Resultados de Busca

Agora exibindo 1 - 5 de 5
  • Item
    Estimation of the DNA damage in Girardia tigrina (Girard, 1850) after exposure to radiation under extreme conditions
    (Brazilian Journals Publicações de Periódicos) Benitz, Tabatha; Oliveira, Matheus Salgado de; Lopes, Karla Andressa Ruiz; Soares, Cristina Pacheco; Morais, Flavia Villaça; Velho, Nádia Maria Rodrigues de Campos
    The use of planarians as experimental models has been increased worldwide especially due to their high capacity of tissue regeneration and ease of laboratory maintenance. The current study aims to assess the genetic damage of Girardia tigrina after exposure of stressors in conditions such as: critical temperature, critical pH, hypergravity (4.4G) and low power laser (685nm). 18 specimens of G. tigrina were used, the extreme conditions mentioned were experimental group with 3 specimens each, and 3 for the control group, all specimens were submitted to the Comet Assay after exposure of stressors, and control group with no extreme condition exposure. The extreme stimuli of critical temperature and pH, hypergravity and low power laser irradiation, caused genetic damages to the G. tigrina, for hypergravity and low-power laser stressors the damage was higher in the pharyngeal and post-pharyngeal regions of the animal with a greatest area of comet tail dragging for the post-pharyngeal region. The extreme stimuli of critical temperature and pH, hypergravity and low power laser irradiation caused genetic damages in planarians Brazilian Journal of Development ISSN: 2525-8761 12160 Brazilian Journal of Development, Curitiba, v.8, n.2, p.12159-12177 feb. 2022. G. tigrina, especially in samples from the pharyngeal and post-pharyngeal regions of the flatworms body assessed by the Comet Assay.
  • Item
    Performance of Multiplex Detection Method of IgM Class Antibodies against Toxoplasma gondii, Rubella and Human Cytomegalovirus
    (JSciMed Central) Almeida, Rainara Moreno Sanches de; Ogawa, Guilherme Maerschner; Custódio, Paulo Rogério Siqueira; Sampaio, Maria Alcantara Socorro; Silva, Newton Soares da; Soares, Cristina Pacheco
    Serological diagnosis during neonatal screening is crucial in disease prevention. Among the infectious diseases, the most common are toxoplasmosis, rubella, and cytomegalovirus. Traditional diagnostic methods are used to detect a single infectious agent per test. The use of multiplex detection methods increases productivity and reduces the amount of material used, resulting in a more efficient test from a technical, environmental, and economic point of view. The study’s objective was to evaluate the performance of a new diagnostic method aimed at neonatal screening using the multiplex platform of magnetic microspheres from the company Luminex Corporation. For this, tests were carried out for analytical validation of the diagnostic product developed following the rules of the National Health Surveillance Agency (ANVISA) of Brazil. The parameters evaluated were repeatability, reproducibility, linearity, robustness, high dose, minimum detection limit, and analytical specificity. All data obtained met the acceptance criteria of RDC 166/17 of 2017 for the use of the diagnostic product in the national territory. Repeatability and reproducibility tests showed a CV of less than 15% between replicates of the same operator and different operators. The kit showed linearity throughout the operating range with R2 above 0.990, and no effect of high-efficiency dose was observed in the chosen working dilution. In addition, the kit did not show interference from the matrix with the results, and it was observed that small and deliberate changes in the incubation time of each reagent did not have a significant effect on the data obtained.
  • Item
    Influence of Hydrocortisone in Chemotherapy and Photodynamic Therapy in HEp-2 Cells
    (Clinics in Oncology) Moraes, Carlos Dailton Guedes de Oliveira; Godoi, Bruno Henrique; Silva, Newton Soares da; Soares, Cristina Pacheco
    Aim: Cancer cells exhibit resistance to the immune response by regulating and altering the expression of mediators responsible for immune cell recruitment and disease progression. Cortisol is a natural hormone that may be associated with diseases such as cancer by stimulating stress and altering the cellular environment, favoring uncontrolled division and contributing to the inhibition of the immune response. In contrast, current therapeutic strategies do not present significant concerns about stress as a variable in cancer diagnosis and prognosis. The response of HEp-2 cells to stress induced by hydrocortisone and to treatment with Cyclophosphamide (CP) and Photodynamic Therapy (PDT) was analyzed. Methods: One mM of hydrocortisone induced stress in the cells. Cells were treated with 200 μg/ mL of cyclophosphamide or Aluminum Phthalocyanine Tetrasulfonate (AlPcS4) photosensitizer, LED irradiation (660 nm wavelength), intensity of 25 mW/cm2, power of 70 mW, fluence of 5 J/ cm2, characterizing the PDT. All groups were evaluated after 24 h and 48 h. Results: Assessment of stress-inducing mitochondrial activity and cell viability were performed, and the results demonstrated that hydrocortisone significantly altered the rate of cell death, compromising the effects of CP. Conclusion: However, hydrocortisone did not change the cell death rates caused by PDT, indicating the possibility of this hormone as an alternative therapy.
  • Item
    Biomodulatory effect of low intensity laser (830 nm.) in neural model 9L/lacZ
    (CDRR Editor) Zabeu, Antonieta Marques Caldeira; Carvalho, Isabel Chaves Silva; Soares, Cristina Pacheco; Silva, Newton Soares da
    Currently, research is advancing with low-intensity laser (LIL) in cells of the central nervous system, with the aim of evaluating the benefits of this therapy in neurological disorders such as Alzheimer's, stroke, ischemia, epilepsy, among others. The aim of this study was to verify the biomodulatory and biostimulatory effects of LIL in neural cell culture. Diode laser at wavelength λ = 830 nm, power 40 mW, in continuous mode, was applied on the 9L/lacZ cell line with energy densities of 0.5 to 3 J/cm . The analysis was performed 24 hours after irradiation, the results of cell viability showed a difference between the control and irradiated groups. As for the occurrence of apoptosis, no significant manifestation was observed between the control group compared to the irradiated group (P = 0.9956); there was a significant difference between apoptosis and death by necrosis between the control and treated groups (P<0.001). In the comet assay no statistically significant differences were observed. Regarding the objective of evaluating whether LIL promotes early activation of apoptosis or proliferation of 9L/lacZ cells at different energy densities of the infrared diode laser, we observed an increase in the number of neural cells, highlighting the action of biomodulation. Furthermore, LIL did not promote the activation of programmed cell death - apoptosis and did not show any indication of DNA damage by the comet assay. The results of this study are indicative that the laser in the near infrared has a positive interaction with neuronal cells.
  • Item
    Neuroprotective effects of taurine on SH-SY5Y cells under hydrocortisone induced stress
    (CDRR Editors) Rossato, Rafaella Carvalho; Granato, Alessandro Eustaquio Campos; Moraes, Carlos Dailton Guedes de Oliveira; Salles, Geisa Nogueira; Soares, Cristina Pacheco
    Alzheimer's disease (AD) is the most common, progressive and irreversible neurodegenerative disorder, characterized by memory loss, cognitive impairment and behavioral abnormalities. Although there is no cure, several study strategies seek to elucidate mechanisms of the disease. Recent studies address the benefits of taurine. Thus, the present study aims to analyze neuroprotective effects of taurine in human neuroblastoma (SH-SY5Y), using an in vitro experimental model of oxidative stress induced by hydrocortisone. This work showed for the first time that taurine can promote neuroprotection in SH-SY5Y under oxidative stress caused by hydrocortisone. Cell viability was evaluated using crystal violet and the evaluation of cell morphology was performed by scanning electron microscopy (SEM). The viability of SH-SY5Y pre-treated with taurine and stressed with hydrocortisone was preserved, compared to the stressed only group, which was also morphologically observed. Therefore, taurine can represent a considerable therapeutic candidate in the prevention of neurodegenerative diseases, such as AD.