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At least 19 recordsLinked to original sources
PubMed1990

Genetic correlations among inbred strain sensitivities to convulsions induced by 9 convulsant drugs.

Inbred mouse strains differed significantly in sensitivity to convulsions induced by 9 convulsant drugs administered using a timed infusion procedure. Some strains (e.g. BALB/cJ, A/J) were generally seizure-susceptible, while some were generally seizure resistant (e.g. C57BL/6J, SWR/J). However, the overall pattern of strain sensitivities was complex, and depended upon drug and convulsant sign. Five of the drugs (bicuculline, DMCM, picrotoxin, TBPS and pentylenetetrazol (PTZ] produce convulsions, at least in part, through their interactions with the GABA receptor, while the other 4 (strychnine, CHEB, 4-aminopyridine and kainic acid) act through independent mechanisms. We predicted that responses to drugs with similar mechanisms of action would be genetically correlated. However, strains sensitive to picrotoxin-induced convulsions were not necessarily sensitive to convulsions elicited by PTZ or TBPS. Furthermore, different convulsant signs produced by a single drug were not always strongly correlated. Instead, genetic correlations were found among inbred strains for sensitivity to similar convulsant signs produced by different drugs. This suggests that genetic variation in sensitivity to these convulsant drugs arises primarily from variation in systems important for the expression of the convulsion.

Animals↗
PubMed1978

Febrile convulsions followed by nonfebrile convulsions: analysis based on a maximum likelihood method and discriminant function.

Two hundred sixty-two nontreated patients with febrile convulsions only and 107 with later nonfebrile convulsions were analyzed based on a maximum likelihood method and discriminant function. The formula for discrimination is as follows: y = 2.9193 x (basic EEG abnormality at the first examination) + 2.2134 x (more than 20 minutes in duration of convulsion) + 1.7358 (fever under 38.4 degrees C before convulsion) + 1.7005 x (specific EEG abnormality at the first examination) + 1.6703 x (more than 5 recurrences) + 1.5610 x (over 4 years of age at the last convulsion) + 1.4921 x (exogenous causes) + 0.3741 x (family histroy of febrile convulsions among second or third relatives)--3.0397. If an item is positive, coefficient x 1 is to be used, and if it is negative, coefficient x 0 is to be applied. When one classifies patients with y greater than 0 as the FCC group, and those with y less than 0 as the FC group, misclassification may be theoretically expected in 18.9% of cases (accuracy in 81.1%).

Age Factors↗
PubMed1977

Febrile convulsions followed by nonfebrile convulsions. A clinical, electroencephalographic and follow-up study.

103 patients with febrile convulsions followed by nonfebrile convulsions and 512 patients with febrile convulsions only (FC group) under 5 years of age at the first examination were analyzed from many aspects. A trimodal curve in distribution by age at onset of nonfebrile convulsions was seen: 2--3 years of age with occasional grand mal, 5--6 years of age with absence, and 12 years of age with awakening grand mal. Specific EEG abnormality was observed in 40% at the first examination (29% in FC group). Typical or atypical spike-and-wave complex, polyspikes, or continuous EEG abnormality were characteristic (slow wave burst with spike for FC group). Development from febrile convulsions into nonfebrile convulsions was detected in 17% among male and female patients. To identify an effective sign for the prediction of this development, the ratio between correct and incorrect prediction rates was analyzed. Specific paroxysmal EEG abnormality was increased over 3 years of age. EEG change due to aging and the significance of EEG reexamination were indicated.

Age Factors↗
PubMed1992

Effects of malaoxon on phosphatidylinositol signaling in convulsing and non-convulsing non-pregnant and pregnant female rats and their offspring.

Phosphatidylinositol (PI) signaling during organophosphate (OP) induced convulsions and tissue Ca2+ changes in 10 weeks old male, and 14 weeks old non-pregnant and pregnant female rats, and the offspring of the latter were explored. Brain inositol and inositol-1-phosphate (Ins1P) served as indices of alterations in brain PI signaling, and brain tissue Ca2+ as an index of early neuronal injury. A dose of malaoxon OP, which produced convulsions in about 60% of the exposed rats in different rat groups, was 39.2 for male, and 8.2 mg/kg for pregnant female rats, respectively. Malaoxon (8.2 mg/kg) did not produce convulsions in non-pregnant female rats. All the rats were followed for 1 or 4 hr subsequent to malaoxon. Malaoxon decreased cerebral inositol in both male and female rats, and the decrease was similar in spite of the dose difference. The decrease was larger in the convulsing than in the non-convulsing rats. A tendency towards a decrease of brain inositol also occurred in the offspring. Ins1P levels were markedly increased in male, and also in non-pregnant female rats, but not in the brains of pregnant female rats. Ins1P was not markedly changed in the brains of the offspring. Malaoxon elevated brain tissue Ca2+ in male but not in female rats or their offspring. Cholinergic systems and PI signaling in the brain seem to be associated with OP-induced convulsions both in male and female rats; females seem to be more sensitive than males. Malaoxon may also have slightly modified PI signaling in the offspring brain. Hormonal factors are likely to modify OP CNS toxicity and cholinergic stimulation of brain PI signaling.

Animals↗
PubMed1990

[Involvements of neuropeptides in pentylenetetrazol-induced convulsion in rats and effects of TRH and ceruletide on the convulsion].

To study the possible involvements of neuropeptides in the occurrence of convulsion, pentylenetetrazol (PTZ) was given to male Wistar rats weighing 250-350 g, and the concentration of neurotensin (NT), and the maximal number of binding sites (Bmax) and dissociation constant (Kd) of NT receptor in the frontal cortex were measured. The effect of the pretreatment of thyrotropin-releasing hormone (TRH) or ceruletide (CER) on the convulsion was also studied. NT was extracted from the homogenates of rat frontal cortex by boiling, and measured by radioimmunoassay. Membrane fractions were incubated with increasing concentrations of 125I-NT. Nonspecific binding was determined in the presence of unlabeled NT and subtracted from total binding to obtain the specific binding. The Bmax and Kd were calculated by Scatchard analysis. Generalized convulsion appeared after intraperitoneal administration of 50 mg/kg PTZ with a latency of 68.2 +/- 4.4 sec. One hour after the administration, neurotensin-like immunoreactivity (NTLI) concentration was reduced from 4.7 +/- 0.6 to 2.3 +/- 0.1 ng/g wet wt (p less than 0.01) and the Bmax of NT receptor from 17.2 +/- 2.8 to 10.8 +/- 1.1 fmol/mg protein (p less than 0.01). However no significant changes were observed in somatostatin-like immunoreactivity (SSLI) concentration and the Bmax and Kd of SS receptor. These facts indicate that PTZ stimulates the release of NT resulting in down regulation of NT receptor. Pretreatment with intracerebroventricular (icv) administration of 30 micrograms/10 microliters NT 30 min before the 50 mg/kg PTZ administration shortened the duration of the convulsion from 135.0 +/- 42.8 to 11.5 +/- 11.9 sec (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2001

Linkage of benign familial infantile convulsions to chromosome 16p12-q12 suggests allelism to the infantile convulsions and choreoathetosis syndrome.

The syndrome of benign familial infantile convulsions (BFIC) is an autosomal dominant epileptic disorder that is characterized by convulsions, with onset at age 3-12 mo and a favorable outcome. BFIC had been linked to chromosome 19q, whereas the infantile convulsions and choreoathetosis (ICCA) syndrome, in which BFIC is associated with paroxysmal dyskinesias, had been linked to chromosome 16p12-q12. BFIC appears to be frequently associated with paroxysmal dyskinesias, because many additional families from diverse ethnic backgrounds have similar syndromes that have been linked to the chromosome 16 ICCA region. Moreover, one large pedigree with paroxysmal kinesigenic dyskinesias only, has also been linked to the same genomic area. This raised the possibility that families with pure BFIC may be linked to chromosome 16 as well. We identified and studied seven families with BFIC inherited as an autosomal dominant trait. Genotyping was performed with markers at chromosome 19q and 16p12-q12. Although chromosome 19q could be excluded, evidence for linkage in the ICCA region was found, with a maximum two-point LOD score of 3.32 for markers D16S3131 and SPN. This result proves that human chromosome 16p12-q12 is a major genetic locus underlying both BFIC and paroxysmal dyskinesias. The unusual phenotype displayed by one homozygous patient suggests that variability of the ICCA syndrome could be sustained by genetic modifiers.

Age of Onset↗
PubMed1977

[Influence of convulsive and pre-convulsive components of an audiogenic seizure on the process of consolidation of temporary connections].

In comparing the seizures of different severity in rats an amnestic effect of the convulsive phases of the audiogenic attacks on the short-term (in difference from the long-term) memory and the process of consolidation of temporary associations was revealed. Without behavioristic seizures the audiogenic attacks almost failed to derange the short-term memory. The results obtained confirmed the authors' results obtained earlier on different nature of the convulsive and preconvulsive phases of the motor activity during the audiogenic attack in rats. The preconvulsive phase is regarded only as a peculiar motor aura of the audiogenic attack without any convulsive components.

Acoustic Stimulation↗
PubMed1991

Effects of convulsants on handling-induced convulsions in mice selected for ethanol withdrawal severity.

Withdrawal seizure-prone (WSP) mice were genetically selected to express severe handling-induced convulsions (HIC) upon cessation of chronic ethanol vapor inhalation. The HIC is a sensitive measure of CNS excitability, and the current paper compares the effects of eleven convulsant drugs on the HIC in WSP and WSR (withdrawal seizure-resistant) mice, the latter selected for minimal alcohol withdrawal HIC. If WSP and WSR mice were differentially sensitive to a subset of the tested drugs, a common mechanism of action for that subset would imply that genes influencing that mechanism were important in determining ethanol withdrawal severity. All drugs significantly enhanced HIC in WSP mice. The magnitude of enhancement was small for N-methyl-D-aspartate (NMDA), kainic acid, BAY K 8644, Ro 15-4513, and strychnine; greater enhancement in WSP mice was seen after nicotine, and the direct and indirect gamma-aminobutyric acid (GABA) antagonists bicuculline, 3-mercaptopropionic acid, picrotoxin, t-butylcyclophosphorothionate (TBPS), and pentylenetetrazol. Only two drugs, picrotoxin and pentylenetetrazol, had a marked effect on WSR mice: maximal effect of these drugs was equivalent in WSP and WSR mice. However, picrotoxin and pentylenetetrazol were more potent in WSP than in WSR mice. Three other GABA antagonists, bicuculline, 3-mercaptopropionic acid, and TBPS, had a very small effect in WSR mice: these drugs also seemed to be more potent in WSP than in WSR mice. For all other tested drugs, maximal effect in WSP mice was much greater in WSP than in WSR mice.(ABSTRACT TRUNCATED AT 250 WORDS)

Alcoholism↗
PubMed1992

[Risk factors for the occurrence of recurrent convulsions following an initial febrile convulsion].

The results of a follow up study of 155 Dutch children who visited the emergency room of an urban paediatric hospital after experiencing their first febrile seizure are presented. Median follow up time was 38 months (range 27-60). Of these 155 initially untreated children 58 (37%) suffered at least one, 47 (30%) at least two and 27 (17%) at least three recurrent seizures. The recurrence hazard after any seizure was highest in the first six months, and dropped markedly after 6 months without seizures. The effect of the various postulated risk factors on the occurrence of any recurrent seizure and three or more recurrences was assessed. A first degree family history of febrile or nonfebrile seizures appears to be a predictor of multiple recurrences; an age of at least 30 months and a temperature of 40.0 degrees C or higher at the initial seizure are associated with a decreased risk. Several factors act together on the risk of recurrent seizures, sometimes in opposite directions. By considering the action of all relevant factors (age at onset, family history and features of the initial febrile seizure) subgroups of children with one year seizure recurrence rates as low as 15% and as high as 48% were identified.

Age Factors↗