Bacterial contamination of bone marrow grafts intended for autologous and allogeneic bone marrow transplantation. Incidence and clinical significance

In a series of 100 bone marrow harvests, the incidence of bacterial contamination of the bone marrow graft was 17 percent. Ex vivo manipulation of some of the grafts prior to infusion may have caused additional bacterial contamination. All isolated bacteria were common skin flora, and no serious sequelae were observed in the patients receiving the culture-positive bone marrow grafts. Samples of harvested bone marrows purposely contaminated with an isolate of Staphylococcus epidermidis demonstrated a bactericidal property that was maximal early after bone marrow collection. Bone marrow collection and ex vivo manipulation may result in considerable bacterial contamination. Procedures must be developed to assure that marrow collection and processing do not result in clinically significant contamination.     

Rescue by peripheral blood mononuclear cells in dogs from bone marrow failure after total-body irradiation

In order to determine the minimum dose of buffy coat cells necessary to achieve hematopoietic rescue following supralethal irradiation, mongrel dogs under general anesthesia were subjected to leukacytapheresis using three different techniques of cell separation. The buffy coats were frozen with dimethylsulfoxide and stored at -196 degrees C until transfused. Sixteen dogs were irradiated with 800 rads and were supported with antibiotics and transfusions of irradiated homologous blood. They were transfused with the frozen and thawed buffy coat cells, and, if they survived, they were followed for 100 days, sacrificed, and their tissues studied. The mean yield of mononuclear cells during leukocytapheresis ranged from 4.1 +/- 2.0 X 10(9) (mean +/- SD) to 6.0 +/- 4.0 X 10(9) for the three leukacytapheresis methods; one technique was not as satisfactory as the other two. Six of the 16 dogs fully recovered with evidence of marrow rescue; however, only one had a dose of mononuclear cells less than 11.1 X 10(9). These data indicate that seven to 17 leukacytapheresis procedures would be required to reconstitute a 70 kilogram patient. These preliminary findings suggest that, because the yields of transplantable cells with current technology are not adequate, the transplantation potential of buffy coat cells exposed to mobilizing agents should be evaluated.     

Bone marrow processing with the Fresenius AS 104: initial results.

Prior to purging, cryopreservation, or ABO-incompatible bone marrow (BM) transplantation, we have concentrated 23 BM harvests using a modification of the "grancollect-protocol" and the recently available bone marrow stem cell (BMSC) protocol of the Fresenius AS 104 cell separator with the P1-Y set. Within 40-70 minutes, the initial marrow volume of 922 ml (+/- 408 ml) was processed two to three times. A mean of 59% (+/- 20%) of the initial mononuclear cells was recovered in a mean volume of 119 ml (+/- 31 ml). The recovery of clonogenic cells, measured by CFU-GM assays, was 98% (+/- 80%). Red blood cells in the BM concentrates were reduced to 8% (+/- 4%) of the initial number. The procedure was efficient and yielded a BM cell fraction suitable for purging, cryopreservation, and transplantation. All transplanted patients showed fast and sustained engraftments after autologous or allogeneic BM transplantation.     

阵发性睡眠性血红蛋白尿症患者骨髓CD34+CD59+细胞的体外扩增

目的研究阵发性睡眠性血红蛋白尿症(PNH)患者CD34+CD59+细胞的分离、纯化及其体外扩增的条件和性能,为探索PNH新的治疗途径提供实验依据.方法利用免疫磁珠-流式细胞仪二步分选法,从PNH患者骨髓中分选出CD34+CD59+细胞,然后对CD34+CD59+细胞在不同造血生长因子组合条件下,进行体外扩增培养2周.结果体外扩增的最适宜的生长因子组合为SCF+IL-3+IL-6+FL+Tpo+Epo,最适宜的扩增时机为第7天,在此条件下,CD34+CD59+细胞的扩增倍数为22.42±3.73倍.CD34+CD59+细胞在扩增以后,仍保持较好的形成集落形成单位的能力,但是其向多系分化的潜能有所下降.结论 PNH患者CD34+CD59+细胞能够进行体外扩增.按照最佳扩增条件,在对PNH患者进行自体骨髓移植或自体外周血干细胞移植时有一定的应用价值.     

Use of a licensed electrolyte solution as an alternative to tissue culture medium for bone marrow collection

Bone marrow for transplantation is traditionally collected into tissue culture medium with heparin. A licensed electrolyte solution (Plasma- Lyte A [PLA]) was used as a substitute for tissue culture medium in the harvesting of 28 bone marrows, 17 autologous and 11 allogeneic, which were subsequently transplanted. Data that were analyzed from the 25 evaluable patients consisted of the numbers of cells and colony-forming units in the transplanted marrow as well as the time to neutrophil and platelet engraftment. These results were compared with those in the 30 (26 evaluable) preceding transplanted marrows that were collected into a tissue culture medium (RPMI-1640 [RPMI]). The autologous marrow transplant patients in both the PLA and RPMI groups reached a neutrophil count of > or = 0.5 × 10(9) per L a mean of 19 days following transplantation. The patients who underwent transplantation with allogeneic bone marrow collected in RPMI achieved > or = 0.5 × 10(9) per L of neutrophils an average of 20 days following transplantation, while those who received marrow collected in PLA achieved engraftment of neutrophils to that level in a mean of 21 days. Because in vitro and in vivo results with RPMI and PLA are similar in this study, further work using a licensed solution for clinical bone marrow transplantation is indicated.     

Cryopreservation of hematopoietic progenitor cells collected by hemapheresis

Colony-forming units-granulocyte/monocyte (CFU-GM) harvested from normal donors as a byproduct of plateletapheresis can be cryopreserved successfully with 10 percent dimethyl sulfoxide with the use of standard protocols that have been developed for freezing bone marrow. Short-term storage of CFU-GM in polypropylene vials in the liquid phase of liquid nitrogen yielded a recovery rate of 88 +/- 5 percent (mean +/- SEM). Significant loss of committed progenitor cells was not detected until 1 year after freezing (65 +/- 5%). A comparison of CFU-GM recovery with the polyolefin bag technique (107 +/- 13%) was not statistically different from that obtained with polypropylene vials (78 +/- 7%). Although the freezing bags are more expensive and prone to fracture than the vials, they are easier to handle, store, and thaw in the laboratory, and reinfusion to the patient is more convenient. Cryopreservation of CFU-GM harvested from peripheral blood appears feasible in either of two freezing systems.     

Experience with autologous bone marrow harvesting and transfusion of marrow-derived red cells

Marrow red cells (MRBCs) from 56 autologous bone marrow harvests were rescued after processing and transfused as the sole transfusion support after surgery. There was no correlation between volume of harvest and total mononuclear cell (MNC) count. The marrow collection induced a significant decrease in hematocrit values (mean, 6.1; range, -0.3-12.3; p less than 0.001) unrelated to the patient's diagnosis, age, or gender. Processing of the marrows resulted in a mean transfused MRBC mass of 258 mL (range, 101-494 mL), representing 78 percent (range, 43-100%) of the MRBC mass collected. The amount of MRBCs transfused correlated with total MNC count (p less than 0.01). All autologous MRBC transfusions were well tolerated. It can be concluded that autologous MRBC transfusions are safe and may eliminate the need for homologous blood transfusions after marrow harvest.     

Clinical scale expansion of cryopreserved small volume whole bone marrow aspirates produces sufficient cells for clinical use.

Ex vivo expansion of bone marrow (BM) mononuclear cells (MNC) in a perfused culture system produces stem-progenitor cell type(s) in sufficient number(s) for hematopoietic reconstitution. The limitations in using fresh BM MNC for ex vivo expansion include additional cell processing and inflexibility in patient treatment. Cryopreservation of whole bone marrow (WBM) eliminates processing costs of MNC or CD34+ cell selection and allows for flexibility in patient treatment. We developed a convenient system to cryopreserve and thaw small volume WBM aspirations (n = 13) and then compared the expandability of unprocessed normal cryopreserved/thawed (C/T) WBM to that of fresh BM MNC cultured in the presence of erythropoietin, PIXY 321, and Flt3-ligand. Ex vivo expansion potential was retained in WBM aspirates after C/T. When initiated with 225 million viable nucleated cells, clinical scale expansion cultures (n = 6) yielded 9.7+/-2.8 x 10(8) total cells, which contained 10.4+/-5.8 x 10(6) colony-forming units-granulocyte-macrophage (CFU-GM), 1.3+/-1.4 x 10(4) LTCIC, and 2.2 x 10(6) CD34+Lin- cells, sufficient cell numbers for clinical use. These studies demonstrate that ex vivo perfusion culture expansion of unfractionated C/T WBM (< or =30 ml) provides doses of stem-progenitor cells similar in composition to expanded fresh BM MNC, previously demonstrated to achieve hematopoietic reconstitution.     

Direct immunomagnetic method for CD34+ cell selection from cryopreserved cord blood grafts for ex vivo expansion protocols

BACKGROUND: Cord blood is a useful source of HPCs for allogeneic transplantation. HPC ex vivo expansion of a cord blood graft has been proposed as a way to increase the speed of engraftment and thus to reduce the occurrence of transplantation-related complications. OBJECTIVE: The purpose of this study was to optimize a method for CD34+ cell selection of thawed cord blood grafts under clinical grade conditions, intended for application in a static, serum-free expansion culture. MATERIAL AND METHODS: Twelve samples were thawed and washed with dextran, albumin, and rHu-deoxyribo-nuclease I (RHu-DNase) to avoid clumping. CD34+ cells were selected by using a sensitized immunomagnetic bead and 9C5 MoAb complex. A buffer containing rHu-DNase, citrate, albumin, and immunoglobulin in PBS was used during the procedure. CD34+ cells were eluted and detached by using an immunomagnetic cell selection device. Cells from the enriched fraction were cultured for 6 days in serum-free medium supplemented with rHu-SCF, rHu-IL-3, rHu fetal liver tyrosine kinase 3 ligand, and rHu thrombopoietin (50 ng/mL each). Cells were expanded in well plates and in two semipermeable bags. RESULTS: A mean of 1.94 x 10(6) (+/- 1.55) CD34+ cells was obtained, yielding a CD34+ cell recovery of 52 +/- 12 percent. Nonspecific loss of CD34+ cells was 32 +/- 10 percent. CFU-GM and BFU-E/CFU-Mixed recoveries were 33 +/- 15 percent and 27 +/- 12 percent, respectively. CD34+ cells obtained were functionally comparable with fresh CD34+ cells selected for clonogenic potential. The capacity for expansion was not significantly different in the two types of bags studied. HPCs in wells were expanded 33 +/- 14-fold for CD34+ cells and 42 +/- 19-fold for overall colonies. The expansion rates observed in wells were significantly superior to those obtained in bags. CONCLUSION: The feasibility of a clinical-scale cord blood selection procedure based on a direct immunomagnetic method after thawing, followed by an ex vivo expansion culture using semipermeable bags, is shown. After 6 days of expansion, it was possible to generate a 9-fold increase in CD34+ cells, a 6-fold increase in CFU-GM and a 13-fold increase in BFU-E/CFU-Mixed colonies.     

Reinjection of ex vivo-expanded primate bone marrow mononuclear cells strongly reduces radiation-induced aplasia

To assess the therapeutic efficacy of ex vivo-expanded hematopoietic cells in the treatment of radiation-induced pancytopenia, we have set up a non-human primate model. Two ex vivo expansion protocols for bone marrow mononuclear cells (BMMNC) were studied. The first consisted of a 7-day culture in the presence of stem cell factor (SCF), Flt3-ligand, thrombopoietin (TPO), interleukin-3 (IL-3), and IL-6, which induced preferentially the expansion of immature hematopoietic cells [3.1 +/- 1.4, 10.0 +/- 5.1, 2.2 +/- 1.9, and 1.0 +/- 0.3-fold expansion for mononuclear cells (MNC), colony-forming units-granulocyte-macrophage (CFU-GM), burst-forming units erythroid (BFU-E), and long-term culture initiating cells (LTC-IC) respectively]. The second was with the same cytokine combination supplemented with granulocyte colony-stimulating factor (G-CSF) with an increased duration of culture up to 14 days and induced mainly the production of mature hematopoietic cells (17.2 +/- 11.7-fold expansion for MNC and no detectable BFU-E and LTC-IC), although expansion of CFU-GM (13.7 +/- 18.8-fold) and CD34+ cells (5.2 +/- 1.4-fold) was also observed. Results showed the presence of mesenchymal stem cells and cells from the lymphoid and the megakaryocytic lineages in 7-day expanded BMMNC. To test the ability of ex vivo-expanded cells to sustain hematopoietic recovery after radiation-induced aplasia, non-human primates were irradiated at a supralethal dose of 8 Gy and received the product of either 7-day (24 h after irradiation) or 14-day (8 days after irradiation) expanded BMMNC. Results showed that the 7-day ex vivo-expanded BMMNC shortened the period and the severity of pancytopenia and improved hematopoietic recovery, while the 14 day ex vivo-expanded BMMNC mainly produced a transfusion-like effect during 8 days, followed by hematopoietic recovery. These results suggest that ex vivo expanded BMMNC during 7 days may be highly efficient in the treatment of radiation-induced aplasia.     

小鼠骨髓细胞体外扩增及其造血重建的研究

目的：观察干细胞因子（ＳＣＦ）与白细胞介素（ＩＬ）－１或ＩＬ－３联合对经５氟尿嘧啶（５ＦＵ）处理的骨髓细胞的体外扩增作用和体外扩增细胞移植的小鼠造血恢复能力。方法：在含有细胞因子的液体培养体系中培养５ＦＵ处理的骨髓细胞，观察粒－巨噬细胞集落形成单位（ＣＦＵ－ＧＭ）和高增殖潜能集落形成细胞（ＨＰＰ－ＣＦＣ）数量的增加以及移植扩增细胞的小鼠外周血细胞恢复。结果：单用ＳＣＦ无扩增作用，但ＳＣＦ与ＩＬ－１或ＩＬ－３联合时，与对照组相比较ＣＦＵ－ＧＭ分别增加３３．７±１８．１倍和１８．１±６．３倍。ＨＰＰ－ＣＦＣ分别扩增１７．８±１０．５倍和１２．７±９．１倍。移植体外扩增细胞组与对照组比较，外周血细胞恢复时间缩短１～３天，并且生存率也显著提高。结论：在液体培养体系中ＳＣＦ与ＩＬ－１或ＩＬ－３联合对造血细胞扩增有协同作用，并且体外扩增后的骨髓细胞能加速移植受体的早期造血重建。     

自体骨髓单个核细胞移植治疗慢性下肢缺血性疾病的临床研究

目的观察自体骨髓单个核细胞移植对慢性下肢缺血性疾病的治疗效果。方法选取2008年10月~2010年10月期间本院收治的慢性下肢缺血性疾病患者13例,通过采集患者自体骨髓,密度离心法分离骨髓单个核细胞,多点注射至患肢局部,2月后观察患肢疼痛、冰冷、麻木、间歇性跛行等主观指标改善情况及经皮氧分压,踝肱指数,溃疡面积等客观指标改善情况。结果 13例患者均顺利完成了移植手术,2月后评价,患肢疼痛的改善率为87.5%,冰冷感的改善率为86.4%,麻木的改善率为72.2%,间歇性跛行的改善率为66.7%,经皮氧分压移植前为(20.9±4.4)mmHg,移植2月后为(36.8±7.5)mmHg,改善率为87.5%,踝肱指数移植前为0.34±0.14,移植2月后为0.57±0.17,改善率为83.3%,溃疡改善率为80%。结论 自体骨髓单个核细胞移植治疗慢性下肢缺血性疾病是安全和有效的。     

甲基纤维素体外分离骨髓移植物中红细胞的效果

“ABO”血型不合的骨髓移植和一部分自体骨髓移植 ,需分离骨髓移植物中的红细胞。本研究观察了用甲基纤维素分离移植物中红细胞的效果。用生理盐水配制的 0 .5 %甲基纤维素 (MC)与采集的骨髓移植物按一定比例混匀 ,静置 ,然后沉降红细胞。对 1 8份骨髓移植物分离的结果显示 ,单个核细胞和CD34+ 细胞回收率分别达(83 .8± 5 .2 ) %和 (90 .3± 7.2 ) % ,CFU GM产率为 (60 .8± 2 2 .4) / 2× 1 0 5个单个核细胞 ;红细胞残留率仅为 (4.3±1 5) %。结论 :此方法可用于骨髓移植     

基质细胞对体外扩增造血细胞造血重建活性的促进作用

本研究探讨骨髓单个核细胞(13MMNC)在不同的培养条件下扩增后是否具有造血重建的活性。在小鼠BMMNC液体培养体系中，分别在含有几种细胞因子组合和(或)基质细胞层存在的条件下进行体外扩增，然后将不同条件下扩增的细胞经尾静脉回输至经致死量照射的小鼠体内，动态观察小鼠的骨髓有核细胞数及各种祖细胞集落数，以观察其造血重建的效果。结果表明：单纯细胞因子介导BMMNC体外扩增后并不能增进这些细胞的造血重建功能，但含有骨髓基质细胞底层的体外扩增，无论是否加入细胞因子，均有明显的促进移植受体造血功能重建的作用。结论：骨髓基质细胞支持下体外扩增的造血细胞具有促进移植受者造血重建的功能。证实了在维持体外扩增造血细胞的移植活性中，基质细胞具有非常重要的作用。     

糖基化磷脂酰肌醇特异性磷脂酶D(GPI-PLD)对髓性白血病骨髓细胞黏附功能的影响及机制探讨

为了探讨糖基化磷脂酰肌醇特异性磷脂酶D(GPIPLD)对髓性白血病骨髓单个核细胞黏附功能的影响及其机制,利用具有完整糖基化磷脂酰肌醇(GPI)结构的胎盘碱性磷酸酶(PLAP)做底物,通过TX114分相,定量检测骨髓单个核细胞中GPIPLD活性,用1,10二氮杂菲抑制GPIPLD的活性,用MTT方法检测抑制组和非抑制组骨髓细胞对纤连蛋白的黏附率,用免疫组织化学方法检测GPI锚定蛋白CD24的表达。结果显示:1,10二氮杂菲(1mmol/L)作用骨髓单个核细胞5小时可使细胞的GPIPLD的活性由(42.08±7.21)%降为(5.4±2.96)%,GPIPLD活性被抑制后细胞的黏附率增加,由(49.78±26.73)%升为(61.19±29.14)%,与此同时,CD24的表达率上调,由(16.02±9.68)%升为(18.5±11.14)%。结论:降低GPIPLD活性能增加骨髓单个核细胞对纤连蛋白的黏附率,与此同时,骨髓单个核细胞上GPI锚定蛋白CD24的表达增强。     

Flow cytometric analysis of proliferative characteristics of human leukemic cells in bone marrows in vivo using bromodeoxyuridine (BrdU) and its monoclonal antibody]

We developed a new method for analyzing the proliferative characteristics of human acute leukemic cells in bone marrows in vivo using BrdU and its monoclonal antibody. The thirty minutes after a bolus BrdU infusion, a 1st bone marrow aspiration (BMP) was performed to calculate BrdU-LI. Then, a 150-minute continuous infusion of BrdU was started. After the infusion, a 2nd BMP was done to calculate the increasing rate of the BrdU-LI for 3 hours. Each of the bone marrow cells was analyzed by FCM. A mean value of 10.4% for BrdU-LI in 22 previously untreated patients was obtained. In 3 of the patients, Ts and Tpot ranged from 13.5 to 33.9 hours and 6.8 to 10.7 days respectively.     

成人慢性髓性白血病骨髓细胞血管内皮生长因子的表达

血管生成出现于实体瘤生长的早期,抗血管生成可能成为治疗实体瘤的一个新的策略。血管内皮生长因子（vascular endothelial growth factor,VEGF）是人类实体瘤中主要的促血管生成细胞因子之一,其在慢性髓性白血病（chronic myelogenous leukemia,CML）病程进展中是否呈现过度表达尚不清楚。为此,本研究采用RT-PCR和ELISA方法对CML病人骨髓细胞及血浆VEGF的表达进行了研究。结果表明,多数CML细胞、白血病细胞系及正常人骨髓细胞均表达VEGF,CML病人VEGF mRNA检测阳性率（93.1%)高于骨髓移植后的CML病人（50%）及正常人（60%）;未治CML病人血浆VEGF浓度（380.6pg/ml）比CML骨髓移植后病人血浆的VEGF浓度（38.0%pg/ml)高9倍;未治CML骨髓细胞分泌的VEGF（499.8pg/ml)比正常人骨髓细胞分泌的（141.3pg/ml)多2.5倍,两之间有显性差异（P＜0.05)。研究结果说明VEGF在CML病人中确实存在过度表达,其在CML发病机制中的作用值得进一步深入研究。     

Processing of major ABO-incompatible bone marrow for transplantation by using dextran sedimentation

BACKGROUND: Various open and semi-closed methods are used for red cell (RBC) depletion and hematopoietic progenitor cell (HPC) enrichment of bone marrow (BM) in vitro, but with variable efficacy. A simple, efficient, and safe method using dextran 110k was developed. STUDY DESIGN AND METHODS: An equal volume of 4.5-percent dextran was applied to major ABO-incompatible BM in transfer bags and sedimentation was allowed for 30 minutes. RBCs, nucleated cells (NCs), and mononuclear cells (MNCs) from BM allografts before and after dextran sedimentation (DS) were counted. Flow cytometry, short-term cultures, and long-term cultures were performed to assay the respective recovery of CD34+ cells, colony-forming units (CFUs), and long-term culture-initiating cells (LTC-ICs). RESULTS: Sixteen BM collections were processed.The mean volume was 666 mL (range, 189-1355 mL).The mean +/-1 SD post-DS NC, MNC, CD34+ cell, and CFU counts per kg of the recipient's body weight were 4.11 +/-1.74 x 10(8), 8.98 +/- 3.68 x 10(7), 2.90 +/- 1.95 x 10(6), and 2.03 +/- 2.01 x 10(5), respectively, with the corresponding post-DS recovery being 90.6 percent, 90 percent, 92.4 percent, and 100.8 percent. The numbers of LTC-ICs in cultures (up to 12 weeks) of pre-DS and post-DS samples of five BM allografts were comparable (p = 0.91). Residual RBCs were 5.1 +/- 4.6 (0.1-14) mL with depletion of 96.5 +/- 3.2 percent. There was no significant difference in the mean absolute RBC count in post-DS BM allografts and in four ficoll-treated BM allografts (8.09 x 10(10) vs. 4.9 x 10(9); p = 0.206) and in eight major ABO-incompatible peripheral blood HPC collections (8.09 x 10(10) vs. 9.81 x 10(10); p = 0.87). No posttransplant hemolysis was encountered. Engraftment occurred at 22 +/- 7 days, which is similar to that of four transplants with ficoll-treated BM allografts (22 +/- 9; p = 0.611) and 54 unprocessed BM allografts (19 +/- 6; p = 0.129). CONCLUSION: DS is an efficient method of depleting RBCs in major ABO-incompatible BM allografts without significant loss of HPCs.     

Isolation of monocytes from leukapheretic products for large-scale GMP-grade generation of cytomegalovirus-specific T-cell lines by means of an automated elutriation device

BACKGROUND: Dendritic cells (DC) act as antigen-presenting cells in immune response-mediated mechanisms against malignant cells and/or viral or fungal pathogens. CD14+ monocytes have been so far isolated by techniques of plastic adherence or by using immunomagnetic methods. Here the effectiveness of a commercially available cell separation system (Elutra, Gambro BCT) in the separation of monocytes and the large-scale production of cytomegalovirus (CMV)-specific T-cell lines were investigated. STUDY DESIGN AND METHODS: Six mononuclear cell (MNC) collections were processed with the Elutra system. Monocyte-enriched fraction was differentiated into DCs by addition of granulocyte-macrophage-colony-stimulating factor and interleukin (IL)-4. After 6 days of culture, DCs were matured in the presence of interferon (IFN)-gamma, IFN-alpha, IL-1beta, tumor necrosis factor-alpha, and poly(I:C) and pulsed with a pool of 48 MHC Class I and II-binding CMV peptides. Lymphocytes were then stimulated with mature autologous CMV peptide-pulsed DCs. RESULTS: After elutriation, the mean monocyte yield was 0.89 x 10(9) +/- 0.65 x 10(9), with a 51.0 +/- 31.6 percent recovery and a 51.1 +/- 35.4 percent purity. A significant correlation was observed when basal monocyte content was related to the postelutriation recovery (p < 0.0116). More than 60 percent of plated monocytes were differentiated into DCs, which after pulsing with CMV peptides, were able to stimulate a robust enrichment in CMV antigen-specific T cells in all tested samples (mean percentage of pentamer-positive CD8+ cells, 35% compared to the initial 2%). CONCLUSION: Our findings might be helpful for an appropriate MNC collection, to maximize the efficiency of the elutriation system and subsequently obtain an optimal monocyte-enriched yield for further DC generation and T-cell stimulation.     

Measurement of tumour protein synthesis in vivo in human colorectal and breast cancer and its variability in separate biopsies from the same tumour.

1. A method is described for measuring the rates of protein synthesis in vivo in human colorectal and breast tumours by the intravenous injection of L-[1-13C]leucine as a 'flooding dose'. 2. The incorporation of isotope into colorectal tumour protein was measured in six patients, whose tumours were biopsied after the injection. Fractional rates of protein synthesis were calculated from the enrichment of leucine in protein and the average free leucine enrichment in plasma. The range of rates obtained was 17.2-33.9%/day, with a mean rate (+/- SEM) of 22.5 +/- 2.6%/day. 3. Tumour protein synthesis rates were also measured in 15 patients with breast cancer. The range of rates obtained was 5.3-15.9%/day, with a mean rate (+/- SEM) of 10.3 +/- 0.8%/day. These rates are significantly lower than those obtained with colorectal tumours (P less than 0.001). 4. In 9 of the breast cancer patients, protein synthesis was measured in multiple random biopsies taken from the same tumour. The mean (+/- SEM) difference between the highest and lowest rates in biopsies from the same tumour was only 1.1 +/- 0.3%/day. Only 13% of the variation in protein synthesis between separate tumours could be explained by sampling error because of variation within the tumour itself, the remainder being genuine variation between individual tumours.