76
|
Hamerschlak N, Rodrigues M, Moraes DA, Oliveira MC, Stracieri ABPL, Pieroni F, Barros GMN, Madeira MIA, Simões BP, Barreira AA, Brum DG, Ribeiro AAF, Kutner JM, Tylberi CP, Porto PP, Santana CL, Neto JZ, Barros JC, Paes AT, Burt RK, Oliveira EA, Mastropietro AP, Santos AC, Voltarelli JC. Brazilian experience with two conditioning regimens in patients with multiple sclerosis: BEAM/horse ATG and CY/rabbit ATG. Bone Marrow Transplant 2009; 45:239-48. [DOI: 10.1038/bmt.2009.127] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
77
|
Roriz‐Filho JS, Roriz ST, Foss MP, Foss‐Freitas MC, Ferriolli E, Lima NK, Santos AC, Moriguti JC. IC‐P‐118: Correlation between Alzheimer's disease, pre‐diabetes and diabetes mellitus evaluated by quantitative magnetic resonance imaging. Alzheimers Dement 2009. [DOI: 10.1016/j.jalz.2009.05.090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
78
|
Franco R, Nascimento HF, Cruz AA, Santos AC, Souza-Machado C, Ponte EV, Souza-Machado A, Rodrigues LC, Barreto ML. The economic impact of severe asthma to low-income families. Allergy 2009; 64:478-83. [PMID: 19210355 DOI: 10.1111/j.1398-9995.2009.01981.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND To estimate the direct and indirect costs of severe asthma and the economic impact of its management to low-income families in Salvador, Brazil. METHODS One hundred and ninety-seven patients with severe asthma and referred to a state-funded asthma center providing free treatment were evaluated. At registration, they were asked about family cost-events in the previous year and had a baseline assessment of lung function, symptoms and quality of life. During the subsequent year, they were reassessed prospectively. RESULTS One hundred-eighty patients concluded a 12-month follow-up. Eighty-four percent were female patients, and the median family income was US$ 2955/year. Forty-seven percent of family members had lost their jobs because of asthma. Total cost of asthma management took 29% of family income. After proper treatment, asthma control scores improved by 50% and quality of life by 74%. The income of the families increased by US$ 711/year, as their members went back to work. The total cost of asthma to the families was reduced by a median US$ 789/family/year. Consequently, an annual surplus of US$ 1500/family became available. CONCLUSIONS Family costs of severe asthma consumed over one-fourth of the family income of the underprivileged population in a middle-income country. Adequate management brings major economic benefit to individuals and families.
Collapse
|
79
|
Mamere AE, Saraiva LAL, Matos ALM, Carneiro AAO, Santos AC. Evaluation of delayed neuronal and axonal damage secondary to moderate and severe traumatic brain injury using quantitative MR imaging techniques. AJNR Am J Neuroradiol 2009; 30:947-52. [PMID: 19193759 DOI: 10.3174/ajnr.a1477] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Traumatic brain injury (TBI) is a classic model of monophasic neuronal and axonal injury, in which tissue damage mainly occurs at the moment of trauma. There is some evidence of delayed progression of the neuronal and axonal loss. Our purpose was to test the hypothesis that quantitative MR imaging techniques can estimate the biologic changes secondary to delayed neuronal and axonal loss after TBI. MATERIALS AND METHODS Nine patients (age, 11-28 years; 5 male) who sustained a moderate or severe TBI were evaluated at a mean of 3.1 years after trauma. We applied the following techniques: bicaudate (BCR) and bifrontal (BFR) ventricle-to-brain ratios; T2 relaxometry; magnetization transfer ratio (MTR); apparent diffusion coefficient (ADC); and proton spectroscopy, by using an N-acetylaspartate/creatine (NAA/Cr) ratio measured in normal-appearing white matter (NAWM) and the corpus callosum (CC). The results were compared with those of a control group. RESULTS BCR and BFR mean values were significantly increased (P < or = .05) in patients due to secondary subcortical atrophy; increased T2 relaxation time was observed in the NAWM and CC, reflecting an increase in water concentration secondary to axonal loss. Increased ADC mean values and reduced MTR mean values were found in the NAWM and CC, showing damage in the myelinated axonal fibers; and decreased NAA/Cr ratio mean values were found in the CC, indicating axonal loss. CONCLUSIONS These quantitative MR imaging techniques could noninvasively demonstrate the neuronal and axonal damage in the NAWM and CC of human brains, secondary to moderate or severe TBI.
Collapse
|
80
|
S Roriz-Filho J, Sá-Roriz TM, Rosset I, Camozzato AL, Santos AC, Chaves MLF, Moriguti JC, Roriz-Cruz M. (Pre)diabetes, brain aging, and cognition. Biochim Biophys Acta Mol Basis Dis 2008; 1792:432-43. [PMID: 19135149 DOI: 10.1016/j.bbadis.2008.12.003] [Citation(s) in RCA: 239] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2008] [Revised: 12/08/2008] [Accepted: 12/08/2008] [Indexed: 12/14/2022]
Abstract
Cognitive dysfunction and dementia have recently been proven to be common (and underrecognized) complications of diabetes mellitus (DM). In fact, several studies have evidenced that phenotypes associated with obesity and/or alterations on insulin homeostasis are at increased risk for developing cognitive decline and dementia, including not only vascular dementia, but also Alzheimer's disease (AD). These phenotypes include prediabetes, diabetes, and the metabolic syndrome. Both types 1 and 2 diabetes are also important risk factors for decreased performance in several neuropsychological functions. Chronic hyperglycemia and hyperinsulinemia primarily stimulates the formation of Advanced Glucose Endproducts (AGEs), which leads to an overproduction of Reactive Oxygen Species (ROS). Protein glycation and increased oxidative stress are the two main mechanisms involved in biological aging, both being also probably related to the etiopathogeny of AD. AD patients were found to have lower than normal cerebrospinal fluid levels of insulin. Besides its traditional glucoregulatory importance, insulin has significant neurothrophic properties in the brain. How can clinical hyperinsulinism be a risk factor for AD whereas lab experiments evidence insulin to be an important neurothrophic factor? These two apparent paradoxal findings may be reconciliated by evoking the concept of insulin resistance. Whereas insulin is clearly neurothrophic at moderate concentrations, too much insulin in the brain may be associated with reduced amyloid-beta (Abeta) clearance due to competition for their common and main depurative mechanism - the Insulin-Degrading Enzyme (IDE). Since IDE is much more selective for insulin than for Abeta, brain hyperinsulinism may deprive Abeta of its main clearance mechanism. Hyperglycemia and hyperinsulinemia seems to accelerate brain aging also by inducing tau hyperphosphorylation and amyloid oligomerization, as well as by leading to widespread brain microangiopathy. In fact, diabetes subjects are more prone to develop extense and earlier-than-usual leukoaraiosis (White Matter High-Intensity Lesions - WMHL). WMHL are usually present at different degrees in brain scans of elderly people. People with more advanced WMHL are at increased risk for executive dysfunction, cognitive impairment and dementia. Clinical phenotypes associated with insulin resistance possibly represent true clinical models for brain and systemic aging.
Collapse
|
81
|
Pestana CR, Phelippin DPS, Polizello ACM, Dorta DJ, Uyemura SA, Santos AC, Doro FG, Rodrigues FP, Tfouni E, Curti C. Effects on mitochondria of mitochondria-induced nitric oxide release from a ruthenium nitrosyl complex. Nitric Oxide 2008; 20:24-30. [PMID: 18950724 DOI: 10.1016/j.niox.2008.10.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2008] [Revised: 09/09/2008] [Accepted: 10/01/2008] [Indexed: 10/21/2022]
Abstract
The ruthenium nitrosyl complex trans-[Ru(NO)(NH(3))(4)(py)](PF(6))(3) (pyNO), a nitric oxide (NO) donor, was studied in regard to the release of NO and its impact both on isolated mitochondria and HepG2 cells. In isolated mitochondria, NO release from pyNO was concomitant with NAD(P)H oxidation and, in the 25-100 microM range, it resulted in dissipation of mitochondrial membrane potential, inhibition of state 3 respiration, ATP depletion and reactive oxygen species (ROS) generation. In the presence of Ca(2+), mitochondrial permeability transition (MPT), an unspecific membrane permeabilization involved in cell necrosis and some types of apoptosis, was elicited. As demonstrated by externalization of phosphatidylserine and activation of caspase-9 and caspase-3, pyNO (50-100 microM) induced HepG2 cell death, mainly by apoptosis. The combined action of the NO itself, the peroxynitrite yielded by NO in the presence of reactive oxygen species (ROS) and the oxidative stress generated by the NAD(P)H oxidation is proposed to be involved in cell death by pyNO, both via respiratory chain inhibition and ROS levels increase, or even via MPT, if Ca(2+) is present.
Collapse
|
82
|
Koenigkam-Santos M, Santos AC, Borduqui T, Versiani BR, Hallak JEC, Crippa JAS, Castro M. Whole-brain voxel-based morphometry in Kallmann syndrome associated with mirror movements. AJNR Am J Neuroradiol 2008; 29:1799-804. [PMID: 18768731 DOI: 10.3174/ajnr.a1202] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND AND PURPOSE There are 2 main hypotheses concerning the cause of mirror movements (MM) in Kallmann syndrome (KS): abnormal development of the primary motor system, involving the ipsilateral corticospinal tract; and lack of contralateral motor cortex inhibitory mechanisms, mainly through the corpus callosum. The purpose of our study was to determine white and gray matter volume changes in a KS population by using optimized voxel-based morphometry (VBM) and to investigate the relationship between the abnormalities and the presence of MM, addressing the 2 mentioned hypotheses. MATERIALS AND METHODS T1-weighted volumetric images from 21 patients with KS and 16 matched control subjects were analyzed with optimized VBM. Images were segmented and spatially normalized, and these deformation parameters were then applied to the original images before the second segmentation. Patients were divided into groups with and without MM, and a t test statistic was then applied on a voxel-by-voxel basis between the groups and controls to evaluate significant differences. RESULTS When considering our hypothesis a priori, we found that 2 areas of increased gray matter volume, in the left primary motor and sensorimotor cortex, were demonstrated only in patients with MM, when compared with healthy controls. Regarding white matter alterations, no areas of altered volume involving the corpus callosum or the projection of the corticospinal tract were demonstrated. CONCLUSION The VBM study did not show significant white matter changes in patients with KS but showed gray matter alterations in keeping with a hypertrophic response to a deficient pyramidal decussation in patients with MM. In addition, gray matter alterations were observed in patients without MM, which can represent more complex mechanisms determining the presence or absence of this symptom.
Collapse
|
83
|
Dorta DJ, Pigoso AA, Mingatto FE, Rodrigues T, Pestana CR, Uyemura SA, Santos AC, Curti C. Antioxidant activity of flavonoids in isolated mitochondria. Phytother Res 2008; 22:1213-8. [DOI: 10.1002/ptr.2441] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
84
|
Lopes MA, Litvoc J, Furtado EF, Santos AC, Bottino CM. P4‐088: Community‐based prevalence of structural brain changes in dementia and cognitively impaired nondemented elderly from Brazil. Alzheimers Dement 2008. [DOI: 10.1016/j.jalz.2008.05.2153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
85
|
Martins NM, Santos NAG, Curti C, Bianchi MLP, Santos AC. Cisplatin induces mitochondrial oxidative stress with resultant energetic metabolism impairment, membrane rigidification and apoptosis in rat liver. J Appl Toxicol 2008; 28:337-44. [PMID: 17604343 DOI: 10.1002/jat.1284] [Citation(s) in RCA: 143] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Cisplatin is a potent and widely used chemotherapeutic agent. Nephrotoxicity induced by this drug has been well documented. However, very little information is available on cisplatin-induced hepatotoxicity and its underlying mechanism remains unclear. High doses of cisplatin have been known to produce hepatotoxicity. Additionally, elevated expression of CYP 2E1 has been associated with enhanced cisplatin-induced hepatotoxicity. Several studies suggest that cisplatin toxicity occurs by the increased generation of reactive oxygen species (ROS) in mitochondria. Therefore, the present study examined, in vivo, the cisplatin-induced effects on hepatic mitochondrial structure and function as well as the occurrence of hepatocellular death by apoptosis. Adult male Wistar rats (200-220 g) were divided into two groups (n=8) treated as follows: (1) control group (saline solution, 1 ml 100 g(-1) body weight, i.p.) and (2) cisplatin group (10 mg kg(-1) body weight, i.p.). The animals were killed 72 h after the treatment. Hepatotoxicity was evidenced in the cisplatin group by the increased serum levels of alanine (ALT) and aspartate (AST) aminotransferases. The mechanism of cisplatin-induced hepatotoxicity was found to involve membrane rigidification; decreased GSH/GSSG ratio, ATP, GSH and NADPH levels; lipid peroxidation; oxidative damage of cardiolipin and protein sulfhydryl groups. Moreover, cell death by apoptosis was also demonstrated and the findings strongly suggest the participation of the mitochondrial signaling pathway in this process. Therefore, the results show the key role of mitochondria in the hepatotoxicity induced by cisplatin and delineate several mitochondrial processes that could be targeted in future cytoprotective therapy approaches.
Collapse
|
86
|
Martins NM, Santos NAG, Curti C, Bianchi MLP, Santos AC. Cisplatin induces mitochondrial oxidative stress with resultant energetic metabolism impairment, membrane rigidification and apoptosis in rat liver. J Appl Toxicol 2008. [PMID: 17604343 DOI: 10.1002/jat.1284.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Cisplatin is a potent and widely used chemotherapeutic agent. Nephrotoxicity induced by this drug has been well documented. However, very little information is available on cisplatin-induced hepatotoxicity and its underlying mechanism remains unclear. High doses of cisplatin have been known to produce hepatotoxicity. Additionally, elevated expression of CYP 2E1 has been associated with enhanced cisplatin-induced hepatotoxicity. Several studies suggest that cisplatin toxicity occurs by the increased generation of reactive oxygen species (ROS) in mitochondria. Therefore, the present study examined, in vivo, the cisplatin-induced effects on hepatic mitochondrial structure and function as well as the occurrence of hepatocellular death by apoptosis. Adult male Wistar rats (200-220 g) were divided into two groups (n=8) treated as follows: (1) control group (saline solution, 1 ml 100 g(-1) body weight, i.p.) and (2) cisplatin group (10 mg kg(-1) body weight, i.p.). The animals were killed 72 h after the treatment. Hepatotoxicity was evidenced in the cisplatin group by the increased serum levels of alanine (ALT) and aspartate (AST) aminotransferases. The mechanism of cisplatin-induced hepatotoxicity was found to involve membrane rigidification; decreased GSH/GSSG ratio, ATP, GSH and NADPH levels; lipid peroxidation; oxidative damage of cardiolipin and protein sulfhydryl groups. Moreover, cell death by apoptosis was also demonstrated and the findings strongly suggest the participation of the mitochondrial signaling pathway in this process. Therefore, the results show the key role of mitochondria in the hepatotoxicity induced by cisplatin and delineate several mitochondrial processes that could be targeted in future cytoprotective therapy approaches.
Collapse
|
87
|
Uchida RR, Del-Ben CM, Busatto GF, Duran FLS, Guimarães FS, Crippa JAS, Araújo D, Santos AC, Graeff FG. Regional gray matter abnormalities in panic disorder: a voxel-based morphometry study. Psychiatry Res 2008; 163:21-9. [PMID: 18417322 DOI: 10.1016/j.pscychresns.2007.04.015] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2006] [Revised: 01/05/2007] [Accepted: 04/23/2007] [Indexed: 11/26/2022]
Abstract
Although abnormalities in brain structures involved in the neurobiology of fear and anxiety have been implicated in the pathophysiology of panic disorder (PD), relatively few studies have made use of voxel-based morphometry (VBM) magnetic resonance imaging (MRI) to determine structural brain abnormalities in PD. We have assessed gray matter volume in 19 PD patients and 20 healthy volunteers using VBM. Images were acquired using a 1.5 T MRI scanner, and were spatially normalized and segmented using optimized VBM. Statistical comparisons were performed using the general linear model. A relative increase in gray matter volume was found in the left insula of PD patients compared with controls. Additional structures showing differential increases were the left superior temporal gyrus, the midbrain, and the pons. A relative gray matter deficit was found in the right anterior cingulate cortex. The insula and anterior cingulate abnormalities may be relevant to the pathophysiology of PD, since these structures participate in the evaluation process that ascribes negative emotional meaning to potentially distressing cognitive and interoceptive sensory information. The abnormal brain stem structures may be involved in the generation of panic attacks.
Collapse
|
88
|
Faria PEP, Okamoto R, Bonilha-Neto RM, Xavier SP, Santos AC, Salata LA. Immunohistochemical, tomographic and histological study on onlay iliac grafts remodeling. Clin Oral Implants Res 2008; 19:393-401. [DOI: 10.1111/j.1600-0501.2007.01485.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
89
|
Santos NAG, Medina WSG, Martins NM, Mingatto FE, Curti C, Santos AC. Aromatic antiepileptic drugs and mitochondrial toxicity: effects on mitochondria isolated from rat liver. Toxicol In Vitro 2008; 22:1143-52. [PMID: 18434079 DOI: 10.1016/j.tiv.2008.03.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2007] [Revised: 02/22/2008] [Accepted: 03/10/2008] [Indexed: 12/24/2022]
Abstract
Idiosyncratic hepatotoxicity is a well-known complication associated with aromatic antiepileptic drugs (AAED), and it has been suggested to occur due to the accumulation of toxic arene oxide metabolites. Although there is clear evidence of the participation of an immune process, a direct toxic effect involving mitochondria dysfunction is also possible. The effects of AAED on mitochondrial function have not been studied yet. Therefore, we investigated, in vitro, the cytotoxic mechanism of carbamazepine (CB), phenytoin (PT) and phenobarbital (PB), unaltered and bioactivated, in the hepatic mitochondrial function. The murine hepatic microsomal system was used to produce the anticonvulsant metabolites. All the bioactivated drugs (CB-B, PB-B, PT-B) affected mitochondrial function causing decrease in state three respiration, RCR, ATP synthesis and membrane potential, increase in state four respiration as well as impairment of Ca2+ uptake/release and inhibition of calcium-induced swelling. As an unaltered drug, only PB, was able to affect mitochondrial respiration (except state four respiration) ATP synthesis and membrane potential; however, Ca2+ uptake/release as well as swelling induction were not affected. The potential to induce mitochondrial dysfunction was PT-B>PB-B>CB-B>PB. Results suggest the involvement of mitochondrial toxicity in the pathogenesis of AAED-induced hepatotoxicity.
Collapse
|
90
|
Kabeya LM, Kanashiro A, Azzolini AECS, Santos AC, Lucisano-Valim YM. Antioxidant activity and cytotoxicity as mediators of the neutrophil chemiluminescence inhibition by butylated hydroxytoluene. DIE PHARMAZIE 2008; 63:67-70. [PMID: 18271307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The tissue damage found in some inflammatory and autoimmune diseases has been shown to be mediated by an increased activation of neutrophil effector functions. In this study, we investigated the inhibitory effect of the phenolic compound butylated hydroxytoluene (BHT) on reactive oxygen species (ROS) generation by opsonized zymosan-stimulated neutrophils, assessed by luminol- and lucigenin-enhanced chemiluminescence (CL-lum and CL-luc, respectively), and some aspects of its mechanism of action. BHT showed concentration-dependent: (a) inhibitory effect on CL-lum and CL-luc; (b) cytotoxic effect, expressed by increased lactate dehydrogenase leakage by the cells; (c) interaction with neutrophil membranes; (d) ROS scavenger activity. These biological effects were observed in the same range of concentrations (0-5 x 10(-5) mol/l). Taken together, the results suggest that inhibition of neutrophil chemiluminescence by BHT was a result of multiple mechanisms, especially a cytotoxic effect probably mediated by BHT interaction with neutrophils membranes, and the ROS scavenging effect.
Collapse
|
91
|
Devienne KF, Cálgaro-Helena AF, Dorta DJ, Prado IMR, Raddi MSG, Vilegas W, Uyemura SA, Santos AC, Curti C. Antioxidant activity of isocoumarins isolated from Paepalanthus bromelioides on mitochondria. PHYTOCHEMISTRY 2007; 68:1075-80. [PMID: 17337023 DOI: 10.1016/j.phytochem.2007.01.014] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2006] [Revised: 07/05/2006] [Accepted: 01/20/2007] [Indexed: 05/14/2023]
Abstract
The isocoumarins (1-50 microM) paepalantine (9,10-dihydroxy-5,7-dimethoxy-1H-naptho(2,3c)pyran-1-one), 8,8'-paepalantine dimer, and vioxanthin isolated from Paepalanthus bromelioides, were assessed for antioxidant activity using isolated rat liver mitochondria and non-mitochondrial systems, and compared with the flavonoid quercetin. The paepalantine and paepalantine dimers, but not vioxanthin, were effective at scavenging both 1,1-diphenyl-2-picrylhydrazyl (DPPH(*)) and superoxide (O(2)(-)) radicals in non-mitochondrial systems, and protected mitochondria from tert-butylhydroperoxide-induced H(2)O(2) accumulation and Fe(2+)-citrate-mediated mitochondrial membrane lipid peroxidation, with almost the same potency as quercetin. These results point towards paepalantine, followed by paepalantine dimer, as being a powerful agent affording protection, apparently via O(2)(-) scavenging, from oxidative stress conditions imposed on mitochondria, the main intracellular source and target of those reactive oxygen species. This strong antioxidant action of paepalantine was reproduced in HepG2 cells exposed to oxidative stress condition induced by H(2)O(2).
Collapse
|
92
|
Santos NAG, Bezerra CSC, Martins NM, Curti C, Bianchi MLP, Santos AC. Hydroxyl radical scavenger ameliorates cisplatin-induced nephrotoxicity by preventing oxidative stress, redox state unbalance, impairment of energetic metabolism and apoptosis in rat kidney mitochondria. Cancer Chemother Pharmacol 2007; 61:145-55. [PMID: 17396264 DOI: 10.1007/s00280-007-0459-y] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2006] [Accepted: 03/04/2007] [Indexed: 01/23/2023]
Abstract
Nephrotoxicity is the major dose-limiting factor of cisplatin chemotherapy. Reactive oxygen species generated in mitochondria are thought to be the main cause of cellular damage in such injury. The present study examined, in vivo, the protective potential of the hydroxyl radical scavenger dimethylthiourea (DMTU) against cisplatin-induced effects on renal mitochondrial bioenergetics, redox state and oxidative stress. Adult male Wistar rats (200 to 220 g) were divided into four groups of eight animals each. The control group was treated only with an intraperitoneal (i.p.) injection of saline solution (1 ml/100 g body weight). The second group was given only DMTU (500 mg/kg body weight, i.p, followed by 125 mg/Kg, i.p., twice a day until they were killed). The third group was given a single injection of cisplatin (10 mg/kg body weight, i.p.). The fourth group was given DMTU (500 mg/kg body weight, i.p.), just before the cisplatin injection (10 mg/kg body weight, i.p.), followed by injections of DMTU (125 mg/kg body weight, i.p.) twice a day until they were killed. Animals were killed 72 h after the treatment. Besides not presenting any direct effect on mitochondria, DMTU substantially inhibited cisplatin-induced mitochondrial injury and cellular death by apoptosis, suppressing the occurrence of acute renal failure. All the following cisplatin-induced effects were prevented by DMTU: (1) increased plasmatic levels of creatinine and blood urea nitrogen (BUN); (2) decreased ATP content, calcium uptake and electrochemical potential; (3) oxidation of lipids, including cardiolipin; and oxidation of proteins, including sulfhydryl, and aconitase enzyme, as well as accumulation of carbonyl proteins; (4) depletion of the antioxidant defense (NADPH and GSH) and (5) increased activity of the apoptosis executioner caspase-3. Our findings show the important role played by mitochondria and hydroxyl radicals in cisplatin-induced nephrotoxicity, as well as the effectiveness of DMTU in preventing the renal mitochondrial damage caused by cisplatin. These results strongly suggest that protection of mitochondria by hydroxyl radical scavengers may be an interesting approach to prevent the kidney tissue damage caused by cisplatin-chemotherapy.
Collapse
|
93
|
Freitas CS, Dorta DJ, Pardo-Andreu GL, Pestana CR, Tudella VG, Mingatto FE, Uyemura SA, Santos AC, Curti C. 4-hydroxy nimesulide effects on mitochondria and HepG2 cells. A comparison with nimesulide. Eur J Pharmacol 2007; 566:43-9. [PMID: 17459371 DOI: 10.1016/j.ejphar.2007.03.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2006] [Revised: 03/05/2007] [Accepted: 03/13/2007] [Indexed: 01/14/2023]
Abstract
We previously reported that the nonsteroidal anti-inflammatory drug, nimesulide (N-[4-nitro-2-phenoxyphenyl]-methanesulfonamide), is an uncoupler and oxidizes NAD(P)H in isolated rat liver mitochondria, triggering mitochondrial Ca2+ efflux or, if this effect is inhibited, eliciting mitochondrial permeability transition (Mingatto et al., Br. J. Pharmacol. 131:1154-1160, 2000). We presently demonstrated that nimesulide's hydroxylated metabolite (4-hydroxy nimesulide) lacks the uncoupling property of the parent drug, while keeping its ability to oxidize mitochondrial NADPH. In the presence of 10 microM Ca2+, low (5-50 microM) concentrations of 4-hydroxy nimesulide elicited mitochondrial permeability transition, as assessed by cyclosporin A-sensitive mitochondrial swelling, associated with mitochondrial Ca2+ efflux/membrane potential dissipation (Deltapsi), apparently occurring on account of the oxidation of mitochondrial protein thiols; no involvement of reactive oxygen species was observed. While nimesulide (0.5 or 1 mM, 30 h incubation) did not lead to significant HepG2 cell death, 4-hydroxy nimesulide caused a low extent (approximately 15%) of cell necrosis, partly prevented by cyclosporine A, suggesting the involvement of mitochondrial permeability transition. Both nimesulide and 4-hydroxy nimesulide caused NADPH oxidation and Deltapsi dissipation in HepG2 cells. Because such Deltapsi dissipation induced by the metabolite was almost completely inhibited by cyclosporine A, it probably results from the mitochondrial permeability transition. Therefore, mitochondrial permeability transition, in apparent association with NADPH oxidation, constitutes the most probable cause of HepG2 cell death elicited by 4-hydroxy nimesulide.
Collapse
|
94
|
Santos NAG, Catão CS, Martins NM, Curti C, Bianchi MLP, Santos AC. Cisplatin-induced nephrotoxicity is associated with oxidative stress, redox state unbalance, impairment of energetic metabolism and apoptosis in rat kidney mitochondria. Arch Toxicol 2007; 81:495-504. [PMID: 17216432 DOI: 10.1007/s00204-006-0173-2] [Citation(s) in RCA: 215] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2006] [Accepted: 11/28/2006] [Indexed: 10/23/2022]
Abstract
The clinical use of cisplatin (cis-diamminedichloroplatinum II) is highly limited by its nephrotoxicity. The precise mechanisms involved in cisplatin-induced mitochondrial dysfunction in kidney have not been completely clarified. Therefore, we investigated in vivo the effects of cisplatin on mitochondrial bioenergetics, redox state, and oxidative stress as well as the occurrence of cell death by apoptosis in cisplatin-treated rat kidney. Adult male Wistar rats weighing 200-220 g were divided into two groups. The control group (n = 8) was treated only with an intraperitoneal (i.p.) injection of saline solution (1 ml per 100 g body weight), and the cisplatin group (n = 8) was given a single injection of cisplatin (10 mg/kg body weight, i.p.). Animals were sacrificed 72 h after the treatment. The cisplatin group presented acute renal failure characterized by increased plasmatic creatinine and urea levels. Mitochondrial dysfunction was evidenced by the decline in membrane electrochemical potential and the substantial decrease in mitochondrial calcium uptake. The mitochondrial antioxidant defense system was depleted, as shown by decreased GSH and NADPH levels, GSH/GSSG ratio, and increased GSSG level. Moreover, cisplatin induced oxidative damage to mitochondrial lipids, including cardiolipin, and oxidation of mitochondrial proteins, as demonstrated by the significant decrease of sulfhydryl protein concentrations and increased levels of carbonylated proteins. Additionally, aconitase activity, which is essential for mitochondrial function, was also found to be lower in the cisplatin group. Renal cell death via apoptosis was evidenced by the increased caspase-3 activity. Results show the central role of mitochondria and the intensification of apoptosis in cisplatin-induced acute renal failure, highlighting a number of steps that might be targeted to minimize cisplatin-induced nephrotoxicity.
Collapse
|
95
|
Saggioro FP, Colli BO, Paixão-Becker ANP, de Rezende GG, Santos AC, Neder L. Primary low-grade MALT lymphoma of the dura. Histopathology 2006; 49:323-6. [PMID: 16918987 DOI: 10.1111/j.1365-2559.2006.02433.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
96
|
Sales LV, Velasco TR, Funayama S, Ribeiro LT, Andrade-Valença LP, Neder L, Fernandes RMF, Araujo D, Machado HR, Santos AC, Leite JP. Relative frequency, clinical, neuroimaging, and postsurgical features of pediatric temporal lobe epilepsy. Braz J Med Biol Res 2006; 39:1365-72. [PMID: 16906314 DOI: 10.1590/s0100-879x2006001000013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2005] [Accepted: 06/20/2006] [Indexed: 11/22/2022] Open
Abstract
We describe the relative frequency, clinical features, neuroimaging and pathological results, and outcome after pharmacological or surgical intervention for a series of pediatric patients with temporal lobe epilepsy (TLE) from an epilepsy center in Brazil. The medical records of children younger than 12 years with features strongly suggestive of TLE were reviewed from January 1999 to June 1999. Selected children were evaluated regarding clinical, EEG, and magnetic resonance imaging (MRI) investigation and divided into three groups according to MRI: group 1 (G1, N = 9), patients with hippocampal atrophy; group 2 (G2, N = 10), patients with normal MRI, and group 3 (G3, N = 12), patients with other specific temporal lesions. A review of 1732 records of children with epilepsy revealed 31 cases with TLE (relative frequency of 1.79%). However, when the investigation was narrowed to cases with intractable seizures that needed video-EEG monitoring (N = 68) or epilepsy surgery (N = 32), the relative frequency of TLE increased to 19.11 (13/68) and 31.25% (10/32), respectively. At the beginning of the study, 25 of 31 patients had a high seizure frequency (80.6%), which declined to 11 of 31 (35.5%) at the conclusion of the study, as a consequence of pharmacological and/or surgical therapy. This improvement in seizure control was significant in G1 (P < 0.05) and G3 (P < 0.01) mainly due to good postsurgical outcome, and was not significant in G2 (P > 0.1, McNemar's test). These results indicate that the relative frequency of TLE in children was low, but increased considerably among cases with pharmacoresistant seizures. Patients with specific lesions were likely to undergo surgery, with good postoperative outcomes.
Collapse
|
97
|
Alexandre V, Walz R, Bianchin MM, Velasco TR, Terra-Bustamante VC, Wichert-Ana L, Araújo D, Machado HR, Assirati JA, Carlotti CG, Santos AC, Serafini LN, Sakamoto AC. Seizure outcome after surgery for epilepsy due to focal cortical dysplastic lesions. Seizure 2006; 15:420-7. [PMID: 16787751 DOI: 10.1016/j.seizure.2006.05.005] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2004] [Revised: 11/25/2005] [Accepted: 05/23/2006] [Indexed: 10/24/2022] Open
Abstract
Neocortical development is a highly complex process encompassing cellular proliferation, neuronal migration and cortical organization. At any time this process can be interrupted or modified by genetic or acquired factors causing malformations of cortical development (MCD). Epileptic seizures are the most common type of clinical manifestation, besides developmental delay and focal neurological deficits. Seizures due to MCD are frequently pharmacoresistant, especially those associated to focal cortical dysplasia (FCD). Surgical therapy results have been reported since 1971, however, currently available data from surgical series are still limited, mainly due to small number of patients, distinct selection of candidates and surgical strategies, variable pathological diagnosis and inadequate follow-up. This study addresses the possibilities of seizure relief following resection of focal cortical dysplasia, and the impact of presurgical evaluation, extent of resection and pathological findings on surgical outcome. We included 41 patients, 22 adults and 19 children and adolescents, with medically intractable seizures operated on from 1996 to 2002. All were submitted to standardized presurgical evaluation including high-resolution MRI, Video-EEG monitoring and ictal SPECT. Post-surgical seizure outcome was classified according to Engel's schema. Univariate and multivariate analysis were performed. Fifteen patients had temporal and 26 extratemporal epilepsies. Of the total 26 patients (63.4%) reached seizure-free status post-operatively. There was no correlation between outcome and age at surgery, duration of epilepsy, frequency of seizures, and pathological findings. There was, however, a clear correlation with topography of FCD (temporal versus extratemporal) and regional ictal EEG onset, on univariate as well as multivariate analysis.
Collapse
|
98
|
Cálgaro-Helena AF, Devienne KF, Rodrigues T, Dorta DJ, Raddi MSG, Vilegas W, Uyemura SA, Santos AC, Curti C. Effects of isocoumarins isolated from Paepalanthus bromelioides on mitochondria: Uncoupling, and induction/inhibition of mitochondrial permeability transition. Chem Biol Interact 2006; 161:155-64. [PMID: 16716282 DOI: 10.1016/j.cbi.2006.04.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2006] [Revised: 04/12/2006] [Accepted: 04/13/2006] [Indexed: 12/17/2022]
Abstract
Isolated mitochondria may undergo uncoupling, and in presence of Ca(2+) at different conditions, a mitochondrial permeability transition (MPT) linked to protein thiol oxidation, and demonstrated by CsA-sensitive mitochondrial swelling; these processes may cause cell death either by necrosis or by apoptosis. Isocoumarins isolated from the Brazilian plant Paepalanthus bromelioides (Eriocaulaceae) paepalantine (9,10-dihydroxy-5,7-dimethoxy-1H-naptho(2,3c)pyran-1-one), 8,8'-paepalantine dimer, and vioxanthin were assayed at 1-50 microM on isolated rat liver mitochondria, for respiration, MPT, protein thiol oxidation, and interaction with the mitochondrial membrane using 1,6-diphenyl-1,3,5-hexatriene (DPH). The isocoumarins did not significantly affect state 3 respiration of succinate-energized mitochondria; they did however, stimulate 4 respiration, indicating mitochondrial uncoupling. Induction of MPT and protein thiol oxidation were assessed in succinate-energized mitochondria exposed to 10 microM Ca(2+); inhibition of these processes was assessed in non-energized organelles in the presence of 300 microM t-butyl hydroperoxide plus 500 microM Ca(2+). Only paepalantine was an effective MPT/protein thiol oxidation inducer, also releasing cytochrome c from mitochondria; the protein thiol oxidation, unlike mitochondrial swelling, was neither inhibited by CsA nor dependent on the presence of Ca(2+). Vioxanthin was an effective inhibitor of MPT/protein thiol oxidation. All isocoumarins inserted deeply into the mitochondrial membrane, but only paepalantine dimer and vioxantin decreased the membrane's fluidity. A direct reaction with mitochondrial membrane protein thiols, involving an oxidation of these groups, is proposed to account for MPT induction by paepalantine, while a restriction of oxidation of these same thiol groups imposed by the decrease of membrane fluidity, is proposed to account for MPT inhibition by vioxanthin.
Collapse
|
99
|
Velasco TR, Zanello PA, Dalmagro CL, Araújo D, Santos AC, Bianchin MM, Alexandre V, Walz R, Assirati JA, Carlotti CG, Takayanagui OM, Sakamoto AC, Leite JP. Calcified cysticercotic lesions and intractable epilepsy: a cross sectional study of 512 patients. J Neurol Neurosurg Psychiatry 2006; 77:485-8. [PMID: 16543527 PMCID: PMC2077509 DOI: 10.1136/jnnp.2005.078675] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Neurocysticercosis is a major cause of epilepsy in developing countries and is endemic in Brazil. To test the hypothesis that the aetiological profile of patients with intractable epilepsy in Brazil includes neurocysticercosis, we conducted a cross sectional study investigating the aetiology of intractable epilepsy. METHODS A total of 512 patients evaluated at the outpatient clinic for intractable epilepsy at the Ribeirão Preto School of Medicine were included in the survey. Medical intractability was determined on the basis of seizure incidence and severity, and response to appropriate epilepsy management. Neuroimaging included brain CT with non-contrasted and contrasted phases and high resolution MRI. Patients were divided into neurocysticercosis and non-neurocysticercosis groups according to previous diagnostic criteria. RESULTS The most common epileptogenic lesions were mesial temporal sclerosis (MTS; 56.0%), malformations of cortical development (12.1%), and brain tumours (9.9%). Neuroimaging was normal in 8.7% of patients. Calcifications were found in 27% of patients and were significantly more common in patients with MTS than in those without MTS (p<0.001). Isolated neurocysticercosis was found in only eight patients (1.56%). CONCLUSIONS These data suggest that neurocysticercosis is an uncommon cause of intractable epilepsy, even in an endemic region such as Brazil, and that it may only represent a coexistent pathology. However, an analysis of our findings reveals that neurocysticercosis was more common in patients with MTS. This finding could suggest either that there is a cause-effect relationship between MTS and neurocysticercosis, or that MTS and neurocysticercosis co-vary with a missing variable, such as socio-economic status.
Collapse
|
100
|
Pontes-Neto OM, Wichert-Ana L, Terra-Bustamante VC, Velasco TR, Bustamante GO, Fernandes RMF, Azevedo-Marques PM, Oliveira LF, Santos AC, Kato M, Inuzuka LM, Machado HR, Sakamoto AC. Pontine activation during focal status epilepticus secondary to hamartoma of the floor of the fourth ventricle. Epilepsy Res 2006; 68:265-7. [PMID: 16377133 DOI: 10.1016/j.eplepsyres.2005.11.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2005] [Revised: 10/29/2005] [Accepted: 11/04/2005] [Indexed: 11/21/2022]
Abstract
Epileptic seizures associated with hamartoma of the floor of the fourth ventricle (HFFV) are generally resistant to antiepileptic medication, may evolve into status epilepticus, and can respond favorably to surgical therapy. HFFV are rare, and during the neonatal or infantile period may be associated with repetitive and stereotyped attacks of hemifacial spasm, eye blinking, facial movements, head deviation and dysautonomic manifestations. Similarly, to gelastic seizures provoked by hypothalamic hamartomas, it has been suggested that these spells arise from within the HFFV, thus constituting a type of non-cortical seizure. We report an infant female patient that developed continuous left hemifacial attacks since she was 2-month-old, and that underwent presurgical investigation when she was 18-month-old. MRI disclosed a left sided HFFV, Video-EEG showed non-localizing and non-lateralizing findings, and SPECT aligned with MRI showed marked hyperperfusion within the hamartoma, spreading to ipsilateral cerebellar parenchyma and brainstem nuclei. Patient underwent lesionectomy and became seizure-free. We found two evidences on literature supporting the hypothesis of non-cortical seizures related to HFFV. The first, intra-cerebellar recordings surrounding hamartoma showed electrical activity related to seizures. The second, subtracted SPECT co-registered MRI showed hyperemia within hamartoma. The present report provides the third additional evidence. We found the involvement not only of the hamartoma, and pars of cerebellar hemisphere, but also an intense hyperemia involving brainstem nuclei during seizures. We believe that all these findings suggest a short subcortical network responsible for generating seizures in HFFV patients.
Collapse
|