Mofarotene (Ro 40-8757) inhibits hematopoiesis in vitro by preventing maturation from primitive progenitor cells

The effect of the arotinoid mofarotene (Ro 40-8757; 4-[2-[p-[(E)- 2(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl)- propenyl]phenoxy]ethyl]morpholine) on stromal cell-mediated hematopoiesis was examined in murine long-term bone marrow cultures. Whether added at week 2 to regenerating cultures or at week 4 to plateau-phase cultures, mofarotene strongly inhibited total cell production in a dose-dependent manner. Progenitor cell production was also inhibited, but to a lesser extent. When added at the initiation of culture, 1 mumol/L mofarotene did not affect formation of the adherent layer, but production of total nucleated cells and progenitors was inhibited over the next 10 weeks by 95% and 96%, respectively. However, after mofarotene treatment ceased, progenitor cell levels began increasing immediately, and cell production reached plateau levels comparable with those of control cultures within 4 weeks. Hematopoiesis was maintained for 14 more weeks, indicating that long-term culture- initiating cells survived the treatment. Assays of spleen colony- forming units (CFU-S) in the adherent layers showed an enrichment of day-13 CFU-S relative to the more mature day-9 CFU-S. Mofarotene did not inhibit colony formation by bone marrow cells stimulated by exogenous growth factors and did not decrease production of growth factors by stromal cells in the cultures, as determined by functional assays and by mRNA levels. These results suggest that mofarotene blocks differentiation of very primitive progenitors, inhibiting production of more mature hematopoietic elements.     

The use of the synthetic peptide, Gly-Pro-Arg-Pro, in the preparation of thrombin-degranulated rabbit platelets

The method for preparing thrombin-degranulated platelets has been modified to avoid the use of plasmin or successive treatments with small amounts of thrombin, while still achieving more than 90% release of platelet amine storage granule contents. It was necessary to prevent the fibrinogen released from the platelets during thrombin treatment from forming an insoluble fibrin mesh that could trap the platelets and hinder their deaggregation. To accomplish this we have treated rabbit platelets with 0.73 U/ml of thrombin for 1 min in the presence of the synthetic peptide, Gly-Pro-Arg-Pro, which prevents the polymerization of fibrin molecules. We have demonstrated that it also prevents 125I, initially added as 125I-fibrinogen, from associating with the platelets in a form that was not removed by centrifuging and washing during the preparation of thrombin-degranulated platelets, and we infer that products formed from the fibrinogen released from the platelets would also be prevented from associating with them. Thrombin-degranulated platelets prepared by this method have lost 92% of their granule contents and they can be washed and resuspended. These platelets aggregate normally upon stimulation with thrombin, adenosine diphosphate (ADP), or arachidonate. Thus, Gly-Pro-Arg-Pro is useful in preparing thrombin-degranulated platelets for studying platelet reactions without the complicating effects of released materials such a ADP and fibrinogen.     

Incidence of activated protein C resistance caused by the ARG 506 GLN mutation in factor V in 113 unrelated symptomatic protein C-deficient patients. The French Network on the behalf of INSERM

Because multiple risk factors in one patient may increase the clinical expression of thrombophilia, we assessed the presence in protein C- deficient patients of the factor V Arg 506 Gln mutation responsible for activated protein C resistance. Using a strategy allowing rapid screening of factor V exon 10, we studied 113 patients with protein C deficiency and 104 healthy volunteers. We detected the Arg 506 Gln mutation in 15 patients (14%) and in one healthy subject (1%). We identified a previously unpublished sequence variation leading to an Arg 485 Lys substitution in three normal subjects and seven protein C- deficient patients. A significant difference in the allelic frequency of the Arg 506 Gln factor V mutation was found between protein C- deficient patients heterozygous for an identified protein C mutation (n = 84; allelic frequency, 4.8%) and protein C-deficient patients with no identified mutation in the protein C gene coding regions (n = 25; allelic frequency, 14%). The results demonstrate that a significant subset of thrombophilic patients has multiple genetic risk factors although additional secondary genetic risk factors remain to be identified for the majority of symptomatic protein C-deficient patients.     

Cytochemical, cytogenetic, immunophenotypic and tumorigenic characterization of two hairy cell lines

Two cell lines (EH and HK) were derived from two patients with hairy cell leukemia (HCL). Both patients exhibited a clinical picture characteristic of HCL, including splenomegaly, cytopenias, and tartrate- resistant acid phosphatase (TRAP)-positive "hairy" lymphocytes in blood and marrow. EH and HK were demonstrably of B lineage, as judged by cytochemistry and immunophenotype, including expression of B1, B2, and LEU-12 antigens and of monoclonal surface immunoglobulins (slgs). Monoclonality was confirmed by clonal karyotype abnormality demonstrated in cell line HK. HCL parentage suggested by cytochemistry and electron microscopy was confirmed by the immunophenotypic observation that HCL lines expressed antigens alpha S-HCL1, alpha S- HCL3, and cCLLa. While alpha S-HCL1 and alpha S-HCL3 are nonspecific, their co-expression is characteristic of HCL cells. The cCLLa is a novel 69-kd membrane HCL-associated polypeptide antigen not shared by circulating normal T or B lymphocytes nor by malignant cells from unrelated lymphoid or nonlymphoid malignancies. The doubling time of EH and HK was 24 and 36 hours, respectively. While HK included a small subset of Epstein-Barr virus (EBV) nuclear antigen-positive cells, EH cells were homogeneously negative for the presence of this antigen. Both cell lines were consistently implantable in irradiation- preconditioned immunodeficient mice giving rise to primary tumors and widespread metastasis.     

Autologous stem cell transplantation after first remission induction treatment in multiple myeloma: a report of the French Registry on autologous transplantation in multiple myeloma

Eighteen French centers reported 133 autologous stem cell transplantations performed after first remission induction in multiple myeloma. The source of stem cell was marrow (81 cases), blood (51 cases) or marrow plus blood (1 case). The immediate outcome after transplantation was 49 (37%) complete remissions (CRs) (13 maintained, 36 achieved), 61 (46%) partial remissions, 17 failures and 5 toxic deaths. With a median follow-up of 35 months, the median remission duration was 33 months, the median time to treatment failure was 22 months. The median survival was 46 months overall, 54 months for the 103 patients responding to primary treatment, and 30 months for the 30 nonresponders. In univariate analysis, the outcome was influenced by age, Ig isotype, initial beta 2 microglobulin level, response to initial chemotherapy, plasma cell marrow involvement at the time of harvest, albumin and beta 2 microglobulin level at the time of transplantation, and CR achievement after transplantation. In multivariate analysis, the most important prognostic factor was the quality of response after transplantation. The conditioning regimen and the source of stem cell had no significant impact on immediate and long- term results. Maintenance therapy with interferon alpha did not appear to prolong remission duration or survival. Autologous stem cell transplantation is an effective consolidation for patients responding to primary treatment and a salvage therapy for some nonresponding patients. This approach has to be compared to conventional chemotherapy in prospective randomized studies. The critical impact of CR achievement on survival implies new strategies to increase the CR rate.     

Receptor specificity of clinical Plasmodium falciparum isolates: nonadherence to cell-bound E-selectin and vascular cell adhesion molecule-1

The pathogenicity of Plasmodium falciparum is due largely to the parasite's unique ability to adhere to capillary and postcapillary venular endothelium during the second-half of the 48-hour life cycle. The resulting sequestration of infected erythrocytes (IRBC) in deep vascular beds leads to tissue hypoxia, metabolic disturbances, and organ dysfunction which characterize severe falciparum malaria. Several endothelial receptors of cytoadherence have been identified, but their clinical relevance remains controversial. In the present report, the receptor specificity of 60 clinical P falciparum isolates was determined using transfectants each expressing one of CD36, intercellular adhesion molecule-1 (ICAM-1), E-selectin, and vascular cell adhesion molecule-1 (VCAM-1). All isolates tested adhered to CD36 and ICAM-1, but the adherence to CD36 was at least 10-fold higher. Seven isolates adhered to E-selectin whereas none of 19 isolates adhered to VCAM-1. From a population standpoint, about 30% of IRBC in each isolate adhered to CD36, and 2% to 3% adhered to ICAM-1. The percentage adherent to E-selectin and VCAM-1 was negligible. IRBC selected on CD36 adhered almost exclusively to CD36 whereas 80% to 90% of IRBC selected on ICAM-1 could also adhere to CD36. Selected IRBC did not adhere to E-selectin or VCAM-1. These findings indicate that cytoadherence to multiple endothelial receptors is a rare occurrence with natural P falciparum isolates, but do not exclude a role for the adhesion molecules in promoting other IRBC-endothelial interactions such as rolling under flow conditions. Receptor specificity in vivo may be dictated by the ligand-receptor combination which provides the best survival potential for the parasite.     

Immunocytochemical localization of fibrinogen during thrombin-induced aggregation of washed human platelets

Because thrombin aggregates afibrinogenemic platelets and platelets from patients with the gray platelet syndrome and because antibodies to fibrinogen inhibit thrombin-induced aggregation only at low concentrations of thrombin, the role of fibrinogen in the formation of thrombin-induced aggregates was investigated further with human platelets washed and resuspended in Tyrode-albumin solution containing apyrase, either with or without added Ca2+ (2 mmol/L). Samples for immunocytochemical assessment of fibrinogen distribution were taken at several times (up to five minutes) after aggregation induced by 0.5 U/mL of thrombin. Glutaraldehyde-fixed samples were embedded in Lowicryl K4M, sectioned, incubated with goat antihuman fibrinogen, washed, reacted with gold-labeled antigoat IgG, and prepared for electron microscopy. By 10 seconds, small aggregates formed, and granules were centralized; alpha granules were heavily labeled with immunogold, but the platelet surface was not. As large aggregates formed, granule swelling or fusion occurred, and in some areas granule material seemed to be in contact with the exterior. In these experiments with no added fibrinogen, there were some clusters of gold particles on the platelet surfaces remote from sites of granule discharge, but there were large areas where platelets were in close contact with little or no fibrinogen detectable between them. No fibrin was visible up to five minutes after the addition of thrombin, which indicated that fibrinogen from the granules does not readily become available for fibrin formation in the ambient fluid. Similar results were obtained in media with and without added Ca2+. Thus at least some aggregation in response to thrombin can occur without the participation of released fibrinogen, and much of the granule fibrinogen appears to remain localized at sites where granules fuse with the plasma membrane or the open canalicular system. Incubation of unstirred samples with thrombin for ten minutes resulted in the formation of small aggregates, extensive gold label in regions connected to the exterior of the platelets, but very little gold labeling of the platelet membrane and no visible fibrin formation. When the platelets were aggregated in the presence of external fibrinogen, the morphological changes within the platelets were the same, but fibrinogen rapidly became associated with the entire platelet surface, and visible fibrin formed within 30 seconds in the medium containing 2 mmol/L Ca2+.(ABSTRACT TRUNCATED AT 400 WORDS)     

护士职业压力及应对方式与工作满意度的关系

目的:分析护士职业压力、应对方式和工作满意度之间的关系。方法:于2006-02/03采用按一定护士人数比例随机抽取四川省乐山市和眉山市10所二级和三级医院的600名临床护士为调查对象进行问卷调查。①采用护士工作压力源量表调查职业压力情况,该量表分为护理工作及专业方面的问题、工作量及时间分配问题、工作环境及资源问题、患者护理方面的问题和管理及人际关系方面的问题等5个方面,共35个条目,采用1～4级评分法,分数越高,表明引起压力的程度越大。②选用肖计划编制的应付方式问卷调查护士的应对方式,该问卷包括解决问题、合理化、求助、自责、幻想、退避六种类型,共有62个条目,每个条目有"是"或"否"两个答案。③采用自编的护士工作满意度问卷调查护士对工作的满意程度,该问卷包括工作成就感、人际关系、专业发展、工作条件和福利待遇5个因素,共16个条目,采用1～5级评分法,分数越高,表明对工作的满意程度越高。对结果数据进行相关分析、回归分析和结构方程分析。结果:发放问卷600份,回收有效问卷530份,有效率为88.3%。从护士职业压力、应对方式和工作满意度的关系模型中分析发现:职业压力中各因素对工作满意度均有显著性的影响。护理专业及工作方面对工作满意度既有直接的非常显著的负向预测作用,也通过退避方式间接影响工作满意度;管理与人际关系通过合理化、退避等方式对满意度产生间接的负向作用;工作环境及资源通过解决问题等方式对满意度产生间接的正向作用;工作量及时间分配既可直接对满意度产生负向作用,也通过退避和解决问题方式间接影响工作满意度;患者护理对满意度产生直接的正向作用。在应对方式中,解决问题方式对工作满意度有直接的正向预测作用,而退避对满意度有直接的负向预测作用;其他几种应对方式均是通过退避或解决问题间接影响满意度(模型所有的路径系数均>0.05,达到显著水平)结论:护士职业压力不同,应对方式存在差异;应对方式不同,工作满意度也不同;职业压力既可以直接影响工作满意度,也可以通过应对方式间接影响工作满意度。     

腰神经根受压模型大鼠神经根局部炎症因子对温和灸的反应

目的:观察温和灸对腰神经根受压模型大鼠受压神经根局部炎症因子白细胞介素1和白细胞介素6的调节作用,并与灌胃给药莫比可相比较。方法:实验于2005-09/2006-04在上海第六人民医院实验中心完成。①分组:将40只SD大鼠随机分为4组,正常对照组,模型对照组,温和灸组及莫比可组,每组10只。②方法:温和灸组、莫比可组、模型对照组通过手术建立大鼠腰神经根压迫模型,正常对照组做与以上各组相同的捆绑固定,不予手术。温和灸组穴位选取受压神经根相应节段右侧的夹脊穴,采用精制清艾条以穴位为中心、半径为5mm的区域进行温和灸,20min/次,1次/d,7次为1个疗程,共治疗14次。莫比可组按3.75mg/kg灌胃莫比可(10mL生理盐水含药物5mg),每天灌胃1次。正常对照组及模型对照组:生理盐水灌胃10mL/kg,每日灌胃1次。于治疗14d后麻醉下处死取受压神经根组织。③评估:于光镜下观察受压神经根组织形态学变化;用免疫组织化学技术检测神经根局部炎症因子白细胞介素1、白细胞介素6水平。结果:40只大鼠均进入结果分析。光镜下观察温和灸组神经节细胞、神经纤维结构基本正常,见极少量炎细胞。与模型对照组相比,温和灸组与莫比可组神经根局部炎症因子白细胞介素1、白细胞介素6的含量有不同程度的减少(P<0.05);温和灸治疗组白细胞介素1、白细胞介素6的水平低于莫比可组(P<0.01)。结论:温和灸及西药莫比可均能有效抑制神经根局部炎症因子分泌,其中温和灸作用迅速,其效果明显优于莫比可。