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An unknown HLA-B allele which was similar to HLA-B*270401 was detected by FLOW-SSOPCR-SSP and heterozygous sequence-based typing (SBT) in Chinese Han individual. Its anomalous patterns suggested the possible presence of new allele. Amplifying exon 2-5(include intron 2-4) of the HLA-B*27 allele separately by using allele-specific primers and sequencing in both directions. Identifying the difference between the novel B*27 allele and B*270401. The sequence of novel B*27 from exon 2 to partial exon 5 is 1 815 bp. There are 10 nt changes from B*270401 in exon 3-4, at nt634where A-->C(codon130 AGC-->CGC, 130 S-->R); nt670 where A-->T (codon142 ACC-->TCC, 142 T-->S); nt683 where G-->T (codon146 TGG-->TTG, 146 W-->L); nt698 where A-->T (codon151 GAG-->GTG, 151 E-->V); nt774 where G-->C (codon176 GAG-->GAC, 176 E-->D); nt776 where C-->A (codon177 ACG-->AAG, 177 T-->K); nt781 where C-->G (codon179 CAG-->GAG, 179Q-->E); nt789 where G-->T (codon181 GCG-->GCT) resulting no coding change; nt1438 where C-->T (codon206 GGC-->GGT) resulting no coding change; nt1449 where G-->C (codon210 GGG-->GCG, 210G-->A). In IMGT/HLA database, only three alleles (B*270502/2706/2732) have sequences of introns. The same sequence in intron 2 showed homology between the novel HLA-B*27 allele and B*2706, but their homology could not be supported in intron 3-4. Comparing the sequence of the novel B*27 allele in intron 3 and 4 with B*27 group, it showed there are three mutations at nt106 C-->G, nt179 G-->A, nt536 G-->A and one deletion at nt168 in intron 3 and one mutations at nt82 T-->C in intron 4, but the sequence of the novel B*27 allele in intron 3 and 4 was all the same to B*070201. The sequence was submitted to Gen-Bank and the accession number was DQ915176. The allele has been confirmed as an extension of B*2736 by the WHO Nomenclature committee in November 2006.

Objective: To discuss the possibility of microneurosurgery techniques in the treatment of multisegmental intramedullary cervical spinal cord ependymomas., Methods: The clinical data of 26 cases of multisegmental intramedullary cervical spinal cord ependymomas patients was reviewed and analyzed., Results: There were 14 cases of cervical spinal cord ependymomas, 12 cases of cervical and thoracic spinal cord ependymomas. 4.5 spinal cord segments were involved in average. Incompletely inferior paraplegia was in 18 cases, incompletely high paraplegia in 8 cases, dyspnea in 6 cases, sphincter dysfunction in 10 cases. MRI detected syringomyelia formation in 24 cases. Vertebral lamina reposition were done in 20 cases. Muscle strength recovered in 21 cases, no change in 4 cases, aggravated in 1 case. All cases had total resection and 1 cases vertebral had instability in MRI., Conclusions: Total resection of intramedullary cervical spinal cord ependymomas can be achieved by microneurosurgery. Most of the symptoms can be released after microsurgical treatment. After multisegmental laminotomy, the vertebral plate reposition should be done to ensure the stability.

Objective: To evaluate the feasibility, safety and short-term efficacy of stent-assisted angioplasty and/or drug therapy for elderly patients with symptomatic vertebrobasilar insufficiency., Methods: Elderly patients (> or = 60 years old) with symptomatic vertebrobasilar stenosis (> or = 50%) demonstrated by cerebral angiography were treated with drug therapy and some with endovascular stenting further from April 2001 to June 2006. The clinical, imaging, intervention and follow-up data were collected and analyzed., Results: Eighty-one elderly patients were chosen for study, including 68 males and 13 females. The mean age is 70 years (60 - 87 years); stroke rate of 4.9% (4/81) and stroke-related mortality rate of 2.5% (2/81) were found in this group during hospitalization and follow-up (mean 28.1 months), and symptoms resolved or improved clinically in 66 (81.5%). Fifty-two balloon expandable stents were placed in 48 (59.3%) patients of this group with a technical success rate of 98.1% and the mean degree of stenosis was reduced from (82.4 +/- 13.1)% to (6.4 +/- 3.2)% (t = 22.4, P = 0.00)., Conclusions: Appropriate management including endovascular stenting and/or drug therapy may improve short-term outcomes of elderly patients with symptomatic vertebrobasilar insufficiency; meanwhile, stent-assisted angioplasty is technically feasible and relatively safe.

Objective: To study the genetic polymorphisms of 9 Y-chromosome specific STR loci that the allele size is less than 180 bp in length in the southern Chinese Han population, and to utilize the studied result to forensic science., Methods: Nine Y-STR loci were amplified by single multiplex PCR, and the PCR products were sequenced by using ABI Prism 3100 DNA Sequencer. The allele and haplotype frequencies at 9 Y-STR loci were determined in a total of 213 unrelated males from southern Chinese Han population. Eighty-four father/son pairs with demonstrated paternity and thirty-six non-paternity father/son pairs were detected by using our Y-STR multiplex system., Results: Three Y-STR alleles for DYS426, five alleles for DYS393, DYS460, DYS391 and DYS389 I respectively, six alleles for DYS456, seven alleles for both H4 and DYS388, and eight alleles for DYS458 loci were detected in 213 unrelated male individuals. Except for the DYS426 locus with a low GD value of 0.1489, the GD values for other 8 Y-STR loci ranged from 0.5064 to 0.9133. A total of 178 haplotypes were found at 9 Y-STR loci, of which 154 haplotypes were observed only once, and the haplotype diversity was 0.9983. None of Y-STR allele mutation was observed in the 84 father/son pairs with demonstrated paternity. Among the 36 non-paternity father/son pairs, two cases could get the paternity exclusions at 2 Y-STR loci; and the paternity of 33 cases could be ruled out by 3 or more Y-STR loci; only one case was found no exclusion of paternity regardless of detecting 9 Y-STR loci., Conclusion: This result indicates that the 9 Y-STR loci with short fragment size alleles are highly polymorphic. The fluorescent multiplex amplification system that we developed is suitable for personal identification and paternity testing.

Objective: To study the ABO allele molecular characteristics of Ael blood subgroup., Methods: Five individuals of diagnosed as Ael blood subgroup were subjected to PCR amplify ABO alleles using four pairs of sequence-specific primers. Exon 6 and exon 7 at ABO locus of all samples were sequenced. An individual with AelB phenotype was chosen for further analysis of transcript structure of ABO gene., Results: Sequence analysis indicated one Ael phenotype sample with reported Ael01 allele, one Ael phenotype sample with an Ael05 allele, and two AelB and one Ael individuals did not contain referred A allele, but contain O01 or O02 allele with 261G deletion., Conclusion: Molecular bases for the Ael have highly polymorphism. The mechanism responsible for the express weak A antigen of O allele with 261G deletion awaits to be elucidated.

The ABO blood group is one of the main blood group systems, and it plays an important role in transfusion medicine and transplantation. To date, most of the many ABO subgroups with a weak expression of the A or B antigen on red blood cells have been elucidated to have specific molecular genetic background with respect to the ABO gene. The ABO*B(A) allele or CisAB allele is a type of dual ABO allele which can encode glycosyltransferases responsible for the conversion of H substance to both A and B antigen. We report here our characterization of a novel B(A) allele which differs from those reported previously.

Chitosan scaffolds were modified with RGDS (Arg-Gly-Asp-Ser) in the present work via an imide-bond forming reaction between amino groups in chitosan and carboxyl groups in peptides. Successful immobilization was verified with FTIR spectroscopy, and the immobilized amount was determined to be on the order of 10(-12) mol/cm2 through analysis of the immobilized amino acids. Results of experiments of cell culture with rat osteosarcoma (ROS) cells demonstrated that RGDS immobilization could enhance the attachment of ROS cells onto the chitosan, resulting in higher cell density attached to the RGDS-modified scaffold than to the unmodified scaffold. It should be noted that only RGDS, but not other peptide such as RGES, is effective in enhancing cell attachment and possible proliferation. Experiments of in vitro mineralization indicated that there were more cells on the RGDS-modified scaffold than on the unmodified scaffold, which tended to form bone-like tissues. The results presented in this work suggest that immobilization of RGDS can make chitosan scaffolds more compatible for the culture of osteoblast-like cells and the regeneration of bone-like tissues.

To investigate the allele distribution of HLA-B* 40 gene family in Chinese Han population and to study its influence on the selection of clinical transplantation donor, the HLA-B genetypes of 381 individuals randomly selected from Chinese National Marrow Donor Project were identified by PCR-SSO, and then all the HLA-B* 40 positive samples from the above population and the B* 40 homozygote samples received from another 1 270 registered donors were analyzed by PCR-SBT and PCR-SSP at high resolution. The results showed that the population of 381 registered donors was examined at HLA-B locus by using Hardy-Weinberg equilibrium, the gene frequency of HLA-B* 40 was 0.1692. Four different HLA-B* 40 alleles (B* 4001, B* 4002, B* 4003, B* 4006) were identified, and the serological specificity was B60 and B61 respectively. The relative frequency of each allele was 0.1192 for B* 4001, 0.0154 for B* 4002, 0.0038 for B* 4003, 0.0308 for B* 4006. The distribution of B* 40 homozygote revealed a certain regularity at high-resolution, B* 40XX (B* 4001 group), at low-resolution; B* 4001 at high resolution; B* 40XX (B* 4002 group), at low-resolution; B* 4002 or B* 4006 or heterozygote of both at high-resolution. It is concluded that in Chinese Han population, predominant allele in HLA-B* 40 gene family is B* 4001, the high-resolution typing may be recommended to use for the selection of clinical transplantation donor.

Objective: To investigate the distributions of HLA-A*02 alleles in Han populations and compare their difference between the south and north in China., Methods: A total of 208 individuals from south China and 109 from north China were randomly selected from registered bone marrow donors in Chinese Han population, who were tested positive for HLA-A*02 alleles by PCR with sequence-specific primers (PCR-SSP). Genotyping of the alleles was performed using PCR-sequence-based typing (PCR-SBT)., Results: Six different HLA-A*02 alleles (A*020101, A*0203, A*0205, A*0206, A*0207 and A*0210) were identified in the two Chinese Han populations, of which A*0207(37%) was the predominant allele in southerners and A*020101(48%) in the northerners. A*020101(31%), A*0203(16%) and A*0206(14%) were common alleles in the southerners in comparison with A*0206(21%) and A*0207(23%) alleles in the northerners. The overall distribution of A*02 alleles and the frequencies of A*020101, A*0203 and A*0207 in the two populations differed significantly. The heterozygosity of A*02 in the southerners and northerners was higher than 90% and 80% at the high- and low-resolution levels, respectively, and the distribution of A*02 homozygote at low-resolution level in both populations showed diversity and regularity at high-resolution level., Conclusions: HLA-A*02 alleles possess high heterogeneity and genetic diversity in Chinese Han population with significantly different distributions in the two populations. HLA-A**020101, A*0203 and A*0207 may serve as the genetic markers for dividing Chinese Han individuals into southerners and northerners in anthropological studies.

Objective: To clarify and discuss the diagnosis and minimally invasive surgery of spinal cord hemangioblastoma., Methods: The clinical data of 16 patients with spinal cord hemangioblastoma who were operated on between 1992 and 2001 were analyzed retrospectively with a review of the literature., Results: Twelve patients were subjected to MRI examination, nine to spinal cord angiography, and six to preoperative embolization. Thirteen patients underwent complete excision, and three underwent partial excision due to massive bleeding and anterior location of the tumor in spinal cord. Eleven patients showed improvement of their symptoms, four no change at all, and tumor recurrence was seen in one patient with aggravation., Conclusion: MRI and spinal angiography are essential for preoperative diagnosis and surgical planning. Early diagnosis and microsurgical resection greatly preserve the neurological function of the patients. Preoperative embolization sometimes is helpful in surgery.

Objective: To analyze human leukocyte antigen (HLA) polymorphism and search for new alleles in Chinese Han population bone marrow registry donors., Methods: DNA-based HLA genotyping methods were used including PCR-SSP, BST and molecular cloning., Results: A total of 6965 unrelated donors, 4707 from South China origin and 2258 from north, were typed for HLA-A, B, and DRB1 loci. Seventy-two specificities of HLA alleles were identified. The HLA-A25, A34, A74, B41, B42, B53, B73 and B81 that were rarely reported in previously Chinese population studies were identified in this study. Estimation of gene frequency indicated that the blank gene frequency was less than 0.2% for HLA-A, 0.25% for HLA-B and 0.70% for HLA-DRB1 loci. Three novel alleles were identified and officially assigned by the World Health Organization (WHO) Nomenclature Committee as A*0253N, A*1114 and B*5610., Conclusion: Large-scale DNA-based HLA genotyping used in bone marrow registry donors is highly accurate and reliable for estimating gene frequency and searching for new alleles. The discrepancy of HLA gene distribution between South and North China Han population showed the necessity of setting the more regions in South and North China to screen the bone marrow registry donors for bone marrow transplant.

Objective: To evaluate the validity of intraoperative magnetic MEP (motor evoked potentials) monitoring in a spinal-cord-menaced surgery., Methods: 32 rabbits were employed in weight-drop spinal cord contusion model. After anesthetized with a combination of Ketamine and Droperidol the spinal cords were surgically exposed with the dura intact, and the contusion injuries were delivered except the rabbits in control group. The MEPs were recorded and the relationship between the variation of the MEPs and the residual locomotor capacity after spinal cord injury was analyzed., Results: The 6 rabbits in mild-spinal-cord-injury group experienced transient attenuation of their TMS-MEPs, and the locomotor capacity remained intact (scores of 5) in almost all rabbits (5 of 6) when assessed 24 hours later; In the moderate-spinal-cord-injury group the 8 rabbits lost their TMS-MEP immediately after the weight-drop contusion, but they regained them partly in 1 hour one after another and scored 4 or 5 in the assessment of muscle power next day except for one score of 2; 8 rabbits had their spinal cords impaired severely in the contusion procedure and lost their TMS-MEP too but without recovery, their locomotor capacity outcomes were very poor, 5 of them had no response to transcranial magnetic stimulation next day, and in the other 3 rabbits we only found some polyphase waves with variant latency and lower amplitude which did not resemble common compound muscle action potential (CMAPs) evoked by TMS., Conclusions: Myogenic TMS-MEPs was very sensitive to the spinal cord injury and should be a valid technique for intraoperative monitoring, and a slight change of them, even if a transient lose, should be unnecessarily related to a severe movement disorder. The warning threshold for a given patient should depend on the malady itself.