从脐血单个核细胞定向诱导巨核细胞的生成

采用 SCF、TPO、IL- 3、IL- 6、IL- 1细胞因子 ,从脐血单个核细胞定向诱导巨核细胞的形成。比较了 SCF+ TPO+ IL- 1、SCF+ TPO+ IL- 3、SCF+ TPO+ IL- 63种细胞因子组合对刺激巨核细胞生成的作用 ,经体外培养 8d后 ,CD41 + 细胞占培养物的比例分别达到 ( 5 .64± 0 .77) %、( 5 .73± 1 .2 4 ) %和 ( 2 0 .1± 2 .5 3) % ;每 1 0 4个细胞可形成巨核祖细胞集落形成单位 ( CFU- MK)为( 1 3.7± 5 .7)个、( 1 5 .0± 3.6)个和 ( 93.7± 1 6.0 )个。在 SCF+ TPO+ IL- 6体系中增加 IL- 6的浓度 ,可提高培养液中 CD41 + 细胞的纯度。当 IL- 6的浓度从 1 0μg/L增加到 5 0μg/L时 ,CD41 + 细胞的比例可从 ( 2 0 .1± 2 .5 3) %提高到 ( 2 6.81± 3.2 0 ) % ,但每 1 0 4个细胞形成 CFU- MK数目却从( 93.7± 1 6.0 )个减少到 ( 4 5± 8.6)个 ;这说明 IL- 6对巨核细胞的刺激主要作用在其发育的后期。采用 SCF+ TPO+ IL- 3+ IL - 6细胞因子组合 ,由 1× 1 0 6个单个核细胞培养一周后可诱导出 ( 1 .61±0 .5 8)× 1 0 5个 CD41 + 细胞 ,占培养物的比例可达到 ( 1 8.8± 1 .64) % ,每 1 0 4个细胞形成 CFU- MK数目可达到 ( 1 2 1 .8± 1 0 .3)个。这一结果为进一步体外大量扩增巨核细胞提供了基础     

Thrombopoietin: a tool for understanding thrombopoiesis

Summary.  Although first proposed to be the primary regulator of platelet production 45 years ago, the gene for thrombopoietin was cloned only within the last decade. Since then, our understanding of megakaryocyte and platelet production has increased substantially, and it is now appreciated that in addition to its critical role in regulating thrombopoiesis, the hormone affects multiple aspects of hematopoiesis, including playing a non-redundant role in stem cell survival, self-renewal and expansion. In addition to this greater physiological understanding of thrombopoietin biology, the molecular mechanisms by which the hormone affects cell survival and proliferation are coming under increased scrutiny. At least four signaling pathways have been identified that play important and non-overlapping roles in stem cell and megakaryocyte growth and development, potentially providing new strategies to therapeutically intervene in hematopoiesis. This review will focus on our current understanding of these processes.     

Platelet production: a computer based biological interpretation

The platelet volume distribution was measured in rat and rabbit in normal steady state platelet production. The animals were then sacrificed and the planimetric megakaryocyte and nuclear areas in each animal were measured using histological techniques. These areas were used to obtain an estimate of the megakaryocyte, megakaryocyte cytoplasm and nuclear volume distributions. The production, by physical fragmentation, of the platelet population from the measured megakaryocyte cytoplasm volume distribution was simulated on a computer. The platelet volume distribution predicted by physical fragmentation was then compared with the measured circulating platelet volume distribution from each animal. The physical fragmentation theory gave an accurate quantitative prediction of the observed platelet volume distribution over the whole volume range. Furthermore fragmentation theory predicted the mean platelet volume, the mode, the maximum frequency of the platelet volume distribution and the range of this distribution. Autopsy studies of megakaryocytes volume distributions in healthy man were fragmented to obtain predicted normal platelet volume distributions from the computer simulation. These distributions were compared with measured circulating platelet volume distributions from apparently healthy men who had a similar mean platelet volume. The platelet volume distribution predicted by physical fragmentation was again in quantitative agreement with the measured distribution over the whole volume range. This study provides further evidence that platelet production from megakaryocyte cytoplasm is by physical fragmentation. Furthermore the computer simulation suggests that the mode of production has a specific form. It also explains why different mammals have different mean platelet volumes.     

The expression of mRNA for fibrinogen in megakaryocytes isolated from patients with T-cell lymphoma

Summary. The expression of fibrinogen mRNA was studied by in situ hybridization in freshly isolated megakaryocytes in 14 newly-diagnosed patients: seven with non-Hodgkin's lymphoma (NHL), three with immune thrombocytopenic purpura (ITP) and four haematologically normal patients prior to coronary artery bypass surgery. Fibrinogen mRNA in megakaryocytes was not detected in ITP, B-cell lymphomas or in healthy donors. However, it was present in all patients with the high-grade T-cell lymphomas, both with and without thrombocytopenia.     

Ⅱ型登革病毒对人骨髓造血细胞抑制机制的初步探讨

用Ⅱ型登革病毒(D_2 V)与人骨髓细胞混合培养48小时后,测定上清液中干扰素的浓度,发现D_2 V感染组的干扰素浓度明显高于空白对照组(P<0.001)。在骨髓CFU-GM培养中,加入D_2 V及抗γ-干扰素后,CFU-GM集落产率明显高于只加D_2 V而不加抗γ-干扰素组(P0.05)。实验研究结果提示D_2 V对人骨髓的抑制与免疫及体液因素有关。     

Distribution of nervous system-specific forms of enolase in peripheral tissues

The distribution of 3 forms of rat enolase (αα, αγ and γγ forms), including nervous system-specific forms (αγ and γγ), was determined in various tissues with a sensitive enzyme immunoassay system. The brain and spinal cord contained more than 100 pmol/mg protein of the αα, αγ and γγ enolases. Organs such as the lungs, heart, spleen, liver and kidney contained similarly high levels of αα enolase, but these tissues contained αγ and γγ enolases at levels less than 1% of the central nervous tissues. High levels of the αγ (10pmol/mg) and the γγ (1.5pmol/mg) forms were found in rectum, bladder, and uterus. In gut, major portions of the nervous system-specific forms were localized in the muscle layers. Skeletal muscle and diaphragm, which are composed of striated muscle, contained low levels of the 3 forms of enolase. Megakaryocytes separated from the suspension of bone marrow contained 11.3, and 0.53 amol/cell of the αα and γγ enolases, respectively, with little, if any, of the αγ form.     

A novel recombinant human thrombopoietin for treating prolonged isolated thrombocytopenia after allogeneic stem cell transplantation

Patients with prolonged isolated thrombocytopenia (PT) after allogeneic stem cell transplantation (allo-SCT) are known to have a poor prognosis. However, there is no standard treatment for PT. The present study aimed to investigate the potential effect of a novel recombinant human thrombopoietin (rhTPO) in a cohort of patients with PT following allo-SCT. A total of 24 patients with PT (including delayed platelet engraftment and secondary failure of platelet recovery) were treated with rhTPO from July 1, 2016 to May 31, 2017. rhTPO injections were administered at 300 IU/kg/d for 28 consecutive days or until platelet counts were ≥ 50 × 10⁹/L, independent of platelet transfusion. Response was defined as platelet recovery to ≥ 20 × 10⁹/L for seven consecutive days without transfusion support during or within 7 days of the end of rhTPO treatment. All patients completed the 28 days of treatment, and none were withdrawn due to adverse effects. The overall response was 45.8%, which was significantly higher than historical data (12.2%, p < 0.001). The median response time was 12 (7–25) days from the initiation of rhTPO treatment. A response to rhTPO was associated with megakaryocytes in the bone marrow (positive vs. negative, 81.8 vs. 22.2%; p = 0.022). Among 11 patients exhibiting a response to rhTPO, the median number of megakaryocytes in bone marrow was increased significantly (10 vs. 2; p = 0.036) after rhTPO treatment. In conclusion, the results of this preliminary study suggest that rhTPO may represent a therapeutic option, with a response of 45.8% for patients with PT after allo-SCT, and especially for those with megakaryocytes in the bone marrow. However, this should be further confirmed in randomized prospective clinical trials.     

Non-neuronal glutamate signalling pathways

It is becoming increasingly apparent that the role of glutamate receptors in signalling at synapses is not confined to the CNS, as once believed, and that they also function in several non-neuronal tissues. The aim of this review is to summarise current knowledge regarding peripheral glutamate signalling and discuss the role of glutamate as a more ubiquitous signalling agent. As one avenue for therapeutic intervention may be by manipulation of intercellular communication pathways, increased awareness and understanding of glutamate signalling will help in the design of treatment schedules for a range of biological disorders including skin disease, osteoporosis, blood clotting disorders and diabetes. These avenues have the possibility to advance rapidly into clinical practice because agents developed to modulate central glutamate receptor function could be targeted to new sites without the requirement for completely new drug discovery or clinical chemistry programmes.