Glomerular procoagulant activity in human proliferative glomerulonephritis.

Mechanisms for initiation of glomerular fibrin deposition were studied using renal tissue obtained from two patients with rapidly progressive, crescentic glomerulonephritis. Histological examination showed extensive glomerular monocyte infiltration and fibrin deposition in both patients. Sonicated cell suspensions of isolated glomeruli from these patients contained markedly augmented levels of procoagulant activity (PCA) compared with the levels found in normal glomeruli. This PCA was characterized as tissue factor by its functional dependence on Factors VII and V, independence of Factors VIII and XII, inhibition by concanavalin A and phospholipase C, and association with cell membranes. Its coagulant activity was also inhibited by a specific monoclonal anti-human tissue factor antibody. Tissue factor could be identified in glomeruli from these two patients by indirect immunofluorescence using this antibody. These studies implicate extrinsic pathway activation via tissue factor in intraglomerular deposition of fibrin in these patients. Activated monocytes, known to be a potent source of procoagulant activity and seen in large numbers within glomeruli from these patients, are a likely source of this tissue factor.     

p120 GAP requirement in normal and malignant human hematopoiesis

There is evidence to suggest that the p120 GAP (GAP), originally described as an inhibitor of p21ras, may also serve as a downstream effector of ras-regulated signal transduction. To determine whether GAP expression is required for the growth of human normal and leukemic hematopoietic cells, we used GAP antisense oligodeoxynucleotides to inhibit it and analyzed the effects of this inhibition on the colony- forming ability of nonadherent, T lymphocyte-depleted mononuclear cells and of highly purified progenitors (CD34+ MNC) obtained from the bone marrow and peripheral blood of healthy volunteers or chronic myeloid leukemia (CML, bcr-abl-positive) patients. The acute myelogenous leukemia cell line MO7, the Philadelphia BV173 cell line, and the acute promyelocytic leukemia NB4 and HL-60 cell lines were similarly examined. GAP antisense treatment inhibited colony formation from normal myelo-, erythro-, and megakaryopoietic progenitor cells as well as from CML progenitor cells. Proliferation of MO7 (growth factor- dependent) and BV173 (bcr-abl-dependent) cells, but not that of NB4 and HL-60 (growth factor-independent) cells, was also inhibited, even though a specific downregulation of GAP was observed in each cell line, as analyzed by either or both mRNA and protein expression. Stimulation of MO7 cells with hematopoietic growth factors increased the expression of GAP as well as the levels of active GTP-bound p21ras. Stimulation of GAP expression was inhibited upon GAP antisense treatment. These data indicate that p120 GAP is involved in human normal and leukemic hemopoiesis and strongly suggest that GAP is not only a p21ras inhibitor (signal terminator), but also a positive signal transducer.     

Recombinant human granulocyte colony-stimulating factor. Effects on hematopoiesis in normal and cyclophosphamide-treated primates

We examined the in vivo effects of recombinant human granulocyte colony-stimulating factor (rhG-CSF) in primates (cynomolgus monkeys) treated with subcutaneous doses of rhG-CSF for 14-28 d. A dose-dependent increase in the peripheral white blood cells (WBC) was seen, reaching a plateau after 1 wk of rhG-CSF treatment. The elevation of WBC was due to an increase in the absolute neutrophil count. These results demonstrate that rhG-CSF is a potent granulopoietic growth and differentiation factor in vivo. In cyclophosphamide (CY)-induced myelosuppression, rhG-CSF was able to shorten the time period of WBC recovery in two treated monkeys to 1 wk, as compared to more than 4 wk for the control monkey. Its ability to significantly shorten the period of chemotherapy-induced bone marrow hypoplasia may allow clinicians to increase the frequency or dosage of chemotherapeutic agents. In addition, the increase in absolute numbers of functionally active neutrophils may have a profound effect in the rate and severity of neutropenia-related sepsis. Furthermore, the activities reported here indicate a potential role for rhG-CSF in the treatment of patients with myelodysplastic syndrome, congenital agranulocytosis, radiation-induced myelosuppression, and bone marrow transplantation.     

Animal models for human hematopoiesis.

Despite seminal contributions provided by in vitro studies to the field of hematopoiesis, our present knowledge of mammalian lymphohemopoiesis and the mechanisms governing differentiation and self-renewal of hematopoietic stem cells has been derived in most part from elegant in vivo studies. The inability to apply such an approach to the examination of the human hematopoietic system is the primary reason why several aspects of human hematopoiesis including human stem cell biology are still poorly understood. To overcome the inability to probe human hematopoiesis in vivo, researchers have "humanized" animals via the transplantation of human hematopoietic progenitor cells and other tissues in an attempt to create human-animal chimera suitable for investigating human lymphohematopoiesis in vivo. To date, several of these "humanized" animal models have been developed. During their relatively short existence, human-animal models have contributed substantially to the field of experimental hematology. The development, peculiarities, shortcomings, and applications of these animal models as well as their potential use in exploring the field of human lymphohematopoiesis are the focus of this review.     

负压引流对人慢性创面愈合过程中细胞增生活性的影响

目的:研究封闭式负压引流技术对人慢性创面细胞增生活性的影响,探讨其组织修复创面愈合的机制。方法:2003-01/2004-08武装警察部队总医院烧伤整形科慢性创面患者5例。对5例慢性创面患者给予持续性负压引流治疗(-1.6kPa压力),分别于吸引前以及吸引后1,3,5,7d天切取创缘组织,采用免疫组织化学技术,检测PCNA表达及其标记指数的变化,AgNOR染色观察其核仁区AgNORs颗粒数的变化。结果:负压吸引前,PCNA阳性表达较少,主要分布在表皮基底和皮肤毛囊以及皮脂腺细胞,随封闭式负压引流技术使用时间的延长,真皮层中的成纤维细胞、血管内皮细胞及炎性细胞中,出现PCNA阳性细胞;Ag-NORs颗粒数增加(P<0.05)。第一组病例治疗前PCNA标记指数和AgNOR颗粒数分别为0.21,1.01,治疗5d后为0.49和2.12。结论:封闭式负压引流技术能明显增强慢性创面修复细胞的增生活性,激活修复细胞,促进慢性创面愈合。     

Measures of tumor proliferative activity.

Tumor proliferative activity, or labeling index, is of interest for gaining insight into the biologic properties of human neoplasm and for providing clinical information that might guide patient management. There has been an abundance of literature reporting experience with standard and newer techniques of measuring tumor proliferative activity. These methods are reviewed with emphasis on technical issues. Particular attention is paid to the development and use of monoclonal antibodies, Ki-67 and anti-PCNA/cyclin. These antibodies are readily available and relatively simple to use. The former has recently been shown to be of prognostic value in non-Hodgkin's large cell lymphomas. A number of studies suggest that indices using these techniques could be useful for a variety of carcinomas, soft tissue tumors, and tumors of the central nervous system.     

Retinoids. Structure-function relationship in normal and leukemic hematopoiesis in vitro.

Retinoids were studied both to identify what skeletal components are important in the modulation of normal and leukemic human myeloid clonal proliferation and differentiation in vitro and to elucidate the mechanism by which retinoids modulate proliferation of hematopoietic cells. Retinoids with a derivatized terminal carboxyl group were significantly less active than all-trans-retinoic acid, and those with the addition of two methyl groups to the cyclohexenyl ring of retinoic acid or substitution of its beta-cyclogeranylidene group with a 1,1,3,3-5-indanyl ring system were markedly more active than all-trans-retinoic acid. Five of the retinoids strongly inhibited clonal growth of the HL-60 and KG-1 human leukemic cell lines (50% inhibition in the range of 3 X 10(-10)-1 X 10(-8) M) and markedly stimulated normal human myeloid colony formation (granulocyte-macrophage colony-forming cells [GM-CFC] 150% stimulation in the range of 3 X 10(-9)-3 X 10(-8) M). Further studies suggested that: Common structural requirements of the retinoids were important in the modulation of both normal and leukemic hematopoiesis. The retinoids were able to inhibit leukemic proliferation without induction of differentiation of the neoplastic cells. Studies on normal human GM-CFC suggested that the retinoids did not act by themselves as a colony-stimulating factor (CSF), or by stimulating accessory cells to produce CSF, but either required earlier progenitor cells to become GM-CFC or enhanced the sensitivity of GM-CFC to the action of CSF.     

Alpha-L-fucosidase activity in normal human lymphocytes

After DEAE-Trisacryl chromatography two forms of alpha-L-fucosidase have been characterized in normal human lymphocytes. These enzymatic forms were different with respect to their optimum pH, kinetic properties and isoelectric behaviour. After neuraminidase treatment two forms are still observed with a neutral shift in pI values. These results suggest that at least two structurally different alpha-L-fucosidase units exist.     

Prolyl hydroxylase activity in human normal skins and post-burn scars.

Post-burn granulation tissues showed an extraordinary high prolyl hydroxylase (EC 1.14.11.2; proline, 2-oxoglutarate dioxygenase) activity, 25 to 50 times higher than the mean value of human normal skins from the frontal thighs of 15 subjects, 385 +/- 247 (S.D.) cpm/min/g of wet weight tissue. The activity in the scars decreased sharply within 4 to 5 months, and then gradually decreased to the normal range after 2 years or so. Well-aged scars tended to show lower values than the mean value of normal skins.     

Lysyl oxidase activity in human normal skins and postburn scars.

Lysyl oxidase activity of human normal skins derived from the frontal thighs of 33 subjects showed large variations and the mean value was 11 455 +/- 7 172 (S.D.) cpm/g of wet weight tissue. The age of lesion affected the lysyl oxidase activity in postburn scars. Granulation tissues showed a fairly low activity; however, the activity increased sharply within 2--3 months, and reached a significantly higher value than that of normal skin. The high level of activity continued for up to 2--3 years, then gradually decreased to normal range after 5 years or so. Lysyl oxidase activity was detected only after 4 M urea treatment of tissues. Benzylamine oxidase activity also showed large variations in both normal skins and postburn scars, with mean values of: 0.128 +/- 0.077 (S.D.) and 0.145 +/- 0.090 (S.D.) mmol/g of wet weight/h, respectively. No correlation was observed between lysyl oxidase and benzylamine oxidase activities. The granulation tissues showed significantly high values of benzylamine oxidase activity in contrast to the low values of lysyl oxidase activity.     

Bus use by disabled arthritics: functional requirements.

Twenty-five rheumatoid arthritic patients were studied to determine the extent of independence and functional requirements necessary to use public bus transportation in Philadelphia. To measure the extent of independence, a functional assessment scale was developed that evaluates 19 bus activities, each according to a four-point scale. Of the 11 subjects who stated that they used the public bus prior to admission, only 4 were found to be able to use the public bus independently at the time of evaluation. Ascending, descending and motion activities provided considerable difficulty for the sample population. Functional requirements of boarding and disembarking the bus are described in detail.     

Analysis of histocompatibility requirements for proliferative and helper T cell activity. T cell populations depleted of alloreactive cells by negative selection

T cell populations were prepared from donors immunized with hapten-carrier conjugates and were depleted of alloreactive cells by negative selection. This was accomplished by injection of the cells into H-2-disparate irradiated recipients and recovery from the thoracic duct after 18-40 h. The genetic requirements for the proliferative and helper activity of these populations was determined. The proliferative response to antigen presented on adherent, Thy-1-negative cells was determined, and a requirement for syngeneic antigen-presenting cells (APC) was demonstrated. The same T cells were assayed for their ability to give help to hapten primed B cells. It was shown that there was a requirement for syngeneic APC and for linked recognition of hapten and carrier determinants on the same molecule by the B cell and T cell. There was no requirement for the B cell to be H-2 compatible with the T cell. The requirement for linked recognition was taken as evidence that the responses in allogeneic combinations were not a result of positive allogeneic effects. Precisely comparable restrictions were found with positively selected cells.     

碱性成纤维细胞生长因子在胚胎卵黄囊造血过程中的表达

目的 探讨人胚胎发育过程中碱性成纤维细胞生长因子1(FGF1)对造血细胞形成的影响,研究FGF1、血管内皮生长因子受体(KDR)、CD133、CD34和转录凶子Ihh、SCL、GATA-1、GATA-2和PU.1在卵黄囊中的表达,了解FGF1、造血细胞和转录因子在胚胎造血过程中的作用和关系.方法 采用药物流产孕3～12周人胚胎,冰冻切片,免疫组织化学SP染色,并应用分析软件进行分析,同时进行造血相关转录因子RT-PCR扩增分析.结果 孕3～12周人胚卵黄囊血岛均由外周的血管内皮细胞和中心的造血细胞组成.在16 d的卵黄囊中脏壁中胚层嗣血岛周边表达FGF1阳性产物,而血岛内少有FGF1表达,低表达KDR,不表达CD34、CD133;21 d上述抗体均有表达,灰度值减少,染色增强;30d时在血岛和中胚层发现强染色CD34+、CD133+和KDR+细胞,灰度值分别由156±16、173±18和160±14降低为53±7、52±6和69±8;FGF1呈强阳性表达,灰度值由161±13急降至40±5,达到最低值.有些阳性细胞沿血岛边缘形成血管样结构.45 d时中等程度表达CD34、CD133、KDR细胞数量增多,细胞聚集成团分布于血岛中;FGF1阳性细胞也多聚集分布在血岛中,中胚层少有分布,灰度值增加.7周后CD133+、KDR+、CD34+细胞明显减少,灰度值增加,染色变浅,卵黄囊弱表达FGF1,灰度值增加为179±22.RT-PCR结果显示,不同时间的卵黄囊均表达Ihh、SCL、GATA-1和GATA-2,PU.1在16 d不表达,此后表达.结论 卵黄囊造血细胞的发育受FGF1和转录因子的诱导和调节,提示FGF1介导的信号通路对造血中胚层模式的形成、成血管血液干细胞的扩增以及造血十细胞的动态平衡具有重要意义.FGF通路可能通过调节GATA1等转录因子表达水平和活性来调控卵黄囊造血.