Changes in the expression of satellite glial cell-specific markers during postnatal development of rat sympathetic ganglia.

The sympathetic ganglia represent a final motor pathway that mediates homeostatic "fight and flight" responses in the visceral organs. Satellite glial cells (SGCs) form a thin envelope close to the neuronal cell body and synapses in the sympathetic ganglia. This unique morphological feature suggests that neurons and SGCs form functional units for regulation of sympathetic output. In the present study, we addressed whether SGC-specific markers undergo age-dependent changes in the postnatal development of rat sympathetic ganglia. We found that fatty acid-binding protein 7 (FABP7) is an early SGC marker, whereas the S100B calcium-binding protein, inwardly rectifying potassium channel, Kir4.1 and small conductance calcium-activated potassium channel, SK3 are late SGC markers in the postnatal development of sympathetic ganglia. Unlike in sensory ganglia, FABP7 + SGC was barely detectable in adult sympathetic ganglia. The expression of connexin 43, a gap junction channel gradually increased with age, although it was detected in both SGCs and neurons in sympathetic ganglia. Glutamine synthetase was expressed in sensory, but not sympathetic SGCs. Unexpectedly, the sympathetic SGCs expressed a water-selective channel, aquaporin 1 instead of aquaporin 4, a pan-glial marker. However, aquaporin 1 was not detected in the SGCs encircling large neurons. Nerve injury and inflammation induced the upregulation of glial fibrillary acidic protein, suggesting that this protein is a hall marker of glial activation in the sympathetic ganglia. In conclusion, our findings provide basic information on the in vivo profiles of specific markers for identifying sympathetic SGCs at different stages of postnatal development in both healthy and diseased states.

Interleukin-21 receptor gene polymorphisms in kawasaki disease.

BACKGROUND AND OBJECTIVES: Interleukin-21 receptor (IL-21R) gene polymorphism is related with the development of systemic vasculitis. In this study, we investigated the polymorphisms of IL-21R gene in patients with Kawasaki disease (KD). SUBJECTS AND METHODS: We genotyped the promoter region of IL-21R gene (-2500 bp to +1 bp) in 100 patients with KD and 100 healthy controls. All study subjects were Korean. We designed five pairs of primers and performed polymerase chain reaction (PCR) and direct sequencing. We analyzed whole promoter sequences of 200 individuals with comparison to reference sequences of IL-21R gene (NG_012222.1/NC_000016.9). RESULTS: We found five single nucleotide polymorphisms (SNPs) of which minor allele frequency (MAF) >0.01 in the promoter region of IL-21R gene. Those are -1681 G>T (chromosome site 27411802), -379 G>A (27413104), -332 G>C (27413151, rs2214537), -237 A>T (27413246), and -53 G>A (27413430). There is no significant difference in MAF of each SNP between patients with KD and healthy controls except -237 A>T. Twenty five patients with KD had more than 1 SNP in contrast to only seven healthy controls had. The patients with KD have significantly more IL-21R gene polymorphisms than controls (odds ratio: 3.0, 95% confidence interval: 1.6-5.6, p=0.0005). There was no significant correlation between IL-21R gene polymorphisms and the serum level of IL-21. The serum level of total IgE was not significantly correlated with the presence of IL-21R gene polymorphisms. CONCLUSION: Our data suggest that the genetic susceptibility profile for KD may include IL-21R gene.

Elevated Serum Levels of IL-21 in Kawasaki Disease.

PURPOSE: The serum level of immunoglobulin (Ig)E has been reported to be elevated in patients with Kawasaki disease (KD). We investigated whether interleukin (IL)-21, rather than IL-4, could be related to elevated serum levels of IgE in KD. METHODS: Sera from 48 patients with KD and 12 controls with high fever were collected to determine the level of IgE using an immunoassay system and the levels of IL-4 and IL-21 were determined using enzyme-linked immunosorbent assay kits. RESULTS: The median IL-21 level of KD patients was significantly elevated, at 499.5 pg/mL (range: <62.5-1,544 pg/mL), whereas that of controls was <62.5 pg/mL (<62.5-825 pg/mL; P<0.001). The median IL-4 level of KD patients was not elevated (4.0 pg/mL; 2.1-7.6 pg/mL). The median level of total IgE in KD patients was 58.0 IU/mL (5-1,109 IU/mL). No statistically significant correlation was found between IL-21 and total IgE levels (Spearman's R=0.2; P=0.19). CONCLUSIONS: Patients with KD have elevated levels of IL-21 in the serum. IL-21 may play a role in the pathogenesis of KD.

Predicting factors for refractory kawasaki disease.

BACKGROUND AND OBJECTIVES: About 10-15% of Kawasaki disease (KD) is refractory to intravenous immunoglobulin (IVIG) therapy. This study was designed to investigate the predicting factors for refractory KD. SUBJECTS AND METHODS: We reviewed retrospectively the clinical records of 77 patients with typical KD admitted at Wonju Christian Hospital from January, 2005, to December, 2008. The variance of laboratory and demographic parameters between the IVIG-responsive group and IVIG-resistant group were analyzed. Thirteen patients with urinary tract infections were randomly collected as a febrile control group. RESULTS: Among 77 patients diagnosed with complete KD, 13 patients (16.9%) were IVIG-resistant. The febrile period and hospital days were significantly longer in the IVIG-resistant group than IVIG-responsive group (p<0.001, p=0.002). Serum levels of albumin and sodium were significantly lower in the IVIG-resistant group (p=0.025). The Kobayashi score could differentiate these two groups (p=0.015). Fewer lymphocytes was observed during the subacute phase in the IVIG-resistant group (p=0.032). Coronary arterial dilatations (CADs) were observed in 10.9% (7/64) of IVIG-responders and 38.5% (5/13) of IVIG-resistant patients (p=0.038). CONCLUSION: The percentage of neutrophils and lymphocytes in patients with KD, in addition to known risk factors for refractory KD, may help predict IVIG-resistance in patients with KD.

Relationship between gallbladder distension and lipid profiles in kawasaki disease.

BACKGROUND AND OBJECTIVES: Kawasaki disease (KD) is an acute systemic vasculitis in children which causes coronary arterial dilatation (CAD) and gallbladder distension (GBD). There is a dearth of investigating the relationship between the severity of KD and GBD with lipid profiles. SUBJECTS AND METHODS: A total of 80 patients with 'complete KD' who were diagnosed from January 2005 to May 2009 was enrolled in this study. Serum cholesterol {total, high density lipoprotein-cholesterol (HDL-C) and low density lipoprotein-cholesterol (LDL-C)}, triglyceride (TG), complete blood count, inflammation markers {erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP)} were measured at the time of admission during febrile period. Echocardiography and abdominal sonogram were performed in all patients to determine CAD and gallbladder size. According to GBD, patients with KD were classified as patients with GBD and patients without GBD. Between two groups, demographic and clinical data were analyzed. RESULTS: The serum level of LDL-C was significantly lower in patients with GBD (p=0.03) compared with patients without GBD or febrile control. There was no significant difference in inflammatory indices between patients with GBD and patients without GBD. GBD was not significant risk factor of CAD in this study (odds ratio=2.0, 95% confidence interval=0.82-5.3, p=0.16). CONCLUSION: This is the first study that highlights the relationship between the GBD and lipid metabolism in patients with KD. This study provides clinical insights about potential mechanism underpinning the relationship between the GBD and lipid metabolism.

The comparative evaluation of expanded national immunization policies in Korea using an analytic hierarchy process.

The purpose of this paper is to propose new evaluation criteria and an analytic hierarchy process (AHP) model to assess the expanded national immunization programs (ENIPs) and to evaluate two alternative health care policies. One of the alternative policies is that private clinics and hospitals would offer free vaccination services to children and the other of them is that public health centers would offer these free vaccination services. Our model to evaluate the ENIPs was developed using brainstorming, Delphi techniques, and the AHP model. We first used the brainstorming and Delphi techniques, as well as literature reviews, to determine 25 criteria with which to evaluate the national immunization policy; we then proposed a hierarchical structure of the AHP model to assess ENIPs. By applying the proposed AHP model to the assessment of ENIPs for Korean immunization policies, we show that free vaccination services should be provided by private clinics and hospitals rather than public health centers.

Spontaneous recurrent seizure following status epilepticus enhances dentate gyrus neurogenesis.

It is known that evoked seizures can increase neurogenesis in the dentate gyrus in adult rats. Whether spontaneous seizures occurring after status epilepticus (SE) also results in alterations in neurogenesis is not known. Here, we measured neurogenesis in rats with and without spontaneous seizures following SE. Lithium-pilocarpine was used to induce seizures in postnatal (P) day 20 rats. Spontaneous seizure frequency was assessed 2 months using video monitoring. Rats then received bromodeoxyuridine to label dividing DNA and were sacrificed 24 h later. Animals with spontaneous seizures (n = 9) had a modest increase in neurogenesis compared to animals with SE (n = 6) and no spontaneous seizures and control rats (n = 10). These findings demonstrate that the hippocampus is capable of generating new neurons weeks following SE and further that recurrent seizures enhance the production of new neurons. These alterations in neurogenesis may contribute to ongoing pathological changes week and months following SE.

Long-term effects of status epilepticus in the immature brain are specific for age and model.

PURPOSE: Status epilepticus (SE) is more common in children than adults and has a high mortality and morbidity rate. SE in adult rats results in long-term disturbances in learning and memory, as well as an enhanced seizure susceptibility to further seizures. In contrast, a number of studies suggest that the immature brain is less vulnerable to the morphologic and physiologic alterations after SE. The goal of this study was to determine whether the long-term consequences of SE during development on hippocampal plasticity and cognitive function are age and model specific. METHODS: We used lithium-pilocarpine (Li-PC) to induce SE at different age points during development (P12, P16, P20) and evaluated the effects of this abnormal neural activity on spatial memory performance and seizure susceptibility in the animals beginning at P55, corresponding to young adulthood. RESULTS: We demonstrated that SE at P12 did not result in any structural or functional changes detectable in adulthood, whereas SE at both P16 and P20 induced cell loss and mossy fiber sprouting within the hippocampus and cognitive impairment when the animals were tested as adults. CONCLUSIONS: Whereas the seizure threshold to generalized seizures was not altered, animals with SE at P20 showed an increased susceptibility to kindling in adulthood.

Effectiveness of muscimol-containing microparticles against pilocarpine-induced focal seizures.

PURPOSE: To investigate the efficacy of in situ lipid-protein-sugar particles (LPSPs) in mitigating the epileptogenic and histologic effects of intrahippocampal pilocarpine in rats. METHODS: LPSPs with and without muscimol were produced by spray-drying, sized by Coulter counter, and muscimol content determined by high-pressure liquid chromatography (HLPC). Particles, free muscimol or saline, were injected into the hippocampi of Sprague-Dawley rats before 40 mM pilocarpine, and seizure activity was scored. The trajectories of behavioral scores between groups were compared with two-way repeated measures analysis of variance. Animals were killed after 2 weeks. Brain sections were stained (Timm and thionin) and scored. RESULTS: LPSPs were 4 to 5 microm in diameter, and contained 0 or 2% (wt/wt) muscimol. In vitro, muscimol was released over a 5-day period. Intrahippocampal injections of normal saline and blank LPSPs did not deter seizure activity from pilocarpine. The rise of the trajectory in behavior scores in animals given LPSPs containing 5 microg muscimol was significantly slower than in those receiving saline, blank particles, or 5 microg of unencapsulated muscimol. There was less apparent neuronal injury and CA3 and supragranular mossy fiber sprouting in hippocampi of animals receiving muscimol-containing particles than in animals that did not receive muscimol. Hippocampi of animals that received 5 microg of encapsulated muscimol showed less supragranular sprouting than did those receiving 5 microg of unencapsulated muscimol, but showed no difference in cell loss or CA3 sprouting. CONCLUSIONS: Focally delivered biodegradable microparticles loaded with muscimol are effective in reducing seizure activity from pilocarpine in animals and mitigate the histologic effects.

Effects of lesions of basal forebrain cholinergic neurons in newborn rats on susceptibility to seizures.

The cholinergic system modulates cerebral excitability. We recently reported that immunolesions of the basal forebrain (BF) cholinergic neurons in adult rats increase the susceptibility to generalized seizures. In this study we investigated the effects of lesions of the BF cholinergic neurons in neonatal rats on seizure susceptibility and cognitive function. Neonatal rats at postnatal day (P) 7 received intracerebroventricular (i.c.v.) injections of 192 IgG-saporin (SAP) or phosphate-buffered saline. Following 3 weeks after the injection the first group of rats was implanted with hippocampal electrodes for electroencephalogram (EEG) recordings while the second group of rats was tested for visual spatial memory using the hidden platform version of the water maze test. The first group of rats was then tested for seizure susceptibility using flurothyl 1 week after the electrode implantation. Rats that received immunolesions of the BF cholinergic neurons at P7 had significantly shorter latencies to onset of myoclonic jerks and tonic-clonic seizures than controls. However, no significant differences were found in the duration of seizures, or EEG ictal duration. No significant deficits in spatial learning were found between rats that received i.c.v. injections of SAP at P7 and controls. As in adult rats, lesions of the BF cholinergic system in rat pups result in subsequent increase in seizure susceptibility.

Effect of topiramate following recurrent and prolonged seizures during early development.

Topiramate, an antiepileptic drug with a number of mechanisms of action including inhibition of glutamate activity at the AMPA and KA receptors, was assessed as a neuroprotective agent following seizures. We administered topiramate, 80 mg/kg, or saline for 4 weeks following a series of 25 neonatal seizures or status epilepticus (SE) induced by lithium-pilocarpine in postnatal day 20 rats. Age-matched control rats without a history of seizures were administered topiramate or saline. Following completion of the topiramate injections, animals were tested in the water maze for spatial learning and the brains examined for cell loss and sprouting of mossy fibers. While there was a trend for improved visual-spatial performance in the water maze following topiramate therapy in rats with neonatal seizures, no differences were found in the histological examination of the hippocampus. Neonatal rats exposed to 4 weeks of topiramate did not differ from non-treated controls in water maze performance or histological examination. In weanling rats subjected to SE, topiramate provided a moderate degree of neuroprotection, with topiramate-treated rats performing better in the water maze than rats receiving saline. However, no differences in cell loss or mossy fiber sprouting were found in the histological examination of the brains. These findings demonstrate that chronic treatment with topiramate following SE improves cognitive function. In addition, long-term administration of high-dose topiramate in the normal developing rat brain does not appear to impair cognitive performance.

Memory impairment following status epilepticus in immature rats: time-course and environmental effects.

Status epilepticus (SE) has a high mortality and morbidity rate in children. Disturbances in learning and memory are frequently associated with SE although it is not clear when the cognitive deficits occur. If cognitive dysfunction occurs immediately following the seizure, the window of opportunity for therapeutic intervention is limited. The first goal of this study was to determine the timing of cognitive dysfunction following SE in weanling rats. As there is evidence that enriching the environment can improve cognitive and motor deficits following brain injury, our second goal was to determine whether environmental enrichment improves cognitive function following SE. Rats underwent lithium-pilocarpine-induced SE at postnatal (P) day 20 and were then tested for visual-spatial memory in the water maze at P22, P25, P30, or P50. Rats with SE performed significantly worse in the water maze than control rats at all time points. Once the time-courses of visual-spatial memory deficits were determined, a second group of P20 rats were subjected to SE and were then placed in an enriched environment (enriched group) or remained in standard cages in the vivarium (nonenriched group) for 28 days. Following environmental manipulation, the animals were tested in the water maze. Rats housed in an enriched environment following the SE performed substantially better in the water maze than rats housed in standard cages. However, no differences were found between the enriched and nonenriched groups in EEG or histological evaluation. Although SE results in cognitive impairment within days of the seizure, housing in an enriched environment after SE has a beneficial effect on cognitive performance in rats.