An increased HLA DR2 frequency is seen in aplastic anemia patients

The underlying etiology of aplastic anemia is unknown in the majority of patients, although medications, chemical exposure, or viral infections can be implicated in some. Genetic susceptibility to a variety of diseases has been shown and it has recently been suggested that aplastic anemia is more common in individuals who are HLA DR2+ than in the general population. To examine this question, we retrospectively analyzed the results of HLA-DR typing in 75 aplastic anemia patients who received antithymocyte globulin (ATG) therapy or an HLA-matched sibling bone marrow transplant at UCLA between 1978 and 1989. Thirty-one patients were DR2+, a 1.9-fold higher incidence than the expected number of 16.6 patients (P < .0005). Of the 37 patients who received ATG, 33 were evaluable for a response; 14 patients had either a complete (4 patients) or partial (10 patients) response, for an overall response rate of 42.4%. Of the 14 DR2+ patients who received ATG, 7 responded, for a 50% response rate, which is not significantly higher than the response rate for the DR2- patients (7 of 19 [36.8%]; P = .50). The median survival of patients who are DR2+ was slightly, but not significantly, longer than that of the DR2- patients in the ATG group (P = .19). Although the incidence of HLA DR2 was clearly increased in these patients with aplastic anemia, response rates to ATG were not significantly different in the DR2+ and DR2- patients.     

世界胃肠病学组织(WGO-OMGE)临床指南——发展中国家幽门螺杆菌感染

我非常高兴向大家推荐这份发展中国家幽门螺杆菌（H．priori）临床指南。该指南的编译是由数位在该领域具有丰富临床经验的世界知名专家共同完成的。     

Homing receptors on human and rodent lymphocytes--evidence for a conserved carbohydrate-binding specificity

Lymphocyte recirculation begins with the attachment of circulating cells to the structurally distinctive postcapillary venules of lymphoid organs termed high-endothelial venules (HEVs). In both rodents and humans, the attachment of lymphocytes to the HEVs of peripheral lymph nodes (PNs) on the one hand and gut-associated lymphoid tissues (GALTs) on the other appears to involve discrete adhesive structures on the surfaces of the interacting cells. In rodents, we previously showed that a carbohydrate-binding receptor at the lymphocyte surface participates in the attachment to the HEV of peripheral nodes. The studies reported herein document the involvement of a similar receptor in the selective attachment of human peripheral blood lymphocytes to the HEVs of PNs. We argue that the close functional relationship between the human and rodent receptors indicates that this component of the adhesive interaction has been conserved through evolution.     

美国白人与中国人原发性结直肠癌病理特点对照

目的　比较研究美国白人与中国患者原发性结直肠癌 (CRC)的病理学特征。方法　回顾性分析 1990～ 2 0 0 0年美国克里夫兰佛罗里达临床中心结直肠外科 6 90例和中国第一军医大学南方医院普外科 870例连续完整的CRC患者资料。结果　美国白人与中国患者比较 :36 .3%比 2 6 .0 %的肿瘤位于近侧 (右侧 )结肠 (P <0 .0 0 1) ,6 3.7%比 74 .0 %位于远侧 (左侧 )结肠 (P <0 .0 0 1) ;中位年龄 72比5 4岁 (P <0 .0 0 1) ;腺癌 84 .3%比 85 .3% ,黏液腺癌 13.6 %比 11.4 % ,印戒细胞癌 1.5 %比 2 .7% ,腺鳞癌 0 .6 %比 0 .6 % (P >0 .0 5 ) ;高分化癌 16 .7%比 4 0 .2 % ,中分化 6 1.9%比 4 8.5 % ,低分化 2 1.4 %比11.3% (P <0 .0 0 1) ,近侧结肠癌中低分化比例在两种族患者中均较高 ;TNM分期 ,0期 5 .4 %比 1.3%(P <0 .0 0 1) ,Ⅰ期 34.8%比 18.9% (P <0 .0 0 1) ,Ⅱ期 2 9.9%比 33.2 % (P >0 .0 5 ) ,Ⅲ期 2 0 .3%比2 2 .8% (P >0 .0 5 ) ,Ⅳ期 9.6 %比 17.0 % (P <0 .0 0 1)。进展期癌更常见于近侧结肠和中国患者。结论　美国白人易患近侧结肠癌 ,中国患者远侧结直肠癌更常见 ,进展期比例高 ,年龄明显小。低分化和进展期癌更常见于近侧结肠。     

Molecular cloning, chromosomal location, and tissue-specific expression of the murine cathepsin G gene

We previously have characterized a cluster of genes encoding cathepsin G (CG) and two other CG-like hematopoietic serine proteases, CGL-1 and CGL-2, on human chromosome 14. In this report, we clone and characterize a novel, related murine hematopoietic serine protease gene using human CG (hCG) cDNA as the probe. This murine gene spans approximately 2.5 kb of genomic DNA, is organized into five exons and four introns, and bears a high degree of homology to hCG at both nucleic acid (73%) and deduced amino acid (66%) levels. The predicted cDNA contains an open reading frame of 783 nucleotides that encodes a nascent protein of 261 amino acids. Processing of a putative signal (pre) peptide of 18 residues and an activation (pro) dipeptide would generate a mature enzyme of approximately 27 Kd that has an estimated pI of 12.0. Conserved residues at His44, Asp88, and Ser181 form the characteristic catalytic triad of the serine protease superfamily. The gene is tightly linked to the CTLA-1 locus on murine chromosome 14, where the serine protease genes mCCP1-4 are clustered. Expression of this gene is detected only in the bone marrow and is restricted to a small population of early myeloid cells. These findings are consistent with the identification of the gene encoding murine CG.     

Characterization of CD33 as a new member of the sialoadhesin family of cellular interaction molecules

CD33 is a member of the Ig superfamily that is restricted to cells of the myelomonocytic lineage but whose functions and binding properties are unknown. It shares sequence similarity with sialoadhesin, CD22, and the myelin-associated glycoprotein, which constitute the Sialoadhesin family of sialic acid-dependent cell adhesion molecules. In the present study, we show that CD33 is a fourth member of this family. As a model for sialic acid-dependent binding, human erythrocytes were derivatized with N-acetylneuraminic acid (NeuAc) in different linkages. A recombinant soluble form of CD33, Fc-CD33, bound red blood cells with a specificity similar to that of sialoadhesin, preferring NeuAc alpha 2,3Gal in N- and O-glycans over NeuAc alpha 2,6Gal in N-glycans. Fc- CD33 also bound selectively to the myeloid cell lines HL-60 and U937. However, CD33 was unable to mediate cell binding after transient expression in COS cells, despite high levels of surface expression. Pretreatment of the CD33-transfected cells with sialidase rendered them capable of mediating sialic acid-dependent binding. These results show that CD33 can function as a sialic acid-dependent cell adhesion molecule and that binding can be modulated by endogenous sialoglycoconjugates when CD33 is expressed in a plasma membrane.     

Effects of phonemic awareness instruction on the encoding skills of children with severe speech impairment

Purpose: To examine the effects of phoneme-grapheme correspondence and phonemic awareness instruction on the encoding abilities of three pre-reading children with severe speech impairment (SSI). Method: Using a single subject multiple baseline design across behaviours and participants, children received phoneme-grapheme awareness instruction followed by instruction in segmenting, manipulating, and encoding consonant-vowel-consonant (CVC) pseudowords. Results: Generalization occurred to encoding of novel CVC pseudo- and real words for two of the three participants. Conclusions: Results suggest that phoneme-grapheme correspondence and phonemic awareness instruction is effective in developing encoding skills in children with SSI. Findings are consistent with those for other at-risk children.