脐血间充质干细胞分离培养的理论研究与应用

目的:间充质干细胞具有多向分化潜能,在一定的实验条件控制下可分化为骨、软骨、肌肉、神经、肝和内皮等多种细胞,本文在于进一步综合分析脐血间充质干细胞的优化分离培养条件。资料来源:应用计算机检索Medline、PubMed数据库1980-01/2006-12期间有关脐血间充质干细胞分离培养的文献,检索词“mesenchymal stem cells,human umbilical cord blood(HUCB),isolation,culture”,并限定文章语言种类为English。同时计算机检索CNKI,万方数据库1990-01/2006-12期间相关文献,限定文章语言种类为中文,检索词“间充质干细胞,脐血,分离,培养”。并手工查阅相关书籍。资料选择:检索有关脐血间充质干细胞分离培养的综述和实验论据,参考综合各文献中脐血间充质干细胞培养的方法条件,选择比较典型和比较新颖的文献进行综合。资料提炼:共检索到79篇有关脐血间充质干细胞分离纯化、培养扩增的文献,纳入30篇。资料综合:国内外有大量的实验证实,间充质干细胞具有肯定的支持造血功能,而且在一定实验条件控制下可分化为骨、软骨、脂肪、肌腱、肌肉、神经、基质、肝、内皮等多种细胞。脐血来源间充质干细胞具有低免疫原性等很多优点已成为干细胞研究领域的热点,目前分离培养间充质干细胞的方法多样,日趋成熟,但仍存在许多不足,需进一步探索间充质干细胞的分离纯化技术。结论:目前已经建立了多种脐血间充质干细胞分离纯化培养扩增的方法,为其在细胞工程和组织工程的应用提供了基础。     

A point score system for predicting the likelihood of blood transfusion after hip or knee arthroplasty

BACKGROUND: Given the high cost of autologous blood donation for elective surgery, it would be desirable to predict which patients are most likely to benefit from the procedure. The purpose of this study was to develop a point score system for predicting the likelihood of blood transfusion in hip and knee arthroplasty. STUDY DESIGN AND METHODS: A database of 599 patients undergoing elective surgery at a teaching hospital was used for the analysis. Variables were analyzed to determine their univariate association with postoperative blood transfusion. Significant factors were entered into a multiple logistic regression model, and a point score system was developed on the basis of the regression coefficients. Four strata of transfusion risk were constructed. RESULTS: Factors independently associated with blood transfusion included preoperative hemoglobin, type of arthroplasty, primary versus revision surgery, autologous donor status, and patient weight. Four factors were used to create a point score system with four strata. The likelihood of blood transfusion for patients in the four risk strata was 1.7, 11.0, 40.0, and 78.3 percent. The calculated area under the receiver operating characteristic curve was 0.86. CONCLUSION: The likelihood of a postoperative blood transfusion can be predicted by using this simple point score system. Autologous blood donation can subsequently be targeted to the high-risk patients.     

Lack of detection of human immunodeficiency virus type 1 DNA by polymerase chain reaction in the plasma and lymphocytes of seronegative exposed hemophiliacs

Direct detection of human immunodeficiency virus type 1 (HIV-1) DNA in serum or plasma samples has been reported in seronegative as well as seropositive individuals. An alkaline lysis procedure was adapted for polymerase chain reaction (PCR) analysis of plasma specimens. Eighty- five seronegative hemophiliacs, 52 of whom had been exposed to HIV- contaminated blood components, and 19 seronegative at-risk individuals were studied. Each sample was extracted and amplified with SK38/39 gag primers at least three times. Seventy-six samples (72%) were consistently negative for HIV-1 DNA, 24 (22%) were positive only once, and 4 (3%) were positive twice. Genomic DNA from peripheral mononuclear cells was prepared from 12 of 76 negative samples, 18 of 24 samples that were positive once, and 2 of 4 samples that were positive twice and analyzed with both gag and long terminal repeat primers. None (0/32) of these cellular DNAs were positive for HIV-1, which suggests that these seronegative exposed hemophiliacs were not latently infected with HIV-1. In contrast, all (10/10) control cells from seropositive patients were positive with both primer pairs. The detection of HIV-1 DNA in serum or plasma may be prone to a high level of false-positive PCR signals and should be interpreted with caution.     

嗅鞘细胞修复脊髓损伤的实验室研究现状

目的:在成年哺乳动物中损伤的脊髓缺乏轴突再生能力,损伤平面以下运动、感觉、反射功能全部或部分永久丧失。在许多脊髓损伤的动物模型中,移植的嗅鞘细胞显示了促进轴突再生的能力。为此就嗅鞘细胞对脊髓损伤修复的实验室相关研究现状进行综述。资料来源:应用计算机检索Pubmed和Elsevier数据库和中国期刊网数据库1979-01/2006-05期间的相关文章,检索词为“olfactory ensheathing cell”,并限定文章语言种类为English和中文。资料选择:对资料进行初审,并查看每篇文献后的引文。纳入标准:文章所述内容应与嗅鞘细胞修复脊髓损伤的动物实验或临床研究相关。排除标准:重复研究或Meta分析类文章。资料提炼:共收集到50篇相关文献,30篇文献符合纳入标准,排除的20篇文献为内容陈旧或重复。符合纳入标准的30篇文献中,分别涉及嗅鞘细胞的生物学特点、嗅鞘细胞修复脊髓损伤的动物实验研究、嗅鞘细胞修复脊髓损伤的临床实验研究。资料综合:现代社会脊髓损伤的发生率逐渐升高,造成脊髓损伤平面以下机体功能永久性丧失,给患者、家庭和社会带来沉重的负担。嗅鞘细胞以其独特的生物学特性与在脊髓损伤动物模型中明确地促进轴突再生的作用为治疗脊髓损伤燃起新的希望。嗅鞘细胞属于神经胶质细胞,存在于鼻腔的嗅上皮、嗅神经和中枢神经系统的嗅球,兼有许旺细胞和星状胶质细胞的特性,研究发现有辅助轴突再生和改善神经功能的作用。嗅鞘细胞治疗脊髓损伤的临床试验也已展开,初步证实了移植的安全性、可行性和潜在的修复作用。结论:嗅鞘细胞移植能够促进损伤脊髓的轴突再生,但因其促进轴突再生的确切机制仍不甚明确,部分应用于临床的病例尚缺乏长期随访结果,故需要对嗅鞘细胞移植治疗脊髓损伤这一课题进行更深入的研究。     

Comparison of three different A1 adenosine receptor antagonists on infarct size and multiple cycle ischemic preconditioning in anesthetized dogs

A(1) adenosine receptor (AR) antagonists are effective diuretic agents that may be useful for treating fluid retention disorders including congestive heart failure. However, antagonism of A(1)ARs is potentially a concern when using these agents in patients with ischemic heart disease. To address this concern, the present study was designed to compare the actions of the A(1)AR antagonists CPX (1,3-dipropyl-8-cyclopentylxanthine), BG 9719 (1,3-dipropyl-8-[2-(5,6-epoxynorbornyl)]xanthine), and BG 9928 (1,3-dipropyl-8-[1-(4-propionate)-bicyclo-[2,2,2]octyl]xanthine) on acute myocardial ischemia/reperfusion injury and ischemic preconditioning (IPC) in an in vivo dog model of infarction. Barbital-anesthetized dogs were subjected to 60 min of left anterior descending coronary artery occlusion followed by 3 h of reperfusion, after which infarct size was assessed by staining with triphenyltetrazolium chloride. IPC was elicited by four 5-min occlusion/5-min reperfusion cycles produced 10 min before the 60-min occlusion. Multiple-cycle IPC produced a robust reduction ( approximately 65%) in infarct size; this effect of IPC on infarct size was not abrogated in dogs pretreated with any of the three AR antagonists. Surprisingly, in the absence of IPC, pretreatment with CPX or BG 9928 before occlusion or immediately before reperfusion resulted in significant reductions ( approximately 40-50%) in myocardial infarct size. However, treatment with an equivalent dose of BG 9719 had no similar effect. We conclude that the A(1)AR antagonists BG 9719, BG 9928, and CPX do not exacerbate cardiac injury and do not interfere with IPC induced by multiple ischemia/reperfusion cycles. We discuss the possibility that the cardioprotective actions of CPX and BG 9928 may be related to antagonism of A(2B)ARs.     

A Quest For the Relief of Atherosclerosis: Potential Role of Intrapulmonary Heparin--A Hypothesis

Recent progress in the treatment of coronary artery diseaseis reviewed from the standpoint of changes in lifestyle, surgicaltechniques to revascularize the myocardium and a variety ofmedical interventions. Among the medical modalities, heparinappears to have a greater potential than any other agent testedto neutralize the atherogenic process at most of its stages.This potential is supported by success in clinical trials ofheparin administered by intravenous, subcutaneous, pulmonary,sublingual and topical routes. The suggested self-administrationof low-dose heparin by inhalation appears to be well justifiedand easily adaptable to home therapy. The summarized evidencesuggests the need for further clinical trials to test the useof heparin in the prophylaxis of atherosclerotic disease.     

Multiple bilateral spinal nerve root calcifications in Charcot‐Marie‐Tooth disease

We present a patient with Charcot‐Marie‐Tooth disease with multiple bilateral symmetrical cervical nerve root calcifications. To our knowledge, such a finding has not been described in the literature in association with this disease. We propose that multiple bilateral symmetrical spinal nerve root calcifications may be an additional imaging feature, possibly diagnostic, in this hereditary motor and spinal neuropathy.     

Dental material artifacts on MR images

Magnetic resonance (MR) imaging of the head and neck is becoming an important aid in evaluating pathologic conditions of the brain, midface, and pharynx. Certain dental materials cause artifacts during MR imaging of the lower midface. These artifacts can obscure the normal anatomy. This study describes the degree of artifact production caused by various materials commonly used in dental restorations. Of the materials tested, those causing artifacts were made of stainless steel, such as orthodontic bands used for braces, and pins or posts that are commonly drilled into teeth to provide structure or stability before filling. Materials used as temporary or permanent fillings or crowns--such as amalgam, gold alloy, aluminum, microfilled resin, and polyvinyl acrylics--did not cause artifacts in the images.     

Improvement of diagnostic criteria in growth hormone insensitivity syndrome: solutions and pitfalls

A survey to identify children and adolescents with primary growth hormone insensitivity syndrome (GHIS) yielded 38 patients who were positively identified using a scoring system that included five criteria: height, basal growth hormone (GH), GH binding protein, basal insulin-like growth factor 1 (1GF-I) and the increase of IGF-I after 4 days of GH administration (IGF generation test). Because of an overlap of the accepted and excluded groups with respect to points scored, an attempt was made to improve the scoring system. The new criteria were: height below –3 SDS, basal GH 4 mU/I or above, GH binding below 10%, basal IGF-I and basal IGF binding protein-3 (IGFBP-3) below the 0.1 centile for age, an increase of IGF-I in the IGF generation test less than 15 μg/1, and the increase of IGFBP-3 less than 0.4 mg/1. With this scoring system, a clear separation between the accepted and the excluded groups was obtained. IGFBP-3 was included to give the GH-dependent parameters of the IGF system more weight and because the accuracy of IGFBP-3 in the IGF generation tests was greater than the accuracy of IGF-I, when the group of patients with GHIS was compared with a group of patients with GH deficiency. Unexpectedly, the IGF generation test was unable to segregate both cohorts completely. In the GHIS-positive group, a significant correlation was found between basal IGF-I or IGFBP-3 levels corrected for age (SDS) and height SDS ( r = 0.49, p < 0.002 and r = 0.61, p < 0.0001, respectively). There was also a significant correlation between the changes of IGF-I or IGFBP-3 in the IGF generation test and height SDS. That is, the patients with a slight response to GH were those with the least growth retardation, suggesting the existence of partial GH insensitivity.     

Generation of CD4+ cytotoxic T-lymphocyte clones from a patient with severe graft-versus-host disease after allogeneic bone marrow transplantation: implications for graft-versus-leukemia reactivity

HLA-identical bone marrow transplantation (BMT) is associated with both graft-versus-host disease (GVHD) and graft-versus-leukemia (GVL) reactivity. Different T-cell subsets from the bone marrow (BM) graft may be responsible for GVHD and GVL reactivity after BMT. In the etiology of GVHD, not only CD8+ but also CD4+ donor T lymphocytes may play an important role. Here we report a patient with chronic myeloid leukemia (CML) who was transplanted with the BM from his HLA- genotypically identical sister. After BMT there was complete engraftment, but the patient died because of acute GVHD grade III-IV in complete remission. Cytotoxic T-lymphocyte (CTL) lines were generated after BMT using the irradiated leukemic cells from the patient as stimulator cells and the donor-originated peripheral blood mononuclear cells, procured from the patient after BMT, as responder cells. The generated CTL lines showed specific lysis of the recipient lymphocytes and leukemic cells in a 51Cr release assay. Two types of CTL clones could be established from these CTL lines, both phenotypically CD4+. Clone type I showed male-specific HLA-DQ5-restricted lysis of the recipient lymphocytes, but not of the circulating relatively mature leukemic cells from the patient. This may be explained by the low HLA- DQ5 expression of the more mature CML cells. Clone type II showed HLA- DR2-restricted minor histocompatibility antigen-specific lysis of the recipient lymphocytes and leukemic cells. Both types of CTL clones showed antigen-specific cell-mediated growth inhibition of the recipient clonogenic leukemic precursor cells. These CD4+ CTL clones produced several activating cytokines including tumor necrosis factor alpha, interferon gamma, granulocyte-macrophage colony-stimulating factor (GM-CSF), and macrophage CSF. Our results illustrate that these CD4+ CTL clones may have induced GVHD directly by cytolysis and indirectly by activating cytokines. Because both types of CTL clones recognized the recipient leukemic progenitor cells, they may also contribute to GVL reactivity after BMT.