RESUMO
Cysteinyl leukotrienes (CysLTs) are potent pro-inflammatory and immune modulating lipid mediators involved in inflammatory diseases and were boosted in human brain after acute phase of cerebral ischemia. The antagonism of CysLTs receptors may offer protection against ischemic damage. Therefore it seemed interesting to study the possible neuroprotective effect of Montelukast, a CysLTR1 antagonist in global cerebral ischemia/reperfusion (IR) injury in rats. Global cerebral ischemia-reperfusion was induced by bilateral carotid artery occlusion for 15 min followed by 60 min reperfusion period. Animals were randomly allocated into three groups (n = 30 per group): Sham operated, I/R control and rats treated with montelukast (0.5 mg/kg, po) daily for 7 days then I/R was induced 1 h after the last dose of montelukast. After reperfusion rats were killed by decapitation, brains were removed and both hippocampi separated and the following biochemical parameters were estimated; lactate dehydrogenase activity, oxidative stress markers (lipid peroxides, nitric oxide and reduced glutathione), inflammatory markers (myeloperoxidase, tumor necrosis factor-alpha, nuclear factor kappa-B, interleukin-6 and interleukin-10), apoptotic biomarkers (caspase 3 and cytochrome C), neurotransmitters (glutamate, gamma aminobutyric acid), Cys-LTs contents and CysLT1 receptor expression; as well as total brain infarct size and histopathological examination of the hippocampus were assessed. Montelukast protected hippocampal tissue by reducing oxidative stress, inflammatory and apoptotic markers. Furthermore, it reduced glutamate and lactate dehydrogenase activity as well as infarct size elevated by I/R. These results were consistent with the histopathological findings. Montelukast showed a neuroprotective effects through antioxidant, anti-inflammatory and antiapoptotic mechanisms.
Assuntos
Acetatos/uso terapêutico , Hipocampo/patologia , Ataque Isquêmico Transitório/tratamento farmacológico , Ataque Isquêmico Transitório/patologia , Antagonistas de Leucotrienos/uso terapêutico , Quinolinas/uso terapêutico , Receptores de Leucotrienos/efeitos dos fármacos , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/patologia , Animais , Proteínas Reguladoras de Apoptose/metabolismo , Biomarcadores/metabolismo , Infarto Cerebral/patologia , Ciclopropanos , Mediadores da Inflamação/metabolismo , Masculino , Neurotransmissores/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ratos , Ratos Wistar , SulfetosRESUMO
AIMS: Acinetobacter baumannii is a global health problem, which threatens many healthcare settings. The current study aims to develop a detection assay for Ac. baumannii using unmodified gold nanoparticles (AuNPs). METHODS AND RESULTS: Fifty-three Ac. baumannii clinical isolates were collected from Egyptian hospitals. Bacterial isolation and biochemical identification of isolates were carried out followed by DNA extraction using boiling method and PCR amplification of the 23S-16S rRNA intergenic spacer sequences (ITS). AuNPs were synthesized using citrate reduction method. Detection and optimization of Ac. baumannii amplicons using unmodified spherical AuNPs were performed using species-specific DNA oligonucleotide. The nano-gold assay was able to colorimetrically detect and distinguish Ac. baumannii from other Gram-negative bacteria. The turnaround time of the assay is about 2 h including sample treatment and amplification. The assay detection limit is 0·8125 ng of DNA. CONCLUSIONS: The developed colorimetric assay is sensitive, fast and reliable and can be used for identification of Ac. baumannii. SIGNIFICANCE AND IMPACT OF THE STUDY: There is a need to develop robust, rapid, and specific methods for detection of Ac. baumannii isolated from clinical specimens. The developed nanogold assay prototype allows sensitive, specific and rapid detection of amplified DNA of A. baumannii and represents a reliable diagnostic tool to aid routine laboratory identification of this pathogen.
Assuntos
Acinetobacter baumannii/isolamento & purificação , Colorimetria/métodos , Ouro , Nanopartículas Metálicas , Acinetobacter baumannii/genética , DNA Intergênico/química , Humanos , Nanopartículas Metálicas/ultraestrutura , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/genéticaRESUMO
INTRODUCTION: It has been argued recently that ischemic preconditioning (IPre) and postconditioning (IPost) have beneficial effects in many ischemic disorders however; their effects on global ischemia/reperfusion (I/R) are poorly understood. Thus, the present work aimed to study the possible mechanisms underlying the neuroprotective effects of IPre and IPost. METHODS: Animals were randomly allocated into 4 groups (n = 30): (1) Sham operated (SO); (2) I/R group, animals were subjected to 15 min global ischemia followed by 60 min reperfusion; (3) IPre, animals were subjected to 3 episodes of 5 min ischemia followed by 10 min reperfusion before I/R; (4) IPost, animals were subjected to three episodes of 10s of ischemia and 10s of reperfusion after the period of ischemia followed by a 60 min reperfusion period. Lactate dehydrogenase activity, oxidative stress, inflammatory and apoptotic biomarkers, as well as neurotransmitters, infarct size and histopathological examination were assessed. RESULTS: I/R induced hippocampal damage through increasing oxidative stress, inflammatory, excitotoxic and apoptotic markers as well as lactate dehydrogenase activity and infarct size. Both, IPre and IPost attenuated most markers induced by I/R. CONCLUSIONS: IPre and IPost neuroprotective effects can be explained through their anti-oxidant, anti-inflammatory and anti-apoptotic mechanisms.
Assuntos
Isquemia Encefálica/patologia , Hipocampo/irrigação sanguínea , Hipocampo/patologia , Precondicionamento Isquêmico , Traumatismo por Reperfusão/patologia , Animais , Apoptose , Biomarcadores/metabolismo , Encefalite/metabolismo , Encefalite/patologia , Ácido Glutâmico/metabolismo , Hipocampo/metabolismo , Pós-Condicionamento Isquêmico , L-Lactato Desidrogenase/metabolismo , Masculino , Estresse Oxidativo , Ratos Wistar , Traumatismo por Reperfusão/terapia , Ácido gama-Aminobutírico/metabolismoRESUMO
Previous behavioral studies on triazolam (TZ), which are small in number, could only speculate about tolerance to the anxiolytic effect of TZ, as the experiments did not cover sufficient time (of 4 to 7 days) for tolerance to develop. Therefore longer time for chronic TZ administration is used. We investigated the effects of TZ on motor activity and exploratory behavior using plus maze and open field. Three experiments were conducted. In the first, five groups of rats were acutely treated with different doses of TZ (0.25 mg/kg-4.0 mg/kg). In the second set of experiments, rats were treated chronically with a single daily dose of TZ (started with 0.25 mg/kg and increased by time to 1.0 mg/kg) for 5 weeks (representing clinical use). In the third, rats were treated chronically with three daily doses of TZ (started with 0.25 mg/kg and increased by time to 0.5 mg/kg) for 20 days (mimicking drug abuse). Acute TZ administration produced dose dependent anxiolytic effects and a decrease in motor activity with higher doses. Chronically treated rats, either once daily or three times daily doses, showed tolerance to both anxiolytic and sedative effects of TZ. It may be concluded that tolerance to the anxiolytic and sedative effects of TZ would develop after chronic administration either with clinical use or its abuse.
Assuntos
Ansiolíticos/farmacologia , Comportamento Animal/efeitos dos fármacos , Triazolam/farmacologia , Animais , Comportamento Animal/fisiologia , Relação Dose-Resposta a Droga , Tolerância a Medicamentos , Comportamento Exploratório/efeitos dos fármacos , Comportamento Exploratório/fisiologia , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Aprendizagem em Labirinto/fisiologia , Atividade Motora/efeitos dos fármacos , Atividade Motora/fisiologia , Ratos , Ratos WistarRESUMO
The effect of acute and chronic treatments of the calcium-channel blockers, isradipine, diltiazem and flunarizine in protecting against lorazepam dependence has been demonstrated in mice. Dependence was induced by twice-daily administration of lorazepam (1 mg kg-1) for 10 days, doubling the dose during the next 10 days. Withdrawal symptoms and changes in the noradrenaline, dopamine and 5-hydroxytryptamine content of different regions of the brain were observed after either 24-h withdrawal or flumazenil administration. Isradipine inhibited lorazepam withdrawal symptoms, the effect being accompanied in the 24-h withdrawal group by significant decreases in the noradrenaline and dopamine content of the thalamus and hypothalamus and in the noradrenaline content of the mid-brain. In the flumazenil-treated group isradipine produced significant decreases in mid-brain noradrenaline and dopamine levels and in the dopamine content of the thalamus and hypothalamus. Diltiazem did not, on the other hand, afford significant protection against lorazepam withdrawal symptoms and did not induce any significant change in the neurotransmitters studied. Flunarizine significantly inhibited lorazepam withdrawal symptoms, an effect accompanied by significant reduction in noradrenaline and dopamine levels in the thalamus and hypothalamus. Dopamine was also significantly reduced in the cerebral cortex. Similar effects were produced in the flumazenil-treated group, and the noradrenaline content was reduced in the medulla, pons and cerebellum. It was concluded that isradipine and flunarizine might be of value in ameliorating lorazepam withdrawal symptoms.
Assuntos
Bloqueadores dos Canais de Cálcio/farmacologia , Lorazepam , Transtornos Relacionados ao Uso de Substâncias/prevenção & controle , Animais , Química Encefálica/efeitos dos fármacos , Bloqueadores dos Canais de Cálcio/administração & dosagem , Diltiazem/administração & dosagem , Diltiazem/farmacologia , Dopamina/análise , Flunarizina/administração & dosagem , Flunarizina/farmacologia , Isradipino/administração & dosagem , Isradipino/farmacologia , Lorazepam/efeitos adversos , Masculino , Camundongos , Norepinefrina/análise , Serotonina/análise , Síndrome de Abstinência a Substâncias/metabolismo , Síndrome de Abstinência a Substâncias/prevenção & controle , Transtornos Relacionados ao Uso de Substâncias/metabolismoRESUMO
The present study investigated the effects of acute and chronic intraperitoneal administration of Triazolam on g-aminobutyric acid (GABA) levels in different brain areas of albino rats. Three experiments were conducted. In the first, five groups of rats were acutely treated with different doses of Triazolam (0.25 mg/kg-4.0 mg/kg). In the second experiment, rats were treated chronically with a single daily dose of Triazolam (started with 0.25 mg/kg and increased by time to 1.0 mg/kg) for 5 weeks, simulating clinical use. In the third, rats were treated chronically with three daily doses of Triazolam (started with 0.25 mg/kg and increased by time to 0.5 mg/kg) for 20 days, representing a form of drug abuse. Brain levels of GABA and plasma levels of Triazolam were measured using high performance liquid chromatography (HPLC). The acute Triazolam administration produced an increase in GABA levels in all brain areas studied. The chronic administration of single daily dose of Triazolam produced normal GABA levels in all brain areas except brain stem where the levels were significantly decreased; this indicates the development of tolerance to Triazolam action on increasing GABA content. The chronic administration of three daily doses of Triazolam produced a decrease in GABA levels in all brain regions studied. In conclusion, chronic single daily dose treatment (representing normal use) produces tolerance to Triazolam effects on brain GABA levels, while chronic three daily doses administration (akin to drug abuse) causes a fall in GABA levels.
Assuntos
Encéfalo/metabolismo , Triazolam/farmacologia , Ácido gama-Aminobutírico/metabolismo , Animais , Encéfalo/efeitos dos fármacos , Tronco Encefálico/metabolismo , Cerebelo/metabolismo , Córtex Cerebral/metabolismo , Corpo Estriado/metabolismo , Esquema de Medicação , Masculino , Mesencéfalo/metabolismo , Ratos , Ratos Wistar , Triazolam/administração & dosagem , Triazolam/farmacocinéticaRESUMO
Worldwide usage of different colouring agents in the food industry prompted us to study their toxicity. The potential adverse effects of erythrosine (ER, FD & C Red No. 3) on the spermatogenesis process were investigated in adult mice. Testicular lactic dehydrogenase isoenzyme activity (LDH-X), a pachytene spermatocyte marker of testicular toxicity, was significantly decreased to 71.8% and 68.6% of the control value after daily p.o. administration of ER (21 days) in doses of 68 and 136 mg kg-1 respectively. At the same time, the normal average epididymal sperm count as well as the percentage of motile sperms were significantly inhibited by about 50% and 57% respectively. Moreover, ER was shown to disrupt the normal morphology of the sperm head. Thus, after 5 daily p.o administrations of ER in doses of 680 and 1360 mg kg-1 (equivalent to 10 and 20% of its LD50) it increased the incidence of sperms with abnormal head by about 57% and 65% respectively. The induced increase in sperm abnormalities could enhance the spermatogenic dysfunction and germ cell mutagenicity. These findings indicate that ER in the used doses has a potential toxic effect on spermatogenesis in mice and in turn, it may affect its testicular function and reproductive performance.
Assuntos
Corantes/toxicidade , Eritrosina/toxicidade , Infertilidade Masculina/induzido quimicamente , Animais , Isoenzimas , L-Lactato Desidrogenase/metabolismo , Masculino , Camundongos , Mutação , Contagem de Espermatozoides/efeitos dos fármacos , Cabeça do Espermatozoide/efeitos dos fármacos , Cabeça do Espermatozoide/ultraestrutura , Motilidade dos Espermatozoides/efeitos dos fármacos , Espermatogênese/efeitos dos fármacos , Testículo/citologia , Testículo/efeitos dos fármacos , Testículo/enzimologiaRESUMO
The present study investigates the effects of acute and chronic administration of triazolam in albino rats on glycine levels in different brain areas. Three experiments were conducted. In the first, five groups of rats were acutely treated with different doses of triazolam (0.25 mg/kg-4.0 mg/kg i.p.). In the second experiment, rats were treated chronically by a single daily dose of triazolam (started by 0.25 mg/kg and increased by time to 1.0 mg/kg) for 5 weeks, simulating clinical use. In the third, rats were treated chronically three daily doses of triazolam (started by 0.25 mg/kg and increased by time to 0.5 mg/kg) for 20 days, simulating a form of drug abuse. Brain levels of glycine and plasma levels of triazolam were measured using HPLC technique. The acute triazolam administration produced an increase in glycine levels in almost all brain areas studied. The chronic administration of single daily dose of triazolam produced normal glycine levels in most of the brain areas; this indicates the development of tolerance to glycine content increasing action of triazolam. The chronic administration of three daily doses of triazolam produced a decrease in glycine levels in almost all brain regions studied, which might be a prerequisite for oncoming withdrawal syndrome.
Assuntos
Ansiolíticos/administração & dosagem , Química Encefálica/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Glicina/metabolismo , Síndrome de Abstinência a Substâncias/metabolismo , Transtornos Relacionados ao Uso de Substâncias/metabolismo , Triazolam/administração & dosagem , Animais , Relação Dose-Resposta a Droga , Esquema de Medicação , Masculino , Ratos , Ratos WistarRESUMO
Nephrotoxicity is a dose-limiting factor in the use of cisplatin against solid tumours. Methimazole, an antithyroid drug containing a free SH group, has a nephroprotective potential against chemically-induced nephrotoxicity. We tried to explore the nephrotoxic effect of the experimentally therapeutic dose of cisplatin (7 mg kg(-1), i.p.), particularly on the nuclear level of kidney cells in male albino rats, as well as the possible protective effect of methimazole. Furthermore, the drug interaction regarding the oncolytic effect of cisplatin was examined in Ehrlich ascites carcinoma (EAC)-bearing mice. A single dose of cisplatin caused kidney damage, 6 days after injection, manifested by 219% increase in serum creatinine, 384% increase in blood urea nitrogen and 170% increase in kidney content of lipid peroxides. Kidney DNA showed clear fragmentations detected by gel electrophoresis. However, kidney reduced glutathione was unchanged at that time period. Histological examination of kidney confirmed the toxic effect of cisplatin. Methimazole (40 mg kg(-1), i.p., 30 min before cisplatin injection) significantly protected the kidney from the nephrotoxic effect of cisplatin as judged from the biochemical parameters investigated as well as the histopathological examination. On the other hand, the survival data in EAC-bearing mice treated with both drugs indicated the persistence of an effective cytotoxic action. This study points to a promising use of this combination and necessitates further experimental and clinical studies.