Segmental Liver Transplantation from Non-Heart Beating Donors—An Early Experience with Implications for the Future

We report our experience of pediatric liver transplantation with partial grafts from non-heart beating donors (NHBD). Controlled donors less than 40 years of age with a warm ischemia time (WI) of less than 30 min were considered for pediatric recipients. Death was declared 5 min after asystole. A super-rapid recovery technique with aortic and portal perfusion was utilized. Mean donor age was 29 years and WI 14.6 min (range 11–18). Seven children, mean age 4.9 years (0.7–11), median weight 20 kg (8.4–53) received NHBD segmental liver grafts. Diagnoses included seronegative hepatitis, neonatal sclerosing cholangitis, familial intrahepatic cholestasis, hepatoblastoma, primary hyperoxaluria and factor VII deficiency (n = 2).The grafts included four reduced and one split left lateral segments, one left lobe and one right auxiliary graft. Mean cold ischemia was 7.3 h (6.2–8.8). Complications included one pleural effusion and one biliary collection drained percutaneously. At 20 months (10–36) follow-up all children are alive and well with functioning grafts.
Donation after cardiac death is a significant source of liver grafts for adults and children with careful donor selection and short cold ischemic times.     

深低温冷冻肌腱细胞活性的研究

目的研究深低温冷冻方法对肌腱细胞活性的影响,比较程序性降温和普通深低温冷冻法对腱细胞活性的影响.方法纯种SD大鼠24只（出生21 d）,随机分为3组,取双侧跟腱.新鲜肌腱对照组（A）,常规深低温冷冻组（B）,程序性降温深低温冷冻组（C）.采用相同的方法对3组肌腱细胞进行细胞培养.相差显微镜观察原代和传代后细胞的生长,绘制细胞的生长曲线,考察细胞的活性;对细胞进行成纤维细胞染色、胶原染色和对细胞进行形态观察（扫描电镜）;水解法定量分析细胞培养基中羟脯氨酸浓度的变化,检测细胞合成胶原的能力.结果原代细胞培养时A组细胞的生长速度快于B组和C组（P＜0.01）,C组细胞的生长速度快于B组（P＜0.01）,这种生长速度的差异在细胞传代后消失.细胞的形态学和组织学符合成纤维细胞形态.3组细胞培养基中羟脯氨酸浓度变化的差异无统计意义（P＞0.05）.结论经深低温冷冻处理的肌腱中仍存在具有活性的腱细胞,但数量显著少于新鲜肌腱中活细胞的数量.应用计算机控制程序性慢速降温方法处理的肌腱其活细胞的数量有所提高,但仍低于新鲜肌腱中活细胞的数量.     

Cigarette smoke toxicants alter growth and survival of cultured mammalian cells.

Our purpose was to determine the effects of six cigarette toxicants (pyridine, nicotine, 2-ethylpyridine, 3-ethylpyridine, p-cresol, and pyrazine) on three types of cultured mammalian cells (human umbilical vein endothelial cells [HUVECs], human microvascular endothelial cells [HMVECs], and NIH 3T3 cells) using a cell proliferation/survival assay. Synchronized cells were cultured in proliferation or survival medium containing various doses (10(-18)M-10(-2)M) of the tested chemicals. After 48 h, cells were counted using a hemacytometer. The no observable adverse effect level (NOAEL), lowest observable adverse effect level (LOAEL), and the efficacy were determined for each compound in the cell proliferation and survival assays. Pyridine and p-cresol did not show significant effects with any cell types, except at high doses. Derivitization of the pyridine ring altered its potency, especially when an ethyl group or nitrogen was added. In survival medium, nicotine stimulated proliferation of all three cell types at doses found in smoker's serum (10(-8)M-10(-7)M). For HUVEC and HMVEC, 2-ethylpyridine, 3-ethylpyridine, and pyrazine inhibited proliferation in proliferation medium and induced cell death in survival medium at attomolar and femtomolar doses. All chemicals, except pyridine and pyrazine, stimulated NIH 3T3 cell proliferation at low doses and induced cell death at high doses. LOAELs and efficacies revealed that endothelial cells from a developing organ (umbilical cord) were more sensitive to these chemicals than endothelial cells from an adult organ (lung). 3-Ethylpyridine and pyrazine, which induced cell death at low doses, are added to consumer products and should be subjected to further toxicological testing.     

氯胺酮对体外培养大鼠神经干细胞增殖与凋亡的影响

目的探讨氯胺酮对体外培养夫鼠神经干细胞(NSC)增殖与凋亡的影响。方法采用无血清培养和单细胞克隆技术,在大鼠海马分离培养具有单细胞克隆能力的细胞群,采用免疫荧光细胞化学技术证实为NSC。将NSC以5×10~4/孔接种于96孔培养板中,分别加入浓度为0(未加氯胺酮)、5、10、20、50、100、200、500、1000 mmol·L~(-1)氯胺酮,每个浓度5孔。采用四甲基偶氮唑蓝比色法检测NSC光密度(OD),并计算生长抑制率(RI)。采用流式细胞仪测定氯胺酮浓度为0、10、100、500、1000 mmol·L~(-1)时NSC凋亡率。结果与氯胺酮浓度0时比较,200、500、1000 mmol/L氯胺酮可降低NSC OD,升高RI,10、100、500、1000 mmol·L~(-1)氯胺酮可升高NSC凋亡率(P＜0．05或0．01)。结论氯胺酮对体外培养大鼠NSC增殖有抑制作用,并能诱导NSC凋亡,且该作用与氯胺酮浓度有关     

脑肿瘤干细胞体外分化过程中的回逆现象分析

目的探讨脑肿瘤干细胞（BTSCs）体外分化过程中的回逆现象，为研究其分化抑制机制奠定基础。方法利用CD133免疫磁珠筛选系统，从肿瘤组织中分离获得的CD133^＋细胞（BTSCs）分成4组进行培养：（1）含10％胎牛血清（FCS）；（2）10％FCS＋丙戊酸钠注射液（VPA）；（3）无FCS＋生长因子；（4）无FCS＋生长因子＋VPA。取不同时间点上的细胞，相差显微镜观察其形态变化：流式细胞术检测与分化相关的标志物、细胞周期和DNA倍体变化；利用免疫激光共聚焦分析与分化相关标志物的共表达情况。结果无FCS条件下培养的BTSCs呈悬浮球状生长，高表达CD133和巢蛋白（nestin），不表达胶质纤维酸性蛋白（GFAP）和β-微管蛋白Ⅲ（β-TubulinⅢ）。G0／G1期细胞占大多数，G2／M期细胞接近0％，DNA都是异倍体，对VPA反应不敏感。含FCS培养的原本悬浮的细胞约4h开始贴壁。均呈圆形。此后逐渐向多形性分化，至7d时分化的细胞部分又返回至圆形。至10d-21d时，有的还能重新恢复球形，并呈悬浮生长。培养3d、7d、10d和21d时，CD133、nestin阳性细胞数先降后升，GFAP^＋和β-TubulinⅢ^＋细胞数始终处于较低水平。含FCS培养液中加入VPA。细胞形态上未见上述的回逆现象，CD133和nestin表达的先降后升现象消失，GFAP和β-TubulinⅢ在第7天以后表达明显升高，但极大部分细胞共表达nestin。而神经干细胞（NSCs）在含FCS培养至10d时，即以GFAP和β-TubulinⅢ表达为主，未见CD133^＋细胞。此外，含血清培养时BTSCs仍以异倍体为主。含少量的G2／M期细胞，加VPA诱导后细胞周期和DNA倍体变化不明显。结论BTSCs在含血清条件下培养出现的多向分化表型不稳定，时有去分化所导致的回逆。加入诱导分化剂VPA培养，虽然能阻止回逆现象出现，并有代表星形胶质细胞和神经元标志物表达上升．但因其共表达nestin而仍属于未完全分化细胞，表明BTSCs分化始终处于受抑状态。     

成年大鼠神经元和星形胶质细胞细胞周期蛋白依赖性激酶抑制因子表达的差异研究

目的比较研究成年大鼠细胞周期蛋白依赖性激酶抑制因子在神经元和星形胶质细胞的表达差异。方法应用免疫荧光和激光扫描共聚焦显微镜观察成年大鼠生理状态下大脑皮层或海马CA1、CA3、DG区神经元和星形胶质细胞细胞周期蛋白依赖性激酶抑制因子(CDKI)p15Ink4b、p21cipl的表达。结果成年大鼠海马区和大脑皮层的神经元有p15Ink4b和p21cipl的表达,细胞核和细胞浆均有表达,且以胞核为主;星形胶质细胞也有上述细胞周期调控蛋白的表达,便细胞数目较少,并且表达这些指标的星形胶质细胞多聚集在海马区。结论成年大鼠大脑皮层和海马区的神经元和星形胶质细胞均表达p15Ink4b和p21cipl,而其在神经元的表达较星形胶质细胞更为普遍。     

丁酸对人结肠癌细胞株SW1116增殖及分化状态的影响

目的:探讨结肠中膳食纤维的酵解产物丁酸对人结肠癌细胞株生长、增殖及分化状态的影响。方法:将传代人结肠癌SW1116细胞株接种于不含及合不同浓度(2、3、4、7、10 mmol/L)丁酸的培养基中。经6、24、48和72h后,用四唑蓝(MTT)法测定细胞增殖率、细胞匀浆中癌胚抗原(CEA)及和碱性磷酸酶(ALP)的表达;同时用电镜观察细胞形态的改变。结果:丁酸对SW1116细胞株的生长抑制作用呈浓度依赖性,在所观察的丁酸浓度及时限内,最高抑制率达53.9％。同时丁酸能大大增加SW1116细胞CEA和ALP的表达;当丁酸浓度≥7mmol/L和培养时间≥48h时,二者增加最为显著(P<0.001)。电镜显示丁酸能使细胞表面微绒毛明显增多。结论:丁酸能抑制SW1116细胞株的生长并诱导其分化。     

Fifteen-year follow-up of 92 hospitalized adults with Down's syndrome: incidence of cognitive decline, its relationship to age and neuropathology

Background The clinical and neuropathological features associated with dementia in Down’s syndrome (DS) are not well established. Aims To examine clinico‐pathological correlations and the incidence of cognitive decline in a cohort of adults with DS. Method A total of 92 hospitalized persons with DS were followed up from 1985 to December 2000. At outset, 87 participants were dementia‐free, with a median age of 38 years. Assessments included the Prudhoe Cognitive Function Test (PCFT) and the Adaptive Behavior Scale (ABS), to measure cognitive and behavioural deterioration. Dementia was diagnosed from case records and caregivers’ reports. Results Eighteen (21%) patients developed dementia during follow‐up, with a median age of onset 55.5 years (range 45–74). The PCFT demonstrated cognitive decline among those with a less severe intellectual disability (mild and moderate) but not among the profoundly disabled people (severe and profound). Clinical dementia was associated with neuropathological features of Alzheimer’s disease, and correlated with neocortical neurofibrillary tangle densities. At the age of 60 years and above, a little more than 50% of patients still alive had clinical evidence of dementia. Conclusions Clinical dementia associated with measurable cognitive and functional decline is frequent in people with DS after middle age, and can be readily diagnosed among less severely intellectually disabled persons using measures of cognitive function such as the PCFT and behavioural scales such as the ABS. In the more profoundly disabled people, the diagnosis of dementia is facilitated by the use of behavioural and neurological criteria. In this study, the largest prospective DS series including neuropathology on deceased patients, the density of neurofibrillary tangles related more closely to the dementia of DS than senile plaques. In people with DS surviving to middle and old age, the development of dementia of Alzheimer type is frequent but not inevitable, and some people with DS reach old age without clinical features of dementia.     

Cell transplantation to improve ventricular function in the failing heart

Current therapies for congestive heart failure are limited in efficacy or in applicability. Cardiac cell transplantation offers a novel therapeutic approach to improve heart function. Although significant progress has been made over the past decade in the development of cell transplantation, only recently have investigators studied the changes in ventricular function following cell transplantation. This review article describes the latest research developments, evaluates recent studies of ventricular function after cell transplantation, and discusses the future directions of cell transplantation as a new therapy to ‘repair broken hearts’.     

100例SARS患者外周血T淋巴细胞亚群分析

目的 :探讨SARS患者外周血T淋巴细胞亚群变化。方法 :采用流式细胞仪检测10 0例SARS住院患者外周血T淋巴细胞亚群。结果 :与正常组比较 ,SARS组白细胞总数显著下降 ,淋巴细胞百分数和绝对数显著下降 ,粒细胞绝对数显著下降 ,CD3 、CD4 、CD8 细胞绝对数显著下降 ,CD4 细胞百分数 ,CD8 细胞百分数及CD4 /CD8 比值差异无统计学意义。比较SARS患者各病程CD3 、CD4 、CD8 ,于病程第一至第三周较第四周下降明显 (P <0 .0 5 ) ,病程第一至第三周之间差别无显著性 (P >0 .0 5 ) ;结论 :SARS患者外周血T淋巴细胞亚群的变化对阐明SARS的发病机制有一定意义。