Papers by Iraci L S Torres
Clinical & Biomedical Research
Introduction: Postmenopausal women are more susceptible to chronic conditions, such as osteoporos... more Introduction: Postmenopausal women are more susceptible to chronic conditions, such as osteoporosis, arthritis, and other inflammatory diseases. We investigated the effects of transcranial direct current stimulation (tDCS) on biomarker levels in ovariectomized rats subjected to an inflammatory model. Methods: Twenty adult female Wistar rats underwent ovariectomy and complete Freund's adjuvant (CFA)-induced inflammation. We divided them into 2 groups: OAS (sham tDCS) and OAT (active tDCS). Fifteen days later, the rats underwent bimodal tDCS treatment (20 min, 0.5 mA, 8 days). After 24 h of the last tDCS session, we killed the rats and collected tissue samples (hypothalamus, cerebral cortex, and brainstem) for biomarker analysis by ELISA. We removed the paws for histological analysis. Results: Active tDCS increased hypothalamic and cortical TNF-α and NGF levels, hypothalamic and brainstem IL-1β levels, and hypothalamic IL-10 levels. Histology of paws showed an inflammatory profile. We observed a small tDCS effect, not statistically significant. Discussion: Bimodal tDCS had an effect on the central inflammatory axis, with a small effect on the peripheral site as evaluated by histology in the current study.
protocols led to 27.26% less pain at the end of treatment compared to sham [95% CI: 15.89% to 32.... more protocols led to 27.26% less pain at the end of treatment compared to sham [95% CI: 15.89% to 32.90%]. Protocol varied in terms of anodal or cathodal stimulation, areas of stimulation, number of sessions and current intensity. Conclusions: In comparison with sham, tDCS demonstrated a superior effect in reducing chronic pain conditions. This gives the perspective that tDCS may be a promising approach to treat refractory chronic pain and to enhance dysfunctional neuronal circuitries involved in the DPIS, improving pain control with a therapeutic opioidfree.
Results: We found 48 articles in PubMed and 95 articles in LILACS, MEDLINE regarding Alexithymia ... more Results: We found 48 articles in PubMed and 95 articles in LILACS, MEDLINE regarding Alexithymia in fibromyalgia. For these findings support the need for further study. These difficulties in the processing of emotional information, discrimination of different emotional states and visceral proprioception of physiological manifestations associated with the emotional activation of alexithymia are present in fibromyalgia. For in alexithymia the two cerebral hemispheres altered by these symptoms that affect the affective modulation, being this region rich in dopaminergic receptors that make neuronal connection with motivational limbic system. These regions when injured or underactive alter emotional perception, decision making, planning and initiative. This review of studies will serve as a facilitator for the development of psychological treatments as well as viable neuromodulatory targets in the fibromyalgia process. Conclusion: Although the etiology of fibromyalgia is unclear, intervention with tDCS in the dopaminergic receptor-rich prefrontal cortex regions supports possible future tDCS interventions.
Clinical & Biomedical Research, Jul 11, 2022
Introduction: Considering the lack of specific treatments for neuropathic pain, this study aimed ... more Introduction: Considering the lack of specific treatments for neuropathic pain, this study aimed to evaluate the effect of a single dose of adenosine A 3 receptor IB-MECA on inflammatory and neurotrophic parameters in rats subjected to a neuropathic pain model. Methods: 64 adult male Wistar rats were used. Neuropathic pain was induced by chronic constriction injury (CCI) of the sciatic nerve and the treatment consisted of a 0.5 μmol/kg dose of IB-MECA, a selective A 3 adenosine receptor agonist, dissolved in 3% DMSO; vehicle groups received DMSO 3% in saline solution, and morphine groups received 5 mg/kg. Cerebral cortex and hippocampus IL-1β, BDNF, and NGF levels were determined by Enzyme-Linked Immunosorbent assay. Results: The main outcome was that a single dose of IB-MECA was able to modulate the IL-1β hippocampal levels in neuropathic pain induced by CCI and the DMSO increased IL-1β and NGF hippocampal levels in sham-operated rats. However, we did not observe this effect when the DMSO was used as vehicle for IB-MECA, indicating that IB-MECA was able to prevent the effect of DMSO. Conclusions: Considering that the IL-1β role in neuropathic pain and the contributions of the hippocampus are well explored, our result corroborates the relationship between the A 3 receptor and the process of chronic pain maintenance.
Journal of Visualized Experiments, Jul 14, 2018
Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation (NIBS) method,... more Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation (NIBS) method, which modulates the membrane potential of neurons in the cerebral cortex by a low-intensity direct current. tDCS is a low-cost technique with minimal adverse effects and easy application. This neurostimulation method has a promising future to improve pain therapy, treatment of neuropsychiatric disorders, and physical rehabilitation. Current studies demonstrate the benefits of using tDCS over consecutive multiple sessions. However, the daily displacement to the specialized centers, travel costs, and disruptions to daily activities are some of the difficulties faced by patients. Thus, to be more comfortable, easy-to-use, and not disrupt daily commitments, a home-based tDCS was designed. Therefore, the objective of this study was to evaluate the feasibility of a portable tDCS device for home use in healthy subjects and fibromyalgia patients. Despite increased tDCS use and a reasonably large body of research on the effects across a range of clinical conditions, there is a limited amount of research on developing secure devices that guarantee the dose and contain a block system to avoid excessive use. Therefore, we used a tDCS device with a security system to permit daily use for 20 minutes with a minimal interval of 12 hours between sessions. A programmer preconfigures the equipment, which has a neoprene cap that allows the electrode positions in any assembly, according to individualized protocols for treatments or research. After, researchers can assess the effectiveness of treatment, and its adherence using information kept in the device software. Results suggest that the device is feasible for home use, with proper monitoring of adherence and contact impedance. There were reports of a few adverse effects, which do not differ from those reported in the literature in studies with the treatment under direct supervision.
PLOS ONE, May 27, 2022
Introduction The association between descending pain modulatory system (DPMS) dysfunction and fib... more Introduction The association between descending pain modulatory system (DPMS) dysfunction and fibromyalgia has been previously described, but more studies are required on its relationship with aberrant functional connectivity (FC) between the motor and prefrontal cortices. Objectives The objective of this cross-sectional observational study was to compare the intra-and interhemispheric FC between the bilateral motor and prefrontal cortices in women with fibromyalgia, comparing responders and nonresponders to the conditioned pain modulation (CPM) test. Methods A cross-sectional sample of 37 women (23 responders and 14 nonresponders to the CPM test) with fibromyalgia diagnosed according to the American College of Rheumatology criteria underwent a standardized clinical assessment and an FC analysis using functional nearinfrared spectroscopy. DPMS function was inferred through responses to the CPM test, which were induced by hand immersion in cold water (0-1˚C). A multivariate analysis of covariance for main effects between responders and nonresponders was conducted using the diagnosis of multiple psychiatric disorders and the use of opioid and nonopioid analgesics as covariates. In addition, we analyzed the interaction between the CPM test response and the presence of multiple psychiatric diagnoses.
Research Square (Research Square), Apr 7, 2023
Brain areas and oscillations have been pointed out as markers of chronic pain. We used electroenc... more Brain areas and oscillations have been pointed out as markers of chronic pain. We used electroencephalography (EEG) to compare the linear and non-linear connectivity of regions of interest (ROIs) related to the pain matrix in people with bromyalgia (FM) and healthy controls (HC). Sixty-four women (49 FM and 15 HC) volunteered to participate in a resting-state EEG session with eyes open (EO) and eyes closed (EC), as well as clinical, psychological, and serum brain-derived neurotrophic factor (BDNF). The connectivity of 10 ROIs was computed for 7 different EEG frequencies. In EC conditions, FM exhibits decreased non-linear connectivity in the beta-2 band between the right-insula and left mPFC (F=-4.09, p = .035). Considering the differences between EO and EC, FM present increased linear connectivity between the left insula and right thalamus in the beta-3 band (F = 3.46, p = .009) and increased non-linear connectivity between the right insula and left medial prefrontal cortex (mPFC) in the beta-2 band (F = 3.78, p = .025). These results mainly indicate the insula role in different circuits in FM and highlight the beta oscillations activity. Insular brain connectivity at rest could be an objective biomarker of how pain is processed, and it is related to the severity of clinical symptoms in bromyalgia.
Anticancer Research, Apr 1, 2023
Background/aim: Central nervous system cancer is still a major public health issue. The effective... more Background/aim: Central nervous system cancer is still a major public health issue. The effectiveness of treatments is limited and varies depending on the severity of disease. Therefore, there is a demand for the development of novel therapies. Static magnetic stimulation (SMS) emerges as a new therapeutic option. The aim of this study was to evaluate the SMS effects on neuroblastoma cells in culture. Materials and methods: SH-SY5Y neuroblastoma cells were exposed to 0.3T SMS for 6, 12, 24, 36, 72 h, and 6 days. Cell viability (MTT), cell death (annexin-V/PI staining) and cell cycle (DNA content), cell proliferation (CFSE), autophagy (acridine orange), and total mitochondrial mass (MitoTracker™ Red) were analyzed to establish the cellular response to SMS. Results: The viability of SH-SY5Y cells was reduced after exposure to SMS for 24 h and 6 days (p<0.05), without differences for the other times (p>0.05); however, this effect was not related to cell death or cell cycle arrest (p>0.05). In contrast, the viability of human malignant melanoma (HMV-II) cells, used as a tumoral control, was not affected. In addition, stimulated SH-SY5Y cells presented a decrease in mitochondrial mass at both exposure times and a reduction in autophagy and cell proliferation after 6 days (p<0.05). Conclusion: SMS application appears to be a promising adjuvant therapy for the treatment of neuroblastoma since it decreases the survival of SH-SY5Y neuroblastoma cells.
Clinical & Biomedical Research
Introduction: Considering the lack of specific treatments for neuropathic pain, this study aimed ... more Introduction: Considering the lack of specific treatments for neuropathic pain, this study aimed to evaluate the effect of a single dose of adenosine A 3 receptor IB-MECA on inflammatory and neurotrophic parameters in rats subjected to a neuropathic pain model. Methods: 64 adult male Wistar rats were used. Neuropathic pain was induced by chronic constriction injury (CCI) of the sciatic nerve and the treatment consisted of a 0.5 μmol/kg dose of IB-MECA, a selective A 3 adenosine receptor agonist, dissolved in 3% DMSO; vehicle groups received DMSO 3% in saline solution, and morphine groups received 5 mg/kg. Cerebral cortex and hippocampus IL-1β, BDNF, and NGF levels were determined by Enzyme-Linked Immunosorbent assay. Results: The main outcome was that a single dose of IB-MECA was able to modulate the IL-1β hippocampal levels in neuropathic pain induced by CCI and the DMSO increased IL-1β and NGF hippocampal levels in sham-operated rats. However, we did not observe this effect when the DMSO was used as vehicle for IB-MECA, indicating that IB-MECA was able to prevent the effect of DMSO. Conclusions: Considering that the IL-1β role in neuropathic pain and the contributions of the hippocampus are well explored, our result corroborates the relationship between the A 3 receptor and the process of chronic pain maintenance.
Journal of Basic and Applied Pharmaceutical Sciencies, 2015
The objective of this study was to evaluate the long term nociceptive response determined by use ... more The objective of this study was to evaluate the long term nociceptive response determined by use of two general anesthetics, one intravenous and the other inhalatory, in young animals. In the first experiment, the animals of 21 days of age were divided into control (saline) and thiopental (35 mg/kg, i.p.) groups. In the second experiment, rats of the same age were divided in two groups – halothane (2%) and control. In experiment 1, there was difference between groups – reduction of tail-flick latency in the group thiopental (P 0.05; F(1,19)=0.032 for the interaction, P>0.05). The results obtained in this study showed that halothane did not alter the nociceptive response in young animals. However, the thiopental induced hyperalgesic response in rats. Key words: Rats. Sodium thiopental. Halothane. Nociception. Tail flick latency. RESUMO O objetivo desse estudo foi avaliar a resposta nociceptiva a longo prazo relacionada ao uso de dois anestesicos gerais – um intravenoso e outro ina...
Features and Assessments of Pain, Anaesthesia, and Analgesia, 2022
Ultra-processed food consumption, which is highly palatable, rich in fat, sugar, and salt causes ... more Ultra-processed food consumption, which is highly palatable, rich in fat, sugar, and salt causes uncontrolled food intake and has contributed to a sharp increase in obesity worldwide. This study evaluated the effects of soft drink and/or ultra-processed food intake on eating behavior and metabolic parameters in rats fed with a cafeteria diet. Male Wistar rats were divided into six groups. 1) CON: standard chow and water; 2) CD: cafeteria diet, standard chow, and water; 3) CS: caloric soft drink, standard chow, and water; 4) NCS: non-caloric soft drink, standard chow, and water; 5) CD + CS: cafeteria diet, caloric soft drink, standard chow, and water; and 6) CD + NCS: cafeteria diet, non-caloric soft drink, standard chow, and water. The cafeteria diet intake resulted in higher energy consumption (30% increase on average), a 450% increase in lipid consumption, and a 50% reduction in protein intake, which contributed to a 60% increase in body weight relative to the controls. This diet ...
The Thoracic and Cardiovascular Surgeon, 2009
The overproduction of reactive oxygen species plays an important role in the cascade of events du... more The overproduction of reactive oxygen species plays an important role in the cascade of events during lung ischemia-reperfusion leading to graft failure. An evaluation of the peripheral markers of oxidative stress and antioxidant enzyme activities was carried out after reperfusion in a rat lung transplant model. The decrease in lipid peroxidation immediately after transplantation ( P < 0.05) may suggest an adaptative response and/or a protective effect of low potassium dextran against lipid peroxidation through natural scavenging mechanisms.
NeuroImage, 2010
Preliminary positive results of transcranial direct current stimulation (tDCS) in enhancing the e... more Preliminary positive results of transcranial direct current stimulation (tDCS) in enhancing the effects of cognitive and motor training indicate this technique might also be beneficial in traumatic brain injury or patients who had decompressive craniectomy for trauma and cerebrovascular disease. One perceived hurdle is the presence of skull defects or skull plates in these patients that would hypothetically alter the intensity and location of current flow through the brain. We aimed to model tDCS using a magnetic resonance imaging (MRI)-derived finite element head model with several conceptualized skull injuries. Cortical electric field (current density) peak intensities and distributions were compared with the healthy (skull intact) case. The factors of electrode position (C3-supraorbital or O1-supraorbital), skull defect size, skull defect state (acute and chronic) or skull plate (titanium and acrylic) were analyzed. If and how electric current through the brain was modulated by defects was found to depend on a specific combination of factors. For example, the condition that led to largest increase in peak cortical electric field was when one electrode was placed directly over a moderate sized skull defect. In contrast, small defects midway between electrodes did not significantly change cortical currents. As the conductivity of large skull defects/plates was increased (chronic to acute to titanium), current was shunted away from directly underlying cortex and concentrated in cortex underlying the defect perimeter. The predictions of this study are the first step to assess safety of transcranial electrical therapy in subjects with skull injuries.
eP2124 Exercício físico e estimulação transcraniana por corrente contínua (ETCC) modulam os nívei... more eP2124 Exercício físico e estimulação transcraniana por corrente contínua (ETCC) modulam os níveis de Interleucina-4 no córtex cerebral de ratos submetidos a um modelo de dor neuropática
International Journal of Developmental Neuroscience, 2020
Objectives: Caffeine is extensively consumed as a psychostimulant drug, acting on A 1 and A 2A ad... more Objectives: Caffeine is extensively consumed as a psychostimulant drug, acting on A 1 and A 2A adenosine receptors blockade. Chronic exposure to caffeine during gestation and breast-feeding may be involved in infant rat's behavioral and biochemical alterations. Our goal was to evaluate the effect of chronic caffeine exposure during gestation and breast-feeding in the functionality of adenosine A 1 receptors in infant rats at P14. NTPDase and 5'-nucleotidase activities were also evaluated. Methods: Mating of adult female Wistar rats was confirmed by presence of sperm in vaginal smears. Rats were divided into three groups on the first day of pregnancy: (1) control: tap water, (2) caffeine: 0.3 g/L until P14, and (3) washout caffeine: caffeine was changed to tap water at P7. Evaluation of nociceptive response was performed at P14 using hot plate (HP) and tail-flick latency (TFL) tests. A 1 receptor involvement was assessed using caffeine agonist (CPA) and antagonist (DPCPX). Enzymatic activities assays were conducted in the spinal cord. Results: Gestational and breastfeeding exposure to caffeine (caffeine and washout groups) did not induce significant alterations in thermal nociceptive thresholds (HP and TF tests). Both caffeine groups did not show analgesic response induced by CPA when compared to the control group at P14, indicating chronic exposure to caffeine in the aforementioned periods inhibits the antinociceptive effects of the systemic A 1 receptor agonist administration. No effect was observed upon ectonucleotidase activities. How to cite this article: Torres ILS, Assumpção JAF, de Souza A, et al. Effects of gestational and breastfeeding caffeine exposure in adenosine A1 agonist-induced antinociception of infant rats.
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Papers by Iraci L S Torres