Pharmacologic purging of malignant T cells from human bone marrow using 9-beta-D-arabinofuranosylguanine

Arabinosylguanine (araG) is a nucleoside analog that is rapidly converted by cells of the T lymphoid lineage to its corresponding arabinosylguanine nucleotide triphosphate, resulting in inhibition of DNA synthesis and selective in vitro toxicity to T lymphoblastoid cell lines as well as to freshly isolated leukemia cells from patients with T cell acute lymphoblastic leukemia. In this report, we demonstrate that araG is an effective agent to use for chemoseparation of malignant T lymphoblasts from human bone marrow. When freshly isolated human T leukemia cells or T lymphoblastoid cells were treated with 100 microM araG for 18 hr, up to 6 logs of clonogenic T cells could be eliminated without appreciable toxicity to the normal myeloid, erythroid, and megakaryocytoid clonal progenitor cells. We discuss the use of this agent in ex vivo elimination of residual malignant T cells from marrow of patients requiring myeloablative chemotherapy with autologous bone marrow rescue.     

Phase I-II evaluation of intra-arterial diaziquone for recurrent malignant astrocytomas

Diaziquone (AZQ) is a lypophilic alkylating agent that crosses the blood-brain barrier and has shown broad activity in animal tumor models. Five of 12 patients with malignant astrocytoma treated with iv AZQ had clinical and/or radiographic improvement (Schold, Neurology 34:615, 1984). Intra-arterial administration of AZQ to patients with brain tumors should produce higher peak levels of drug in the tumor and should reduce systemic toxicity. Twenty-one patients with astrocytoma (grade II, four; grade III, 11; and grade IV, six), in all of whom irradiation and intra-arterial carmustine chemotherapy failed, received intra-arterial AZQ as a single dose every 28 days. Two of 20 evaluable patients experienced partial responses of 5 and 8+ months, respectively. Four patients had disease stabilization of 3, 4, 5, and 8 months' duration, respectively, and one of these patients had tumor shrinkage (partial response) after seven courses of AZQ. The initial dose in the first three patients was 10 mg/m2, and doses in subsequent groups of three patients were begun at increases of 5 mg/m2. The within-group dose escalation was 5 mg/m2 per course if there was no hematologic toxicity. Dose-limiting toxicity was myelosuppression, which occurred at doses greater than 15 mg/m2. The maximum tolerated dose was 25 mg/m2. Intra-arterial AZQ appears to be of marginal effectiveness in patients refractory to carmustine and offers no advantage over iv AZQ in efficacy or toxicity.     

克隆测序确认HLA新等位基因B*3712

目的：由于技术原理的限制，目前尚不能对所有的HLA等位基因进行严格的区分，特别是以往没有发现的新基因序列只能通过测序的方法解决，然而，当遇到等位基因杂合时，测序给出的结果仍然无法确认新的序列改变发生在等位基因的哪一侧，这时需要用分子生物学方法分离杂合子然后进行测序才能确定新的基因序列。采用基因克隆方法确认HLA新等位基因。 方法：实验于2006-01／05在河南省红十字血液中心HLA实验室，美国海军骨髓库HLA实验室完成。造血干细胞血样由中华骨髓库提供。采用荧光微珠HLA分型方法对中华骨髓库捐献者血样进行HLA分型检测，无法给出确切结果的摸棱两可结果标本用基因克隆（TOPO TA Cloning）、DNA测序的方法确认新的HLA基因序列。 结果：通过克隆分离杂合等位基因，再进行测序确认发现新的序列与B^＊3709相比，出现4个核苷酸改变：1．355nt C〉A，2．363nt C〉G，3．412nt G〉A，4．477ntC〉G，而且均发生在H哺B基因外显子3（exon3）。4处改变引起氨基酸编码改变：①编码95CTC〉ATC，氨基酸改变L〉1（亮氨酸〉异亮氨酸）。②97AGC〉AGG．S〉R（丝氨酸〉精氨酸）。③114GAC〉AACD〉N（天门冬氨酸〉天冬酰胺）。（9135GCC〉GCGA=A无氨基酸改变。 结论：①新的基因序列已经在GenBnak注册，被WHO的HLA因子命名委员会得到正式命名为HLA-B^＊3712基因。②基因克隆是确认HLA新基因的根本方法。     

A Technique for Border Molding Edentulous Impressions Using Vinyl Polysioxane Material

A technique for making selective tissue placement final impressions for complete dentures using vinyl polysiloxane and custom trays with peripheral relief is presented. This technique is an alternative to the conventional method of border molding using modeling plastic impression compound.     

Gamma-carboxylated isoforms of recombinant human protein S with different biologic properties

Human protein S (HPS), a regulator of hemostasis, is a vitamin K- dependent plasma protein with potential clinical utility. We have obtained high-level expression of the cDNA for HPS in two mammalian cell lines. Both cell lines secreted single chain recombinant HPS (rHPS) in serum-free medium as determined by Western blot analysis. The ability of the rHPS from both cell lines to act as a cofactor for human protein C (HPC) was determined; the rHPS secreted from the human 293 cell line had an activity six times that of the rHPS from the AV12-664 Syrian hamster cell line. Furthermore, the relative specific cofactor activity of rHPS from the 293 cell line was actually 2.5-fold higher than that of single-chain human plasma-derived HPS. Essentially all of the rHPS secreted from the 293 cell line exhibited a calcium-dependent elution profile on anion exchange chromatography, whereas only 25% to 35% of the hamster cell-derived rHPS exhibited this profile. However, the calcium-eluted rHPS from the AV12 cell line had a high specific cofactor activity, equivalent to that of the 293-derived rHPS. A NaCl- elutable rHPS fraction (calcium nondependent) was isolated from the recombinant AV12-664 cell line, further purified, and found to have reduced activity, only 40% that of the calcium-dependent rHPS. The only observable difference in the calcium-dependent and nondependent rHPS molecules was in the content of gamma-carboxyglutamic acid (Gla); the calcium-dependent material contained approximately 10 mol Gla/mol protein whereas the calcium-nondependent material contained only approximately 8 mol Gla/mol of protein. In addition, the calcium- nondependent rHPS had reduced ability to interact with phospholipid vesicles as evidenced by an eightfold increase in the apparent kd. Our data demonstrate the isolation of rHPS with high specific activity, and show that a reduction in as few as two Gla residues dramatically decreases its functional cofactor activity for HPC, due to a reduction in ability to interact with the phospholipid bilayer.