Identification of 19 protein S gene mutations in patients with phenotypic protein S deficiency and thrombosis. Protein S Study Group

Protein S is a protein C-dependent and independent inhibitor of the coagulation cascade. Deficiency of protein S is an established risk factor for venous thromboembolism. We have used a strategy of specific amplification of the coding regions and intron/exon boundaries of the active protein S gene (PROS1) and direct single-strand solid phase sequencing, to seek mutations in 35 individuals with phenotypic protein S deficiency. Nineteen point mutations (16 novel) in 19 probands (or relatives of probands) with venous thromboembolism are reported here. Fifteen of the 19 mutations were expected to be causal and included 10 missense mutations (Lys9Glu, Glu26Ala, Gly54Glu, Cys145Tyr, Cys200Ser, Ser283Pro, Gly340Asp, Cys408Ser, Ser460Pro, and Cys625Arg). Three of the 15 mutations resulted in premature stop codons (delete T 635 producing a stop codon at position 126, Lys368stop and Tyr595stop) and two were at intron/exon boundaries (+1 G to A in intron d and +3 A to C in intron j). Of the remaining four mutations, three were within intronic sequence and one was a silent mutation within the coding region and did not alter amino acid composition. In two of the 10 missense mutations, reduced plasma protein S activity compared with antigen level suggested the presence of variant (type II) protein S.     

化瘀通络方对局灶性脑缺血大鼠再灌注(MCAO)后脑组织氧自由基和NOS表达的影响

目的:观察化瘀通络方治疗大鼠局灶性脑缺血-再灌注损伤对脑组织自由基及一氧化氮合成酶(NOS)和iNOS变化的影响。方法:制备大鼠局灶性脑缺血再灌注损伤模型,给予化瘀通络方治疗后观察丙二醛(MDA)、超氧化物歧化酶(SOD)及一氧化氮合成酶(NOS)和诱导型一氧化氮合成酶(iNOS)的变化。结果:化瘀通络方可显著降低MDA含量以及iNOS和NOS活性,SOD含量升高。结论:在脑缺血再灌注损伤后,化瘀通络方能抑制脑缺血再灌注后脂质过氧化反应,促进自由基清除,对抗自由基损伤,提高脑组织自身抗氧化能力,降低NOS和iNOS介导脑缺血-再灌注时的神经损伤,保护脑细胞。     

Validating self-reported strokes in a longitudinal UK cohort study (Whitehall II): Extracting information from hospital medical records versus the Hospital Episode Statistics database

Background

Quantiles are a staple of epidemiologic research: in contemporary epidemiologic practice, continuous variables are typically categorized into tertiles, quartiles and quintiles as a means to illustrate the relationship between a continuous exposure and a binary outcome.

Discussion

In this paper we argue that this approach is highly problematic and present several potential alternatives. We also discuss the perceived drawbacks of these newer statistical methods and the possible reasons for their slow adoption by epidemiologists.

Summary

The use of quantiles is often inadequate for epidemiologic research with continuous variables.     

左腋动脉和臂丛神经走行变异1例

笔者在标本解剖操作观察腋窝结构时发现1例左侧腋动脉与臂丛神经位置及走行出现变异,既往文献报道的变异多为腋动脉发出的分支与臂丛神经之间的位置与走行之间变异^[1-3],本次解剖观察发现腋动脉与臂丛神经的内侧束、外侧束和后束之间的位置关系出现变异,与既往报道有所不同,现报告如下。     

VEGF-C表达和微淋巴管密度与胃癌淋巴转移的关系及意义

目的探讨胃癌组织血管内皮生长因子C(VEGF-C)表达和微淋巴管密度(MLVD)及两者与胃癌淋巴转移的关系。方法应用免疫组织化学方法检测208例人胃癌组织、40例癌浸润前缘组织及139例人胃正常粘膜组织中VEGF-C、D2-40的表达,对D2-40阳性脉管进行MLVD计数,并结合病理资料进行统计学分析。结果胃癌组织VEGF-C的表达明显高于正常胃粘膜组织(χ2=109.199,P<0.01);胃癌组织中有淋巴结转移(χ2=14.496,P<0.01)或浸润透浆膜(χ2=11.586,P<0.01)组VEGF-C表达水平分别较无转移或浸润未及浆膜组增高。癌浸润前缘组织中MLVD(18.36±15.60个/mm2)明显高于胃癌组(9.41±9.32个/mm2,t=-3.681,P<0.01)和胃正常粘膜组织(7.70±7.69个/mm2,t=-4.180,P<0.01);胃癌淋巴结转移组MLVD(9.81±9.97个/mm2)高于无转移组(6.41±7.85个/mm2,t=2.516,P<0.01),而在浸润透浆膜组(11.20±10.55个/mm2)和未及浆膜组(8.54±9.36个/mm2)MLVD无差别(t=1.467,P=0.472)。另外,在胃癌组织中VEGF-C表达与MLVD呈正相关(F=2.910,P<0.05)。结论VEGF-C在胃癌中的高表达与胃癌浸润深度、淋巴转移密切相关。     

Reciprocal effect of Waardenburg syndrome mutations on DNA binding by the Pax-3 paired domain and homeodomain

The Pax-3 protein contains two DNA-binding domains, a paired domain and a homeodomain. Mutations in Pax-3 cause Waardenburg syndrome (WS) in humans and the mouse Splotch (Sp) phenotype. In the Sp-delayed mouse, a mutation in the Pax-3 paired domain (G9R) abrogates the DNA-binding activity of both the paired domain and the homeodomain, suggesting that they may functionally interact. To investigate this possibility further, we have analyzed the DNA-binding properties of additional point mutants in the Pax-3 paired domain and homeodomain that occur in WS patients (F12L, N14H, G15S, P17L, R23L, G48A, S51F and G66D in the paired domain, V47F and R53G in the homeodomain), the Pax-1 un mutation (G15A) and a substitution associated with Peters' anomaly in the PAX-6 gene (R23G). Within the paired domain, seven of 10 mutations were found to abrogate DNA-binding by the paired domain. Remarkably, these seven mutations also affected DNA binding by the homeodomain, causing either a complete loss (P17L and G66D), a reduction (R23G, R23L, G15S and G15A) or an increase in DNA-binding activity (N14H). In addition, the effect of paired domain mutations occurred at the level of monomer formation by the homeodomain, while the dimerization potential of this domain seemed unaffected in mutants where it could be analyzed. Furthermore, while both homeodomain mutations were found to abolish DNA binding by this domain, the R53G mutation also abrogated DNA binding by the paired domain. The important observation that independent mutations in either domain can affect DNA binding by the other in the intact Pax- 3 protein strongly suggests that the two domains are not functionally independent but bind DNA through cooperative interactions. Modeling the deleterlous mutations on the three-dimensional structure of the paired domain of Drosophila Prd shows that these mutations cluster at the DNA interface, thus suggesting that a series of DNA contacts are essential for DNA binding by both the paired domain and the homeodomain of Pax-3.      

1140919448CD200-dependent suppression of human NK activity by IVIG requires CD200 receptor type 2

Problem: IVIG prepared from plasma of stored human blood can be efficacious in improving pregnancy success in a selected subgroup of patients but RCTs using an IVIG showing inferior suppression of NK activity in vitro have been negative (J Assist Reprod Genet 2006). A significant component of NK suppression by IVIG appears to be due to CD200 released into plasma from PBL during storage at 4C. CD200 receptors (CD200R) are expressed at the fetomaternal interface prior to onset of abortion; CD200R1 mediates direct effects on gamma‐delta T cell development and suppresses alpha‐beta T cell responses in vitro, whereas CD200R2 alters DC so as to facilitate development of alpha‐beta Treg cells. Which receptor(s) mediate NK cell suppression? Methods: Purified human PBL or the CD56⁺ NK cell subset of PBL were used to lyse 51Cr‐labeled K562 cells in vitro. Different IVIG preparations were tested for suppressive ability, and suppression was blocked by either anti‐huCD200 mAb or rabbit anti‐huCD200R1 or R2 antibodies. Results: CD200‐dependent IVIG NK suppressive potency differed among IVIG types (Gammagard>Gamunex>>Gamimmune). CD200‐dependent suppression was blocked by anti‐CD200R antibody able to react with the type 2 receptor. K562 cells did not express receptor, and purified CD56⁺ NK cells were suppressed effectively without the need for non‐NK cells. Conclusions: IVIG may directly express NK cell activity via CD200 binding to CD200R2.