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Purpose: To provide straightforward instructions for daily practice in delineating emerging organs-at-risk (OARs) of the female pelvis and to discuss the interobserver variability in a two-step multicenter study. Methods and materials: A contouring atlas with anatomical boundaries for each emerging OAR was realized by radiation oncologists and radiologists who are experts in pelvic imaging, as per their knowledge and clinical practice. These contours were identified as quality benchmarks for the analysis subsequently carried out. Radiation oncologists not involved in setting the custom-built contouring atlas and interested in the treatment of gynecological cancer were invited to participate in this 2-step trial. In the first step all participants were supplied with a selected clinical case of locally advanced cervical cancer and had to identify emerging OARs (Levator ani muscle; Puborectalis muscle; Internal anal sphincter; External anal sphincter; Bladder base and trigone; Bladder neck; Iliac Bone Marrow; Lower Pelvis Bone Marrow; Lumbosacral Bone Marrow) based on their own personal knowledge of pelvic anatomy and experience. The suggested OARs and the contouring process were then presented at a subsequent webinar meeting with a contouring laboratory. Finally, in the second step, after the webinar meeting, each participant who had joined the study but was not involved in setting the benchmark received the custom-built contouring atlas with anatomical boundaries and was requested to delineate again the OARs using the tool provided. The Dice Similarity Coefficient (DSC) and the Jaccard Similarity Coefficient (JSC) were used to evaluate the spatial overlap accuracy of the different volume delineations and compared with the benchmark; the Hausdorff distance (HD) and the mean distance to agreement (MDA) to explore the distance between contours. All the results were reported as sample mean and standard deviation (SD). Results: Fifteen radiation oncologists from different Institutions joined the study. The participants had a high agreement degree for pelvic bones sub-structures delineation according to DICE (IBM: 0.9 ± 0.02; LPBM: 0.91 ± 0.01). A moderate degree according to DICE was showed for ovaries (Right: 0.61 ± 0.16, Left: 0.72 ± 0.05), vagina (0.575 ± 0.13), bladder sub-structures (0.515 ± 0.08) and EAS (0.605 ± 0.05), whereas a low degree for the other sub-structures of the anal-rectal sphincter complex (LAM: 0.345 ± 0.07, PRM: 0.41 ± 0.10, and IAS: 0.4 ± 0.07). Conclusion: This study found a moderate to low level of agreement in the delineation of the female pelvis emerging OARs, with a high degree of variability among observers. The development of delineation tools should be encouraged to improve the routine contouring of these OARs and increase the quality and consistency of radiotherapy planning.
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In intensive care, beta-lactams can be reconstituted in 50 mL polypropylene syringes with NaCl 0.9 % and administered for 8 to 12 h at various concentrations with motor-operated syringe pumps. The feasibility and/or the stability of these antibiotic therapies are often poorly known by clinicians. The purpose of this study was to determine the stability of seven antipyocyanic beta-lactam antibiotics and cilastatin under real-life conditions. Stability indicating HPLC methods allowing quantification in pharmaceutical preparations and subsequent stability studies were performed. The stability studies showed that continuous infusion of piperacillin/tazobactam 80/10 mg/mL, of cefepime 20 and 40 mg/mL and of aztreonam 40 and 120 mg/mL can be used over 12 h. Moreover, continuous infusion of cefepime 120 mg/mL can be used over 10 h, whereas meropenem 10 and 20 mg/mL and ceftazidime 40 mg/mL remained stable only over 8 h, and meropenem 40 mg/mL was significantly degraded after 6 h. Finally, imipenem/cilastatin 5/5 mg/mL and piperacillin/tazobactam 320/40 mg/mL should not be used as continuous infusion. These data allow the establishment of protocols of administration of antipyocyanic beta-lactams by continuous infusion. Some of them are not appropriate to this mode of administration (imipenem/cilastatin, piperacillin/ tazobactam 320/40 mg/mL) or must be avoided if possible (ceftazidime 40 mg/mL).
Assuntos
Antibacterianos/química , beta-Lactamas/antagonistas & inibidores , Aztreonam/química , Cefepima/química , Ceftazidima/química , Cilastatina/química , Combinação Imipenem e Cilastatina/química , Imipenem/química , Meropeném/química , Piperacilina/química , Combinação Piperacilina e Tazobactam/química , Tazobactam/químicaRESUMO
The observed increase in cancer led to a continuous rise in anticancer drug preparations in Hospital Centres. The quality and security of these preparations are essential to ensure the efficacy and to limit the risk of iatrogenic toxicity. Several methods have been described to secure the process of preparation (i.e. non-analytical methods for the control during the fabrication; analytical methods for the final product evaluation). These different methods have been presented in many studies, in particular in descriptive studies, but in practice, selecting a method is difficult and related to needs and hospital priorities. Therefore, we decided to conduct this present review focused on various existing methods allowing enhancement in security of anti-cancer drugs preparation process. A proactive hazard analysis method was applied, considering preparation and control steps, to discuss the choice of a method in terms of quality and security and to identify potential risks of failure. The results show that none method is perfect. Methods with the lowest criticality score are the robotization closely followed by Drugcam® in the case of re-labelling of all containers. According to these elements a University Hospital Centre could consider these risk indexesimplementing control methods.
Assuntos
Antineoplásicos/administração & dosagem , Antineoplásicos/química , Composição de Medicamentos/métodos , Antineoplásicos/efeitos adversos , Técnicas de Química Analítica/métodos , Humanos , Medicina de Precisão/métodos , Avaliação de Processos em Cuidados de Saúde , Controle de Qualidade , Gestão de Riscos/métodos , Robótica , Gestão da Segurança/métodosRESUMO
Hemolytic uremic syndrome is a rare disease, frequently responsible for renal insufficiency in children. Recent findings have led to renewed interest in this pathology. The discovery of new gene mutations in the atypical form of HUS and the experimental data suggesting the involvement of the complement pathway in the typical form, open new perspectives for treatment. This review summarizes the current state of knowledge on both typical and atypical hemolytic uremic syndrome pathophysiology and examines new perspectives for treatment.
Assuntos
Síndrome Hemolítico-Urêmica/fisiopatologia , Animais , Antibacterianos/uso terapêutico , Anticorpos Monoclonais Humanizados/uso terapêutico , Infecções Bacterianas/complicações , Toxinas Bacterianas/efeitos adversos , Ensaios Clínicos como Assunto , Proteínas do Sistema Complemento/fisiologia , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Infecções por Escherichia coli/complicações , Infecções por Escherichia coli/microbiologia , Previsões , Predisposição Genética para Doença , Síndrome Hemolítico-Urêmica/classificação , Síndrome Hemolítico-Urêmica/etiologia , Síndrome Hemolítico-Urêmica/genética , Síndrome Hemolítico-Urêmica/microbiologia , Síndrome Hemolítico-Urêmica/terapia , Humanos , Transplante de Rim , Transplante de Fígado , Camundongos , Papio , Plasma , Substitutos do Plasma , Toxina Shiga/efeitos adversos , Escherichia coli Shiga Toxigênica/imunologia , Escherichia coli Shiga Toxigênica/patogenicidade , Trombofilia/etiologia , Fator A de Crescimento do Endotélio Vascular/uso terapêuticoRESUMO
Reactive oxygen species (ROS) are important mediators in a number of neurodegenerative diseases and molecules capable of scavenging ROS may be a feasible strategy for protecting neuronal cells. We previously demonstrated a powerful iron-chelating action of Guttiferone-A (GA), a naturally occurring polyphenol, on oxidative stress injuries initiated by iron overload. Here we addressed the neuroprotective potential of GA in hydrogen peroxide and glutamate-induced injury on rat's primary culture of cortical neurons and PC12 cells, respectively, and antioxidant properties concerning scavenging and anti-lipoperoxidative activities in cell-free models. The decrease in cell viability induced by each of the toxins, assessed by [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] (MTT) assay, was significantly attenuated by GA. In addition, GA was found to be a potent antioxidant, as shown by (i) inhibition of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical reduction (EC50=20.0 µM), (ii) prevention against chemically or electrochemically generated superoxide radicals, (iii) inhibition of spontaneous brain lipid peroxidation and (iv) interference with the Fenton reaction. These results indicate that GA exerts neuroprotective effects against H2O2 or glutamate toxicity and its antioxidant activity, demonstrated in vitro, could be at least partly involved. They also suggest a promising potential for GA as a therapeutic agent against neurodegenerative diseases involving ROS and oxidative damage.
Assuntos
Benzofenonas/farmacologia , Sequestradores de Radicais Livres , Fármacos Neuroprotetores , Animais , Compostos de Bifenilo/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Córtex Cerebral/citologia , Córtex Cerebral/efeitos dos fármacos , Corantes , Eletroquímica , Frutas/química , Garcinia/química , Ácido Glutâmico/toxicidade , Humanos , Peróxido de Hidrogênio , Ferro , Peroxidação de Lipídeos/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Células PC12 , Picratos/metabolismo , Prenilação , Ratos , Espécies Reativas de Oxigênio/metabolismo , Sais de Tetrazólio , TiazóisRESUMO
The vitamin E derivative (+)α-tocopheryl succinate (α-TOS) exerts pro-apoptotic effects in a wide range of tumors and is well tolerated by normal tissues. Previous studies point to a mitochondrial involvement in the action mechanism; however, the early steps have not been fully elucidated. In a model of acute promyelocytic leukemia (APL) derived from hCG-PML-RARα transgenic mice, we demonstrated that α-TOS is as effective as arsenic trioxide or all-trans retinoic acid, the current gold standards of therapy. We also demonstrated that α-TOS induces an early dissipation of the mitochondrial membrane potential in APL cells and studies with isolated mitochondria revealed that this action may result from the inhibition of mitochondrial respiratory chain complex I. Moreover, α-TOS promoted accumulation of reactive oxygen species hours before mitochondrial cytochrome c release and caspases activation. Therefore, an in vivo antileukemic action and a novel mitochondrial target were revealed for α-TOS, as well as mitochondrial respiratory complex I was highlighted as potential target for anticancer therapy.
Assuntos
Arsenicais/uso terapêutico , Complexo I de Transporte de Elétrons/antagonistas & inibidores , Leucemia Promielocítica Aguda/tratamento farmacológico , Mitocôndrias/efeitos dos fármacos , Óxidos/uso terapêutico , Tretinoína/uso terapêutico , alfa-Tocoferol/farmacologia , alfa-Tocoferol/uso terapêutico , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Apoptose/efeitos dos fármacos , Trióxido de Arsênio , Caspases/metabolismo , Linhagem Celular Tumoral , Citocromos c/metabolismo , Modelos Animais de Doenças , Complexo II de Transporte de Elétrons/antagonistas & inibidores , Humanos , Leucemia Promielocítica Aguda/mortalidade , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Camundongos Transgênicos , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Proteínas de Fusão Oncogênica/metabolismo , Estabilidade Proteica/efeitos dos fármacos , Ratos , Espécies Reativas de Oxigênio/metabolismo , Transplante IsogênicoRESUMO
Cisplatin is a highly effective chemotherapeutic agent which causes severe nephrotoxicity. Studies have suggested that reactive oxygen species, mainly generated in mitochondria, play a central role in cisplatin-induced renal damage. A wide range of antioxidants have been evaluated as possible protective agents against cisplatin-induced nephrotoxicity; however a safe and efficacious compound has not yet been found. The present study is the first to evaluate the protective potential of carvedilol, a beta-blocker with strong antioxidant properties, against the mitochondrial oxidative stress and apoptosis in kidney of rats treated with cisplatin. The following cisplatin-induced toxic effects were prevented by carvedilol: increased plasmatic levels of creatinine and blood urea nitrogen (BUN); lipid peroxidation, oxidation of cardiolipin; oxidation of protein sulfhydryls; depletion of the non-enzymatic antioxidant defense and increased activity of caspase-3. Carvedilol per se did not present any effect on renal mitochondria. It was concluded that carvedilol prevents mitochondrial dysfunction and renal cell death through the protection against the oxidative stress and redox state unbalance induced by cisplatin. The association of carvedilol to cisplatin chemotherapy was suggested as a possible strategy to minimize the nephrotoxicity induced by this antitumor agent.
Assuntos
Carbazóis/farmacologia , Cisplatino/toxicidade , Nefropatias/induzido quimicamente , Nefropatias/metabolismo , Mitocôndrias/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Propanolaminas/farmacologia , Animais , Antineoplásicos/toxicidade , Antioxidantes/farmacologia , Apoptose/efeitos dos fármacos , Nitrogênio da Ureia Sanguínea , Carvedilol , Creatinina/sangue , Interações Medicamentosas , Humanos , Malondialdeído/metabolismo , Mitocôndrias/metabolismo , Oxirredução , Ratos , Ratos Wistar , Estatísticas não ParamétricasRESUMO
The outstanding physio-pathological role played by integrin receptors in living subjects motivates the enormous interest shown by scientists worldwide for this topic. More than twenty years of research has spanned across the structural and functional elucidation of these proteins and over their antagonism-based biomedical applications. The proof-of concept stage, aimed at identifying potent inhibitors, covered a decade of studies, and paved the way for a more advanced era of research where these antagonist molecules were thrown into the deep end of applicative studies. This review intends to summarize the major efforts conducted thus far and focuses on the design, synthesis and biomedical applications of cyclic RGD-containing alpha(v)beta(3) integrin antagonists, in both their small and macromolecular formats. In particular, Chapters 1 and 2 offer a comprehensive outlook on the rational basis for the design of integrin inhibitors, Chapter 3 chronicles the biological and medical applications of monofunctional RGD integrin ligands both in their monomeric and multimeric asset, and Chapter 4 illustrates the potential of RGD-based multifunctional systems in molecular medicine.
Assuntos
Integrina alfaVbeta3/antagonistas & inibidores , Oligopeptídeos/química , Peptídeos/química , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Desenho de Fármacos , Humanos , Integrina alfaVbeta3/metabolismo , Ligantes , Neoplasias/diagnóstico , Neoplasias/tratamento farmacológico , Peptídeos/uso terapêuticoRESUMO
The clinical use of cisplatin is highly limited by its nephrotoxicity, which has been associated with mitochondrial dysfunction. We investigated the protective effect of carvedilol, an antihypertensive with strong antioxidant properties, against the nephrotoxicity induced by cisplatin in rats. Carvedilol was able to counteract the renal damage by preventing the mitochondrial dysfunction induced by cisplatin. The mitochondrial eletrochemical potential, calcium uptake, respiration and the phosphorylative capacity were preserved by the co-administration of carvedilol. The mechanism of protection probably does not involve alterations in the cellular and sub-cellular distribution of cisplatin. The study suggests that carvedilol is a potential drug for the adjuvant nephroprotective therapy during cisplatin chemotherapy.
Assuntos
Antineoplásicos/toxicidade , Antioxidantes/farmacologia , Carbazóis/farmacologia , Cisplatino/toxicidade , Nefropatias/prevenção & controle , Mitocôndrias/efeitos dos fármacos , Propanolaminas/farmacologia , Animais , Anti-Hipertensivos/administração & dosagem , Anti-Hipertensivos/farmacologia , Antineoplásicos/administração & dosagem , Antioxidantes/administração & dosagem , Cálcio/metabolismo , Carbazóis/administração & dosagem , Carvedilol , Cisplatino/administração & dosagem , Rim/efeitos dos fármacos , Rim/metabolismo , Rim/ultraestrutura , Nefropatias/induzido quimicamente , Nefropatias/metabolismo , Masculino , Potenciais da Membrana/efeitos dos fármacos , Mitocôndrias/metabolismo , Consumo de Oxigênio/efeitos dos fármacos , Propanolaminas/administração & dosagem , Ratos , Ratos WistarRESUMO
One hypothesis for the etiology of cell damage arising from iron overload is that its excess selectively affects mitochondria. Here we tested the effects of acute iron overload on liver mitochondria isolated from rats subjected to a single dose of i.p. 500 mg/kg iron-dextran. The treatment increased the levels of iron in mitochondria (from 21 +/- 4 to 130 +/- 7 nmol/mg protein) and caused both lipid peroxidation and glutathione oxidation. The mitochondria of iron-treated rats showed lower respiratory control ratio in association with higher resting respiration. The mitochondrial uncoupling elicited by iron-treatment did not affect the phosphorylation efficiency or the ATP levels, suggesting that uncoupling is a mitochondrial protective mechanism against acute iron overload. Therefore, the reactive oxygen species (ROS)/H+ leak couple, functioning as a mitochondrial redox homeostatic mechanism could play a protective role in the acutely iron-loaded mitochondria.
Assuntos
Sobrecarga de Ferro/fisiopatologia , Complexo Ferro-Dextran/toxicidade , Mitocôndrias Hepáticas/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Trifosfato de Adenosina/metabolismo , Animais , Glutationa/efeitos dos fármacos , Glutationa/metabolismo , Injeções Intraperitoneais , Sobrecarga de Ferro/induzido quimicamente , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Mitocôndrias Hepáticas/metabolismo , Oxirredução/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismoRESUMO
The trypanocidal activity of racemic mixtures of cis- and trans-methylpluviatolides was evaluated in vitro against trypomastigote forms of two strains of Trypanosoma cruzi, and in the enzymatic assay of T. cruzi gGAPDH. The cytotoxicity of the compounds was assessed by the MTT method using LLC-MK2 cells. The effect of the compounds on peroxide and NO production were also investigated. The mixture of the trans stereoisomers displayed trypanocidal activity (IC50 approximately 89.3 microM). Therefore, it was separated by chiral HPLC, furnishing the (+) and (-)-enantiomers. Only the (-)-enantiomer was active against the parasite (IC50 approximately 18.7 microM). Despite being inactive, the (+)-enantiomer acted as an antagonistic competitor. Trans-methylpluviatolide displayed low toxicity for LLC-MK2 cells, with an IC50 of 6.53 mM. Furthermore, methylpluviatolide neither inhibited gGAPDH activity nor hindered peroxide and NO production at the evaluated concentrations.
Assuntos
Lactonas/química , Lactonas/farmacologia , Lignanas/química , Lignanas/farmacologia , Tripanossomicidas/química , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Linhagem Celular , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Estrutura Molecular , Óxido Nítrico/biossíntese , Relação Estrutura-AtividadeRESUMO
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.
Assuntos
Anticonvulsivantes/toxicidade , Carbamazepina/toxicidade , Mitocôndrias Hepáticas/efeitos dos fármacos , Fenobarbital/toxicidade , Fenitoína/toxicidade , Trifosfato de Adenosina/biossíntese , Animais , Anticonvulsivantes/metabolismo , Cálcio/metabolismo , Sinalização do Cálcio/efeitos dos fármacos , Carbamazepina/metabolismo , Relação Dose-Resposta a Droga , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/metabolismo , Mitocôndrias Hepáticas/metabolismo , Dilatação Mitocondrial/efeitos dos fármacos , Consumo de Oxigênio/efeitos dos fármacos , Fenobarbital/metabolismo , Fenitoína/metabolismo , Ratos , Ratos WistarRESUMO
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.
Assuntos
Antineoplásicos/toxicidade , Apoptose/efeitos dos fármacos , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Cisplatino/toxicidade , Fígado/efeitos dos fármacos , Fluidez de Membrana/efeitos dos fármacos , Mitocôndrias Hepáticas/efeitos dos fármacos , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , Cardiolipinas/metabolismo , Membrana Celular/efeitos dos fármacos , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Glutationa/metabolismo , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Injeções Intraperitoneais , Fígado/metabolismo , Masculino , Mitocôndrias Hepáticas/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , Transdução de Sinais/efeitos dos fármacosRESUMO
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.
Assuntos
Antineoplásicos/efeitos adversos , Cisplatino/efeitos adversos , Sequestradores de Radicais Livres/uso terapêutico , Nefropatias/induzido quimicamente , Tioureia/análogos & derivados , Animais , Apoptose/efeitos dos fármacos , Nitrogênio da Ureia Sanguínea , Creatinina/sangue , Metabolismo Energético/efeitos dos fármacos , Glutationa/metabolismo , Rim/efeitos dos fármacos , Rim/metabolismo , Nefropatias/metabolismo , Nefropatias/prevenção & controle , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Potenciais da Membrana/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , NADP/metabolismo , Oxirredução/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , Tioureia/uso terapêuticoRESUMO
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.
Assuntos
Injúria Renal Aguda/metabolismo , Apoptose , Metabolismo Energético , Rim/metabolismo , Mitocôndrias/metabolismo , Estresse Oxidativo , Aconitato Hidratase/metabolismo , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/enzimologia , Injúria Renal Aguda/patologia , Trifosfato de Adenosina/metabolismo , Animais , Antineoplásicos , Cálcio/metabolismo , Cardiolipinas/metabolismo , Caspase 3/metabolismo , Cisplatino , Modelos Animais de Doenças , Ativação Enzimática , Glutationa/metabolismo , Rim/enzimologia , Rim/patologia , Peroxidação de Lipídeos , Masculino , Potencial da Membrana Mitocondrial , Mitocôndrias/enzimologia , Mitocôndrias/patologia , Proteínas Mitocondriais/metabolismo , NADP/metabolismo , Oxirredução , Carbonilação Proteica , Ratos , Ratos Wistar , Compostos de Sulfidrila/metabolismoAssuntos
Doenças do Cão/diagnóstico , Doenças do Cão/cirurgia , Neoplasias Ovarianas/veterinária , Teratoma/veterinária , Animais , Doenças do Cão/patologia , Cães , Feminino , Histerectomia/veterinária , Laparotomia/veterinária , Neoplasias Ovarianas/diagnóstico , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/cirurgia , Ovariectomia/veterinária , Teratoma/diagnóstico , Teratoma/patologia , Teratoma/cirurgia , Resultado do TratamentoRESUMO
Dietary modifications may significantly reduce cardiovascular disease (CVD) risk factors, including cholesterol and atherosclerosis. The present study addressed the effects of the crude extract from the pulp fruit of Tamarindus indica L. on lipid serum levels and early atherosclerotic lesions in hypercholesterolemic hamsters in vivo, and the extract's antioxidant action, in vitro. Animals were fed on either chow or atherogenic diet during 10 weeks and concomitantly received either water or T. indica L. extract for drinking. Treatment of hypercholesterolemic hamsters with the T. indica pulp fruit extract (5%) led to a decrease in the levels of serum total cholesterol (50%), non-HDL cholesterol (73%) and triglyceride (60%), and to an increase of high-density lipoprotein (HDL) cholesterol levels (61%). In vitro, the extract presented radical scavenging ability, as assessed by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radicals assays, and led to decreased lipid peroxidation in serum, as assessed by the thiobarbituric acid reactive substances (TBARS) assay. In vivo, the extract improved the efficiency of the antioxidant defense system, as assessed by the superoxide dismutase, catalase and glutathione peroxidase activities. Together these results indicate the potential of tamarind extracts in diminishing the risk of atherosclerosis development in humans.
Assuntos
Antioxidantes/administração & dosagem , Frutas/química , Hipercolesterolemia/tratamento farmacológico , Hipolipemiantes/administração & dosagem , Fitoterapia , Extratos Vegetais/administração & dosagem , Animais , Aorta/patologia , Compostos de Bifenilo , Catalase/análise , Catalase/sangue , Colesterol/sangue , HDL-Colesterol/sangue , Cromatografia Líquida de Alta Pressão , Cricetinae , Dieta , Sequestradores de Radicais Livres , Glutationa Peroxidase/análise , Glutationa Peroxidase/sangue , Hipercolesterolemia/metabolismo , Hipercolesterolemia/patologia , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/enzimologia , Picratos , Superóxido Dismutase/análise , Superóxido Dismutase/sangue , Superóxidos , Tamarindus , Triglicerídeos/sangue , Aumento de PesoRESUMO
The understanding of the controlling factors of calcium homeostasis in Aspergillus fumigatus is very poor, although this ion is involved in several important events of these particular cells. We have cloned, identified and expressed for functional complementation a PMR1-like Ca(2+)-ATPase gene from A. fumigatus. The Afpmr1 gene encodes a protein of 1061 deduced amino acids, containing all the conserved subdomains found in other P-type ATPases: the phosphatase region, phosphorylation site, FITC labelling site, ATP binding domain; E(386), N871, D875 amino acid residues for calcium ion interaction and Q880, a residue that alters ion selectivity in PMR1. The expressed AfPMR1 in S. cerevisiae K616 strain functionally complemented the deficient growth in EGTA (5-20 mM)- and MnCl2 (4 mM)-containing medium. These results demonstrate the first evidence of a Ca(2+)-ATPase in A. fumigatus and strongly suggest a role for this enzyme in calcium and manganese homeostasis.
Assuntos
Aspergillus fumigatus/genética , ATPases Transportadoras de Cálcio/genética , Sequência de Aminoácidos , Aspergillus fumigatus/enzimologia , Sequência de Bases , Cloretos , Meios de Cultura , Ácido Egtázico , Teste de Complementação Genética , Compostos de Manganês , Chaperonas Moleculares/genética , Dados de Sequência Molecular , Filogenia , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/crescimento & desenvolvimento , Proteínas de Saccharomyces cerevisiae/genéticaRESUMO
Recently, we reported a highly active regimen in advanced gastric cancer including a weekly administration of cisplatin, epidoxorubicin, leucovorin, 5-fluorouracil with the support of filgrastim. In order to simplify the administration and to decrease the toxicity of these drugs, mainly epidoxorubicin-induced alopecia, we designed a regimen including an infusional 5-fluorouracil schedule according to the de Gramont regimen, cisplatin and mitomycin C replacing epidoxorubicin. Forty-five patients with advanced or metastatic gastric cancer were treated with cisplatin 50 mg m(-2) i.v. on day 1, every 2 weeks, 6S-stereoisomer-leucovorin 100 mg m(-2) i.v. followed by 5-fluorouracil 400 mg m(-2) i.v. bolus and 600 mg m(-2) i.v. in a 22-h infusion, on days 1 and 2, every 2 weeks, and mitomycin C 7 mg m(-2) i.v. bolus on day 2, every 6 weeks. Grades 3-4 toxicities (National Cancer Institute-Common Toxicity Criteria) consisted mainly of neutropenia and thrombocytopenia. Five patients had a complete response and 16 had a partial response for an overall response rate of 46.7% (95% confidence interval, 32.1-61.2%). The median survival was 11 months. The combination of cisplatin, 5-fluorouracil and leucovorin according to de Gramont, and mitomycin C seems to be an active and safe regimen in the treatment of advanced gastric cancer. Because of its low cost it may be suggested for patients not enrolled into clinical trials.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma/tratamento farmacológico , Neoplasias Gástricas/tratamento farmacológico , Adulto , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/economia , Carcinoma/patologia , Cisplatino/administração & dosagem , Análise Custo-Benefício , Custos de Medicamentos , Feminino , Fluoruracila/administração & dosagem , Humanos , Infusões Intravenosas , Injeções Intravenosas , Masculino , Pessoa de Meia-Idade , Mitomicina/administração & dosagem , Neoplasias Gástricas/patologia , Análise de Sobrevida , Resultado do TratamentoRESUMO
BACKGROUND: Laboratory evidences suggest the possibility that an infusion rate of 10 mg/m2/min may be more effective than the standard 30-min infusion of Gemcitabine (GEM). PATIENTS AND METHODS: Thirty-four patients with histologically verified locally unresectable and/or metastatic pancreatic carcinoma received GEM at the dose of 1,500 mg/m2 with an infusion rate of 10 mg/m2/min, associated to 5-fluorouracil (5-FU) at the dose of 600 mg/m2. Both drugs were administered weekly for two consecutive weeks out of every three weeks. RESULTS: One complete and five partial responses have been observed for an overall response rate of 17% (95% CI: 3%-27%). The time to progression was 3.7 months with a median survival of 5.7 months. A clinical benefit was obtained in 5 of 29 patients (17%). Grade 3-4 WHO toxicities included neutropenia (35%) and thrombocytopenia (10%). CONCLUSION: It is unlikely that a fixed dose rate infusion of GEM, at least with this dose, can improve palliation in comparison with the standard 30-min infusion schedule in advanced pancreatic cancer.