Haemophilia A and haemophilia B: molecular insights

This review focuses on selected areas that should interest both the scientist and the clinician alike: polymorphisms within the factor VIII and factor IX genes, their linkage, and their ethnic variation; a general assessment of mutations within both genes and a detailed inspection of the molecular pathology of certain mutations to illustrate the diverse cause–effect relations that exist; a summary of current knowledge on molecular aspects of inhibitor production; and an introduction to the new areas of factor VIII and factor IX catabolism. An appendix defining various terms encountered in the molecular genetics of the haemophilias is included, together with an appendix providing accession numbers and locus identification links for accessing gene and sequence information in the international nucleic acid databases.     

钾通道阻断剂对低氧/复氧诱导的培养海马神经元死亡的防护作用

目的研究钾通道阻断剂对单纯低氧/复氧诱导的培养海马神经元死亡的防护作用。方法培养8 d的海马神经元置于低氧环境(95% N2/5% CO2)6 h,复氧再培养直至72 h,复氧后0.5 h培养液内分别给予不同钾通道阻断剂,用细胞计数及MTT比色法检测神经元死亡情况。结果低氧/复氧诱导培养海马神经元出现迟发性死亡;四乙铵以剂量依赖性的方式防护低氧/复氧诱导的培养海马神经元免于死亡;大电导钙激活钾通道(BK通道)阻断剂iberiotoxin(IbTX)可完全消除低氧/复氧诱导的神经元死亡(P<0.001);A型钾通道阻断剂4-氨基吡啶不能防护低氧/复氧诱导的神经元免于死亡(P>0.05)。结论钾通道阻断剂四乙铵和IbTX能防护低氧/复氧诱导的培养海马神经元免于死亡,提示某些类型的钾通道尤其是BK通道活动增强可能参与了低氧/复氧诱导的培养海马神经元死亡。     

MMP-9和TIMP-1表达失衡与乳腺癌浸润、转移的相关性

目的 研究乳腺癌组织中基质金属蛋白酶（MMP－9）和金属蛋白酶组织抑制因子（TIMP－1）的表达变化与乳腺癌生物学行为及淋巴结转移的关系。方法 应用SP免疫组织化学方法检测85例乳腺癌组织MMP－9，TIMP－1及细胞增殖核抗原ki-67的表达情况。结果 MMP-9阳性染色率90．59％，MMP－9阳性表达与肿瘤浸润，淋巴结转移，ki-67指数及TNM分期呈正相关（Pearson列联系数分别为P=0.03,P=0.02,P=0.004和P＝0．0000，P＜0．05，0．01。TIMP－1阳性染色率为78．82％，TIMP－1阳性表达与肿瘤浸润，淋巴结转移及TNM分期浸润，转移及ki-67指数显著相关（P＜0．05，P＜0．01，P＜0．001）。结论 MMP－9和TIMP－1表达失衡与乳腺癌浸润及淋巴结转移密切相关。     

Preparation of protected peptidyl thioester intermediates for native chemical ligation by Nα‐9‐fluorenylmethoxycarbonyl (Fmoc) chemistry: considerations of side‐chain and backbone anchoring strategies,and compatible protection for N‐terminal cysteine*,†

Abstract: Native chemical ligation has proven to be a powerful method for the synthesis of small proteins and the semisynthesis of larger ones. The essential synthetic intermediates, which are C‐terminal peptide thioesters, cannot survive the repetitive piperidine deprotection steps of N^α‐9‐fluorenylmethoxycarbonyl (Fmoc) chemistry. Therefore, peptide scientists who prefer to not use N^α‐t‐butyloxycarbonyl (Boc) chemistry need to adopt more esoteric strategies and tactics in order to integrate ligation approaches with Fmoc chemistry. In the present work, side‐chain and backbone anchoring strategies have been used to prepare the required suitably (partially) protected and/or activated peptide intermediates spanning the length of bovine pancreatic trypsin inhibitor (BPTI). Three separate strategies for managing the critical N‐terminal cysteine residue have been developed: (i) incorporation of N^α‐9‐fluorenylmethoxycarbonyl‐S‐(N‐methyl‐N‐phenylcarbamoyl)sulfenylcysteine [Fmoc‐Cys(Snm)‐OH], allowing creation of an otherwise fully protected resin‐bound intermediate with N‐terminal free Cys; (ii) incorporation of N^α‐9‐fluorenylmethoxycarbonyl‐S‐triphenylmethylcysteine [Fmoc‐Cys(Trt)‐OH], generating a stable Fmoc‐Cys(H)‐peptide upon acidolytic cleavage; and (iii) incorporation of N^α‐t‐butyloxycarbonyl‐S‐fluorenylmethylcysteine [Boc‐Cys(Fm)‐OH], generating a stable H‐Cys(Fm)‐peptide upon cleavage. In separate stages of these strategies, thioesters are established at the C‐termini by selective deprotection and coupling steps carried out while peptides remain bound to the supports. Pilot native chemical ligations were pursued directly on‐resin, as well as in solution after cleavage/purification.     

Tacrolimus Exposure and Evolution of Renal Allograft Histology in the First Year After Transplantation

Tacrolimus has a narrow therapeutic window and is characterized by a large inter-individual variability in bioavailability. The impact of tacrolimus exposure on subclinical evolution of graft histology has not been studied in renal recipients. This analysis included 239 protocol biopsies (obtained at implantation, 3 and 12 months) of 120 consecutive kidney recipients treated with tacrolimus, mycophenolate mofetil (MMF) and corticosteroids. Biopsies were scored according to the Banff 2001 criteria and a chronicity score was calculated. Prospective pharmacokinetic data were included in the analysis (5544 tacrolimus predose blood concentrations and tacrolimus AUC(0-12) at 3 and 12 months). Higher donor age and higher number of human leukocyte antigen-DR (HLA-DR) mismatches were independent predictors of subclinical acute rejection at 3 months, present in 8.7% of patients. The number of HLA-DR mismatches was independently associated with biopsy-proven clinical acute rejection. Biopsy-proven acute rejection episodes and low mean tacrolimus exposure were independently associated with higher increase in chronicity scores between 3 and 12 months after transplantation. This observational study suggests that rejection phenomena and immune-mediated mechanisms remain important in the early progression of chronic allograft pathology. Tacrolimus doses or systemic exposure were not associated with lesions of calcineurin inhibitor nephrotoxicity, suggesting that other factors determine susceptibility to tacrolimus nephrotoxicity.     

MMP-9及TIMP-1在大鼠感染性脑水肿的表达及意义

目的探讨MMP-9及TIMP-1在大鼠感染性脑水肿的表达及意义。方法应用免疫组织化学方法（SP法）检测大鼠急性感染性脑水肿模型中MMP-9及TIMP-1的表达情况及其比值变化。结果MMP-9及TIMP-1在LPS组各时间点表达均高于对照纽且各时间点MMP-9／TIMP-1比值均明显升高（P〈0．05）。结论MMP-9及TIMP-1可能参与了感染性脑水肿的发生和发展。