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- Triheptanoin partially restores levels of tricarboxylic acid cycle intermediates in the mouse pilocarpine model of epilepsy. [JOURNAL ARTICLE]
- J Neurochem 2013 Nov 16.
Triheptanoin, the triglyceride of heptanoate, is anticonvulsant in various epilepsy models. It is thought to improve energy metabolism in the epileptic brain by re-filling the tricarboxylic acid (TCA) cycle with C4-intermediates (anaplerosis). Here, we injected mice with [1,2-(13) C]glucose 3.5-4 weeks after pilocarpine-induced status epilepticus (SE) fed either a control or triheptanoin diet. Amounts of metabolites and incorporations of (13) C were determined in extracts of cerebral cortices and hippocampal formation and enzyme activity and mRNA expression were quantified. The percentage enrichment with two (13) C atoms in malate, citrate, succinate, and GABA was reduced in hippocampal formation of control-fed SE compared with control mice. Except for succinate, these reductions were not found in triheptanoin-fed SE mice, indicating that triheptanoin prevented a decrease of TCA cycle capacity. Compared to those on control diet, triheptanoin-fed SE mice showed few changes in most other metabolite levels and their (13) C labeling. Reduced pyruvate carboxylase mRNA and enzyme activity in forebrains and decreased [2,3-(13) C]aspartate amounts in cortex suggest a pyruvate carboxylation independent source of C-4 TCA cycle intermediates. Most likely anaplerosis was kept unchanged by carboxylation of propionyl-CoA derived from heptanoate. Further studies are proposed to fully understand triheptanoin's effects on neuroglial metabolism and interaction. In the hippocampal formation (HF) of a mouse epilepsy model, formation of citrate, GABA, succinate, fumarate, and malate from (13) C-labeled glucose is reduced. Triheptanoin, the triglyceride of heptanoate, inhibits pyruvate carboxylase activity (PC, green arrow), but restores some of these metabolite levels (red arrows). The refilling of the TCA cycle via carboxylation of propionyl-CoA is likely to contribute to triheptanoin's anticonvulsant effects.
- Effect of lithium-pilocarpine-induced status epilepticus on ultrasonic vocalizations in the infant rat pup. [JOURNAL ARTICLE]
- Epilepsy Behav 2013 Nov 12.
Evidence shows that febrile convulsions induced in rat pups increase ultrasonic vocalizations (USVs); however, the effect of status epilepticus (SE) induced in developing rats on USVs has not been fully investigated. The goal of this study was to analyze USVs following lithium-pilocarpine-induced SE in fourteen-day-old (P14) rat pups. The rat pups were given 3-mEq/kg lithium chloride i.p. on the day before the induction of SE, which was carried out at P14 by subcutaneous injection of 100-mg/kg pilocarpine hydrochloride; control animals were given an equal volume of lithium chloride and saline on P13 and P14, respectively. Ultrasonic vocalizations were monitored at P15, P16, and P21 with a Mini 3 Bat Detector Ultra Sound Advice (15kHz-160kHz) set at 40±4kHz and digitally recorded in WAV format using the Audacity 1.3 beta software. A clear box (60×40×30cm) split down the middle with a holed wall was used; each pup was placed alone in one compartment, whereas its dam was placed on the other cage side at room temperature. Vocalizations were recorded over a 5-minute period, converted to sonograms and spectrograms, and analyzed using the Raven software. Parameters evaluated were as follows: USV frequency, latency to the first USV, and mean USV duration. There was a significant decrease in the latency (35.5±6.9s) and duration (50.8±8.6s) of USVs after SE compared with the control group (81.9±10.8s and 78.1±9.9s, respectively). Status epilepticus affected male and female rats differentially.
- Seizure-induced disinhibition of the HPA axis increases seizure susceptibility. [JOURNAL ARTICLE]
- Epilepsy Res 2013 Oct 28.
Stress is the most commonly reported precipitating factor for seizures. The proconvulsant actions of stress hormones are thought to mediate the effects of stress on seizure susceptibility. Interestingly, epileptic patients have increased basal levels of stress hormones, including corticotropin-releasing hormone (CRH) and corticosterone, which are further increased following seizures. Given the proconvulsant actions of stress hormones, we proposed that seizure-induced activation of the hypothalamic-pituitary-adrenal (HPA) axis may contribute to future seizure susceptibility. Consistent with this hypothesis, our data demonstrate that pharmacological induction of seizures in mice with kainic acid or pilocarpine increases circulating levels of the stress hormone, corticosterone, and exogenous corticosterone administration is sufficient to increase seizure susceptibility. However, the mechanism(s) whereby seizures activate the HPA axis remain unknown. Here we demonstrate that seizure-induced activation of the HPA axis involves compromised GABAergic control of CRH neurons, which govern HPA axis function. Following seizure activity, there is a collapse of the chloride gradient due to changes in NKCC1 and KCC2 expression, resulting in reduced amplitude of sIPSPs and even depolarizing effects of GABA on CRH neurons. Seizure-induced activation of the HPA axis results in future seizure susceptibility which can be blocked by treatment with an NKCC1 inhibitor, bumetanide, or blocking the CRH signaling with Antalarmin. These data suggest that compromised GABAergic control of CRH neurons following an initial seizure event may cause hyperexcitability of the HPA axis and increase future seizure susceptibility.
- Complete Vogt-Koyanagi-Harada Disease and Holmes-Adie Syndrome: Case Report. [JOURNAL ARTICLE]
- Ocul Immunol Inflamm 2013 Nov 11.
Abstract We report a 37-year-old woman with uveitic phase of Vogt Koyanagi Harada disease and tonic pupil, the tonic pupil persisted after other clinical features of this syndrome had disappeared; neurological evaluation shows absent knee and arm tendon reflexes and positive cholinergic supersensitivity test with Pilocarpine 0.125% confirming the diagnosis of Holmes Adie Syndrome.
- Amygdala opioid receptors mediate the electroacupuncture-induced deterioration of sleep disruptions in epilepsy rats. [JOURNAL ARTICLE]
- J Biomed Sci 2013 Nov 12; 20(1):85.
Clinical and experimental evidence demonstrates that sleep and epilepsy reciprocally affect each other. Previous studies indicated that epilepsy alters sleep homeostasis; in contrast, sleep disturbance deteriorates epilepsy. If a therapy possesses both epilepsy suppression and sleep improvement, it would be the priority choice for seizure control. Effects of acupuncture of Feng-Chi (GB20) acupoints on epilepsy suppression and insomnia treatment have been documented in the ancient Chinese literature, Lingshu Jing (Classic of the Miraculous Pivot). Therefore, this study was designed to investigate the effect of electroacupuncture (EA) stimulation of bilateral Feng-Chi acupoints on sleep disruptions in rats with focal epilepsy.Our result indicates that administration of pilocarpine into the left central nucleus of amygdala (CeA) induced focal epilepsy and decreased both rapid eye movement (REM) sleep and non-REM (NREM) sleep. High-frequency (100 Hz) EA stimulation of bilateral Feng-Chi acupoints, in which a 30-min EA stimulation was performed before the dark period of the light:dark cycle in three consecutive days, further deteriorated pilocarpine-induced sleep disruptions. The EA-induced exacerbation of sleep disruption was blocked by microinjection of naloxone, mu- (naloxonazine), kappa- (nor-binaltorphimine) or delta-receptor antagonists (natrindole) into the CeA, suggesting the involvement of amygdaloid opioid receptors.The present study suggests that high-frequency (100 Hz) EA stimulation of bilateral Feng-Chi acupoints exhibits no benefit in improving pilocarpine-induced sleep disruptions; in contrast, EA further deteriorated sleep disturbances. Opioid receptors in the CeA mediated EA-induced exacerbation of sleep disruptions in epileptic rats.
- Characteristics of pupillo-accommodative functions according to time of onset, gender and age in tonic pupil. [Journal Article]
- Int J Ophthalmol 2013; 6(5):659-61.
To evaluate the characteristics of pupillo-accommodative functions in patients with idiopathic tonic pupil according to the time of onset, gender, and age.Totally, 15 males and 19 females were divided into 2 groups depending on the time of disease onset: group I (onset <2 months, n=20) and group II (onset >2 months, n=14). A supersensivity test was conducted by applying diluted pilocarpine 0.125% to the eye and accommodative functions were evaluated using the near-point of accommodation (NPA) as the cutoff point, at which the patient experienced blurred vision. Pupil size and the ratio of decrease in the affected pupil after instillation of 0.125% pilocarpine were investigated.There was no significant difference between the 2 groups regarding the various pupillary reflex results, including data on the affected pupil size before and after 0.125% pilocarpine, anisocoria, and ratio of pupil decrease. No significant difference in NPA was found between the 2 groups. However, female patients were noted to have greater anisocoria and a faster constriction ratio than those of the male patients (P=0.02 and P=0.04). On subgroup analysis, female patients from group II had larger affected-pupil sizes before 0.125% pilocarpine instillation and longer NPAs than those of the male patients.No relationship was found between time of onset and dysfunction of pupillo-accommodative functions. Pupillo-accommodative functions and age were not related, except for the NPA.
- Biodegradable in situ gelling delivery systems containing pilocarpine as new antiglaucoma formulations: effect of a mercaptoacetic acid/N-isopropylacrylamide molar ratio. [Journal Article, Research Support, Non-U.S. Gov't]
- Drug Des Devel Ther 2013.:1273-85.
Ocular drug delivery is one of the most commonly used treatment modalities in the management of glaucoma. We have recently proposed the use of gelatin and poly(N-isopropylacrylamide) (PNIPAAm) graft copolymers as biodegradable in situ forming delivery systems for the intracameral administration of antiglaucoma medications. In this study, we further investigated the influence of carrier characteristics on drug delivery performance. The carboxyl-terminated PNIPAAm samples with different molecular weights were synthesized by varying the molar ratio of mercaptoacetic acid (MAA)/N-isopropylacrylamide (NIPAAm) from 0.05 to 1.25, and were determined by end-group titration. The preparation of gelatin-g-PNIPAAm (GN) copolymers from these thermoresponsive polymers was achieved using carbodiimide chemistry. Our results showed that the carboxylic end-capped PNIPAAm of high molecular weight may lead to the lower thermal phase transition temperature and slower degradation rate of GN vehicles than its low molecular weight counterparts. With a decreasing MAA/NIPAAm molar ratio, the drug encapsulation efficiency of copolymers was increased due to fast temperature-triggered capture of pilocarpine nitrate. The degradation of the gelatin network could greatly affect the drug release profiles. All of the GN copolymeric carriers demonstrated good corneal endothelial cell and tissue compatibility. It is concluded that different types of GN-based delivery systems exhibit noticeably distinct intraocular pressure-lowering effect and miosis action, thereby reflecting the potential value of a MAA/NIPAAm molar ratio in the development of new antiglaucoma formulations.
- The kainic acid model of temporal lobe epilepsy. [JOURNAL ARTICLE]
- Neurosci Biobehav Rev 2013 Oct 30.
The kainic acid model of temporal lobe epilepsy has greatly contributed to the understanding of the molecular, cellular and pharmacological mechanisms underlying epileptogenesis and ictogenesis. This model presents with neuropathological and electroencephalographic features that are seen in patients with temporal lobe epilepsy. It is also characterized by a latent period that follows the initial precipitating injury (i.e., status epilepticus) until the appearance of recurrent seizures, as observed in the human condition. Finally, the kainic acid model can be reproduced in a variety of species using either systemic, intrahippocampal or intra-amygdaloid administrations. In this review, we describe the various methodological procedures and evaluate their differences with respect to the behavioral, electroencephalographic and neuropathological correlates. In addition, we compare the kainic acid model with other animal models of temporal lobe epilepsy such as the pilocarpine and the kindling model. We conclude that the kainic acid model is a reliable tool for understanding temporal lobe epilepsy, provided that the differences existing between methodological procedures are taken into account.
- Do pilocarpine drops help dry mouth in palliative care patients: a protocol for an aggregated series of n-of-1 trials. [JOURNAL ARTICLE]
- BMC Palliat Care 2013 Oct 31; 12(1):39.
It is estimated that 39,000 Australians die from malignant disease yearly. Of these, 60% to 88% of advanced cancer patients suffer xerostomia, the subjective feeling of mouth dryness. Xerostomia has significant physical, social and psychological consequences which compromise function and quality of life. Pilocarpine is one treatment for xerostomia. Most studies have shown some variation in individual response to pilocarpine, in terms of dose used, and timing and extent of response.We will determine a population estimate of the efficacy of pilocarpine drops (6 mg) three times daily compared to placebo in relieving dry mouth in palliative care (PC) patients. A secondary aim is to assess individual patients' response to pilocarpine and provide reports detailing individual response to patients and their treating clinician.Aggregated n-of-1 trials (3 cycle, double blind, placebo-controlled crossover trials using standardized measures of effect). Individual trials will identify which patients respond to the medication. To produce a population estimate of a treatment effect, the results of all cycles will be aggregated.Managing dry mouth with treatment supported by the best possible evidence will improve functional status of patients, and improve quality of life for patients and carers. Using n-of-1 trials will accelerate the rate of accumulation of high-grade evidence to support clinical therapies used in PC.Trial registration: Australia and New Zealand Clinical Trial Registry Number: 12610000840088.
- Activation of amygdala opioid receptors by electroacupuncture of Feng-Chi (GB20) acupoints exacerbates focal epilepsy. [JOURNAL ARTICLE]
- BMC Complement Altern Med 2013 Oct 29; 13(1):290.
The effect of seizure suppression by acupuncture of Feng-Chi (GB20) acupoints has been documented in the ancient Chinese literature, Lingshu Jing (Classic of the Miraculous Pivot), however, there is a lack of scientific evidence to prove it. This current study was designed to elucidate the effect of electroacupuncture (EA) stimulation of bilateral Feng-Chi (GB20) acupoints on the epileptic activity by employing an animal model of focal epilepsy.Administration of pilocarpine into the left central nucleus of amygdala (CeA) induced the focal epilepsy in rats. Rats received a 30-min 100 Hz EA stimulation of bilateral Feng-Chi acupoints per day, beginning at 30 minutes before the dark period and performing in three consecutive days. The broad-spectrum opioid receptor antagonist (naloxone), mu-receptor antagonist (naloxonazine), delta-receptor antagonist (naltrindole) and kappa-receptor antagonist (nor-binaltorphimine) were administered directly into the CeA to elucidate the involvement of CeA opioid receptors in the EA effect.High-frequency (100 Hz) EA stimulation of bilateral Feng-Chi acupoints did not suppress the pilocarpine-induced epileptiform electroencephalograms (EEGs), whereas it further increased the duration of epileptiform EEGs. We also observed that epilepsy occurred while 100 Hz EA stimulation of Feng-Chi acupoints was delivered into naive rats. EA-induced augmentation of epileptic activity was blocked by microinjection of naloxone, mu- (naloxonazine), kappa- (nor-binaltorphimine) or delta-receptor antagonists (natrindole) into the CeA, suggesting that activation of opioid receptors in the CeA mediates EA-exacerbated epilepsy.The present study suggests that high-frequency (100 Hz) EA stimulation of bilateral Feng-Chi acupoints has no effect to protect against pilocarpine-induced focal epilepsy; in contrast, EA further exacerbated focal epilepsy induced by pilocarpine. Opioid receptors in the CeA mediated EA-induced exacerbation of focal epilepsy.