Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0494475 (tonic-clonic seizure)
 1,319 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Physiological and behavioral (conditioned avoidance) responses of male Long-Evans rats were determined during exposure to combustion products produced on thermal degradation of three different polymeric materials. Arterial blood samples were obtained for determination of carboxyhemoglobin (COHb) and acid/base status. Material A produced a syndrome of carbon monoxide (CO)-induced anoxia, the severity of which was a function of the mass of material degraded. Material B produced grand mal seizures despite COHb levels of less than 10%. Material C produced metabolic acidosis and a mild degree of CO-induced anoxia. Loss of avoidance responses occurred at significantly lower COHb levels for materials B and C in comparison to CO alone. Using responses to COHb as a reference, it was possible to detect the presence of other toxicants present in combustion products. Compounds found in smoke in very low concentrations may have a high degree of biological activity and be responsible for impairment of survival responses. We have labeled these compounds "limiting" toxicants. They constitute a significant hazard, which is added to that of CO and anoxia.
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PMID:An approach to the toxicology of combustion products of materials. 1 44

Sex related differences of the blood brain barrier permeability was investigated during bicuculline-induced seizures in Wistar rats. The rats were anesthetized with diethyl-ether. Evans-blue, which was used as a blood brain barrier tracer, was injected into femoral vein 5 minutes before administering bicuculline to induced grand mal seizures. Evans-blue albumin extravasation was determined as a macroscopical finding; and a quantitative estimation with spectrophotometer using homogenized brain to release the dye was also performed to evaluate the macroscopic findings. During convulsions the mean arterial blood pressure increased in both female and male rats, but the difference was in the extravasation of Evans-blue being more pronounced in the females. Blood brain barrier lesions were present in 85% of female rats and 61% of male rats. Mean value for Evans-blue dye in the whole brain was found to be 1.197 +/- .402 mg % in the group consisting of all the female rats, and .755 +/- .247 mg % in the group of all male rats during bicuculline-induced seizure. This difference between female and male rats was found to be statistically significant (p < .001). Severe protein leakage was seen in the thalamus, hypothalamus, hippocampus, globus pallidus, nucleus caudatus, periaqueductal gray and mesencephalon bilaterally in female rats. However, in male rats, Evans-blue leakage was similar to that of female rats except that the frequency and intensity of blood brain barrier breakdown was less after convulsions. Our results showed that the extravasation of Evans-blue albumin was most pronounced in the brains of female rats compared to male rats after bicuculline induced seizure.
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PMID:Influence of sex on the blood brain barrier permeability during bicuculline-induced seizures. 134 74

Intravenous injection of 450 mg/kg quinolinic acid (Quin), an endogenous kynurenine metabolite with excitotoxic properties, induced only minor electroencephalographic (EEG) modifications and no neurotoxicity in rats with a mature blood-brain barrier (BBB). BBB permeability was altered in rats by focal unilateral irradiation of the cortex (7 mm in diameter and 5 mm in depth) with protons (60 Gy, 9 Gy/min). Three days after irradiation, Evans blue dye staining showed BBB breakdown in the dorsal hippocampus of the irradiated hemisphere. No neurotoxic or convulsant effects were observed as a consequence of the radiation itself. When BBB-lesioned rats were challenged with 225 mg/kg Quin iv, epileptiform activity was observed on EEG analysis. Tonic-clonic seizures were induced by 225-450 mg/kg Quin. Light microscopic analysis showed a dose-related excitotoxic type of lesion restricted to the hippocampus ipsilateral to the irradiated side. Neuro-degeneration was prevented by local injection of 120 nmol D(-)2-amino-7-phosphonoheptanoic acid, a selective N-methyl-D-aspartate receptor antagonist. No lesions or EEG or behavioral modifications occurred after 450 mg/kg nicotinic acid, an inactive analog of Quin. The potential neurotoxic and convulsant effects of increased blood levels of Quin under conditions of altered BBB permeability are discussed.
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PMID:Studies on the potential neurotoxic and convulsant effects of increased blood levels of quinolinic acid in rats with altered blood-brain barrier permeability. 255 19

The inability of most chemotherapeutic agents to adequately penetrate the blood-brain barrier (BBB), in either normal brain or tumor-infiltrated brain, is a major factor limiting the use of chemotherapy in central nervous system malignancy. This barrier, however, can be opened in a reversible manner by the intra-arterial administration of hyperosmotic agents such as mannitol. It has been suggested that the intravenous administration of dimethyl sulfoxide (DMSO) or 5-fluorouracil (5-FU) can accomplish the same thing in a less invasive manner. We have not been able to confirm these findings. DMSO was administered to 25 rats intravenously at concentrations ranging from 25 to 90% or into the internal carotid artery at a concentration of 30%. The penetration of methotrexate, Evans blue-albumin, and hexosaminidase A was then evaluated at intervals ranging from 1.5 to 3.5 hours after administration. Significant barrier opening was not observed in animals receiving intravenous DMSO. Barrier modification, albeit generally modest, was obtained in animals receiving intracarotid DMSO, but this may have been the result of grand mal seizures, inasmuch as 5 of 6 of these animals had such seizures. Several of the animals receiving i.v. DMSO also had seizures, and all animals developed varying degrees of hematuria. Similarly, 5-FU was administered at a dose of 30 mg/kg i.v. and the permeability of the BBB to either Evans blue-albumin or methotrexate was evaluated. No increased permeability of the BBB to these two markers was observed. In summary, osmotic BBB opening in our hands remains the most consistent and reliable means available to open the BBB in a reversible fashion. Neither intravenous DMSO nor 5-FU seems to increase the delivery of chemotherapy or protein tracer to the central nervous system, and the use of DMSO can result in seizures and hematuria.
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PMID:Inability of dimethyl sulfoxide and 5-fluorouracil to open the blood-brain barrier. 621 98

Hot water epilepsy (HWE) was induced in freely moving Wistar rats by applying hot water jets over the head region. The status of the blood-brain barrier (BBB) during the seizures and during hot water-induced hyperthermia without seizures was examined using Evans blue dye. In order to investigate the contribution of concomitant factors to this process, synchronized body temperature and blood pressure recordings were also made. Tonic-clonic seizure activity was observed within an average of 3.9 min (SE= 0.6 min) in the rats exposed to the hot water jets; this treatment induced BBB opening in the cortical and deep brain areas. Body temperature and blood pressure increased from 36.5 degrees +/- 0.3 degrees C to 40.0 degrees+/- 0.2 degrees C, and from 91+/- 3 mmHg to 153+/- 4 mmHg, respectively. In the group of animals exposed to hot water application without inducing seizures, there were significant increases both in blood pressure and body temperature; however, the extravasation of Evans blue was not pronounced in the brains. Hot water-induced seizures, increased cerebrovascular permeability. Although high blood pressure and hyperthermia contribute to this permeability, the seizure activity is the major factor in this change.
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PMID:Changes in blood-brain barrier permeability during hot water-induced seizures in rats. 1465 37