Current Status, Diagnosis, and Treatment Recommendation for Tic Disorders in China.

Tic disorders (TD) are a group neuropsychiatric disorders with childhood onset characterized by tics, i.e. repetitive, sudden, and involuntary movements or vocalizations; and Tourette syndrome (TS) is the most severe form of TD. Their clinical manifestations are diverse; and are often associated with various psychopathological and/or behavioral comorbidities, including attention deficit hyperactivity disorder (ADHD), obsessive-compulsive disorder (OCD), anxiety, depression, and sleep disorders. Individual severity and response to treatment are highly variable, and there are some refractory cases, which are less responsive to conventional TD treatment. TD/TS are also common in the Chinese pediatric population. To help improve the understanding of TD for pediatricians and other health professionals, and to improve its diagnosis and treatment in China, the Chinese Child Neurology Society (CCNS) has developed an Expert Consensus on Diagnosis and Treatment of TD in China, which is based on our clinical experience and the availability therapeutic avenues. It is focused on clinical diagnosis and evaluation of TD and its comorbidities, psychological and educational intervention, nonpharmacological therapy, pharmacological treatment, including traditional Chinese medicine and acupuncture, as well as prognosis in children with TD in China. A summary of the current status of TD and up-to-date diagnosis and treatment recommendations for TD in China is presented here.

Asymmetric Slow-Spike-Wave Patterns with Maximal Discharges Contralateral to MRI Lesions Predict Better Surgical Prognosis in Symptomatic Lennox-Gastaut Syndrome or Lennox-Gastaut Phenotypes.

INTRODUCTION: Lennox-Gastaut syndrome (LGS) is a severe subtype of childhood-onset epileptic encephalopathy with drug-resistant and poor surgical prognosis. However, electroencephalogram (EEG) patterns of symptomatic LGS or LG phenotypes with structural brain lesions including focal abnormalities or asymmetric slow-spike-wave (SSW) patterns remain largely unknown. Due to the contradictory lateralization difference between MRI lesions and EEG pattern in symptomatic LGS or LG phenotypes, it is difficult to determine the precise lateralization of epileptic lesions, which is crucial to better surgical prognosis. This study is aim to ascertain the clinical characteristics of the EEG patterns, and its relationship with MRI lesions and to evaluate its prognostic value of surgical treatment in symptomatic LGS or LG phenotypes. METHODS: Twenty-four symptomatic LGS cases with asymmetric EEG SSW patterns and contralaterally independent or contralaterally dominant MRI lesions were collected, and their clinical features were analyzed retrospectively. RESULTS: In this cohort, most of lesions were perinatal or acquired during the first 6 months of life. The most common etiology was intracerebral hemorrhage. The LGS patients with both asymmetric SSW and focal sporadic epileptic waves (SEW) patterns showed the best surgical outcome with Engel class I level. Asymmetric SSW patterns with maximal discharges contralateral to MRI lesions were frequently observed in most of symptomatic LGS or LG phenotypes. Predominantly diffuse destructive lesions led to an attenuated voltage of ipsilateral scalp EEG producing an asymmetric SSW pattern in those patients with symptomatic LGS or LG phenotypes. CONCLUSIONS: Our study reveals a special SEW EEG pattern in symptomatic LG patients with asymmetric SSW and MRI lesions contralateral to the dominant EEG patterns. Contradictory lateralization difference between MRI and EEG probably arises from the relative voltage attenuation presenting in EEG ipsilateral to huge destructive lesions from early life. Our study suggests that the independent focal SEW activity remaining ipsilateral to the MRI lesion can potentially predict better surgical prognosis in symptomatic LGS or LG phenotypes.

Efficacy of levetiracetam in electrical status epilepticus during sleep of children: a multicenter experience.

BACKGROUND: Electrical status epilepticus during sleep is characterized by epilepsy, a specific electroencephalographic pattern, and neuropsychological impairment. This study aims to evaluate the efficacy and safety of levetiracetam in treating children with electrical status epilepticus during sleep. METHODS: A multicenter, retrospective, open-label study enrolled 73 children (mean age: 8 years) affected by electrical status epilepticus during sleep. The efficacy was rated according to the seizure frequency and electroencephalography response. RESULTS: After a mean treatment period of 19 months (range: 6 to 24 months), 33 (63.5%) of 52 patients became seizure-free or had experienced remarkable reduction in seizures. The electrical status epilepticus of 41 (56.2%) of 73 patients disappeared off their electroencephalography. The electroencephalography efficacy of levetiracetam treatment was noted in the monotherapy (61.9%) and add-on (53.9%) groups. The clinical (67.7%) and electroencephalography (64.3%) response rates of the idiopathic group were better than those of the symptomatic group (57.1% and 45.2%, respectively). No patient discontinued the trial because of intolerability of side effects. CONCLUSIONS: Levetiracetam is effective in individuals with electrical status epilepticus during sleep with tolerable side effects.

Surgical treatment for epilepsy in 17 children with tuberous sclerosis-related West syndrome.

The efficacy of surgery for the treatment of epilepsy in patients with West syndrome secondary to tuberous sclerosis is unclear. The charts of 17 patients with tuberous sclerosis and secondary West syndrome who underwent a one-stage surgical resection with a combined palliative operative procedure were reviewed. Engel classification was used to classify the patients with regard to seizure status following surgery. After surgery, 11 patients were in Engel class I, 4 in class II, and 2 in class III. The EEG after surgery was normal in 8 patients, significantly improved in 8, and without significant improvement in 1 patient. Six patients had a recurrence of seizures after surgery, which included 3 patients with continuing spasms and 3 patients where the spasms had resolved but had developed either partial seizures or generalized tonic-clonic seizures. There were significant improvements in the Gesell Developmental Schedules for motor field (P=0.003), adaptive field (P=0.003), language field (P=0.033), and personal-social field (P=0.007). Thus, a one-stage surgical approach can be used to produce satisfactory outcomes in young children with tuberous sclerosis who have secondary West syndrome and seizures that do not respond to conventional antiepileptic therapy, even in when there are multiple epileptogenic foci.

[Experimental study on the damage of immature brain induced by chronic treatment with exogenous glucocorticosteroid].

OBJECTIVE: To explore the possibility of brain damage induced by exogenous glucocorticosteroid (GC) at therapeutic level during early life. METHOD: Totally 192 healthy Sprague-Dawley (SD) rats were selected and divided into three groups including PD7, PD15 and PD60 corresponding to three age-groups in human, i.e., the full-term newborn, one-year-old infant and adult, respectively. According to the therapeutic regime for infantile spasms, the dose of prednisone and ACTH was designed as 6 mg/(kg.d) and 150 U/(m(2).d) respectively. SD rats of different age-groups were treated with prednisone or ACTH and normal saline as the control for 4 days. The specimens were collected on Day 4 or 3 weeks after treatment. Body and brain weights were measured when the rats were sacrificed. Histological studies on the tissues of frontal lobe and hippocampus were performed by Nissl staining. Ultrastructural changes of brain were observed by the transmission electron microscopy. Expression of apoptosis-related proteins Bcl-2 and Bax in neurons was detected by immunohistochemistry. Neuronal apoptosis was detected by TUNEL. Mitochondria membrane potential of neurons in frontal lobe and hippocampus were detected by flow cytometry, and the Caspase-3 activity was detected by spectrophotometric assay. RESULT: (1) Significant reduction of brain weight [prednisone group of PD7: (0.78 +/- 0.08) g, control group: (0.89 +/- 0.08) g] and decrease of neurons numbers [(77.7 +/- 4.7) neurons per VF, control group: (102.3 +/- 5.9) neurons per VF] with cellular ultrastructural abnormalities in the frontal cortex were observed in infantile rats, including PD7 and PD15 groups. However none of the differences in brain weight and frontal cerebral cortex neurons were detected 3 weeks after drug discontinuation in PD7 group. (2) Compared with NS control, the numbers of TUNEL-positive cell (prednisone group of PD7: (114.8 +/- 8.1) cells per VF, control group: (56.3 +/- 5.6) cells per VF], Caspase-3 activity (345.3 +/- 13.0, control group: 166.3 +/- 6.4) and Bax protein expression (0.27 +/- 0.02, control group: 0.15 +/- 0.06) in neurons of the infant rats increased significantly but their potentials of mitochondrial membrane (112.9 +/- 8.6, control group: 140.5 +/- 5.6) were reduced remarkably, especially in PD7 group. CONCLUSION: (1) Long-term use of ACTH or prednisone could induce brain damage. The younger the rats were, the more liable they were to the damage and more severe the damages were, and the less possibly to recover completely from the damage. (2) The pathogenesis of the brain injury induced by GC is primarily due to up-regulated Bax protein expression resulted from the enhanced ratio of Bax to Bcl-2 and increased mitochondria membrane potential, followed by Caspase enzymes activation and irreversible excessive apoptosis.

[Activated factor of immature neurons for excessive apoptosis induced by exogenous glucocorticosteroid].

OBJECTIVE: To confirm the key inducing factor of excessive apoptosis in immature brain under the exposure of exogenous glucocorticosteroid and observe the characteristics of mitochondrial oxidative stress and intracellular [Ca(2+)]i overload as compared to healthy adult rats. METHODS: A total of 192 healthy Sprague-Dawley (SD) rats selected for the study were divided into three groups including PD7, PD15 and PD60 corresponding human age stages including full-term newborn, one-year infant and adult respectively. To mimic the therapeutic regime for infantile spasms, 8 rats in each group was treated with prednisone (6 mg x kg(-1) x d(-1)), ACTH (150 U x m(-2) x d(-1)), normal saline for 4 days and drug withdrawal for 3 weeks. Rats were deeply anesthetized and sacrificed by decapitation. The mitochondrial concentrations of GSH, SOD, MDA, Na(+)-K(+)-ATPase and intracellular [Ca2+i] were all determined by spectrophotometer. The cellular NMDA-R1 expression was measured by immunohistochemistry. RESULTS: Both prednisone and ACTH caused neuron reduced and TUNEL-positive cell increased in the frontal lobe, specially in PD7 group of prednisone, that were 77.7 +/- 4.7 neurons per VF (control group: 102.3 +/- 5.9) (P = 0.002), 114.8 +/- 8.14 (control group: 56.3 +/- 5.6) (P = 0.029) respectively. The mitochondrial levels of GSH, SOD and Na+-K+-ATPase decreased after prednisone and ACTH administration at different level in different age groups whereas the concentration of MDA increased. These changes were significant in PD7 group after prednisone administration, that were 158.3 +/- 6.1 mg/g prot of GSH (control group: 225.1 +/- 9.5 mg/g prot) (P = 0.006), 155.8 +/- 4.3 U/mg prot of SOD (control group: 228.1 +/- 9.2 U/mg prot) (P = 0.006), 14.6 +/- 3.5 U/mg prot of Na+-K+-ATPase (control group: 20.8 +/- 5.5 U/mg prot) and 10.4 +/- 0.9 nmol/mg prot of MDA (control group: 4.8 +/- 1.9 nmol/mg prot) (all P < 0.01). [Ca(2+)]i level in neuron increased, specially in PD7 group after prednisone administration, that was 164.6 +/- 11.9 nmol/L (control group: 125.8 +/- 6.03 nmol/L) (P = 0.003). Similar to [Ca(2+)]i changes, the density of NMDA-R1 also increased mostly in PD7 group after prednisone administration, that was 0.36 +/- 0.03 (control group: 0.21 +/- 0.05) while that was only 0.18 +/- 0.05 in PD60 group (control group: 0.15 +/- 0.02). At 3 weeks post-dosing, all of them returned to normal level. CONCLUSION: Dysfunctions of oxidation and antioxidation in mitochondria of immature neurocytes are induced by prednisone or ACTH within the therapeutic levels. Enhanced expressions of NMDA-R1, Bax and superoxide contribute to excessive apoptosis of immature neurocytes induced by exogenous glucocorticosteroid. The possible determining factors for immature brain is more vulnerable to exogenous glucocorticosteroid damage. It may be associated with the physiologically high intracellular level of calcium concentration and NMDA-R1 expression.

[Polyneuro-electrophysiological studies of myoclonus in children].

OBJECTIVE: To explore the clinical and neuroelectrophysiological characteristics of myoclonus of different origins in children. METHOD: Thirty-two children with myoclonic seizure were analyzed by video electroencephalogram-electromyogram (VEEG-EMG) polygraphic recordings, jerk-locked back averaging (JLA) and short latency somatosensory evoked potential (SSEP). They were classified into cortical myoclonus (CM), subcortical myoclonus (SCM), and unidentified group according to their generating locations, and also were classified into epileptic and non-epileptic myoclonus based on their different properties. RESULT: The 32 patients included 14 with CM, 14 with SCM and 4 with unidentified origin. (1) CM group: the myoclonic patients presented as focal and/or multifocal seizures in 11 cases and as generalized in another 3 patients besides focal myoclonus. Arrhythmic jerks were shown completely in 11 cases and rhythmic seizures were concomitant in another 3 patients. Myoclonus sensitivity to sensory stimulus was observed in 10 patients. The durations of EMG burst were 10-52 ms. Background EEGs were presented normal in 4 patients and slowing in 10 patients. The epileptiform discharges in interictal EEG were variable. The ictal EEG showed epileptic discharges with each clinical jerk in 9 cases but only with some jerks in 4 patients. Another one had no any EEG abnormality in each jerk. The myoclonus-related spikes were disclosed in 13 cases by JLA. Of the 10 cases who underwent SSEP, giant SSEPs were seen in 3 cases including the one with normal EEG and JLA analyses. (2) SCM group: myoclonus was presented as generalized in 8 cases and as focal in 6 cases. All the patients showed arrhythmic jerks and 14 cases were not sensitive to stimulus. The durations of EMG burst were from 60 ms to 400 ms. Normal background EEGs were presented in 6 patients and slowing in 8 patients. The interictal EEG showed no consistent abnormality. Epileptic discharges associated with myoclonus seizures were not found in any of 9 patients but were observed with some seizure changes in 5 cases. There was no myoclonus-related spike by JLA in this group. SSEPs were normal in all patients. (3) The group with unidentified origin: the durations of EMG were from 60 ms to 400 ms, and their EEG and SSEP recordings were normal. In addition, 32 patients could be classified as epileptic myoclonus in 14 cases and nonepileptic myoclonus in 18 cases by the polyneurophysiological tests. CONCLUSION: (1) It is not reliable to identify myoclonus seizures and their clinical properties depending on their interictal and ictal EEGs only. (2) Polyneuroelectrophysiological tests, including EEG-EMG, JLA, and SSEP, seem to be valuable and useful to identify the generating locations and properties for different myoclonus in children.

[Establishment of animal model of myoclonus originating from axis of cortex-thalamus].

OBJECTIVE: To develop a series of experimental animal models of myoclonus with different origins consistent with myoclonus seizure in clinic setting. METHODS: GABA(A) antagonist SR95531 was microinjected into the primary motor cortex (PMC), corpus striatum, nucleus reticular of the thalamus (NRT) to induce myoclonus (EMG burst of myoclonus

[Peripheral nerve damage and its pathogenesis induced by antiepileptic drugs in rats].

OBJECTIVE: To explore the possibility of peripheral nerve damage induced by antiepileptic drugs (AEDs) in different age rats and its pathogenesis. METHODS: Adult (2-month-old) and infant (7-day-old) rats were divided into 8 groups (n = 16 in each) and treated with the following 7 AEDs respectively: phenytoin [PHT, 62.5 mg/(kgxd)], phenobarbital [PB, 30.0 mg/(kgxd)], sodium valproate [VPA, 312.5 mg/(kgxd)], clonazepam [CZP, 1.25 mg /(kgxd)], carbamazepine [CBZ, 187.5 mg/(kgxd)], topiramate [TPM, 40 mg/(kgxd)], oxcarbazepine [OXC, 312.5 mg/(kgxd)], remaining one group was used as control. Four weeks later, 8 rats were sacrificed randomly from each group and serum, sciatic nerves and spinal cord samples were collected. The rest half rats were sacrificed 4 week after AEDs withdrawal. Histological observations were performed on the sciatic nerves samples, including teased fibers, semi-thin sections and electron microscopy. The activity of total antioxidant capacity (T-AOC), superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX) in serum and sciatic nerves were detected respectively. Expression of apoptosis-related proteins Bcl-2 and Bax was detected by immunohistochemistry. Neurons apoptosis in the anterior horns of spinal cord were detected by TUNEL. RESULTS: (1) Except for TPM group, various incidence (7.2% - 20.2%) of teased fibers abnormalities were observed in all the other different age groups. PHT group showed the most serious changes followed by PB (adult) or VPA (infant), CBZ, CZP and OXC groups. The predominant abnormality of teased fibers was demyelination. (2) There was no significant difference in the incidence of pathologic changes in teased fibers between adult and infant groups. Four weeks after AEDs withdrawal, recovery of pathologic changes in teased fibers in infant groups was much better than adult. (3) Significantly increased expression of Bax protein and ratio of Bax/Bcl-2 was only found in infant rats treated with PB, CNP or VPA compared with control (P < 0.05), the results of TUNEL was in accordance with immunohistochemistry. (4) Compared with control, the activity of T-AOC and SOD decreased in both infant and adult rats treated with PHT, CZP, CBZ and OXC, and the reduction of SOD activity in serum and sciatic nerves samples was also found in PB groups. Serum activity of GSH-PX was decreased in both age groups treated with PHT, PB, VPA, CZP, CBZ and OXC. The reduction of GSH-PX activity in sciatic nerves samples was remarkably in both adult and infant rats treated with PHT, PB, CBZ, OXC as well as the infant rats treated with CZP. CONCLUSIONS: Six AEDs (PHT, PB, CBZ, VPA, CZP, OXC) showed the potential to cause peripheral nerves damage. Demyelination was the predominant pathologic change. Both adult and infant rats had the same susceptibility. Recovery of pathologic changes in teased fibers in both age groups was slow, but infant rats were prone to revive more quickly. There was no significant correlation between spinal cord neuron apoptosis and peripheral nerves damages in rats treated with AEDs. Breakdown of oxidation-antioxidation balance was closely related to development of peripheral nerves damages caused by most AEDs.

Evaluation of open-label topiramate as primary or adjunctive therapy in infantile spasms.

OBJECTIVE: A multicenter open-label clinical trial was conducted to evaluate the clinical usefulness of topiramate (TPM) as primary or adjunctive therapy for infantile spasms in the postmarketing period in China. METHODS: Thirty-four centers participated in the trial. Patients included in the study had 1 or more seizures per day before treatment. One hundred twenty (22.1%) very young patients with an age younger than 6 month and 64.2% of patients were younger than 1 year at start of treatment. All patients received a starting dose of 0.5 to 1 mg kg d TPM twice daily. The dosage was increased by 0.5 to 1 mg kg d every 5 to 7 days up to 3 to 5 mg kg d. The resulting range of the total TPM dosage was 25 to 200 mg d (3.57-20 mg kg d), with a median value of 73.9 mg d. Seizure outcomes were measured by intention-to-treat analysis. Patients were seen by a neurologist, and their data were evaluated at the day of inclusion and after 4, 8, 12, 16, and 20 weeks (from visit 1 to visit 5) of treatment. RESULTS: Five hundred forty-four patients entered the study. After 20 weeks of TPM treatment, 239 patients (43.9%) were seizure-free. A higher proportion of patients in the monotherapy group than in the add-on therapy group showed a seizure rate reduction. An increase in seizure frequency was observed in 8 patients (1.5%) during the 20-week treatment period. Nineteen patients were withdrawn before completing the study, and in 46 cases, some data of the structured data files and questionnaires were missing. No efficacy of TPM treatment was recorded in these cases. Adverse effects occurred in 211 patients (38.8%). Most frequent side effects were anorexia and somnolence. CONCLUSIONS: Topiramate proved to be an effective and safe monotherapy and add-on therapy in patients with infantile spasms younger than 1 year.

[Clinical and polyneuroelectrophysiological characteristics of infantile spasm].

OBJECTIVE: To explore the characteristics of various seizure types in infantile spasm (IS) and to recognize the clinical and electrophysiological differences among spasm, myoclonic and tonic seizures. METHODS: Totally 681 seizures of 8 infants with IS were analyzed, including 20 episodes of non-cortical myoclonus which were finally ruled out by video-electroencephalogram-electromyogram polygraphic recordings (VEEG-EMG) and off-line analysis of jerk-locked back averaging (JLA). As a control, the data of 58 myoclonic seizures collected from an infant with Aicardi syndrome within two months before his typical clinical presentations of IS were also analyzed. RESULTS: Three types of seizures were recorded from the 8 infants, including spasm, myoclonic and tonic seizures with the incidence of 94.4%, 4.5%, and 1.1%, respectively. Spasms were mostly presented as body muscle contraction axially, which often occurred in clusters and evolved in a crescendo-decrescendo manner; 85.7% of them lasted for 0.4 - 3.0 s and 14.3% for 3 - 7 s. In addition, there were 273 seizures which were identified as subtle spasms according to their ictal EEG with high voltage slow wave (HVS) and fast wave bursts in most. There was no constantly time-locked EEG correlating to spasms even when JLA was applied for analysis. Myoclonic seizures were shock-like muscle constraction lasting for less than 400 ms with or without visible epileptic discharges in its ictal EEG. However, there was a time-locked cortical discharge discerned by JLA in epileptic myoclonus. Tonic seizures were consisted of sustained muscle contractions involving limbs and trunk, lasting for more than 3 s. Its ictal EEGs were more likely low amplitude fast waves and medium amplitude theta activities. Some spasms, named as tonic spasm, could be distinguished from tonic seizure according to the seizure duration which was always less than 2 s in tonic spasms and their different EEG patterns. CONCLUSIONS: There were various seizure types in IS but spasm was the predominant one. With polyneuroelectrophysiological tests including EEG-EMG and JLA, it would be much helpful to precisely recognize the different common seizure types including spasm, tonic spasm, myoclonic and tonic seizure during infancy which is important for the diagnosis, classification and treatment of infantile epilepsy.

[Experimental study on the possibility of brain damage induced by chronic treatment with phenobarbital, clonazepam, valproic acid and topiramate in immature rats].

OBJECTIVE: To explore the possibility of brain damage induced by several anti-epileptic drugs (AEDs) at therapeutic level to immature brain of rat. METHODS: Totally 160 healthy Spraque-Dawley (SD) rats selected for the study were divided into infant and adult groups. Each age group was treated with phenobarbital (PB), clonazepam (CZP), valproic acid (VPA), topiramate (TPM) or normal saline respectively for 2 or 5 weeks with 8 rats in each group. The steady-state plasma concentrations of AEDs at the experimental dosage were coincided with the range of clinical therapeutic concentrations. Drug levels in plasma were determined by fluorescence polarization. Body and brain weights were measured when the rats were sacrificed. Histological studies on the tissues of frontal lobes and hippocampus were performed by Nissl staining. And ultrastructural changes of brain were observed by the transmission electron microscopy. Plasma neuron-specific enolase (NSE) was determined by ELISA. Expression of apoptosis-related proteins Bcl-2 and Bax in neurons was detected by immunohistochemistry. Neuronal apoptosis was detected by terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL). RESULTS: (1) There were no significant differences in brain weight among all adults groups. While remarkable reduction of brain weight was observed in immature rats exposed to CZP or PB (P < 0.01) for long term. (2) Significant neurodegeneration, neuronal necrosis and decrease in the number of neurons can be observed in the immature rats exposed to CZP or PB for long period. (3) For immature rats, concentration of plasma NSE was increased even after short-term treatment with PB [(8.84 +/- 2.10) nmol/L] compared with control group [(6.27 +/- 1.27) nmol/L] (P < 0.01). And it was increased in immature rats exposed to CZP [(8.15 +/- 1.67) nmol/L] or PB [(8.07 +/- 1.27) nmol/L] for long term compared with controls [(6.02 +/- 1.20) nmol/L] (P < 0.01). But there were no significant differences between AEDs-treated adult rats and control rats. (4) The expression of Bcl-2 and Bax protein in mature brain did not change at therapeutic level. In contrast, expression of Bax protein in the frontal lobe was increased significantly in immature rats receiving CZP and PB for long period compared with control. (5) The number of TUNEL positive cells in immature rats exposed to CZP or PB for long term was obviously increased. CONCLUSIONS: PB and CZP may result in remarkable histological abnormalities, neuronal apoptosis and necrosis in immature brain. The brain damage induced by PB was more serious and persistent than that induced by CZP.

[Experimental study on the chitosan-DNA vaccines against campylobacter jejuni invasion].

OBJECTIVE: The immunogenicity and protective efficacy of an experimental Campylobacter jejuni (C. jejuni) chitosan-DNA vaccines were evaluated in mice. METHODS: The chitosan-DNA vaccines were prepared by embedding pcDNA3.1(+)-cadF and pcDNA3.1(+)-peblA with chitosan respectively. BALB/c mice were intranasally immunized in a four-dose primary series (7 d intervals) at doses of 60 microg chitosan-DNA vaccines each time. The comparative immunogenicities of nine formulations were assessed on the basis of the generation of antigen-specific antibodies in serum and intestinal secretions. Mice were attacked repeatedly through intragastric administration of C. jejuni HS:19 at the 8th week after the immunization and protective efficacy was determined by detecting the degrees of protection afforded against C. jejuni invaded. RESULTS: The mice immunized with chitosan-DNA vaccines have generated high levels of IgA and IgG from the sera and IgA from the intestinal secretions and the P/N value went up to 20.58, 30.13 and 6.87 respectively. Meanwhile, the expression of intestinal SIgA increased correspondingly. Moreover the chitosan-DNA vaccines induced strongest level of protection in BALB/c mice against challenge with C. jejuni HS:19 strain and the protective efficacies was 93.70. CONCLUSION: The results of this study indicate that the chitosan-DNA vaccines could induce significant protective immunity against C. jejuni challenge in the mice model.

The sialic acid residue is a crucial component of C. jejuni lipooligosaccharide ganglioside mimicry in the induction Guillain-Barré syndrome.

Guillain-Barré syndrome (GBS) is an autoimmune neuropathy that often follows C. jejuni infection. Sialic acid (N-acetylneuraminic acid, NANA) is a common constituent of lipooligosaccharide (LOS). The molecular mimicry between C. jejuni LOS and human peripheral nerve gangliosides is believed to play an important role in the pathogenesis of GBS. The neuB1 encodes NANA synthetase, required for the synthesis of NANA of C. jejuni LOS. A neuB1 mutant was constructed from a C. jejuni HS:19 wild strain. Mutant LOS could not bind the cholera toxin B subunit, failed to induce anti-GM1 antibodies, and did not cause pathological changes in the peripheral nerves. These data suggest that the NANA residue in LOS is a crucial epitope in realization of ganglioside molecular mimicry.

Carbohydrate mimicry of Campylobacter jejuni lipooligosaccharide is critical for the induction of anti-GM1 antibody and neuropathy.

The expression of ganglioside-mimicking structures of Campylobacter jejuni lipooligosaccharides (LOS) is considered essential for the induction of antiganglioside antibodies that lead to Guillain-Barré syndrome (GBS). The galE gene in C. jejuni is involved in the biosynthesis of the LOS outer-core oligosaccharide structures. We have demonstrated that the C. jejuni HB9313 (HS:19) parental strain expresses a LOS structure containing GM1-like epitopes, and the C. jejuni knockout mutant of the galE gene expresses a truncated LOS structure without GM1-like epitopes. To clarify whether the ganglioside-like structures in Campylobacteri LOS are crucial for induction of antiganglioside antibody responses and neuropathy, we performed immunization experiments in guinea pig models using the parental strain HB9313 and its galE mutant derivative. The anti-GM1 IgG antibody responses in immunized animals were measured by enzyme-linked immunosorbent assay. Sciatic nerve specimens were evaluated pathologically. High levels of the anti-GM1 IgG antibody were induced in guinea pigs immunized with HB9313, but not in those immunized with the galE mutant. The mean percentage of abnormality of sciatic-nerve teased fibers from animals sensitized with C. jejuni HB9313 was significantly higher than from animals immunized with the galE mutant. Furthermore, significant changes were found in semithin sections of the sciatic nerve from animals inoculated with C. jejuni HB9313. The major pathological finding was axonal degeneration; no significant morphological findings, except for occasional demyelination, were observed in animals immunized with the galE mutant. These results indicate that ganglioside-mimicry structures in C. jejuni LOS are necessary for induction of antiganglioside antibody response and neuropathy.