Genetic polymorphisms of orosomucoid and alpha-2-HS-glycoprotein in Thai,Sri Lankan and Paraguayan populations

The genetic polymorphism of orosomucoid (ORM) and alpha-2-HS-glycoprotein (AHSG) were studied in Thai, Sri Lankan and Paraguayan populations using isoelectric focusing. Gene frequencies in these populations were compared with those in other populations. Four new ORM variants were detected:ORM1 ^* 15 in Thai,ORM1 ^* 16 in Paraguayan,ORM2 ^* 21 andORM2 ^* 22 in Sri Lankan.     

乳腺管状小叶癌

乳腺管状小叶癌（Tubulolobular carcinoma，TLC）最初是被作为小叶癌的管状变型。作者总结了27例TLC的组织学、免疫表型和临床特征，并与纯小管癌和经典型小叶癌进行了比较。此组患者年龄43-79岁（中位年龄60岁）。1例双侧乳腺受累，5例病变为多灶性。肿瘤直径0．5-2．5cm，色灰褐，质硬。组织学观察：TLC的肿瘤细胞形成管状和条索状两种结构模式并相互混杂，且两者比例相当（统称为管状小叶模式）。     

Characterization of genomic rearrangements of the alpha1-acid glycoprotein/orosomucoid gene in Ghanaians

In this study, the structure of the α₁-acid glycoprotein (AGP), or orosomucoid (ORM), gene was investigated in a Ghanaian mother and her child, who shared an unusual variant, ORM1 S2(C), found by isoelectric focusing. Three remarkable changes of nucleotide sequence were observed: (1) The two ORM1 alleles, ORM1 ^* S and ORM1 ^* S2(C), had the AGP2 gene-specific sequence at one and three regions, respectively, in exon 5 to intron 5. The variant allele originating from ORM1 ^* S was characterized by a G-to-A transition, resulting in an amino acid change from valine to methionine, which is also detected in ORM1 F2, a form that is common in Europeans. (2) The AGP2 gene of the child, inherited from the father, was duplicated, as revealed by long-range polymerase chain reaction. (3) Three new mutations were observed in two exons of the AGP2 genes of the mother and child. All of these novel genomic rearrangements, which were not observed in Japanese subjects, may have arisen through point mutation, gene conversion, and unequal crossover events. It is likely that the rearrangement of the AGP gene has often occurred in Africans. Received: June 15, 2001 / Accepted: July 10, 2001     

Germline mutations of the CDKN2 gene in UK melanoma families

Germline mutations in CDKN2 on chromosome 9p21, which codes for the cyclin D kinase inhibitor p16, and more rarely, mutations in the gene coding for CDK4, the protein to which p16 binds, underlie susceptibility in some melanoma families. We have sequenced all exons of CDKN2 and analysed the CDK4 gene for mutations in 27 UK families showing evidence of predisposition to melanoma. Five different germline mutations in CDKN2 were found in six families. Three of the mutations (Met53Ile, Arg24Pro and 23ins24) have been reported previously. We have identified two novel CDKN2 mutations (88delG and Ala118Thr) which are likely to be associated with the development of melanoma, because of their co-segregation with the disease and their likely functional effect on the CDKN2 protein. In binding assays the protein expressed from the previously described mutation, Met53Ile, did not bind to CDK4/CDK6, confirming its role as a causal mutation in the development of melanoma. Ala118Thr appeared to be functional in this assay. Arg24Pro appeared to bind to CDK6, but not to CDK4. No mutations were detected in exon 2 of CDK4, suggesting that causal mutations in this gene are uncommon. The penetrance of these mutant CDKN2 genes is not yet established, nor is the risk of non-melanoma cancer to gene carriers.      

Induction of antibody synthesis by CD4+ T cells: IL 5 is essential for induction of antigen-specific antibody responses by TH2 but not TH1 clones

Murine B cells stimulated with lipopolysaccharide (LPS) and interleukin (IL) 4 produce IgG1 and IgE, but synthesize IgG2a when stimulated with LPS and interferon-gamma. The cytokines, however, that regulate immunoglobulin (Ig) synthesis induced in normal B cells under antigen-driven major histocompatibility complex (MHC)-restricted conditions in the absence of potent B cell mitogens have not been fully elucidated. We and others have shown that under cognate MHC-restricted conditions, CD4+ T cell clones of the TH1 subset, which produce IL 2 and interferon-gamma, and T cell clones of the TH2 subset, which produce IL 4 and IL 5, are both capable of inducing anti-trinitrophenyl IgG plaque-forming cells. In this report we have examined in further detail the cytokine requirements for the induction of Ig synthesis in B cells cultured directly with TH1 and TH2 T cell clones. Using (a) TH2 clones that varied in the amount of IL 5 secreted, (b) a neutralizing monoclonal antibody against IL 5 and (c) T cell clones pretreated with cyclosporin A to inhibit cytokine secretion, we found that IL 5 was essential for induction of IgG1 synthesis by TH2 but not TH1 T cells. Although we demonstrated that IL 2 could actually up-regulate the synthesis of IL 5 by TH2 clones, the induction of IgG synthesis by TH2 clones was entirely independent of IL 2. In contrast, induction of IgG1 synthesis by TH1 clones was absolutely dependent upon the presence of IL 2 and was not affected by the presence of IL 5. Thus, these studies demonstrate the idea that at least two independent pathways exist for the induction of IgG1 synthesis, and that one of these pathways is IL 4/IL 5 dependent and the other IL 2 dependent.     

Multigenic control of skin tumor susceptibility in SENCARA/Pt mice

Skin tumors induced in mice by initiation-promotion (2 microg DMBA-2 microg TPA) protocols were found to be under multigenic control. Eighty- one N2 mice from the cross (BALB/cAnPt x SENCARA/Pt)F1 x SENCARA/Pt that were either solidly resistant (no papillomas) or highly susceptible (> or = 7 papillomas/mouse) were subjected to a 'genome scan' using 89 microsatellite markers to check for associations with susceptible and resistant phenotypes. A locus on Chr 5 (Skts4) was found to control the susceptibility of SENCARA/Pt mice and the resistance of BALB/cAnPt mice to papilloma formation. In addition, higher than expected linkage scores were seen for the markers D9Mit271, D11Mit268 and D12Mit56. Further work is required to establish whether genes determining papilloma formation are located in these regions of the genome. In general, no evidence was seen for loss of heterozygosity in microsatellite markers on Chrs 5, 9 and 11 in 17 microdissected papillomas from (BALB/c x SENCARA)F1 hybrid mice.      

Molecular analysis of the human orosomucoid gene ORM1*Q0köln responsible for incompatibility in a German paternity case

In a German paternity test, an alleged father was excluded only by reverse homozygosity of ORM1 phenotypes (mother ORM1 S, child ORM1 S and alleged father ORM1 F1) out of the 28 classical and DNA markers investigated. Without the ORM1 system the biostatistical probability of paternity was calculated to exceed 99.9999%. The intensity of the immunoprinted bands of the ORM1 protein for the child and alleged father after isoelectric focusing appeared to be reduced to about half. To identify a possible null allele, gene-specific amplification followed by single-strand conformation polymorphism and sequencing analyses were carried out. Deletion of one of the two copies of a 4 bp direct repeat sequence (GTCT) in exon 4 of the consensus sequence of ORM1*F1 was observed in the child and alleged father. Thus, the sharing of a rare mutant gene, ORM1*Q0_köln, increased the probability of paternity.