open challenge. Here, we show an algorithm for peptide engineering. Our strategy consists of starting with a peptide whose structure is similar to the interaction region of the human ACE2 protein with the SPIKE protein, which is important for SARS-COV-2 infection. Our methodology is based on a genetic algorithm performing systematic steps of random mutation, protein-peptide docking (using the PyRosetta library) and selecting the best-optimized peptides based on the contacts made at the peptide-protein interface. We performed three case studies to evaluate the tool parameters and compared our results with proposals presented in the literature. Additionally, we performed molecular dynamics (MD) simulations (three systems, 200 ns each) to probe whether our suggested peptides could interact with the spike protein. Our results suggest that our methodology could be a good strategy for designing peptides.


Assuntos
COVID-19 , Glicoproteína da Espícula de Coronavírus , Humanos , SARS-CoV-2 , Peptídeos/farmacologia
5.
Scientifica (Cairo) ; 2024: 1960065, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38356694

RESUMO

Moxidectin (MOX) is used to control helminth parasites in ruminant livestock. It is released through feces and remains in the environment for a long period. This study aimed to evaluate the impact of faeces excreted by moxidectin-treated sheep on soil biodiversity (coprophagous insects, soil microbial biomass, and activity) to establish environment-related guidelines regarding the use of MOX in sheep livestock. The study consisted of two experiments. In the first one, faeces from MOX-treated (subcutaneous dose of 0.2 mg·kg-1 body weight) and nontreated rams were placed on an animal-free pasture field, protected or not against rain, for 88 days. Then, coprophagous insects were captured, identified, and counted, and faeces degradation was evaluated by measuring dry weight and carbon (C) and nitrogen (N) contents over time. Diptera, Hymenoptera, Isoptera, and Coleoptera were equally encountered in faeces from MOX-treated and nontreated animals. Faecal boluses of MOX-treated animals (with higher N content) not protected against rain degraded faster than faecal boluses of nontreated animals (with lower N content). In the second experiment, faeces from nontreated animals were amended with increasing amounts of MOX (75 to 3,000 ng·kg-1 faeces), mixed with soil samples from animal-free pasture (1.9 to 75 ng·kg-1 soil), and incubated in a greenhouse for 28 days. Increasing concentrations of MOX did not prevent the growth of cultivable bacteria, actinobacteria, or fungi in culture media. However, even the lower MOX concentration (1.9 ng·kg-1 soil) abruptly decreased soil microbial biomass, basal respiration, and N mineralization. Thus, the results indicate that faeces excreted from sheep treated with MOX under the experimental conditions of this study are not harmful to the coprophagous insects. However, adding MOX to faeces from drug-free sheep had a negative impact on soil microbial activity and biomass.

6.
Biol Trace Elem Res ; 202(4): 1644-1655, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37495827

RESUMO

This study evaluated the effect of prepubertal arsenic exposure in the liver and kidney of pubescent rats and their reversibility 30 days after arsenic withdrawal. Male pups of Wistar rats (21 days old) were divided into two groups (n = 20/group): control animals received filtered water, and exposed rats received 10 mg L-1 arsenic from postnatal day (PND) 21 to PND 51. The liver and kidney of 52 days old rats (n = 10/group) were examined to investigate the effects of arsenic on micromineral content, antioxidant enzyme activity, histology, and biochemistry parameters. The other animals were kept alive under free arsenic conditions until 82 days old and further analyzed by the same parameters. Our results revealed that 52-day-old rats increased arsenic content in their liver and arsenic and manganese in their kidney. In those animals, glycogen and zinc content and catalase activity were reduced in the liver, and the selenium content decreased in the kidney. Thirty days later, arsenic reduced the manganese and iron content and SOD and CAT activity in the liver of 82-day-old rats previously exposed to arsenic, while glycogen and selenium content decreased in their kidney. In contrast, PND 82 rats exhibited higher retention of copper in the liver, an increase in iron and copper content, and CAT and GST activity in the kidney. Significant histological alterations of liver and kidney tissues were not observed in rats of both ages. We conclude that arsenic-induced toxicity could alter differently the oxidative status and balance of trace elements in pubertal and adult rats, demonstrating that the metalloid can cause effects in adulthood.


Assuntos
Arsênio , Selênio , Ratos , Masculino , Animais , Arsênio/metabolismo , Cobre/farmacologia , Ratos Wistar , Selênio/farmacologia , Selênio/metabolismo , Manganês/farmacologia , Catalase/metabolismo , Antioxidantes/metabolismo , Fígado/metabolismo , Rim/metabolismo , Ferro/metabolismo , Estresse Oxidativo , Glicogênio/metabolismo
8.
Parasitol Res ; 123(1): 58, 2023 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-38110570

RESUMO

Neospora caninum is an apicomplexan protozoan that causes neosporosis, which has a high economic impact on cattle herds with no available vaccine. During infection, the secretion of dense granules and the expression of surface antigens play an important role in hosting immunomodulation. However, some epitopes of those antigens are immunogenic, and using these fractions could improve the subunit antigens in vaccine design. This study evaluates the recombinant peptides rsNcGRA1 and rsNcSAG4 derived from NcGRA1 and NcSAG4 native antigens as vaccine candidates produced by a fermentative process in the yeast culture system of Komagataella phaffii strain Km71, confirmed by colony PCR, SDS-PAGE, and western blotting. The assay was conducted in BALB/c mice using the peptides at low (25 µg) and standard (50 µg) dosages in monovalent and combined administrations at three time points with saponin as an adjuvant assessing the immunogenicity by antibodies response and cytokine production. We challenge the females after pregnancy confirmation using 2 × 105 NC-1 tachyzoites previously propagated in Vero cells. We assessed the chronic infection in dams and vertical transmission in the offspring by PCR and histopathology. Mice, especially those immunised with combined peptides and monovalent rsNcGRA1 at a standard dose, controlling the chronic infection in dams with the absence of clinical manifestations, showed an immune response with induction of IgG1, a proper balance between Th1/Th2 cytokines and reduced vertical transmission in the pups. In contrast, dams inoculated with a placebo vaccine showed clinical signs, low-scored brain lesions, augmented chronic infection with 80% positivity, 31% mortality in pups, and 81% vertical transmission. These findings indicate that rsNcGRA1 peptides in monovalent and combined with rsNCSAG4 at standard dose are potential vaccine candidates and improve the protective immune response against neosporosis in mice.


Assuntos
Coccidiose , Neospora , Vacinas Protozoárias , Animais , Feminino , Camundongos , Gravidez , Anticorpos Antiprotozoários , Antígenos de Protozoários , Chlorocebus aethiops , Coccidiose/veterinária , Citocinas , Epitopos , Imunidade , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Camundongos Endogâmicos BALB C , Neospora/genética , Infecção Persistente , Vacinação , Células Vero
9.
Braz J Microbiol ; 54(4): 3085-3099, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37807018

RESUMO

Prebiotics can alter the gastrointestinal environment, favoring the growth of health-promoting bacteria. Although yacon is a functional food, with prebiotic properties (fructooligosaccharides), its effects on the intestinal microbiota have not been investigated yet. The objective of this study was to evaluate the effects of yacon flour consumption and energy-restricted diet in the intestinal microbiota in adults with excess body weight. Twenty-one adults with excess body weight were included in this randomized, parallel, double-blind, placebo-controlled, 6-week clinical trial. Subjects daily consumed at breakfast a drink containing 25 g of yacon flour (n = 11) or not containing yacon (n = 10) and received the prescription of energy-restricted diets. Fecal samples were collected on the first and on last day of the study. 16S rRNA sequencing was assessed to evaluate the effect of yacon fermentation on intestinal microbiota bacterial composition. There was an increase in the genera Bifidobacterium, Blautia, Subdoligranulum, and Streptococcus after the consumption of yacon and energy-restricted diet. In the yacon group, we also observed a positive correlation between the concentrations of short-chain fatty acids versus the genera Coprococcus and Howardella, besides a negative correlation between the concentrations of advanced glycation end products and early glycation products versus the genera Ruminococcus and Prevotella, respectively. Consumption of yacon flour and energy-restricted diet selectively changed the intestinal microbiota composition in adults with excess body weight. TRIAL REGISTRATION: Register number: RBR-6YH6BQ. Registered 23 January, 2018.


Assuntos
Farinha , Prebióticos , Humanos , Adulto , RNA Ribossômico 16S , Obesidade , Fezes , Dieta
10.
J Chem Inf Model ; 63(20): 6344-6353, 2023 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-37824286

RESUMO

The folding process of multidomain proteins is a highly intricate phenomenon involving the assembly of distinct domains into a functional three-dimensional structure. During this process, each domain may fold independently while interacting with others. The folding of multidomain proteins can be influenced by various factors, including their composition, the structure of each domain, or the presence of disordered regions, as well as the surrounding environment. Misfolding of multidomain proteins can lead to the formation of nonfunctional structures associated with a range of diseases, including cancers or neurodegenerative disorders. Understanding this process is an important step for many biophysical analyses such as stability, interaction, malfunctioning, and rational drug design. One such multidomain protein is growth factor receptor-bound protein 2 (GRB2), an adaptor protein that is essential in regulating cell survival. GRB2 consists of one central Src homology 2 (SH2) domain flanked by two Src homology 3 (SH3) domains. The SH2 domain interacts with phosphotyrosine regions in other proteins, while the SH3 domains recognize proline-rich regions on protein partners during cell signaling. Here, we combined computational and experimental techniques to investigate the folding process of GRB2. Through computational simulations, we sampled the conformational space and mapped the mechanisms involved by the free energy profiles, which may indicate possible intermediate states. From the molecular dynamics trajectories, we used the energy landscape visualization method (ELViM), which allowed us to visualize a three-dimensional (3D) representation of the overall energy surface. We identified two possible parallel folding routes that cannot be seen in a one-dimensional analysis, with one occurring more frequently during folding. Supporting these results, we used differential scanning calorimetry (DSC) and fluorescence spectroscopy techniques to confirm these intermediate states in vitro. Finally, we analyzed the deletion of domains to compare our model outputs to previously published results, supporting the presence of interdomain modulation. Overall, our study highlights the significance of interdomain communication within the GRB2 protein and its impact on the formation, stability, and structural plasticity of the protein, which are crucial for its interaction with other proteins in key signaling pathways.


Assuntos
Neoplasias , Transdução de Sinais , Sequência de Aminoácidos , Proteína Adaptadora GRB2 , Fosfotirosina , Ligação Proteica , Domínios de Homologia de src
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA