A prospective, multicenter, noninterventional study in Taiwan to evaluate the safety and tolerability of lacosamide as adjunctive therapy for epilepsy in clinical practice

RATIONALE

Lacosamide (LCM) was initially approved in Taiwan in March 2014 for use as adjunctive therapy for focal impaired awareness seizures and secondarily generalized seizures (SGS) in patients with epilepsy ≥16 years of age. The efficacy and tolerability of adjunctive LCM for the treatment of patients with focal seizures have been demonstrated in randomized, placebo-controlled trials. However, the trials do not reflect a flexible dose setting. This study (EP0063) was conducted to assess the safety and tolerability of LCM in real-world clinical practice in Taiwan. Effectiveness of LCM was also assessed as an exploratory objective.

METHODS

EP0063 was a multicenter, prospective, noninterventional study with an expected observation period of 12 months ± 60 days. Eligible patients were ≥16 years of age, had focal impaired awareness seizures and/or SGS (in line with approved indication in Taiwan at the time of the study), were taking at least one concomitant antiseizure medication (ASM), and had at least one seizure in the 3 months before baseline. Patients were prescribed LCM by their treating physician in the course of routine clinical practice. The primary safety variable was treatment-emergent adverse events (TEAEs) spontaneously reported to, or observed by, the treating physician. Based on safety data from previous studies of LCM and known side effects of other ASMs, certain TEAEs (including but not limited to cardiac and electrocardiogram, suicidality, and rash related terms) were analyzed separately. Effectiveness variables included Clinical Global Impression of Change (CGIC) and change in 28-day seizure frequency from baseline to 12 months (or final visit), and freedom from focal seizures.

RESULTS

A total of 171 patients were treated with LCM, of whom 139 (81.3%) completed the study. The Kaplan-Meier estimated 12-month retention was 82.9%. Patients had a mean (standard deviation [SD], range) age of 38.5 (14.0, 16-77) years, and 96 (56.1%) were male. Patients were taking a mean (SD, range) of 2.8 (1.1, 1-6) ASMs at baseline. Mean (SD, range) duration of LCM treatment was 288.7 (111.9, 2-414) days, and the mean (SD, range) daily dosage of LCM was 205.0 (82.7, 50.0-505.2) mg/day. Overall, 95 (55.6%) patients reported at least one TEAE, most commonly dizziness (33 [19.3%] patients). Drug-related TEAEs were reported in 74 (43.3%) patients, and drug-related TEAEs leading to discontinuation of LCM were reported in 14 (8.2%) patients. Two (1.2%) patients died during LCM treatment, which were considered not related to LCM. Two (1.2%) patients had suicidality-related TEAEs; these TEAEs were considered either not related to LCM or the relationship was not recorded. Rash-related TEAEs were reported in five (2.9%) patients (considered LCM-related in two patients). Based on the CGIC, at 12 months (or final visit), 109 (63.7%) patients were considered to have improved, 54 (31.6%) had no change, and the remaining eight (4.7%) were minimally worse. At 12 months (or final visit), the median percentage change in focal seizure frequency was -50.0. During the first 6 months of the study, 21 (12.3%) patients were free from focal seizures; 37 (21.6%) patients were free from focal seizures in the last 6 months of the study; and 14 (8.2%) were free from focal seizures for the full 12 months of the study.

CONCLUSIONS

Results of this prospective, noninterventional study suggest that adjunctive LCM was generally safe and well tolerated in this patient group in real-world practice in Taiwan. Effectiveness was also favorable, with more than 60% of patients considered to be improved by their physician at 12 months (or final visit).

Effects of N6 -(4-hydroxybenzyl) adenine riboside in stress-induced insomnia in rodents

Adenosine exhibits a somnogenic effect; however, there is no adenosinergic hypnotic because of cardiovascular effects. This study investigated whether N6-(4-hydroxybenzyl) adenine riboside (T1-11), extracted from Gastrodia elata, produces somnogenic effects in rodents. We determined the involvement of adenosine 2A receptors (A2ARs) in GABAergic neurons of the ventrolateral preoptic area (VLPO) and the cardiovascular effects. Change of cage bedding is employed as a stressor to induce insomnia in rodents, and electroencephalograms and electromyograms were used to acquire and analyse sleep-wake activity. We found that intracerebroventricular administration of T1-11 before a dark period increased non-rapid eye movement (NREM) and rapid eye movement (REM) sleep during a dark period, and T1-11-induced sleep increases were blocked by the A2AR antagonist, SCH58261, in naïve rats. Oral administration of T1-11 increased NREM sleep during both dark and light periods. Microinjection of the A2AR antagonist, SCH58261, into the VLPO blocked sleep effects of T1-11. In addition to the somnogenic effect in naïve mice, T1-11 suppressed the stress-induced insomnia and this suppressive effect was blocked by SCH58261. C-fos expression in GABAergic neurons of VLPO was increased after administration of T1-11 in Gad2-Cre::Ai14 mice, suggesting the activation of GABAergic neurons in the VLPO. T1-11 exhibited no effects on heart rate and the low frequency/high frequency ratio of heart rate variability. We concluded that T1-11 elicited somnogenic effects and effectively ameliorated acute stress-induced insomnia. The somnogenic effect is mediated by A2ARs to activate GABAergic neurons in the VLPO. This adenosine analogue could be a potential hypnotic because of no sympathetic and parasympathetic effects on the cardiovascular system.

Serum Levels of Brain-Derived Neurotrophic Factor and Insulin-Like Growth Factor 1 Are Associated With Autonomic Dysfunction and Impaired Cerebral Autoregulation in Patients With Epilepsy

Background: Brain-derived neurotrophic factor (BDNF) and insulin-like growth factor 1 (IGF-1) may regulate the autonomic nervous system (ANS) in epilepsy. The present study investigated the role of IGF-1 and BDNF in the regulation of autonomic functions and cerebral autoregulation in patients with epilepsy. Methods: A total of 57 patients with focal epilepsy and 35 healthy controls were evaluated and their sudomotor, cardiovagal, and adrenergic functions were assessed using a battery of ANS function tests, including the deep breathing, Valsalva maneuver, head-up tilting, and Q-sweat tests. Cerebral autoregulation was measured by transcranial doppler during the breath-holding test and the Valsalva maneuver. Interictal serum levels of BDNF and IGF-1 were measured with enzyme-linked immunosorbent assay kits. Results: During interictal period, reduced serum levels of BDNF and IGF-1, impaired autonomic functions, and decreased cerebral autoregulation were noted in patients with epilepsy compared with healthy controls. Reduced serum levels of BDNF correlated with age, adrenergic and sudomotor function, overall autonomic dysfunction, and the autoregulation index calculated in Phase II of the Valsalva maneuver, and showed associations with focal to bilateral tonic-clonic seizures. Reduced serum levels of IGF-1 were found to correlate with age and cardiovagal function, a parameter of cerebral autoregulation (the breath-hold index). Patients with a longer history of epilepsy, higher seizure frequency, and temporal lobe epilepsy had lower serum levels of IGF-1. Conclusions: Long-term epilepsy and severe epilepsy, particularly temporal lobe epilepsy, may perturb BDNF and IGF-1 signaling in the central autonomic system, contributing to the autonomic dysfunction and impaired cerebral autoregulation observed in patients with focal epilepsy.

Correlation of vocals and lyrics with left temporal musicogenic epilepsy

Whether the cognitive processing of music and speech relies on shared or distinct neuronal mechanisms remains unclear. Music and language processing in the brain are right and left temporal functions, respectively. We studied patients with musicogenic epilepsy (ME) that was specifically triggered by popular songs to analyze brain hyperexcitability triggered by specific stimuli. The study included two men and one woman (all right-handed, aged 35-55 years). The patients had sound-triggered left temporal ME in response to popular songs with vocals, but not to instrumental, classical, or nonvocal piano solo versions of the same song. Sentimental lyrics, high-pitched singing, specificity/familiarity, and singing in the native language were the most significant triggering factors. We found that recognition of the human voice and analysis of lyrics are important causal factors in left temporal ME and provide observational evidence that sounds with speech structure are predominantly processed in the left temporal lobe. A literature review indicated that language-associated stimuli triggered ME in the left temporal epileptogenic zone at a nearly twofold higher rate compared with the right temporal region. Further research on ME may enhance understanding of the cognitive neuroscience of music.

Manipulation of Epileptiform Electrocorticograms (ECoGs) and Sleep in Rats and Mice by Acupuncture

Ancient Chinese literature has documented that acupuncture possesses efficient therapeutic effects on epilepsy and insomnia. There is, however, little research to reveal the possible mechanisms behind these effects. To investigate the effect of acupuncture on epilepsy and sleep, several issues need to be addressed. The first is to identify the acupoints, which correspond between humans, rats, and mice. Furthermore, the depth of insertion of the acupuncture needle, the degree of needle twist in manual needle acupuncture, and the stimulation parameters for electroacupuncture (EA) need to be determined. To evaluate the effects of acupuncture on epilepsy and sleep, a feasible model of epilepsy in rodents is required. We administer pilocarpine into the left central nucleus of the amygdala (CeA) to simulate focal temporal lobe epilepsy (TLE) in rats. Intraperitoneal (IP) injection of pilocarpine induces generalized epilepsy and status epilepticus (SE) in rats. Five IP injections of pentylenetetrazol (PTZ) with a one-day interval between each injection successfully induces spontaneous generalized epilepsy in mice. Recordings of electrocorticograms (ECoGs), electromyograms (EMGs), brain temperature, and locomotor activity are used for sleep analysis in rats, while ECoGs, EMGs, and locomotor activity are employed for sleep analysis in mice. ECoG electrodes are implanted into the frontal, parietal, and contralateral occipital cortices, and a thermistor is implanted above the cerebral cortex by stereotactic surgery. EMG electrodes are implanted into the neck muscles, and an infrared detector determines locomotor activity. The criteria for categorizing vigilance stages, including wakefulness, rapid eye movement (REM) sleep, and non-REM (NREM) sleep are based on information from ECoGs, EMGs, brain temperature, and locomotor activity. Detailed classification criteria are stated in the text.

Interleukin-1 receptor (IL-1R) mediates epilepsy-induced sleep disruption

Background

Sleep disruptions are common in epilepsy patients. Our previous study demonstrates that homeostatic factors and circadian rhythm may mediate epilepsy-induced sleep disturbances when epilepsy occurs at different zeitgeber hours. The proinflammatory cytokine, interleukin-1 (IL-1), is a somnogenic cytokine and may also be involved in epileptogenesis; however, few studies emphasize the effect of IL-1 in epilepsy-induced sleep disruption. We herein hypothesized that IL-1 receptor type 1 (IL-1R1) mediates the pathogenesis of epilepsy and epilepsy-induced sleep disturbances. We determined the role of IL-1R1 by using IL-1R1 knockout (IL-1R1 −/− KO) mice.

Results

Our results elucidated the decrease of non-rapid eye movement (NREM) sleep during the light period in IL-1R −/− mice and confirmed the somnogenic role of IL-1R1. Rapid electrical amygdala kindling was performed to induce epilepsy at the particular zeitgeber time (ZT) point, ZT13. Our results demonstrated that seizure thresholds induced by kindling stimuli, such as the after-discharge threshold and successful kindling rates, were not altered in IL-1R −/− mice when compared to those obtained from the wildtype mice (IL-1R +/+ mice). This result suggests that IL-1R1 is not involved in kindling-induced epileptogenesis. During sleep, ZT13 kindling stimulation significantly enhanced NREM sleep during the subsequent 6 h (ZT13-18) in wildtype mice, and sleep returned to the baseline the following day. However, the kindling-induced sleep alteration was absent in the IL-1R −/− KO mice.

Conclusions

These results indicate that the IL-1 signal mediates epilepsy-induced sleep disturbance, but dose not participate in kindling-induced epileptogenesis.

Zonisamide: Review of Recent Clinical Evidence for Treatment of Epilepsy

Zonisamide is an orally administered antiepileptic drug that was first approved for clinical use in Japan in 1989. Since then, it has been licensed in Korea for a broad spectrum of epilepsies in adults and children, and in the USA for adjunctive therapy of adults with partial seizures, and in Europe for monotherapy of adults with newly diagnosed partial seizures and adjunctive therapy of adults and adolescents and children aged ≥6 years with partial seizures with or without secondary generalization. Zonisamide is a benzisoxazole derivative with a unique chemical structure, predictable dose-dependent pharmacokinetics, and multiple complementary mechanisms of action. Treatment with zonisamide is well tolerated and is not known to be associated with clinically significant drug-drug interactions, including with oral contraceptives or other antiepileptic drugs. There have been >2 million patient-years of experience with zonisamide for treatment of epilepsy, and this drug has International League Against Epilepsy level A evidence for efficacy/effectiveness as initial monotherapy for adults with partial-onset seizures. This review presents the evidence for zonisamide across the spectrum of epilepsy, with emphasis on real-world clinical practice and special populations of patients (children, elderly patients, and women of childbearing age) who are likely to be treated in daily clinical practice.

Low-frequency electroacupuncture suppresses focal epilepsy and improves epilepsy-induced sleep disruptions

Background

The positive effects of acupuncture at Feng-Chi acupoints on treating epilepsy and insomnia have been well-documented in ancient Chinese literature. However, there is a lack of scientific evidence to elucidate the underlying mechanisms behind these effects. Our previous study demonstrated that high-frequency (100 Hz) electroacupuncture (EA) at Feng-Chi acupoints deteriorates both pilocarpine-induced focal epilepsy and sleep disruptions. This study investigated the effects of low-frequency (10 Hz) EA on epileptic activities and epilepsy-induced sleep disruptions.

Results

In rats, the Feng-Chi acupoint is located 3 mm away from the center of a line between the two ears. Rats received 30 min of 10 Hz EA stimuli per day before each day’s dark period for three consecutive days. Our results indicated that administration of pilocarpine into the left CeA at the beginning of the dark period induced focal epilepsy and decreased both rapid eye movement (REM) sleep and non-REM (NREM) sleep during the consequent light period. Low-frequency (10 Hz) EA at Feng-Chi acupoints suppressed pilocarpine-induced epileptiform EEGs, and this effect was in turn blocked by naloxone (a broad-spectrum opioid receptor antagonist), but not by naloxonazine (a μ-receptor antagonist), naltrindole (a δ-receptor antagonist) and nor-binaltorphimine (a κ-receptor antagonist). Ten Hz EA enhanced NREM sleep during the dark period, and this enhancement was blocked by all of the opioid receptor antagonists. On the other hand, 10 Hz EA reversed pilocarpine-induced NREM suppression during the light period, and the EA’s effect on the sleep disruption was only blocked by naloxonazine.

Conclusions

These results indicate that low-frequency EA stimulation of Feng-Chi acupoints is beneficial in improving epilepsy and epilepsy-induced sleep disruptions, and that opioid receptors in the CeA mediate EA’s therapeutic effects.

Activation of GABAergic pathway by hypocretin in the median raphe nucleus (MRN) mediates stress-induced theta rhythm in rats

The frequency of electroencephalograms (EEGs) is predominant in theta rhythm during stress (e.g., footshock) in rats. Median raphe nucleus (MRN) desynchronizes hippocampal theta waves via activation of GABAergic neurons in the medial septum-diagonal band of Broca (MS-DBB), a theta rhythm pacemaker. Increased hypocretin mediates stress responses in addition to the maintenance of wakefulness. Hypocretin receptors are abundant in the MRN, suggesting a possible role of hypocretin in modulating stress-induced theta rhythm. Our results indicated that the intensity of theta waves was enhanced by footshock and that a hypocretin receptor antagonist (TCS1102) suppressed the footshock-induced theta waves. Administration of hypocretin-1 (1 and 10 μg) and hypocretin-2 (10 μg) directly into the MRN simulated the effect of footshock and significantly increased theta waves. Co-administration of GABA(A) receptor antagonist, bicuculline, into the MRN blocked the increase of theta waves induced by hypocretins or footshock. These results suggested that stress enhances the release of hypocretins, activates GABAergic neurons in the MRN, blocks the ability of MRN to desynchronize theta waves, and subsequently increases the intensity of theta rhythm.

Visualization of melatonin's multiple mitochondrial levels of protection against mitochondrial Ca(2+)-mediated permeability transition and beyond in rat brain astrocytes

Melatonin protects cells against various types of oxidative stress-induced apoptosis due primarily to its ability to effectively scavenge pathological and disease condition-augmented generation of mitochondrial reactive oxygen species (mROS). Once produced, mROS indiscriminately damage mitochondrial components and more importantly they crucially activate directly the mitochondrial permeability transition (MPT), one of the critical mechanisms for initiating post mitochondrial apoptotic signaling. Whether or not melatonin targets directly the MPT, however, remains inconclusive, particularly during oxidative stress. This study, thus, investigated this possibility of an 'oxidation free Ca(2+) stress' in the presence of vitamin E after ionomycin exposure as a sole Ca(2+)-mediated MPT in order to exclude melatonin's primary antioxidative effects as well as Ca(2+)-mediated oxidative stress. The studies were carried out using cultured rat brain astrocytes RBA-1. With the application of laser scanning multiple fluorescence imaging microscopy, we visualized for the first time multiple mitochondrial protective effects provided by melatonin during Ca(2+) stress. First, melatonin, due to its primary antioxidative actions, completely prevented mCa(2+)-induced mROS formation during ionomycin exposure. Secondly, when melatonin(')s antioxidative effects were prevented due to the addition of vitamin E, melatonin significantly prevented mCa(2+)-mediated MPT and apoptosis suggesting its direct targeting of the MPT. Surprisingly, in the presence of cyclosporin A, a MPT inhibitor, melatonin reduced further mCa(2+)-mediated apoptosis during ionomycin exposure also suggesting its targeting beyond the MPT. As astrocytes are actively involve in regulating synaptic transmission and neurovascular coupling in the CNS, these multiple mitochondrial layers of protection provided by melatonin against mCa(2+)-and/or mROS-mediated apoptosis in astrocytes may be crucial for future therapeutic prevention and treatment of astrocyte-mediated neurodegenerative diseases in the CNS.

Melatonin protects against common deletion of mitochondrial DNA-augmented mitochondrial oxidative stress and apoptosis

Defected mitochondrial respiratory chain (RC), in addition to causing a severe ATP deficiency, often augments reactive oxygen species (ROS) generation in mitochondria (mROS) which enhances pathological conditions and diseases. Previously, we demonstrated a potent endogenously RC defect-augmented mROS associated dose-dependently with a commonly seen large-scale deletion of 4977 base pairs of mitochondrial DNA (mtDNA), i.e. the common deletion (CD). As current treatments for CD-associated diseases are rather supplementary and ineffective, we investigated whether melatonin, a potential mitochondrial protector, provides beneficial protection for CD-augmented mitochondrial oxidative stress and apoptosis particularly upon the induction of a secondary oxidative stress. Detailed mechanistic investigations were performed by using laser scanning dual fluorescence imaging microscopy to provide precise spatial and temporal resolution of mitochondrial events at single cell level. We demonstrate, for the first time, that melatonin significantly prevents CD-augmented mROS formation under basal conditions as well as at early time-points upon secondary oxidative stress induced by H2O2 exposure. Thus, melatonin prevents mROS-mediated depolarization of mitochondrial membrane potential (DeltaPsim) and subsequent opening of the mitochondrial permeability transition pore (MPTP) and cytochrome c release. Moreover, melatonin prevents depletion of cardiolipin which appears to be crucial for postponing later MPTP opening, disruption of the mitochondrial membrane and apoptosis. Finally, the protection provided by melatonin is superior to those caused by the suppression of mitochondrial Ca2+ regulators including the mitochondrial Na+-Ca2) exchanger, the MPTP, and the mitochondrial Ca2+ uniporter and by antioxidants including vitamin E and mitochondria-targeted coenzyme Q, MitoQ. As RC defect-augmented endogenous mitochondrial oxidative stress is centrally involved in a variety of pathological conditions and diseases, melatonin thus may serve as a therapeutic drug to benefit many clinical conditions that involve malfunction of the mitochondria.

Confusion or delirium in patients with posterior cerebral arterial infarction

OBJECTIVE

To identify the possible anatomic sites and risk factors for the development of confusion or delirium in patients with posterior cerebral arterial (PCA) infarction.

MATERIALS AND METHODS

Twenty-nine patients aged 34-86 years with PCA infarction were divided into two groups: one with and the other without perturbed mentation. The clinical and laboratory data, including neuroimages, were retrospectively reviewed. Student-t, chi-square and Fisher's exact tests were performed for data analysis.

RESULTS

Confusion or delirium tended to develop in the left (10/13) or bilateral (5/5) PCA infarction as compared to the right PCA infarction (3/15) (P< 0.05) and medial occipital-temporal gyri involvement was crucial for its development (P< 0.05). The results were also noted in the patients with first-ever stroke. Diabetes mellitus was the sole biochemical factor to be associated with confusion or delirium (P< 0.01).

CONCLUSIONS

The involvement of the medial occipito-temporal gyri, especially on the left side was the pivotal factor for the development of confusion or delirium in patients with PCA infarction. Higher prevalence of diabetes mellitus was also observed in the group with mental perturbation.

Visualization of the antioxidative effects of melatonin at the mitochondrial level during oxidative stress-induced apoptosis of rat brain astrocytes

Oxidative stress-induced mitochondrial dysfunction has been shown to play a crucial role in the pathogenesis of a wide range of diseases. Protecting mitochondrial function, therefore, is vital for cells to survive during these disease processes. In this study, we demonstrate that melatonin, a chief secretory product of the pineal gland, readily rescued mitochondria from oxidative stress-induced dysfunction and effectively prevented subsequent apoptotic events and death in rat brain astrocytes (RBA-1). The early protection provided by melatonin in mitochondria of intact living cells was investigated by the application of time-lapse conventional, confocal, and multiphoton fluorescent imaging microscopy coupled with noninvasive mitochondria-targeted fluorescent probes. In particular, we observed that melatonin effectively prevented exogenously applied H2O2-induced mitochondrial swelling in rat brain astrocytes at an early time point (within 10 min) and subsequently reduced apoptotic cell death (150 min later). Other early apoptotic events such as plasma membrane exposure of phosphatidyl serine and the positive YOPRO-1 staining of the early apoptotic nucleus were also prevented by melatonin. A mechanistic study at the mitochondrial level related to the early protection provided by melatonin revealed that the indole molecule significantly reduced mitochondrial reactive oxygen species (ROS) formation induced by H2O2 stress. Melatonin also prevented mitochondrial ROS generation caused by other organic hydroperoxides including tert-butyl hydroperoxide and cumene hydroperoxide. This antioxidative effect of melatonin is more potent than that of vitamin E. Via its ability to reduce mitochondrial ROS generation, melatonin prevented H2O2-induced mitochondrial calcium overload, mitochondrial membrane potential depolarization, and the opening of the mitochondrial permeability transition (MPT) pore. As a result, melatonin blocked MPT-dependent cytochrome c release, the downstream activation of caspase 3, the condensation and karyorrhexis of the nucleus and apoptotic fragmentation of nuclear DNA. Thus, the powerful mitochondrial protection provided by melatonin reinforces its therapeutic potential to combat a variety of oxidative stress-induced mitochondrial dysfunctions as well as mitochondria-mediated apoptosis in various diseases.

Activation of alpha1A-adrenoceptors by genistein at concentrations lower than that to inhibit tyrosine kinase in cultured C2C12 cells

Genistein, an isoflavonoid natural product, is widely used to inhibit protein tyrosine kinase (PTK). In the present study, we investigated the possible influence of genistein on alpha (1)-adrenoceptors (AR) in cultured C2C12 cells. Genistein enhanced the uptake of radioactive glucose into C2C12 cells in a concentration-dependent manner. Similar results were also observed in samples treated with daidzein, the inactive congener for PTK inhibition. The effect of genistein on alpha (1)-AR was further characterized using the displacement of [ (3)H]prazosin binding in C2C12 cells. The increase in radioactive glucose uptake by genistein was abolished by RS17053 at a concentration sufficient to block alpha (1A)-AR. The pharmacological inhibition of phospholipase C (PLC) by U73122 resulted in a concentration-dependent reduction of genistein-stimulated glucose uptake in C2C12 cells. This inhibition by U73122 was specific because the inactive congener, U73343, failed to modify the action of genistein. Moreover, genistein can activate alpha (1A)-AR at a concentration (1 micromol/L) lower than that (50 micromol/L) needed to abolish the insulin-stimulated phosphorylation of PTK. The obtained data indicate an activation of alpha (1A)-AR by genistein to increase the glucose uptake into C2C12 cells and this supports the application of genistein as a TK inhibitor.

Novel CLCN1 mutations in Taiwanese patients with myotonia congenita

We have performed genetic screening on the skeletal muscle chloride channel gene (CLCN1) in Taiwanese population. A total of four patients with myotonia congenita (MC) together with 106 normal individuals were examined. All 23 exons of the CLCN1 gene were analysed by direct sequencing of PCR products to detect the nucleotide changes. Five mutations and three polymorphisms were identified in this study. Among these, three missense mutations (S471F, P575S, D644G) and one polymorphism (T736I) are novel and could be unique to the Taiwanese. In addition, a previously documented recessive G482R mutation was identified in a heterozygous patient and his nonsymptomatic father, indicating that this mutation might indeed function recessively or dominantly with incomplete penetrance. In conclusion, this is the first report of MC in Taiwan with proven CLCN1 gene mutations and showing high molecular heterogeneity in Taiwanese MC patients.

Mitochondrial reactive oxygen species generation and calcium increase induced by visible light in astrocytes

Mitochondria contain photosensitive chromophores that can be activated or inhibited by light in the visible range. Rather than utilizing light energy, however, mitochondrial electron transport oxidation-reduction reaction and energy coupling could be stimulated or damaged by visible light. Our previous work demonstrated that reactive oxygen species (ROS) were generated in cultured astrocytes after visible laser irradiation. With confocal fluorescence microscopy, we found that ROS were generated mostly from mitochondria. This mitochondrial ROS (mROS) formation plays a critical role in photoirradiation-induced phototoxicity and apoptosis. In this study, we measured changes of mitochondrial calcium level ([Ca(2+)](m)) in cultured astrocytes (RBA-1 cell line) irradiated with blue light and examined the association between mROS formation and [Ca(2+)](m) level changes. Changes of intracellular ROS and [Ca(2+)](m) were visualized using fluorescent probes 2',7'-dichlorodihydrofluorescein (DCF), and rhod-2. After exposure to visible light irradiation, RBA-1 astrocytes showed a rapid increase in ROS accumulation particularly in the mitochondrial area. Increase in [Ca(2+)](m) was also induced by photoirradiation. The levels of increase in DCF fluorescence intensity varied among different astrocytes. Some of the cells generated much higher levels of ROS than others. For those cells that had high ROS levels, mitochondrial Ca(2+) levels were also high. In cells that had mild ROS levels, mitochondrial Ca(2+) levels were only slightly increased. The rate of increase in DCF fluorescence seemed to be close to the rate of rhod-2 fluorescence increase. There is a positive and close correlation between mitochondrial ROS levels and mitochondrial Ca(2+) levels in astrocytes irradiated by visible light.

Activation of imidazoline receptor by agmatine to lower plasma glucose in streptozotocin-induced diabetic rats

In the present study, we use agmatine, an endogenous ligand, to investigate the role of imidazoline receptor in plasma glucose regulation in streptozotocin-induced diabetic rats (STZ-diabetic rats). After injection into the central lateral ventral (i.c.v.) of fasting STZ-diabetic rats for 30 min, agmatine produced plasma glucose lowering action in a concentration-dependent manner without alteration the mean arterial pressure (MAP). However, the plasma glucose was markedly raised in STZ-diabetic rats receiving similar injection of clonidine at dose (1 micromol/rat, i.c.v.) sufficient to lower MAP. Mediation of alpha(2)-adrenoceptor in this action of agmatine seems unlikely. The plasma glucose lowering action of agmatine (1 micromol/rat, i.c.v.) was abolished by the pretreatment with BU-224 at concentration (100 nmol/rat) sufficient to block cerebral I(2)-imidazoline receptors. Also, this action of agmatine in STZ-diabetic rats disappeared by spinal cord truncation between C6 and C7. Activation of cerebral I(2)-imidazoline receptor by agmatine can thus be considered for the lowering of plasma glucose. In conclusion, we suggest that an activation of I(2)-imidazoline receptors in the brain may lower plasma glucose without insulin in animal.

Multifocal acquired demyelinating sensory and motor neuropathy: report of a case and review of the literature

Multifocal acquired demyelinating sensory and motor (MADSAM) neuropathy is characterized by an asymmetric multifocal pattern of motor and sensory loss, and conduction block and other features of demyelination in nerve conduction studies. MADSAM neuropathy needs to be differentiated from chronic inflammatory demyelinating polyneuropathy (CIDP) and multifocal motor neuropathy (MMN). In classic CIDP, there are symmetric proximal and distal weakness, sensory deficit in both upper and lower extremities and reduced deep tendon reflex. In MMN, limb weakness without sensory loss is asymmetric in the distribution of individual peripheral nerves and the weakness typically begins in the distal upper extremities. We report one patient with chronic progression of asymmetric numbness and weakness in four extremities. MADSAM neuropathy was diagnosed after extensive clinical and laboratory evaluations. It is very important to distinguish between CIDP, MADSAM neuropathy, and MMN by clinical, laboratory, and histological features because of different effective therapeutic strategies.

Epidemiological and genetic studies of myotonic dystrophy type 1 in Taiwan

To investigate the prevalence and genetic characteristics of myotonic dystrophy type 1 (DM1) in Taiwan, DM-suspected patients and their families identified during the period of 1990-2001 had their clinical records reevaluated and the CTG repeat sizes at the DM1 locus examined. A total of 96 subjects belonging to 26 families were identified as DM1 patients, which gave a minimal disease prevalence of 0.46/100,000 inhabitants. Clinical anticipation was frequently observed in affected families, even in some parent-child pairs with transmission contraction of the CTG repeat size. The inverse correlation between age at onset and CTG repeat length was significant only in patients with small expansions. In addition, a DM1 carrier with a childhood-onset son was found to have CTG length heterogeneity in the range of 40-50, indicating that premutation alleles could be unstable during gametogenesis as well as in somatic tissues. Our data demonstrated that DM1 is a rare disease in Taiwan and showed that transmission contraction of repeat size is more likely to occur in alleles with large repeats.

Critical role of mitochondrial reactive oxygen species formation in visible laser irradiation-induced apoptosis in rat brain astrocytes (RBA-1)

Laser irradiation-induced phototoxicity has been intensively applied in clinical photodynamic therapy for the treatment of a variety of tumors. However, the precise laser damage sites as well as the underlying mechanisms at the subcellular level are unknown. Using a mitochondrial fluorescent marker, MitoTracker Green, severe mitochondrial swelling was noted in laser-irradiated rat brain astrocytes. Nucleus condensation and fragmentation revealed by propidium iodide nucleic acid staining indicated that laser-irradiated cells died from apoptosis. Using an intracellular reactive oxygen species (ROS) fluorescent dye, 2',7'-dichlorofluorescin diacetate, heterogeneous distribution of ROS inside astrocytes was observed after laser irradiation. The level of ROS in the mitochondrial compartment was found to be higher than in other parts of the cell. With another ROS fluorescent dye, dihydrorhodamine-123, and time-lapse laser scanning confocal microscopy, a substantial increase in mitochondrial ROS (mROS) was visualized in visible laser-irradiated astrocytes. The antioxidants melatonin and vitamin E largely attenuated laser irradiation-induced mROS formation and prevented apoptosis. Cyclosporin A (CsA), a mitochondrial permeability transition (MPT) blocker, did not prevent visible laser irradiation-induced mROS formation and apoptosis. In conclusion, mROS formation contributes significantly to visible laser irradiation-induced apoptosis via an MPT-independent pathway.

Protein kinase C and changes in manganese superoxide dismutase gene expression in cultured glial cells

1. To study the role of protein kinase C (PKC) in the increase in manganese superoxide dismutase (Mn-SOD) gene expression following transient hypoxia in glial cells, we examined the mRNA levels of Mn-SOD using northern blot analysis. 2. The Mn-SOD mRNA levels were markedly increased after exposure to nitrogen gas for 5 min. 3. Pretreatment with chelerythrine or GF109203x, inhibitors of PKC, attenuated the increase in Mn-SOD mRNA following hypoxia in a concentration-dependent manner. 4. Incubation with phorbol 12-myristate 13-acetate, the PKC activator, enhanced the increase in Mn-SOD gene expression in response to transient hypoxia. 5. The results suggest that hypoxia increases Mn-SOD gene expression in cultured glial cells mainly through activation of a PKC pathway.

Virtual reality orthopedic surgery simulator

This paper describes a highly interactive virtual reality orthopedic surgery simulator. The simulator allows surgeons to use various surgical instruments to operate on virtual rigid anatomic structures, such bones, prostheses and bone grafts, to simulate every procedure on the rigid structures for complex orthopedic surgeries, including arthroplasty, corrective or open osteotomy, open reduction of fractures and amputation. A comparative study of the simulator with paper simulation was performed and showed that interns and residents found the simulator to be a useful learning tool, and that visiting doctors could use it effectively for planning verification and rehearsal of operations.

Delineation of CTG repeats and clinical features in a Taiwanese myotonic dystrophy family

Myotonic dystrophy (DM) is an inherited, autosomal dominant muscular disease which is primarily caused by a CTG trinucleotide expansion mutation on chromosome 19q13.3. The size of this trinucleotide repeat is related both to the age of onset and to the severity of the clinical manifestation. This disease is very rare in Taiwan, and clinical and genetic study on DM has not yet been documented in this area. Here, we present both clinical features and degrees of CTG expansion for a Taiwanese DM family. All of the DM patients examined in this family showed obvious clinical manifestations by age 30, which included facial and limb muscle weakness with atrophy, myotonia, and ptosis. In addition, individual DM members also exhibited variable phenotypes, which may reflect the complexity of the pathogenic mechanism. Because the collection of blood specimens was considered to be an invasive procedure, a genetic study on this DM family was performed using buccal cells. Our results confirmed that four members showing classic symptoms of DM had CTG repeat expansion in the DMI locus, and that one member with ptosis and minor muscle weakness in the right foot was a normal homozygote for CTG repeat. These data demonstrate that buccal cells can provide clear and reliable results, and thus, are suitable for a family study of DM.

Decrease of adenosine A-1 receptor gene expression in cerebral cortex of aged rats

Changes of adenosine A-1 receptor (A1-AR) gene expression in aging were investigated in cerebral cortex using the rat aged from 2 months (adult) to 24 months (aged). Quantification of A1-AR protein level by immunoblotting analysis showed an age-related decrease of A1-AR in cerebral cortex of Wistar rats. Compared to the preparations from 2-month-old animals, the levels of A1-AR in the 6-, 12-, and 24-month-old rats were reduced by 14.3+/-5.2, 32.5+/-4.5 and 28.2+/-5.7%, respectively. Similar decrease of mRNA level in A1-AR was also obtained using Northern blotting analysis. Two representative spots of mRNA, a 3.4-kb transcript and a 5.6-kb transcript, were observed in X-ray film from cerebral cortex of rat hybridized with rat A1-AR cDNA probe. Compared to the 2 month-old rats, levels of the 5.6-kb transcript were decreased by 17.9+/-2.5, 27.4+/-3.2 and 23.1+/-2.1% in the 6-, 12- and 24-month-old rats, respectively. These results indicated an age-related decrease of A1-AR in cerebral cortex of the rat that seems responsible for the change of response to adenosine.

Modification of superoxide dismutase (SOD) mRNA and activity by a transient hypoxic stress in cultured glial cells

In order to understand the role of superoxide dismutase (SOD) in response to transient hypoxia or hypoxia-reperfusion in astrocytes, the present study performed an in vitro investigation using rat glial cells in culture. Hypoxia was induced by an incubation with nitrogen gas for 10 min and that followed a further reperfusion with air for 10 min was indicating as hypoxia-normoxia. Activity of SOD was determined by the reduction of nitroblue tetrazolium (NTB). Changes of mRNA for Cu,Zn-SOD or Mn-SOD were also characterized using Northern blotting analysis. Transient hypoxia increased the activity of Mn-SOD but not that of Cu,Zn-SOD in glial cells. Expression of mRNA for SOD was also elevated in cells received hypoxia and the mRNA level for Mn-SOD raised higher than that for Cu,Zn-SOD. In cells received hypoxia-reperfusion, these changes of SOD both the activity and the mRNA level were not observed. Otherwise, the SOD protein amount, both Cu,Zn-SOD and Mn-SOD, identified by Western blotting was not changed in glial cells receiving hypoxic stress or not. The obtained results suggest that gene expression and activity of Mn-SOD in glial cells can be activated in response to the transient hypoxic stress.

The role of free radicals in the release of noradrenaline from myenteric nerve terminals of guinea-pig ileum

In an attempt to understand the role of free radicals in the regulation of sympathetic neurotransmission, the in vitro secretion of noradrenaline (NA) from synaptosomal preparations of guinea-pig ileum was investigated. Release of endogenous NA was quantified by an electrochemical detection (HPLC-ECD). In the presence of superoxide dismutase (SOD) and catalase at concentrations sufficient to scavenge the free radicals, secretion of NA was attenuated in samples with stimulation of 4-aminopyrine (4-AP) or not (spontaneous release). However, inducing superoxide radicals via the reaction of hypoxanthine with xanthine oxidase failed to modify the secretion of NA, both the 4-AP-stimulated release and the spontaneous secretion. Then, free radicals were induced in synaptosomes using hypoxia-normoxia exposure. Secretion of NA was markedly increased in samples receiving this treatment in a calcium-dependent way because it was attenuated by the removal of calcium chloride from bathing medium. An increase of SOD activity, both Mn-SOD and Cu, Zn-SOD, was also obtained by this exposure. Changes of SOD activities in response to free radicals produced by hypoxia-normoxia exposure in ileal synaptosomes can thus be considered. In conclusion, these results suggest that free radicals are formed to involve in the regulation of sympathetic neurotransmission via an increase of calcium influx to enhance the NA release in guinea-pig ileum.

Changes of superoxide dismutase (SOD) mRNA and activity in response to hypoxic stress in cultured Wistar rat glioma cells

In an attempt to understand the change of superoxide dismutase (SOD) in tumor cells by hypoxia and hypoxia-normoxia exposure, the present study performed an in vitro investigation using rat glioma cell line in culture. Hypoxia was induced by an incubation with nitrogen gas for 15 h followed the normoxia exposure with air for 30 min. Activity of SOD in cytosolic and particulate of cells was determined by the reduction of nitroblue tetrazolium. Changes of mRNA for Cu,Zn-SOD or Mn-SOD were also characterized using Northern blotting analysis. Hypoxic stress decreased the activity of SOD, both Cu,Zn-SOD and Mn-SOD, in glioma cells. Expression of mRNA for SOD was elevated by hypoxic stress and the increase of mRNA level for Cu,Zn-SOD was more marked than that for Mn-SOD. In response to hypoxia-normoxia exposure, an increase of activity with a lower mRNA level for Mn-SOD was observed in glioma cells. However, changes of Cu,Zn-SOD both the activity and the level of mRNA were not found in glioma cells by hypoxia-normoxia. The obtained results suggest that the SOD in glioma cells can be activated to compensate the damage from free radicals during hypoxic stress.