Hematopoietic cell infusion for the treatment of nuclear disaster victims: New data from the Chernobyl accident

Purpose:?To present previously unavailable data on the use of stem cell administration to aid recovery of victims of the Chernobyl disaster. On 26 April 1986, an accident at Unit 4 of the Chernobyl Nuclear Power Plant took place during the planned test of one of the safety systems. The diagnosis of acute radiation syndrome (ARS) was confirmed in 134 individuals exposed to high levels of radiation. There were nine patients heretofore unreported in the scientific literature who underwent intraosseous injections of allogeneic bone marrow cells in Kyiv.

Conclusions:?Transplantation was associated with significantly shortened time to recovery of granulocyte and platelet counts in these patients. While current guidelines would certainly include the use of cytokines, these data provide an indication of the effectiveness of stem cell transplant to treat victims of radiation exposure.     

Genistein induces radioprotection by hematopoietic stem cell quiescence

Purpose: In this study we addressed whether genistein-induced radioprotection in mice is associated with alterations of the cell cycle of hematopoietic stem and progenitor cells.

Materials and methods: C57BL/6J female mice received a single subcutaneous injection of genistein (200 mg/kg) 24 h prior to a lethal dose (7.75 Gy, ⁶⁰Co) of total body irradiation. Proliferation-associated Ki-67 protein/7-aminoactinomycin-D (Ki67/7AAD) cell cycle staining was used to differentiate between G₀, G₁, and S/G₂/M in bone marrow cell populations negative for expression of mature hematopoietic lineage marker cells but positive for expression of stem cell antigen-1 and tyrosine kinase receptor for stem cell factor (Lin^?Sca-1⁺cKit⁺, LSK⁺). Quantitative real-time polymerase chain reaction (qRT-PCR) microarrays were utilized to examine cell cycle specific genes.

Results: At 24 h following radiation exposure, a greater percentage of LSK⁺ in genistein-treated mice accumulated in the G₀ phase of the cell cycle, whereas a large percentage of LSK⁺ bone marrow cells from untreated and vehicle (PEG-400)-treated mice progressed into the G₁ and S/G₂/M phases. Moreover, the absolute number of marrow total LSK⁺, long-term LSK⁺, and short-term LSK⁺ increased 2.8, 12.1, and 4.2-fold, respectively, at 7 days post-irradiation in genistein-treated vs. untreated irradiated mice. Lin^? cells from genistein-treated mice expressed fewer DNA damage responsive and cell cycle checkpoint genes than LSK⁺ from untreated or vehicle-treated mice.

Conclusion: Pretreatment with genistein provides in vivo protection from acute myelotoxicity through extended quiescence followed by reduced senescence of marrow repopulating LSK⁺.     

骨髓间充质干细胞移植治疗犬急性放射性肠病临床观察

目的建立比格犬急性放射性肠病的损伤模型,观察骨髓间充质干细胞移植治疗犬急性放射性肠病的临床效果。方法将35只比格犬随机分为空白对照组(A组)、10 Gy单独照射组(B组)、12 Gy单独照射组(C组)、14 Gy单独照射组(D组)、10 Gy照射后干细胞治疗组(E组)、12 Gy照射后干细胞治疗组(F组)及14 Gy照射后干细胞治疗组(G组),每组5只。对比格犬腹部进行X线调强照射,观察单独照射、照射后干细胞治疗的比格犬的临床特点、肠镜表现、生存时间,并采用组织病理学评分对放射造成的肠损伤程度进行评估。结果比格犬肠损伤程度与放射剂量呈正相关。E、F组干细胞治疗后肠损伤组织病理学评分明显低于治疗前(P<0.05);G组治疗前后比较,差异无统计学意义(P>0.05)。比格犬生存时间与放射剂量呈负相关。F组生存时间明显长于C组(P<0.05);E组与B组、G组与D组比较,差异无统计学意义(P>0.05)。结论随着放射剂量增大,比格犬急性放射性肠病加重,生存时间缩短。骨髓间充质干细胞移植在12 Gy剂量的急性放射性肠病的治疗中发挥积极作用。     

Lack of association between acute exposure to ionizing radiationand liver cirrhosis

Purpose: Although previous studies have shown significantly increased risks of liver cirrhosis and chronic liver disease for acute radiation exposure among survivors of the atomic bombings of Hiroshima and Nagasaki, Japan, these studies have not taken into account hepatitis B virus (HBV) infections. Because HBV is associated with both A-bomb radiation and liver cirrhosis, our goal was to investigate the relationship of acute ionizing radiation to liver cirrhosis adjusting for HBV, co-occurring primary liver cancer (PLC), and other potential confounders.

Materials and methods: Using a cross-sectional design and pathology review of a cohort of Japanese atomic-bomb survivors, we found that 213 of 335 (63.6%) subjects with PLC and 55 of 776 (7.1%) subjects without PLC had cirrhosis.

Results: We found no association between acute exposure to A-bomb radiation and liver cirrhosis. The adjusted odds ratio of cirrhosis per Sv liver irradiation was 0.59 (95% confidence interval: 0.27 – 1.27). Cirrhosis risks for the highest tertile of radiation exposure (mean exposure 0.7 Sv) were also not elevated (0.8, 0.26 – 2.12 and 0.2, 0.03 – 0.98 among subjects with and without PLC.

Conclusions: Acute exposure to liver irradiation does not increase risks of liver cirrhosis, regardless of PLC status.     

A prospective study on MRI findings and prognostic factors in athletes with MTSS

In medial tibial stress syndrome (MTSS) bone marrow and periosteal edema of the tibia on the magnetic resonance imaging (MRI) is frequently reported. The relationship between these MRI findings and recovery has not been previously studied. This prospective study describes MRI findings of 52 athletes with MTSS. Baseline characteristics were recorded and recovery was related to these parameters and MRI findings to examine for prognostic factors. Results showed that 43.5% of the symptomatic legs showed bone marrow or periosteal edema. Absence of periosteal and bone marrow edema on MRI was associated with longer recovery (P = 0.033 and P = 0.013). A clinical scoring system for sports activity (SARS score) was significantly higher in the presence of bone marrow edema (P = 0.027). When clinical scoring systems (SARS score and the Lower Extremity Functional Scale) were combined in a model, time to recovery could be predicted substantially (explaining 54% of variance, P = 0.006). In conclusion, in athletes with MTSS, bone marrow or periosteal edema is seen on MRI in 43,5% of the symptomatic legs. Furthermore, periosteal and bone marrow edema on MRI and clinical scoring systems are prognostic factors. Future studies should focus on MRI findings in symptomatic MTSS and compare these with a matched control group.     

干细胞在放射医学研究中的进展

电离辐射作用于机体后,可致机体发生急性放射病。辐射损伤的远后效应之一是白血病,含有干细胞的骨髓细胞移植是目前挽救急性放射病病人生命的惟一有效的治疗方法。近年来随着干细胞研究的突破性进展,其多向分化潜能及干细胞相互转化可能为辐射损伤病人提供新的干细胞来源;同时随着辐射防护剂研究的深入,促进了损伤后干细胞的恢复。     

Modelling hematological parameters after total body irradiation

Abstract

Purpose: The time- and dose-dependent reconstitution of hematopoiesis after radiation exposure is strongly related to the stem cell population and can be used to predict hematological parameters. These parameters allow further insight into the hematopoietic system and might lead to the development of novel stem cell transplantation models.

Materials and methods: CD4-/- C57Bl/6 mice, transgenic for human CD4 and HLA-DR3, were irradiated in a single (3, 6, 8 and 12 Gy) and fractionated (6 × 1 Gy, 6 × 1.5 Gy, 6 × 2 Gy; twice daily) dose regimen. Blood was analyzed weekly for red blood cells (RBC), hemoglobin concentration (Hb), hematocrit (HCT) and white blood cells (WBC). Organ and tissue damage after irradiation were examined by histopathology.

Results: The recovery curves for RBC, Hb, HCT and WBC showed the same velocity (< 1 week) for all radiation doses (3–12 Gy) starting at different, dose-dependent times. The only dose-dependent parameter was defined by the beginning of the recovery process (dose-dependent shift) and higher doses were related to a later recovery of the hematopoietic system. The RBC, Hb and HCT recovery was followed by a saturation curve reaching a final concentration independent of the radiation dose. Histological analysis of the bone marrow in the single dose cohort showed a dose-dependent reduction of the cellularity in the bone marrow cavities. The fractioned radiation dose cohort resulted in a regeneration of all bone marrow cavities.

Conclusion: Specific functions were developed to describe the reconstitution of hematological parameters after total body irradiation.     

Chromosome aberrations determined by sFISH and G-banding in lymphocytes from workers with internal deposits of plutonium

Purpose: To examine the influence of α-particle radiation exposure from internally deposited plutonium on chromosome aberration frequencies in peripheral blood lymphocytes of workers from the Sellafield nuclear facility, UK. Materials and methods: Chromosome aberration data from historical single colour fluorescence in situ hybridization (sFISH) and Giemsa banding (G-banding) analyses, together with more recent sFISH results, were assessed using common aberration analysis criteria and revised radiation dosimetry. The combined sFISH group comprised 29 men with a mean internal red bone marrow dose of 21.0 mGy and a mean external γ-ray dose of 541 mGy. The G-banding group comprised 23 men with a mean internal red bone marrow dose of 23.0 mGy and a mean external γ-ray dose of 315 mGy. Results: Observed translocation frequencies corresponded to expectations based on age and external γ-ray dose with no need to postulate a contribution from α-particle irradiation of the red bone marrow by internally deposited plutonium. Frequencies of stable cells with complex aberrations, including insertions, were similar to those in a group of controls and a group of workers with external radiation exposure only, who were studied concurrently. In a similar comparison there is some suggestion of an increase in cells with unstable complex aberrations and this may reflect recent direct exposure to circulating lymphocytes. Conclusions: Reference to in vitro dose response data for the induction of stable aberrant cells by α-particle irradiation indicates that the low red bone marrow α-particle radiation doses received by the Sellafield workers would not result in a discernible increase in translocations, thus supporting the in vivo findings. Therefore, the greater risk from occupational radiation exposure of the bone marrow resulting in viable chromosomally aberrant cells comes from, in general, much larger γ-ray exposure in comparison to α-particle exposure from plutonium.     

Treatment of mice with stem bark extract of Aphanamixis polystachya reduces radiation-induced chromosome damage

Purpose: Normal tissue radiosensitivity is the major limiting factor in radiotherapy of cancer. The use of phytochemicals may reduce the adverse effects of radiation in normal tissue. The effect of ethyl acetate fraction of Aphanamixis polystachya (EAP) was investigated on the radiation-induced chromosome damage in the bone marrow cells of Swiss albino mice exposed to various doses of γ-radiation.

Materials and methods: The mice were divided into two groups, one group was exposed to 0, 1, 2, 3, 4 or 5 Gy of γ-radiation, while another group received 7.5 mg/kg body weight (BW) of EAP 1 h before exposure to 0, 1, 2, 3, 4 or 5 Gy of γ-radiation. Various asymmetrical chromosome aberrations were studied in the bone marrow cells of mice at 12, 24 or 48 h post-irradiation. To understand the mechanism of action of the free radical scavenging activity of 0, 5, 10, 20, 30, 40, 50, 60 or 70 μg/ml EAP, assays were carried out in vitro.

Results: Irradiation of mice to different doses of gamma radiation caused a dose dependent elevation in the frequency of aberrant cells and chromosome aberrations like chromatid breaks, chromosome breaks, dicentrics, acentric fragments and total aberrations at all the post-irradiation times studied. The maximum asymmetrical aberrations were scored at 24 h post-irradiation except chromatid breaks that were highest at 12 h post-irradiation. A maximum number of polyploid and severely damaged cells (SDC) were recorded at 24 h post-irradiation in the SPS + irradiation group. Treatment of mice with 7.5 mg/kg BW of EAP before exposure to 1 – 5 Gy of whole body gamma-radiation significantly reduced the frequencies of aberrant cells and chromosomal aberrations like acentric fragments, chromatid and chromosome breaks, centric rings, dicentrics and total aberrations at all post-irradiation scoring times (p < 0.01). The EAP showed a concentration dependent scavenging of hydroxyl, superoxide, 2,2′-diphenyl-1-picryl hydrazyl (DPPH) radicals and the 2,2-azino-bis-3-ethyl benzothiazoline-6-sulphonic acid (ABTS) cation radicals in vitro. EAP treatment also reduced lipid peroxidation in bone marrow cells in a concentration dependent manner.

Conclusion: Our study demonstrates that EAP protects mouse bone marrow cells against radiation-induced chromosomal aberrations and this reduction in radiation-induced chromosome damage may be due to free radical scavenging and reduction in lipid peroxidation. The radioprotection by EAP is best comparable to that of protection demonstrated by the grape fruit flavonone, naringin, in our earlier studies in mouse bone marrow cells.     

造血干细胞移植中预先全身照射对全身及造血系统的影响及并发症治疗

目的 探讨全身照射联合高剂量化疗对造血干细胞移植患者全身和造血系统影响的特点和治疗,为急性放射病的诊治提供临床经验。方法 回顾分析64例接受造血干细胞移植患者,系统观察急性照射及大剂量化疗后患者血液学改变及临床不良反应,并分析其骨髓重建特点。结果 移植相关病死率3.12%。移植后随访9～72个月 (中位随访时间26个月)。1、3、5年生存率分别为(95.8±3.3)%, (89.8±4.7)%和(81.7±6.9)%。全身照射联合高剂量化疗后,所有患者均出现了血液学不良反应,以白细胞及血小板下降最为明显,白细胞总数最低值为(0.18±0.13) ×10⁹个/L,血小板最低值为(14.48±8.85)×10⁹个/L;在造血干细胞支持及粒细胞集落刺激因子(G-CSF)应用后,均可恢复。此外患者不同程度出现消化道反应、感染、肝功能受损及出血等不良反应,经相关治疗后好转。结论以TBI联合高剂量化疗为预处理,随后进行造血干细胞移植,患者恶性血液系统疾病治疗效果好,并且其临床情况在一定程度上模拟了急性放射病的临床过程,为急性放射病的救治提供了一定的临床经验。     

富氢水减轻造血干祖细胞的辐射损伤

目的 探讨富氢水对辐射诱导的造血干祖细胞（HSPCs）损伤的保护作用。方法 32只C57BL/6小鼠根据体重分层随机区组法分为健康对照组、富氢水组、照射组、照射+富氢水组,共4组,每组8只。富氢水组和照射+富氢水组小鼠于照射前5 min至照后7 d,每天灌胃给予0.5 ml富氢水,其余小鼠每天灌胃给予0.5 ml蒸馏水,照射组和照射+富氢水组小鼠接受2 Gy的¹³⁷Cs γ射线全身照射。照后15 d取小鼠骨髓,检测骨髓中HSPCs比例、骨髓细胞的克隆形成和移植重建能力、骨髓中LSK细胞的活性氧（ROS）水平和细胞凋亡情况。结果 与照射组相比,照射+富氢水组小鼠骨髓中造血祖细胞和LSK细胞比例升高（t=-4.935、-7.898,P<0.05）,骨髓细胞形成克隆的数目增加（t=5.488,P<0.05）,竞争性骨髓移植后受体小鼠的供体嵌合率升高（t=-12.769,P<0.05）,骨髓中LSK细胞的ROS水平和细胞凋亡比例降低（t=4.380、3.954,P<0.05）。结论 富氢水对2 Gy电离辐射诱导的HSPCs损伤具有一定的保护作用。     

Sterilization of bone allografts by microwave and gamma radiation

Abstract

Purpose: Bone allografts are used to enhance healing in osteotomies, arthrodesis, fractures and to replace bone loss resulting from tumour or trauma. However, a major concern associated with the bone allografts is the potential for disease transmission. Various sterilization techniques have been developed to prevent infection through allografts. This study was undertaken with the aim of exploring the use of microwave radiation for sterilization of bone allografts and to compare with gamma radiation sterilization.

Materials and methods: Bone allografts were processed from femoral heads obtained from living donors. The effect of microwave and gamma radiation on the bacteria isolated from bone allograft was evaluated. The microwave radiation treatment was performed at 2450 MHz (frequency) for varying lengths of time at maximum power 900 Watts (W). Viability of three Gram-positive bacteria – Bacillus subtilis, Corynebacterium, Staphylococcus aureus and three Gram-negative bacteria – Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa was examined after irradiation of bacterial suspensions and contaminated processed bone allografts. The sterility test of microwave and gamma irradiated bone allograft was carried out in accordance with ISO (International Organization for Standardization) 11737-2.

Results: Microwave irradiation (2450 MHz and 900 W) of bacterial isolates resulted in complete inactivation within 60 seconds. The contaminated bone samples showed no growth of organisms after 2 minutes of exposure to microwave irradiation. No viable counts were detected in bone grafts inoculated with Gram-negative bacterial species on gamma irradiation to a dose of 15 kGy. Bones contaminated with Gram-positive bacteria required a higher dose of 20 kGy for complete inactivation.

Conclusions: The study shows that sterilization of contaminated femoral head bone allografts can be achieved by short exposure of 2 min to 2450 MHz and 900 W microwave radiation.     

The radiation protection and therapy effects of mesenchymal stem cells in mice with acute radiation injury

The aim of this study was to investigate the effects and mechanisms of mesenchymal stem cells (MSCs) on haematopoietic reconstitution in reducing bone marrow cell apoptosis effects in irradiated mice, and to research the safe and effective dosage of MSCs in mice with total body irradiation (TBI). After BALB/c mice were irradiated with 5.5 Gy cobalt-60 γ-rays, the following were observed: peripheral blood cell count, apoptosis rate, cell cycle, colony-forming unit-granulocyte macrophage (CFU-GM) and colony-forming unit-fibroblast (CFU-F) counts of bone marrow cells and pathological changes in the medulla. The survival of mice infused with three doses of MSCs after 8.0 Gy or 10 Gy TBI was examined. The blood cells recovered rapidly in the MSC groups. The apoptotic ratio of bone marrow cells in the control group was higher at 24 h after radiation. A lower ratio of G0/G1 cell cycle phases and a higher ratio of G2/M and S phases, as well as a greater number of haematopoietic islands and megalokaryocytes in the bone marrow, were observed in the MSC-treated groups. MSCs induced recovery of CFU-GM and CFU-GM and improved the survival of mice after 8 Gy TBI, but 1.5 × 10⁸ kg⁻¹ of MSCs increased mortality. These results indicate that MSCs protected and treated irradiated mice by inducing haematopoiesis and reducing apoptosis. MSCs may be a succedaneous or intensive method of haematopoietic stem cell transplantation under certain radiation dosages, and could provide a valuable strategy for acute radiation syndrome.Currently, substantial progress has been made in the treatment of acute radiation syndrome (ARS) [1–6]. The study of haematopoietic growth factors and haematopoietic stem cell transplantation (SCT) has already progressed to the molecular and genetic level [4, 7, 8]. However, there are still some problems associated with SCT for ARS, such as donor deficiency, a high mortality for conditioning and complications resulting from transplantation. Thus, some experts continue to question the effect of transplantation on ARS. It is known that the microenvironment in bone marrow plays a key role in haematopoietic recovery after irradiation injury. The haematopoietic stem cells (HSCs) and the microenvironment, in a pathological state, often damage and aggravate mutually [9]. Therefore, the treatment of both is indispensable in ARS. Mesenchymal stem cells (MSCs) are adherent cells capable of self renewal and multilineage differentiation [10]. In addition, MSCs can produce several essential haematopoietic growth factors, including interleukin (IL)-6, IL-11, leukemia inhibitor factor (LIF), stem cell factor (SCF), Flt3 ligand and stromal derived factor (SDF) [11]. The microenvironment in bone marrow consists of stroma cells derived from MSCs. Cytokine and extracellular matrices are important factors in HSC growth and multiplication [12]. Transplantation of MSCs is used for both autologous and allogeneic transplant [13, 14], but there are fewer reports on the radiation protection and therapy effects of MSCs on mice with acute radiation injury [15, 16]. The present study was undertaken to examine the effects of three dosages of MSCs on the survival of mice exposed to lethal doses of total body irradiation (TBI), and to explore the mechanisms by which MSCs significantly improve haematopoietic recovery. This was accomplished by observing peripheral blood counts, apoptosis, p53 expression, CFU-GM and CFU-F counts, the cell cycle of bone marrow cells, and pathological changes in variety of the medulla.     

Hematopoietic cell infusion for the treatment of nuclear disaster victims: new data from the Chernobyl accident

PURPOSE: To present previously unavailable data on the use of stem cell administration to aid recovery of victims of the Chernobyl disaster. On 26 April 1986, an accident at Unit 4 of the Chernobyl Nuclear Power Plant took place during the planned test of one of the safety systems. The diagnosis of acute radiation syndrome (ARS) was confirmed in 134 individuals exposed to high levels of radiation. There were nine patients heretofore unreported in the scientific literature who underwent intraosseous injections of allogeneic bone marrow cells in Kyiv. CONCLUSIONS: Transplantation was associated with significantly shortened time to recovery of granulocyte and platelet counts in these patients. While current guidelines would certainly include the use of cytokines, these data provide an indication of the effectiveness of stem cell transplant to treat victims of radiation exposure.     

Initial medical management of patients severely irradiated in the Tokai-mura criticality accident

A nuclear criticality accident occurred in Japan on September 30, 1999, which resulted in severe exposure of three victims to mixed flux of neutrons and gamma-rays. Estimated average doses for the three victims were 5.4 Gy of neutrons and 8.5 Gy of gamma-rays for Patient A, 2.9 Gy of neutrons and 4.5 Gy of gamma-rays for Patient B, and 0.81 Gy of neutrons and 1.3 Gy of gamma-rays for Patient C. They then suffered the consequences of the effects of ionizing radiation resulting in acute radiation syndrome. In Patients A and B, bone marrow failure was so severe that they received haematopoietic stem cell transplantation. The graft initially took successfully in both patients, although in Patient B it was later taken over by his own haematopoietic cells. They also suffered from severe skin lesions, later exhibited gastrointestinal bleeding and eventually died of multiple organ failure 82 and 210 days after the accident, respectively. The survival of these patients beyond the period of agranulocytosis means that bone marrow failure per se caused by exposure to ionizing radiation may now be overcome. Patient C also developed bone marrow failure and was treated with granulocyte colony-stimulating factor as well as supportive care. He recovered without major complications and is now under periodical follow-up. Remarkably, during the prodromal phase, all the patients exhibited hypoxaemia, two of whom also showed interstitial oedema of the lungs. In Patient C these manifestations improved within a week. The circumstances of the accident and the initial medical treatment of the victims are described.     

Lack of Acute Effects of 20 mT, 50 Hz Magnetic Fields on Murine Haemopoiesis

Summary

Some epidemiological studies have drawn attention to a possible association between exposure to extremely low-frequency (ELF) electromagnetic fields and the development of acute myeloid leukaemia (AML) in adults. At present there is no experimental evidence for such an association. We have investigated the acute effects of power frequency magnetic fields on haemopoiesis in CBA/H mice known to be susceptible to the induction of AML after exposure to ionizing radiation. Up to 19 days after exposure to 50 Hz fields at 20 mT for 7 days no significant effects on peripheral blood characteristics were observed. Assays of the bone marrow stem cells and myelomonocytic progenitor cells also failed to reveal significant effects. Our experiments cannot, however, rule out subtle effects on cell population dynamics, and further investigations, including longterm studies, are required to establish the extent to which ELF magnetic fields might affect the haemopoietic system.     

SPECT定义活性骨髓优化宫颈癌术后调强放疗计划的剂量学研究

目的 探讨单光子发射计算机断层扫描（SPECT）骨髓显像结合宫颈癌骨髓保护调强放疗计划的剂量学特点。方法 20例宫颈癌术后患者放疗前行⁹⁹Tc^m硫胶体SPECT骨髓显像确定盆骨中活性骨髓,采用图像融合技术将SPECT与定位CT融合。根据SPECT和盆骨外轮廓定义的骨髓体积,分别制定SPECT-IMRT（SPECT-intensity modulated radiotherapy）和骨髓剂量保护的调强放疗（bone marrow sparing-intensity modulated radiotherapy,BMS-IMRT）计划,比较两种计划的靶区和危及器官（骨髓、小肠、直肠和膀胱）剂量分布。靶区处方剂量45 Gy/25次。结果 SPECT-IMRT计划和BMS-IMRT计划定义的骨髓体积分别为（238.15±36.82）和（1 100.61±109.92）cm³（t=33.273,P<0.05）;SPECT-IMRT计划的骨髓高剂量辐射区V₃₀、V₄₀和V₄₅的平均体积较BMS-IMRT计划分别降低6.9%、5.7%和2.6%,差异有统计学意义（t=3.540、3.426、3.448,P<0.05）;而低剂量辐射区V₁₀和V₂₀的平均体积比较差异无统计学意义（P>0.05）;两种计划PTV的覆盖率和其他危及器官（膀胱、小肠和直肠）的受照剂量差异均无统计学意义（P>0.05）。结论 SPECT骨髓显像能较清晰地在CT断层图像上显示活性骨髓的范围。与BMS-IMRT比较,SPECT-IMRT能进一步降低高剂量辐射的剂量体积（V₃₀、V₄₀和V₄₅）。     

脐带血造血干细胞的“质”“量”研究

目的 对脐带血造血干细胞移植的“质”“量”作出评估，使其更广泛有效地应用于临床。 方法 利用免疫磁珠分离法、ＦＡＣＳ分析与分选、体外液体培养，铺展贴壁等方法对脐带血ＣＤ３４＾＋造血干、粗细胞及其的数量、体外增殖分化性能、生长因子扩增效应，植入成人骨髓基质效率等进行研究，数据经ｔ检验。结果 脐带血有核细胞、ＣＦＣｓ、ＣＤ３４＾＋细胞及其亚群等的绝对数量明显低于常规骨髓移植所需的细胞数量，但脐带血ＣＤ     

异基因外周血造血干细胞移植治疗极重度骨髓型和肠型急性放射病的临床报告

目的 探讨异基因外周血造血干细胞移植在肠型和极重度骨髓型放射病救治中的作用和地位.方法 山东"10·21" 60Co 辐射事故中2例病人受到意外照射,病例A受照射剂量20～25Gy,诊断为"肠型放射病",病例B受照射剂量9～15Gy,诊断为"极重度骨髓型放射病".经联合环磷酰胺、抗淋巴细胞球蛋白和氟达拉滨预处理,2例分别行HLA半相合及全相合外周血造血干细胞移植.采用环孢霉素A和骁悉方案(病例A加用CD25单抗和供者间充质干细胞)预防移植物抗宿主病(GVHD).结果 2例均移植成功,供体完全存活,移植后9～11天白细胞开始恢复,2周后白细胞恢复正常、骨髓造血重建成功.2例均未发生移植排斥和GVHD.病例A照射后33天死于败血症和多器官功能衰竭.病例B照射后75天死于心衰为主的多器官功能衰竭.结论 HLA相合及半相合外周血造血干细胞移植救治极重度骨髓型和肠型急性放射病是完全可能和可行的,联合免疫抑制剂预处理对促进供体稳定植入是必要的,环孢霉素A、骁悉和CD25单抗及供者间充质干细胞对预防GVHD有重要作用.     

中子辐射致骨髓损伤及治疗研究进展

中子相对生物效应较高,能对机体产生十分严重的损伤.骨髓是中子辐射高度敏感的器官,低剂量中子照射即可对骨髓造成严重的辐射损伤,产生骨髓型急性放射病,出现外周血血象改变、造血细胞和骨髓基质细胞损伤等一系列改变.中子辐射致骨髓损伤治疗的难度大,以综合对症治疗为基础,细胞因子的适时应用及对极重度中子骨髓型放射病则实施造血干细胞移植.