Objective To determine the cost effect for cranial CT scans in epileptic patients.Methods The newly diagnosed epileptic patients from 1995 to 2000 were prospectively investigated by cranial CT scan in our clinic for epilepsy. The cost for finding a case of significant pathology was estimated to determine the cost effect of cranial CT scan in patients.Results 572 cases of generalized and 172 of partial epileptic patients were studied. 32% of the overall abnormalities were found by CT scan in all patients, but specific abnormalities were only found in 10% of the patients. None of 480 generalized patients without focal abnormalities in neurological and/or EEG examinations was found having clinically important abnormalities by using CT, the cost for finding a case of significant pathology was estimated to need at least 64 214 yuan. While 50% partial seizure patients having focal abnormalities in the examinations, were found having specific abnormalities by CT, the cost of finding a case of significant pathology was estimated to be 800 yuan (Cost for a CT scan about 400 yuan in our hospital).Conclusion When there is a shrinking availability of health care money, especially in developing countries, CT scan evaluation for a neurological normal patient with generalized seizures is expensive that the cost effect analysis should be taken into account.

Objective To study the single nucleotide polymorphisms (SNP) in 3 sites allele (T189M, R85H, C121W) of SCN1B and the association between gene distribution and epilepsy. Methods All 330 blood samples of refractory (80 cases), non-refractory (100 cases) epilepsy patients and healthy people (150 cases) were collected. Genomic DNA of leucocyte was extracted. SNPs of three sites allele of SCN1B were tested by allele-specific primer-polymerase chain reaction (ASP-PCR).Data were analyzed by SAS 8.1 statistical software. Results Epilepsy group and healthy group had significantly statistical difference in composition of 3 sites allele on single site genotype (x~2=11.19, 11.14 and 6.50, all P < 0.05).There was no statistical significance between refractory and non-refractory epilepsy group. On gene combination, in 27 different combinations of polymorphism, mutation frequency in 3 sites (CT + AG + CG) was highest in epilepsy group (18.40%).The next was one site in CT + GG + CC (16.80%).In healthy group, frequency of non-variant in CC + GG + CC was highest (16.67%), and the next was 2 sites in CT+ AG+CC (13.73%).Thirty-five cases in epilepsy group (28.80%) had 3 sites mutation compared with 10 cases in healthy group (9.71%), and their difference had statistical significance (x~2=12.54, P<0.05).Eighteen cases in refractory epilepsy group (30.51%) had 3 sites mutation compared with 21 cases in non-refractory epilepsy group (28.77%), and the difference had no statistical significance. Fifty cases in epilepsy group (40.00%) had 2 sites mutation compared with 41 cases in healthy group (40.20%), and there was no statistical significance between them; 25 cases in refractory epilepsy group (42.37%) had 2 sites mutation compared with 21 cases in non-refractory epilepsy group (28.71%), and their difference had no statistical significance. Conclusions Mutation, especially multisite mutation of SCN1B is relatively likely to cause epilepsy in human. Gene distribution and combination of three sites allele of SCN1B in refractory epilepsy is close to that in non-refractory epilepsy.

Objective To study the distribution patterns of the SNPs for the 3 sites (Ⅱe105Val, Ala114Val and Asp147Tyr) of glutathione S-transferase pi (GST-pi) in epilepsy patients without definite etiological factors. Methods At the same time, the possible relationship of GST-pi gene mutation with the vulnerability of drug-resistant epilepsy, drug-responsive epilepsy and EEG feature were explored. The SNPs of GST-pi for healthy people, drug-responsive epilepsy patients and drug-resistant epilepsy patients were genotyped by sequence-specific primers (SSP)-based PCR technologies (PCR-SSP). Results In drugresponsive epilepsy group, the frequency for 3 sites of mutated SNP of GST-pi was 59.62%, 55.32% and 50.94%, while it was 58.33%, 51.19% and 45.92% in drug-resistant epilepsy group. The difference of genotype and allele between normal group and foregoing epilepsy group was significant ( P<0.01 ), but no difference was found between drug-respensive epilepsy group and drug-resistant epilepsy group ( P>0.05 ). There was a difference of genotype distribution between groups with typical and untypical epilepsy EEG ( F = 0.0294, 8.867 × 10-6, 1.366 × 10-5, P<0.05 ). Conclusions The results indicate that the SNPs of GST-pi are associated with an increased risk of epilepsy, but not associated with an increased risk of drugresistant epilepsy. The patients present EEG characteristic of typical epilepsy.

Objective To detect the recombinant intermediates of hepatitis B virus (HBV) between genotype B and C in vitro. Methods Vector Plenti6/V5-D-topo-X was genetically modified by genotype B and C to transfect HepG2 cells. Then the HepG2 cells were amplified and sequence of the nucleic acid after the transinfection was tested and compared with RDP3Beta40 software package and bootscanning procedure in SimPlot program package. Results Three recombinant intermediates of HBV between genotype B and C were identified in vitro. Genotype C in the precore region plus the core gene spanning nucleotide positions from 1740-1838 to 2443-2485 contributed to the recombination with genotype B. Isolate R1 recombinant intermediate had 2 break points at nt2170-2172 and nt2188-2189. Nucleic acid changed from CAC to TGT and from GA to AC, respectively. Isolate R2 recombinant intermediate had a break point at nt1740-1 838, and 3 bases changed in different nucleic acid sites: from A to T at nt1740, from C to T at nt1753, and from G to A at nt1838, respectively. Isolate R3 recombinant intermediate had a break point at nt2443-2483, and 4 bases changed in different nucleic acid sites: from C to T at nt2443, from A to G at nt2452, from T to C at nt2480, and from C to T at nt2483, respectively. Conclusion The recombinant intermediates of HBV between genotype B and C have been detected in vitro and the changes have been identified in the precore region plus the core gene in genotype B and C.

On the basis of analyzing the defects in traditional averaging theory for extracting evoked potential (EP), and by realizing the characteristic of spontaneous electroencephalo-signal (S-EES) as well as the special environment for extracting EP, we propose an auto-reference, auto-correlation, adaptive interference cancellation (AAA-ICT) for use in the single trial of flash visual evoked potential (FVEP). Firstly, the segment of reference signal, which has the best correlation with evoked electroencephalo-signal (E-EES), was obtained using the method for calculating the sliding correlation point by point between E-EES and reference signal; then, the cancellation factor between E-EES and the most correlative reference signal segment was derived by the least square method; at last, the single trial of FVEP was acquired by interference cancellation. By this method, FVEP can be extracted perfectly and the FVEP variability of individual inter-stimulation can be obtained.
Algorithms ; Electroencephalography ; methods ; Evoked Potentials, Visual ; physiology ; Humans ; Signal Processing, Computer-Assisted