A Discrete Tetrahedral Indium Cage as an Efficient Heterogeneous Catalyst for the Fixation of CO2 and the Strecker Reaction of Ketones.

A discrete tetrahedral indium cage, {[In12(µ3-OH)4(HCO2)24(tcma)4]} (In12-GL), was synthesized solvothermally by the reaction of indium nitrate with the tripodal tricarboxylic acid ligand N,N,N-tris{(2'-carboxy[1,1'-biphenyl]-4-yl)methyl}methylammonium chloride ([H3tcma]+Cl). This cage consists of four trimeric units [In3(µ3-OH)(µ2-CO2)3(µ2-HCO2)3] and four [tcma]2- ligands, which all perform as 3-connection nodes to bridge each other, resulting in a tetrahedral cage structure. The trimeric unit [In3(µ3-OH)(µ2-CO2)3(µ2-HCO2)3] is observed for the first time in the family of In-based metal-organic structures and can be considered as an evolution of a 6-connected [In3(µ3-O)(µ2-CO2)6] unit. Each In3+ is terminally coordinated by a µ1-HCO2 group. This cage contains potential Lewis acidic/basic active sites endowed by In3+ ions as Lewis acidic sites and the uncoordinated oxygen atoms of µ1-HCO2 moieties as Lewis basic sites and was explored as an effective heterogeneous catalyst in the cycloaddition of CO2 with epoxides and the Strecker reaction for amino nitriles. These catalytic reactions were deduced to happen on the surface of the In12-GL cage.

[Single nucleotide polymorphisms in 22 HLA-Cw alleles in Chinese Han population].

To analyze the molecular genetic polymorphism of full-length HLA-Cw gene, a total of 28 samples with known genotypes from Chinese Han population were amplified by long-range PCR using high-fidelity Pfu polymerase. A fragment 4.5 kb in length of HLA-Cw gene was subjected to cloning and haplotype sequencing. The single nucleotide polymorphisms (SNPs) in all segments of the whole region of HLA-Cw gene were analyzed. As a result, we detected 22 different HLA-Cw alleles in 28 samples, all of which were submitted to GenBank and the IMGT/HLA Database. Among the 22 HLA-Cw alleles, the intronic sequences of Cw*030301, Cw*0706 and Cw*140201 were firstly elucidated. The novel intronic sequence and the SNPs information may help to design allele-specific primers for accurate sequence-based typing (SBT) and to avoid allele dropout events in SBT test. We aligned all the diploid sequences using ClustalX program and imported them into Dnasp4.0 to calculate polymorphism in all coding- and non-coding regions. We found 244 SNPs and 10 insertion/deletions (Indels). According to the analysis of polymorphism level, phylogenetic trees and frequency spectrum, we proposed that the evolution of intron 4 and exon 5 was under balancing selection. Selection on these segments indicated that they may be functionally important in evolution of HLA-Cw gene. The full-length sequences obtained and related SNPs information can be used as resources of markers for high-resolution typing, complex diseases association studies and human evolution.

[An analysis of the reason for HLA-C allele dropout in five samples by sequence-based typing].

OBJECTIVE: To analyze the possible reason for HLA-C allele dropout in routine sequence-based typing (SBT) and improve the accuracy of HLA-C SBT test. METHODS: A total of 620 randomly selected samples from healthy voluntary blood donors in Shenzhen were typed at HLA-C locus by sequence-based typing using the AlleleSEQR HLA-C plus sequence-based typing kit. Samples with no full match result were subjected to cloning and haplotype sequencing of the full-length HLA-C gene. If no novel mutations were found, samples were then retyped, using our self-designed PCR primer pair and PCR conditions replacing the AlleleSEQR HLA-C PCR reagents in the PCR set-up procedure so as to analyze the potential reasons for causing abnormal SBT result. RESULTS: In the 620 samples typed at HLA-C locus using the AlleleSEQR HLA-C SBT commercial kit, 5 samples with no full match result were identified. The closest genotype showed one nucleotide mismatch with many different allele groups at different nucleotide position. Based on the PCR-SBT nucleotide sequence, heterozygous nucleotides were determined only in exon 4, whereas the nucleotides in exon 2 and 3 were all homozygotes. The results showed that HLA-Cw*0706 allele dropout existed in all the 5 samples with abnormal SBT results initially identified by AlleleSEQR HLA-C SBT kit, no novel mutation was found. CONCLUSION: The results indicate that the PCR primer pair incompatible with DNA template may result in allele dropout in HLA-C SBT test. Based on the characterization of HLA-C full-length, it is essential to develop HLA-C SBT kit suitable for Chinese population in the future.

[Establishment of an assay for cloning and sequencing the full-length HLA-Cw gene].

OBJECTIVE: To establish a reliable assay for cloning and sequencing the full-length HLA-Cw gene. METHODS: In this study, a fragment of 4.5 kb full-length HLA-Cw gene was amplified using the self-designed PCR primer pair by long template PCR, purified PCR products was cloned into the pGEM-Teasy plasmid vector and the plasmid DNA isolated from positive clones was subjected to haplotype sequencing by both directions. A total of 12 samples having been previously-genotyped by PCR sequence-based-typing (PCR-SBT) were amplified by using the TaKaRa LA Taq and Stratagene Pfu polymerase, respectively. PCR products of full length HLA-Cw gene were subjected to cloning and sequencing and the obtained haplotype sequence were compared with the PCR-SBT results. RESULTS: The specific target fragment of HLA-Cw gene could be amplified and the full-length HLA-Cw allele sequence covering from nucleotide position -962 in 5'untranslated region (5'-UTR) to nucleotide position 3576 in downstream area of 3'-UTR region could be obtained using our method. The results of cloning and sequencing analysis indicated that the Stratagene Pfu polymerase had better fidelity than the TaKaRa LA Taq polymerase in this experiment. By comparing the sequences of Cw*07020101 with Cw*010201, 11 SNPs as well as 2 insertions/deletions in nt-962--284 of 5'-UTR, and 11 SNPs as well as 1 insertion/deletion in nt3067-3576 downstream of 3'-UTR were identified. CONCLUSION: Our results indicate that the technique for cloning and sequencing full-length HLA-Cw gene has been established, it has a broad application in full-length HLA-Cw gene polymorphism study and the regulation and expression of HLA-Cw gene.

[µ-N,N'-Bis(diphenyl-phosphinometh-yl)benzene-1,4-diamine-κP:P']bis-[(2,2'-bipyridine-κN,N')silver(I)] bis-(per-chlorate) acetone disolvate.

The title complex, [Ag(2)(C(10)H(8)N(2))(2)(C(32)H(30)N(2)P(2))](ClO(4))(2)·2CH(3)COCH(3), is a centrosymmetric dimer with pairs of Ag(I) atoms bridged by N,N'-bis-(diphenyl-phosphinometh-yl)ben-zene-1,4-diamine ligands. In addition, each Ag(I) atom is coordin-ated by one chelating 2,2'-bipyridine ligand, giving a distorted trigonal coordination environment.

Molecular polymorphism of O alleles in the Chinese Han population.

The ABO blood group system is the most important in transfusion medicine. O blood group is common in Chinese Han people, but the distribution of various O alleles is unknown. Sequences of exon6 and exon7 of the O allele at the ABO gene locus were studied in 100 individuals of the O phenotype randomly selected from the Chinese Han population. Some samples, when required, were cloned and sequenced spanning exon6 and exon7. Eight O alleles were found in the Chinese population. Most have the 2 common O01 or O02 alleles. The allele frequency of ABO*O01 was 0.47, and that of ABO*O02 was 0.495. One individual was found to have O05 allele. Five alleles were found to differ from all alleles reported to date. Four of these alleles differed from either the O01 allele (1 out of 4) or O02 allele (3 out of 4) by 1 point mutation at A468G, G489A, T526C, or T1104G. The fifth allele differed from the O01 allele since it does not have nt261G deletion but has C467T mutation. This novel allele occurred in 2 individuals. O genetic analysis suggests that the O01 allele prevails, with O1v accounting for about 97% of these in the Chinese Han population. The O03 allele that has been shown to occur with a frequency of <5% in other populations was not detected. But the novel O allele without 261G deletion has been found in Chinese for the first time. Surely more O alleles will be found in the Chinese population.

[Genetic polymorphisms of Y-STR haplotypes in unrelated male blood donors from the surname of Li, Wang and Zhang population in Shenzhen].

To study the genetic polymorphisms of Y-chromosome-specific STR loci in Chinese of different surnames, 9 Y-STR loci were amplified by single fluorescent multiplex PCR and the PCR products were detected by using ABI PrismTM 3100 DNA Sequencer. Samples were randomly-selected from male blood donors in ShenZhen. These individuals, who were otherwise unrelated, had the most common surnames among Chinese as their surnames, namely Li, Wang or Zhang. There were 139 subjects with surname Li, 118 with surname Wang and 119 with the surname Zhang. In the Li population, a total of 126 haplotypes was found and 118 of them were unique, with a haplotype diversity 0.9974. In the Wang population, a total of 105 haplotypes was found and 94 of them were unique, with a haplotype diversity of 0.9953. In the Zhang population, a total of 101 haplotypes was found and 88 of them were unique, with a haplotype diversity of 0.9964. Our results indicated that the genetic polymorphisms of Y-STR haplotypes at these 9 loci in unrelated male individuals with Chinese surnames of Li, Wang or Zhang are highly polymorphic and showed no significant differences with our previous data of haplotype polymorphisms in unrelated male individuals from the Chinese ethnic Han population.

Polymorphic analysis of the Lutheran blood group system in Chinese.

The Lutheran blood group is a complex system consisting of 19 identified antigens. It belongs to the immunoglobulin family of receptors and adhesion molecules. Four pairs of antigens show allelic relationships while other antigens are of very high incidence. In this study, we performed genetic polymorphism analyses by molecular techniques of the Lutheran blood group system in Chinese subjects. Blood samples were collected from randomly-selected healthy donors and analyzed by PCR-RFLP or SBT methods. LU1/2(Lu(a)/Lu(b)), LU6/9, LU8/14, and LU18/LU19(Au(a)/Au(b)) antigen polymorphisms were detected as follows: 1102 individuals were diagnosed as Lu(a-b+) type; 117 individuals were all LU(6+9-) genotypes; 119 individuals were all LU(8+14-) genotypes. Among 368 individuals, 278 showed homozygous nt1615A, 6 showed homozygous nt1615G, and 84 showed nt1615A/G heterozygosity. The gene frequencies of Au(a) and Au(b) in Chinese subjects were 0.8695 and 0.1304 respectively. A novel allele was identified in 4 Lu(18+19-) phenotype cases from 3 families.

[Genetic polymorphism of 9 Y-STR loci with short fragment size alleles in unrelated male individuals from Zhuang ethnic group].

The aim of this study was to investigate the genetic polymorphism of Y-chromosome specific short tandem repeat (Y-STR) loci in Zhuang ethnic group of China. Nine Y-STR loci were amplified by single multiplex and the PCR products were detected by using ABI Prism(TM) 3100 DNA Sequencer. The allele frequencies and haplotype frequencies at 9 Y-STR loci were determined in a total of 85 unrelated male individuals from Zhuang ethnic group of China. The results indicated that in the 85 unrelated male individuals, except for the DYS426 locus with a low GD value, the GD values for other 8 Y-STR loci ranged from 0.4387 to 0.8129. A total of 70 haplotypes at 9 Y-STR loci were found, the haplotype diversity was 0.9926. It is concluded that the haplotype polymorphism of 9 Y-STR loci are highly polymorphic in Zhuang ethnic group and also significantly different from our previous reported data of unrelated male individnals in southern Chinese Han population.

[Analysis on expression and molecular basis for ABO glycosyltransferase with dual specificity].

In order to elucidate the expression and molecular genetic background of ABO gene seven samples with ABO discrepancy further identified as bi-specific ABO gene were studied. All these samples were subjected to phenotyping by monoclonal and polyclonal antisera and were then genotyped by direct DNA sequencing and haplotype-sequencing at the exon 6 and 7 of ABO gene. As a result, six ABO dual-specific alleles were identified in Chinese population. An antigen expressed by these B (A) or Cis-AB individuals varied from very low level to the normal level, compared with common A blood group samples. In conclusion, molecular genetic backgrounds of two pairs out of four samples in all samples were the same, however, the ABO expression showed diverse.

Genotyping of samples lacking expected antibodies in ABO blood group.

We report nine donations with ABO inconsistency in reverse typing caused by partly or entirely missing antibodies. A and B antigens and antibodies were examined by serological blood typing, and ABO deoxyribonucleic acid (DNA) analyses were performed by sequence-specific priming and sequencing. A B101 allele was demonstrable in a case with O phenotype. The molecular mechanisms in deficiency of natural ABO antibody could be partly clarified. The ABO genotyping technique is an accurate method for determining the blood samples involved in ABO grouping discrepancies and is a valuable complement to serology for correct determination of donor blood status. The mechanisms involved in the absence of potent natural antibodies directed against A and B antigen lacking on an individual's own red cell membranes remain to be further investigated.

[Genotyping of ABO loci in para-Bombay type individuals].

To study the molecular genetic basis of ABO alleles in para-Bombay type individuals, samples from five para-Bombay type individuals identified by serologic tests including absorption-elution tests, saliva neutralizing or inhibitor substances tests, were genotyped by using PCR-SSP based ABO genotyping. Exon 6 and exon 7 at the ABO locus for all 5 samples were sequenced. The results showed that the ABO genotypes of five para-Bombay samples were A102B1, A102B1, A102O1, A102B1, B1O1 respectively, the direct DNA sequencing results were in accordance with the results genotyped by PCR-SSP method, No novel nucleotide mutation was found at the exon 6 and exon 7 of ABO gene. In conclusion, the ABO genotyping assay by PCR-SSP provide a simple, rapid and accurate method for determining the ABO type of para-Bombay cases.