Anticonvulsants ; adverse effects ; Humans ; Seizures ; chemically induced

Although glufosinate ammonium herbicides are considered safe when used properly, ingestion of the undiluted form can cause grave outcomes. Recently, we treated a 34-yr-old man who ingested glufosinate ammonium herbicide. In the course of treatment, the patient developed apnea, mental deterioration, and sixth cranial nerve palsy; he has since been discharged with full recovery after intensive care. This case report describes the clinical features of glufosinate intoxication with a focus on sixth cranial nerve palsy. Our observation suggests that neurologic manifestations after ingestion of a "low-grade toxicity herbicide" are variable and more complex than that was previously considered.
Abducens Nerve Diseases/*chemically induced/drug therapy ; Adult ; Aminobutyrates/*poisoning ; Enzyme Inhibitors/poisoning ; Herbicides/*poisoning ; Humans ; Male ; Seizures/chemically induced ; Surface-Active Agents/poisoning ; Unconsciousness/chemically induced

Glutamine synthetase (GS) is a key enzyme in the regulation of glutamate neurotransmission in the central nervous system. It is responsible for converting glutamate to glutamine, consuming one ATP and NH3 in the process. Glutamate is neurotoxic when it accumulates in extracellular fluids. We investigated the effects of GS in both a spinal cord injury (SCI) model and normal rats. 0.1-ml of low (2-microM) and high (55-microM) concentrations of GS were applied, intrathecally, to the spinal cord of rats under pentobarbital anesthesia. Immediately after an intrathecal injection into the L1-L3 space, the rats developed convulsive movements. These movements initially consisted of myoclonic twitches of the paravertebral muscles close to the injection site, repeated tonic and clonic contractions and extensions of the hind limbs (hind limb seizures) that spread to the fore limbs, and finally rotational axial movements of the body. An EMG of the paravertebral muscles, fore and hind limbs, showed the extent of the muscle activities. GS (2-microM) caused spinal seizures in the rats after the SCI, and GS (6-microM) produced seizures in the uninjured anesthetized rats. Denatured GS (70 degrees C, 1 hour) also produced spinal seizures, although higher concentrations were required. We suggest that GS may be directly blocking the release of GABA, or the receptors, in the spinal cord.
Animals ; Electromyography ; Female ; *Glutamate-Ammonia Ligase/administration & dosage ; Injections, Spinal ; Male ; Rats ; Rats, Long-Evans ; Seizures/*chemically induced/physiopathology ; Spinal Cord Diseases/*chemically induced/physiopathology

Objective To explore the temporal and spatial distribution of CCAAT/enhancer-binding protein homologous protein (CHOP) and calnexin (CNX) in the dentate gyrus of mesial temporal lobe epilepsy (mTLE) mouse model. Methods We used kainic acid (KA) to induce acute phase (12 h and 24 h) mTLE mouse models and performed Western blotting and immunofluorescence to detect the different expressions and distribution pattern of CHOP and CNX in CA3 of the hippocampus. Results Compared with the controls,the expressions of CHOP(F=1.136,P=0.4069) and CNX (F=2.378,P=0.2087) did not increase in CA3 of hippocampus 12 h following KA injection in the acute phase of mTLE mouse models,whereas the expressions in CA1 and CA3 of hippocampus 24 h after injection were significantly higher (F=8.510,P=0.0362;F=6.968,P=0.0497,respectively). As shown by immunofluorescence analysis,CHOP was expressed mainly in CA3 of hippocampus 12 h after KA injection,and increased in CA1 and CA3 24 h after KA administration. Compared with the controls,the expressions of CHOP(F=24.480,P=0.0057) and CNX (F=7.149,P=0.0478) were significantly higher 24 h after KA injection.Conclusions The expression of CHOP increases along with the progression of seizures,indicating the increased level of endoplasmic reticulum stress. An increasing number of CNX,which serves as molecular chaperone,may be needed to facilitate the unfolded protein to complete the folding process.
Animals ; Calnexin ; metabolism ; Dentate Gyrus ; metabolism ; Disease Models, Animal ; Epilepsy, Temporal Lobe ; chemically induced ; metabolism ; Kainic Acid ; Mice ; Seizures ; chemically induced ; metabolism ; Transcription Factor CHOP ; metabolism

The influence of 3α-androstanediol (3α-diol) on twitch and electroencephalogram (EEG) of the epileptic rats induced by pentylenetetrazole (PTZ) has been observed in this experiment in order to comprehensively explore the role of 3α-diol on epileptic attack from the aspects of behavior and EEG. Thirty-two male Sprague-Dawley rats were evenly and randomly divided into 4 groups: the normal and supplied with oil epileptic (N+oil+PTZ) group, the normal and supplied with 3α-diol epileptic (N+3α-diol+PTZ) group, the gonadectomized and supplied with oil epileptic (GDX+oil+PTZ) group and the gonadectomized and supplied with 3α-diol epileptic (GDX+3α-diol+PTZ) group. The changes of the behavior and EEG of epileptic rats in every group were recorded and analyzed. The results of behavior observation showed that the latency to clonic seizure and tonic-clonic seizure was shortened and the number of tonic-clonic seizure was increased significantly in the GDX+oil+PTZ group in comparison with N+oil+PTZ group (P < 0.05); comparing GDX+3α-diol+PTZ group with GDX+oil+PTZ group, or N+3α-diol+PTZ group with N+oil+PTZ group, we found that the latency to clonic seizure and tonic-clonic seizure became prolonged significantly, and the number of clonic seizure and tonic-clonic seizure was decreased significantly (P < 0.05). The results of EEG showed that the latency to epileptic waves was cut and the number of epileptic waves was augmented significantly in the GDX+oil+PTZ group in comparison with N+oil+PTZ group (P < 0.05); comparing GDX+3α-diol+PTZ group with GDX+oil+PTZ group, or N+3α-diol+PTZ group with N+oil+PTZ group, we found that the latency to epileptic waves became lengthened significantly, the number of epileptic waves was reduced significantly and the percentage of change of TP (total power of spectrum) was lessened significantly (P < 0.05). These results indicate that 3α-diol has an antiepileptic activity in the gonadectomized and normal epileptic rats.
Androstane-3,17-diol ; analogs & derivatives ; pharmacology ; Animals ; Anticonvulsants ; pharmacology ; Electroencephalography ; Epilepsy ; chemically induced ; drug therapy ; Male ; Pentylenetetrazole ; adverse effects ; Rats ; Rats, Sprague-Dawley ; Seizures ; chemically induced ; drug therapy

BACKGROUNDLidocaine and ropivacaine are often combined in clinical practice to obtain a rapid onset and a prolonged duration of action. However, the systemic toxicity of their mixture at different concentrations is unclear. This study aimed to compare the systemic toxicity of the mixture of ropivacaine and lidocaine at different concentrations when administered intravenously in rats.

METHODSForty-eight male Wistar rats were randomly divided into 4 groups (n = 12 each): 0.5% ropivacaine (group I); 1.0% ropivacaine and 1.0% lidocaine mixture (group II); 1.0% ropivacaine and 2.0% lidocaine mixture (group III); and 1.0% lidocaine (group IV). Local anesthetics were infused at a constant rate until cardiac arrest. Electrocardiogram, electroencephalogram and arterial blood pressure were continuously monitored. The onset of toxic manifestations (seizure, dysrhythmia, and cardiac arrest) was recorded, and then the doses of local anesthetics were calculated. Arterial blood samples were drawn for the determination of local anesthetics concentrations by high-performance liquid chromatography.

RESULTSThe onset of dysrhythmia was later significantly in group IV than in group I, group II, and group III (P < 0.01), but there was no significant difference in these groups (P > 0.05). The onset of seizure, cardiac arrest in group I ((9.2 + or - 1.0) min, (37.0 + or - 3.0) min) was similar to that in group II ((9.1 + or - 0.9) min, (35.0 + or - 4.0) min) (P > 0.05), but both were later in group III ((7.5 + or - 0.7) min, (28.0 + or - 3.0) min) (P < 0.05). The onset of each toxic manifestation was significantly later in group IV than in group I (P < 0.01). The plasma concentrations of the lidocaine-alone group at the onset of dysrhythmia (DYS), cardiac arrest (CA) ((41.2 + or - 6.8) min, (59.0 + or - 9.0) min) were higher than those of the ropivacaine alone group ((20.5 + or - 3.8) min, (38.0 + or - 8.0) min) (P < 0.05). The plasma concentrations of ropivacaine inducing toxic manifestation were not significantly different among groups I, II, and III (P > 0.05).

CONCLUSIONSThe systemic toxicity of the mixture of 1.0% ropivacaine and 2.0% lidocaine is the greatest while that of 1.0% lidocaine is the least. However, the systemic toxicity of the mixture of 1.0% ropivacaine and 1.0% lidocaine is similar to that of 0.5% ropivacaine alone.

Amides ; toxicity ; Anesthetics, Local ; toxicity ; Animals ; Arrhythmias, Cardiac ; chemically induced ; Cardiovascular System ; drug effects ; Central Nervous System ; drug effects ; Heart Arrest ; chemically induced ; Lidocaine ; toxicity ; Male ; Random Allocation ; Rats ; Rats, Wistar ; Seizures ; chemically induced

To explore the mechanism of interleukin-1beta (IL-1beta) in the onset of seizure and the effect of IL-1beta on the expression of adenylyl cyclase (AC) in rats with seizure induced by L-glutamate. Experimental rats were first injected with IL-1beta and then L-glutamate (a dose under the threshold) was injected into the right lateral ventricle. The rats were sacrificed 4 h after the onset of epileptic activity and examined for changes in behavior, immunohistochemistry and compared with those with seizure induced by L-glutamate alone. It was found that the expression of AC in hippocampal and neocortex of rats with seizure induced by IL-1beta and L-glutamate were stronger than that of control group (P<0.05), without significant difference found between the L-glutamate group and IL-1beta plus L-glutamate group in the expression of AC, the latent period and the severity of seizure. When IL-ra were given (i.c.v.) first, there was no epileptic activity and the expression of AC did not increase. There were no differences in the expression of AC of rats with IL-1ra and that of control rats. But when 2-methyl-2-(carboxycyclopropyl) glycine (MCCG) was given (i.c.v.) first, the strongest expression of AC, the shortest latent period and the the most serious seizure activities were observed. The results indicated that IL-1beta could facilitate the onset of epilepsy induced by L-glutamate through IL-1R, metabotropic glutamate receptors might work with IL-1R and the increased expression of AC might be involved in the process.
Adenylyl Cyclases ; biosynthesis ; genetics ; Animals ; Glutamic Acid ; Hippocampus ; metabolism ; Interleukin-1 ; pharmacology ; Male ; Neocortex ; metabolism ; Rats ; Seizures ; chemically induced ; enzymology

AIMTo further explore the roles of endogenous nitric oxide (NO) or NO derivatives in complex partial seizures and generalized convulsions.

METHODSThe effect of pretreatment with L-nitroarginine (L-NNA), an inhibitor of nitric oxide synthase (NOS), or L arginine (L-Arg), a precursor of NO on kainic acid (KA)-induced seizure in rats and the changes in the concentration of NO2 -/NO- in the hippocampus were determined.

RESULTSThe rats appeared with wet dog shakes (WDS) at 15 min and then occurred generalized convulsions during 1 h to 3 h after administration of KA (10 mg/kg i.p.). However, the pretreatment of L-NNA (50 mg/kg) so dramatically promoted and enhanced KA-induced behavioral seizures that the latency of generalized convulsion was shorten dramatically, and the mortality was greatly high. In contrast, the pretreatment with L-Arg (40 mg/kg) markedly delayed or weakened KA-induced behavioral changes, such as increasing latency of WDS and generalized convulsion, shortening time o f seizure and none of animal died during observed time. The concentration of NO2- /NO3- in the hippocampus increased immediately at 30 min and remained to 7 d after the administration of KA. Compared with control group (pretreatment with NS), the concentration of NO2- / NO3- in the hippocampus apparently increased at 3 h and 3 d after the administration of KA in the rats with L-Arg pretreatment.

CONCLUSIONThe endogenous NO (NO or NO derivatives) mediators may play an important role against excitotoxin induced seizures in rats.

Animals ; Arginine ; pharmacology ; Kainic Acid ; adverse effects ; Male ; Nitric Oxide ; metabolism ; Nitroarginine ; pharmacology ; Rats ; Rats, Wistar ; Seizures ; chemically induced ; metabolism

OBJECTIVETo observe the histopathological changes in rat hippocampus at different maturational stages after repeated kindled seizures, and to explore their underlying epileptogenesis processes.

METHODSThree groups of Wistar rats (postnatal days: P10, P20, P60) were given pentylenetetrazol (PTZ) intraperitoneal injection for 5 days to induce repeated kindled seizures, and the age-matched rats in control group were injected with normal saline. The behavioral changes, the morphology and the neurons counting in hippocampus, as well as the expression of NF-kappaB were observed.

RESULTS(1) In the three groups, the latency of seizure and the latency of IV/V grade were significantly lower in the rats of group P10 and P20 [(1.2 +/- 0.6) min and (14.4 +/- 2.3) min vs. (4.7 +/- 1.6) min and (24.5 +/- 4.5) min] than group P60 [(8.6 +/- 2.0) min and (41.9 +/- 4.5) min], whereas the duration of convulsion in group P10 and P20 [(46.2 +/- 4.8) min and (29.8 +/- 5.9) min] was longer than those of group P60 [(17.1 +/- 5.0) min]. (2) The neuron counting of CA(1), CA(3) and hilar in the P10 and P20 groups showed no differences as compared to their controls, whereas adult rats (P60) had a significant neuron loss in CA(1) and CA(3) pyramidal cells, compared with the control group [(6.3 +/- 1.5)/250 microm(2), (3.6 +/- 1.4)/250 microm(2) vs. (8.2 +/- 1.9)/250 microm(2), (5.6 +/- 1.7)/250 microm(2)]. However, the dentate granule cells in immature rats (P10) with daily seizures had a significant increase as compared with the controls [(23.3 +/- 3.1)/250 microm(2) vs. (16.3 +/- 1.6)/250 microm(2)]. (3) Prominent sprouting was seen in the CA(3) stratum pyramidal layer in all experimental rats with 5 daily seizures, regardless of the age. But the degree of sprouting had significant differences among the experimental groups (P < 0.05). (4) NF-kappaB was expressed significantly in CA(3), CA(1) and dentate granule cells 24 hours after PTZ-kindling when compared with the control groups, with the spectral density decreased with age.

CONCLUSION(1) There were great differences in the vulnerability to the repeated seizure-induced brain damage at different maturational stages in rats. The immature brain appeared to be less vulnerable to the repeated seizures. (2) There was less hippocampus neuron loss and milder mossy fiber sprouting after repeated seizures in the developing rats than mature ones, which may be a pathological evidence underlying the prospect that the immature brain was more resistant to the seizure-induced neuronal injury. (3) The high expression of NF-kappaB may exert a certain biological effects in the seizure-induced neuronal injury.

Age Factors ; Animals ; Hippocampus ; drug effects ; pathology ; NF-kappa B ; metabolism ; Pentylenetetrazole ; adverse effects ; Rats ; Rats, Wistar ; Seizures ; chemically induced

OBJECTIVE: To investigate the application of power spectral entropy (PSE) in epileptic rats induced by penicillin, and to exploreits its value in predicting epileptic seizures. METHODS: Eighteen SD rats were randomly divided into 3 groups: a normal group, a control group and an epileptic group. Acute chemical models were made using penicillin microinjection in the right hippocampus of rats. Sprague-Dawley (SD) rats received continuous electroencephalographic (EEG) monitoring by deep department electrode. Changes of PSE of EEG signal in the epileptic group were analysed in the whole seizure process and compared with those in the normal group and the control group. RESULTS: In the whole seizure process of the rats induced by penicillin, PSE began to decline during the pre-ictal period and dropped sharply during the ictal period. PSE in the pre-ictal and ictal period declined apparently comparing with that in the non-ictal period. PSE in the epileptic group had significant differences during the ictal and pre-ictal period compared with that in the normal group and the control group (P<0.05). CONCLUSION Changes of PSE reveal the changes of the complex ictal EEG signals, and may be useful to predict epileptic seizures.
Animals ; Electroencephalography ; methods ; Entropy ; Epilepsy ; chemically induced ; diagnosis ; Male ; Nonlinear Dynamics ; Penicillins ; Predictive Value of Tests ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Seizures ; chemically induced ; diagnosis ; Signal Processing, Computer-Assisted