DSpace Coleção:

Limiar glicêmico durante teste muscular inspiratório incremental em indivíduos saudáveis e com doença pulmonar obstrutiva crônica

2026-07-29T00:00:00Z

Título: Limiar glicêmico durante teste muscular inspiratório incremental em indivíduos saudáveis e com doença pulmonar obstrutiva crônica Autor(es): Silva, Wasly Santana Abstract: Introduction: The glycemic threshold (GT) during the incremental inspiratory muscle test (IIMT) has been proposed by our research group as a tool for inspiratory muscle functional assessment and individualized inspiratory muscle training (IMT) prescription. However, its agreement with the first lactate threshold (LT1) and its applicability in individuals with chronic obstructive pulmonary disease (COPD) have not yet been investigated. Objectives: To evaluate the agreement between GT and LT1 during the IIMT in healthy individuals and to investigate the determination of GT in individuals with COPD, as well as its associations with clinical and functional variables. Methods: Two studies were conducted using the IIMT. In the first study, healthy individuals performed the IIMT with simultaneous determination of GT, LT1, and the second lactate threshold (LT2). In the second study, individuals with COPD performed the IIMT for GT determination and analysis of its association with rating of perceived exertion, dyspnea, functional capacity, and cardiovascular autonomic balance. The incremental protocol started at 10% of the S-Index, with progressive workload increments until the point of exhaustion (PE). Results: In the first study, GT showed good agreement with LT1. LT1 and GT occurred at 22±8.3% and 26±13.2% of the S-Index, respectively, whereas LT2 and PE were identified at 44±10.1% and 60±14.1% of the S-Index. Bland–Altman analysis demonstrated low bias between methods for relative workload (−3.84±10.44% of the S-Index) and no proportional bias (p=0.06; R²=0.25). In the second study, GT was identified at 25±11.6% of the S-Index and showed a strong correlation with rating of perceived exertion during the IIMT (r=0.84; p<0.01). In addition, PE and ΔGT–PE were correlated with cardiovascular autonomic balance (LF/HF: r=−0.83 and r=−0.71; p<0.01), whereas ΔGT–PE was also correlated with dyspnea assessed by the modified Medical Research Council (mMRC) scale (r=−0.68; p=0.01) and Borg dyspnea at the end of the six-minute walk test (r=−0.83; p<0.01). Conclusion: GT is an identifiable physiological marker during the IIMT, showing agreement with LT1 in healthy individuals and association with important clinical and functional variables in individuals with COPD. These findings support its potential as a tool for inspiratory muscle functional assessment and individualized IMT prescription.

Efeito citotóxico do derivado indólico NM-01-28-22 em linhagem de carcinoma de pulmão

2026-02-13T00:00:00Z

Título: Efeito citotóxico do derivado indólico NM-01-28-22 em linhagem de carcinoma de pulmão Autor(es): Melo, Marcos Vinícius Barbosa de Abstract: Lung cancer is a neoplasm with a high mortality and incidence rate. The main treatments for lung cancer are chemotherapy, radiotherapy, and surgery, depending on the stage of the cancer in the patient. Chemotherapy is the most widely used therapeutic practice, but it has limitations due to adverse effects caused by its low systemic selectivity for normal cells compared to tumor cells. Many studies have demonstrated the importance of indoles and their derivatives in cancer research. Thus, indole and its derivatives allow for greater selectivity for tumor cells. Our study aims to evaluate the indole derivative NM-01-28-22 in cell inhibition in tumor cell lines and its cytotoxic effect on the lung carcinoma cell line. Initially, the compound was tested against cell lines to determine the most susceptible to the derivative. For this purpose, the Sulforhodamine B assay was used to evaluate the degree of inhibition of the NM-01-28-22 derivative in the three cell lines A549 (lung cancer), PC-3 (prostate cancer), and MCF-7 (breast cancer). For cytotoxicity assays in the A549 cell line, cell migration, clone formation, morphological alterations by DAPI and Phalloidin-Fitc staining, mitochondrial membrane potential by rhodamine 123 dye, and ROS production by the DCFH-DA probe were performed. Toxicity in human erythrocytes was verified by the hemolysis assay. In the analysis of the degree of inhibition, the values of the 50% inhibitory concentration (IC50) of the compound were obtained in the A549 (6.5 µM), MCF-7 (17.5 µM), and PC-3 (16.2 µM) cell lines. Given that the indolic derivative showed a low IC50 in A549 cells and considering its relevance in epidemiology, this cell line was used in subsequent cytotoxicity assays. The derivative inhibited cell migration and clone formation in A549 cells at all three concentrations. The derivative also induced loss of mitochondrial membrane potential and ROS production, suggesting cell death by apoptosis. The morphological changes evidenced by treatment with the derivative also show cell death in the A549 cell line. The derivative was tested at high concentrations in human erythrocytes and no toxic effect was observed. These results show that the derivative inhibited cell growth in three distinct tumor cell lines. It also showed a high cytotoxic effect in the A549 cell line without showing a toxic effect in human erythrocytes.

Efeito gastroprotetor de isoflavonas em modelos experimentais de úlcera gástrica

2026-02-06T00:00:00Z

Título: Efeito gastroprotetor de isoflavonas em modelos experimentais de úlcera gástrica Autor(es): Santos, Gideovania de Jesus Abstract: Introduction: Peptic ulcers affect a significant portion of the world's population. Pharmacological treatment is mainly carried out with proton pump inhibitors and H2 antagonists, which can cause significant adverse reactions. New therapeutic approaches are needed, given the adverse effects that current therapy brings to patients, in addition to the high number of disease recurrences. In this context, natural products stand out as sources of new molecules. Among these products, some studies highlight the potential impact of isoflavones in experimental models of gastric lesions. Objectives: To evaluate the scientific evidence on the therapeutic potential of isoflavones in preclinical models of gastric ulcer and the gastroprotective effect of daidzein in an acute model of gastric ulcer. Methods: The systematic review encompassed studies obtained through searches in Web of Science, ScienceDirect, Scopus, and MEDLINE/PubMed, which investigated the effects of isoflavones, tested in isolation, in models of gastric or duodenal ulcer in animals. The risk of bias was assessed using the SYRCLE platform tool. For the experimental study, male Swiss mice (25-35 g) were used. Gastric lesions were induced by acidified ethanol (60% ethanol/0.3 M HCl) in animals pre-treated with Daidzein (10, 30, and 100 mg/kg, p.o.), vehicle (saline + 2% Tween 80), or standard drug (ranitidine 100 mg/kg, p.o.) 60 minutes before induction. The control group (without ulcers) received water instead of acidified ethanol. After 60 min, the percentage of relative ulcerative lesion area (corrected for total stomach area) was measured. Results: Thirteen studies were included out of the 3005 identified with rodents, in models of ulcers induced by ethanol, acetic acid, indomethacin, or stress, in which isoflavones were tested in isolation. The results indicated important benefits associated with the administration of isoflavones, especially as a pretreatment. Most studies demonstrated the effects of genistein and formononetin, but studies with daidzein, osajine, pormiferin, and puerarin were also found. These studies associated the gastroprotective effects of these isoflavones mainly with their ability to reduce oxidative damage and positively regulate the activity of antioxidant enzymes, such as superoxide dismutase and catalase, and reduced glutathione concentrations. Another common characteristic observed in the studies was the reduction in the concentration of pro-inflammatory cytokines, mainly TNF-α and IL-1β, and myeloperoxidase activity. In the experimental study, it was observed that acidified ethanol caused ulcerative lesions (p<0.01 vs. the group that received water) and that pretreatment with ranitidine, but not with daidzein doses, prevented the induction of ulcers (p<0.01). Conclusion: From the review, it was possible to conclude that the studies provide evidence that isoflavones play a protective role against damage to the gastric mucosa caused by various aggressive agents, by producing anti-inflammatory and antioxidant responses. The literature supports the hypothesis that daidzein has a gastroprotective effect; however, its effects have only been investigated at very high doses. Therefore, there are no reports on its action at lower doses, which does not diminish the potential of the isoflavone class as gastroprotective agents.

Análise da suplementação de creatina sobre o dano muscular e a performance em atletas do Powerlifting paralímpico

2026-02-24T00:00:00Z

Título: Análise da suplementação de creatina sobre o dano muscular e a performance em atletas do Powerlifting paralímpico Autor(es): Paixão, Sarah Lisia da Silva Abstract: Creatine monohydrate is the most widely used supplement in the sports field, aiming to improve performance, promote muscle mass gain, and reduce fatigue. It may also exert a protective effect against muscle damage induced by highintensity training. The present study aimed to analyze the short-term effects of creatine supplementation on dynamic strength indicators, muscle temperature, and biomarkers of muscle damage at pre-training, immediately post-training, and 24 h and 48 h after exercise. This is a single-blind crossover study in which participants underwent an upperlimb resistance training program in two experimental conditions: creatine supplementation (20 g/day for seven days) and placebo, both prepared with identical color and flavor. The results indicated that, during exercises performed with a load of 45% of 1RM, creatine supplementation did not promote significant effects on the analyzed variables. In contrast, during training performed at 80% of 1RM, significant effects were observed, particularly for mean propulsive velocity (MPV) and maximal velocity (Vmax), especially in set 2 (MPV: p = 0.013; Vmax: p = 0.023) and set 5 (MPV: p = 0.017). In the analysis of muscle temperature, a significant increase was observed in the pectoralis muscle (clavicular portion) immediately after training (p = 0.049) and after 48 hours (p = 0.038), as well as in the triceps muscle after 24 hours (p = 0.025) and 48 hours (p = 0.022) with supplementation. Regarding tissue damage biomarkers, creatine kinase did not show relevant changes, whereas lactate dehydrogenase presented differences when comparing the placebo group with the supplementation group at the following time points: pre-training (p < 0.001), immediately post-training (p = 0.0007), 24 h post-training (p < 0.001), and 48 h post-training (p < 0.008), suggesting a protective effect of creatine against muscle damage. Significant differences were also observed for aspartate aminotransferase immediately post-training (p = 0.028) and alanine aminotransferase at the pre-training moment (p = 0.048). It can be concluded that creatine supplementation is effective in improving muscle performance, promoting gains in strength and power, and contributing to the prevention of potential injuries, especially when associated with high-intensity exercise.