高龄供者非清髓性异基因造血干细胞移植后低剂量环孢素A治疗老年急性白血病1例

目的:分析高龄供者非清髓性外周血造血干细胞移植治疗老年急性白血病后,采用低剂量环孢素A免疫治疗方案的疗效。方法:选择2005-11-15广州市第一人民医院收治患者1例,男,57岁,诊断为急性非淋巴细胞白血病-M5a。患者知情同意并签署知情同意书。移植前经过化疗达到完全缓解,合并2型糖尿病、肝功能不良、慢性心脏供血不足。供者为患者同胞姐姐,64岁,HLA全相合,血型相同。干预措施:①预处理用药包括氟达拉滨、马利兰针剂和环磷酰胺。于移植前第4～9天氟达拉滨30mg/(m2.d);移植前第3,4天马利兰针0.8mg/kg,Q6h;移植前第1,2天环磷酰胺60mg/(kg.d)。②移植物抗宿主病预防用环孢素A和氨甲蝶呤,形成供者嵌合体后,采用低剂量环孢素A。③移植后并发症防治和支持治疗:更昔洛韦防治巨细胞病毒感染、前列腺素E1防治肝静脉闭塞病、移植后1d予粒细胞集落刺激因子5μg/(kg.d),Hb<70g/L和PLT<20×109L-1时输注红细胞和血小板。④供者采用粒细胞集落刺激因子动员,150μg/d,皮下注射,12h1次,连用5d,第4,5天采集外周血造血干细胞,于第5天一同输注给患者。结果:①移植后患者造血及免疫重建情况:移植后早期获得造血重建,20d时中性粒细胞>0.5×109L-1,18d时血小板>20×109L-1。自然杀伤细胞、CD3 T淋巴细胞和CD3 CD8 数恢复、CD19 B淋巴细胞和CD3 CD4 分别在移植后2,6,14个月恢复。②植入证据:移植后4周,经过DNA短串联重复序列多态性和XX/XY染色体的荧光原位杂交分析证明为供者型完全嵌合体。③移植后并发症:移植过程顺利,无严重感染,未出现急性移植物抗宿主病。移植后112d,出现腹泻、四肢和面部出现红色斑丘疹,伴有感觉功能异常,移植后6个月出现中耳积液、突发性耳聋,经过环孢素A剂量治疗控制至12个月停药。随访14个月,生活正常。结论:采用以氟达拉滨为基础的非清髓性、高龄同胞供者外周血造血干细胞移植治疗有多种合并症老年急性白血病,植入后采用低剂量环孢素A治疗是一种有效安全的方法。     

Use of a BamHI polymorphism in the factor IX gene for the determination of hemophilia B carrier status

A BamHI polymorphism has been identified in the human factor IX gene. This polymorphism, which occurs in approximately 6% of X chromosomes, has been used to determine the carrier status of a female in a family with a history of hemophilia B. This family was uninformative for the previously reported TaqI and Xmnl polymorphisms in the factor IX gene.     

胰腺导管腺癌组织中WT1,IGF-IR表达与细胞凋亡的关系

目的:研究胰腺导管腺癌组织中WT1,IGF-IR的表达与细胞凋亡关系．方法:应用免疫组化技术检测WT1,IGF-IR在49例胰腺导管腺癌及15例正常胰腺组织中的表达,并应用TUNEL法检测细胞凋亡,计算凋亡指数(AI)．结果:WT1,IGF-IR在正常胰腺组织中的阳性表达率分别为26．67％(4／15)、40．00％(6／15);在胰腺导管腺癌组织中的阳性表达率分别为71．43％(35／49)、77．55％(38／49),两者在癌组织中的表达分别明显高于其在正常胰腺组织中的表达(P<0．05),且在癌组织中的表达呈正相关(r=0．385,P<0．05)．正常胰腺组织及癌组织中的AI分别为0．41±0．13、5．93±4．18,两者比较有显著性差异(P<0．05),癌组织中AI随组织分化程度的升高而升高．IGF-IR表达阳性组的AI显著低于阴性组(4．11±3．68 vs 12．21±5．67,P<0．01)．结论:胰腺导管腺癌组织中IGF-IR的高表达抑制细胞凋亡,WT1,IGF-IR的高表达以及细胞凋亡的减少可能在胰腺导管腺癌的发生发展中起重要作用．     

Prevalence of transfusion-transmitted Chagas disease among multitransfused patients in Brazil

Background

Prevalence and risk factors for Chlamydia trachomatis infection among young men in Switzerland is still unknown. The objective of the present study was to assess prevalence and risk factors for C. trachomatis infection in young Swiss men.

Methods

517 young Swiss men were enrolled in this cross-sectional study during their compulsory military recruitment. Participants completed a questionnaire and gave urine samples which were screened for C. trachomatis DNA by PCR. Genotyping of positive samples was done by amplification and sequencing the ompA gene.

Results

The prevalence of chlamydial infection among young Swiss male was 1.2% (95% confidence interval [95%CI], 0.4–2.5%). C. trachomatis infection was only identified among the 306 men having multiple sexual partner. Although frequent, neither unprotected sex (absence of condom use), nor alcohol and drug abuse were associated with chlamydial infection. Men living in cities were more frequently infected (2.9%, 95%CI 0.8–7.4%) than men living in rural areas (0.5%, 95%CI 0.1–1.9%, p = 0.046). Moreover, naturalised Swiss citizens were more often positive (4.9%, 95%CI 1.3–12.5%) than native-born Swiss men (0.5%, 95%CI 0.1–1.7%, p = 0.003).

Conclusion

In comparison with other countries, the prevalence of chlamydial infection in men is extremely low in Switzerland, despite a significant prevalence of risky sexual behaviour. C. trachomatis infection was especially prevalent in men with multiple sexual partners. Further research is required (i) to define which subgroup of the general population should be routinely screened, and (ii) to test whether such a targeted screening strategy will be effective to reduce the prevalence of chlamydial infection among this population.     

Interleukin-12 induces tyrosine phosphorylation and activation of 44-kD mitogen-activated protein kinase in human T cells

Interleukin-12 (IL-12) is a novel cytokine that enhances numerous functional activities of human T cells and natural killer (NK) cells. The present studies were undertaken to characterize some of the early signaling events following IL-12 stimulation of mitogen-activated normal T cells. In these cells, IL-12 induces rapid tyrosine phosphorylation of proteins of 21, 44, and 54 kD. However, IL-12 does not induce tyrosine phosphorylation in normal resting T cells. In conjunction with increased tyrosine phosphorylation of several substrates, IL-12 stimulation resulted in increased in vitro kinase activity of immunoprecipitated tyrosine phosphorylated proteins. The 44- kD protein has been characterized as one isoform of the mitogen- activated protein (MAP) kinase family. Increased tyrosine phosphorylation of MAP kinase following IL-12 stimulation was also associated with enhanced enzymatic activity of this protein in vitro as measured by myelin basic protein phosphotransferase assay. These studies identify MAP kinase as one of the intracellular elements of the IL-12 signaling pathway in human T cells.     

Regulated basal, inducible, and tissue-specific human erythropoietin gene expression in transgenic mice requires multiple cis DNA sequences

Erythropoietin (Epo) gene expression in kidney and liver is inducible by anemia. To localize the sequences necessary for regulated expression of the Epo gene, we constructed transgenic mice containing five human Epo gene constructs and examined Epo expression under basal conditions and with anemia. Mice containing the Epo gene with 0.3 kb of 5' flanking sequence, 0.7 kb of 3' flanking sequence, and either all introns or only intron I alone were polycythemic, had Epo expression in various tissues (including non-Epo-producing tissues), and induction only in liver. In contrast, mice containing the Epo gene with 8.5 kb of 3' flanking sequence and either 9.5 or 22 kb of 5' flanking sequence had basal expression at low levels in appropriate tissues and were less likely to be markedly polycythemic. Mice with the smaller of these two constructs had induction only in the liver, whereas those with the larger construct had induction in the kidney and liver. These studies indicate that sequences sufficient for induction in the liver are located in close proximity to the Epo gene, including the immediate 5' and 3' flanking sequence and the first intron. They also indicate that sequences required for induction in the kidney are located more than 9.5 kb 5' to the gene. Furthermore, comparison of these and prior transgenic studies suggest that sequences that limit the basal expression of the Epo gene are located downstream of the gene. We conclude that multiple cis DNA sequences are required for regulated Epo gene expression.     

Type beta transforming growth factor is a potent inhibitor of murine megakaryocytopoiesis in vitro

To investigate the potential role of platelets in the inhibition of megakaryocytopoiesis, freeze-thawed extracts of human platelets were added to serumless liquid cultures of murine marrow. When acetylcholinesterase (AchE), a marker of megakaryocytic differentiation in mice, was assayed, a significant inhibition of enzymatic activity was noted in cultures containing the equivalent of greater than 5 X 10(6) solubilized platelets per milliliter. Freeze-thawed extracts of granulocytes had significantly less inhibitory effect than did platelets. Transforming growth factor beta (TGF-beta), a growth factor known to be inhibitory to some cell lineages and to be found at relatively high concentrations in platelets, was then added to liquid marrow cultures. A similar inhibition of AchE activity was detected when cultures were stimulated with mitogen-stimulated conditioned medium. The effect was potent with 50% inhibition of AchE activity observed at 4 pmol TGF-beta/L. To determine if TGF-beta inhibited specifically one aspect of megakaryocytic differentiation, the factor was added to isolated single megakaryocytes in serumless culture induced by interleukin 3 (IL3) to increase in size. The number of megakaryocytes increasing in size in response to IL 3 exposure was reduced from 68% to 20% when both factors were simultaneously added to cultures. Colony assays showed that megakaryocytic and granulocyte- macrophage colony detection was inhibited at picomolar concentrations of the factor. These data suggest that TGF-beta is a potent in vitro inhibitor of the murine megakaryocytic lineage, although its effects are not limited to this lineage.     

Biologic and prognostic significance of the presence of more than two mu heavy-chain genes in childhood acute lymphoblastic leukemia of B precursor cell origin

We examined the arrangement of the mu heavy-chain immunoglobulin (Ig) genes in the leukemic blast cell DNA of 93 children with acute lymphoblastic leukemia (ALL). All cases met morphologic and cytochemical criteria for ALL, lacked detectable T cell surface antigens, and expressed HLA-DR (Ia) antigens. Eighty-three of the 93 patients (89%) were positive for the common acute lymphoblastic leukemia antigen (CALLA), and 20 of 91 (22%) tested had detectable cytoplasmic immunoglobulin. As expected, the heavy-chain lg gene was rearranged in all cases, and the pattern of rearrangements was variable; 23 had one allele rearranged and one in the germ line configuration; 15 had one rearranged and one deleted; and 37 had two rearranged. Unexpectedly, in 18 patients the presence of more than two mu gene-hybridizing bands was detected. Combinations of enzymes and heavy-chain gene probes were used to confirm that the extra bands were not the result of underdigestion of the DNA or DNA restriction site polymorphism. In eight of the 18 patients, we identified an extra chromosome 14 as a possible cause of the extra bands' hybridizing to the mu heavy-chain constant-region probe. In the remaining ten patients, the presence of three or four bands hybridizing with the mu probe suggests the presence of two populations of leukemic cells that may have arisen either by separate leukemic transformation events or by clonal evolution of one clone into two related lines. Although preliminary (2-year follow-up), our data suggest that childhood ALL of B lineage with more than two mu heavy-chain genes, but without extra copies of chromosome 14, may be more resistant to therapy.     

Drug-induced endocytosis of neonatal erythrocytes

The erythrocytes of the newborn infant have many properties that distinguish them from those of adults, and their membranes are also different from those of adult erythrocytes. We compared the ability of adult and neonatal RBCs to undergo endocytosis on exposure to drugs. Using a quantitative method, we showed that neonatal erythrocytes undergo a greater degree of endocytosis than do adult RBCs in response to primaquine, vinblastine, and chlorpromazine, and are sensitive to lower concentrations of the drugs. Some forms of drug-induced endocytosis are red cell age-dependent; when RBCs were separated by density gradient centrifugation, the membranes of the younger, less dense populations of both the neonatal and adult RBCs were capable of more extensive internalization than those of the denser, older RBCs. Neonatal RBCs of a given density undergo more endocytosis than do adult RBCs of the same density, suggesting that the membrane of the neonatal RBC is less stable and capable of more of the reorganization reflected in endocytosis than is the adult RBC membrane.