含银介孔二氧化硅-壳聚糖复合材料的制备与性能研究

目的探讨含银介孔二氧化硅-壳聚糖复合材料(Ag/MSN-Chi)的制备方法及其微观表征、细胞毒性、吸水性能、抗菌性能及止血性能。 方法以正硅酸乙酯为前驱体，十六烷基三甲基溴化铵为致孔剂，采用离子交换法在介孔二氧化硅纳米粒子(MSN)中引入银离子，制备出具有抗菌作用的新型有序的含银介孔二氧化硅纳米粒子(Ag/MSN)材料。再利用烷基化壳聚糖负载Ag/MSN，制备出Ag/MSN-Chi。根据所用材料不同将实验分为实验组和空白对照组，实验组又分为3个亚组：MSN组、Ag/MSN组、Ag/MSN-Chi组，空白组为不加任何材料的阳性对照。计算MSN和Ag/MSN的比表面积、孔容、孔径和Ag/MSN与Ag/MSN-Chi的电荷。并通过吸水实验、体外凝血实验、抗菌实验对MSN、Ag/MSN和Ag/MSN-Chi的细胞毒性、吸水性能、止血性能及抗菌性能进行评价，计算细胞相对存活率、吸水率、凝血酶原时间(PT)、凝血活酶时间(APTT)及抑菌率。取健康成年新西兰大白兔18只，随机分成3组：对照组(采用医用纱布处理)、Ag/MSN组(采用Ag/MSN处理)、Ag/MSN-Chi组(采用Ag/MSN-Chi处理)，每组6只，建立肝创伤出血模型，计算止血时间。数据比较采用方差分析和t检验。 结果MSN的比表面积为(523.8±12.4) m²/g、孔容为(1.2±0.4) m³/g、孔径为(3.5±0.9) nm；Ag/MSN的比表面积为(521.6±11.7) m²/g、孔容为(1.15±0.5) m³/g、孔径为(3.6±0.7) nm，2种材料的比表面积、孔容、孔径比较差异均无统计学意义(t＝0.224、0.135、0.015，P值均大于0.05)。经测量，Ag/MSN的Zeta电位为－19.7 mV，Ag/MSN-Chi的Zeta电位为10.27 mV，表明Ag/MSN表面电荷从负值变为正值。Ag/MSN-Chi组、Ag/MSN组和MSN组与小鼠成肌细胞共培养1、4、7 d的细胞相对存活率比较，差异均无统计学意义(F＝2.61、4.72、3.52, P值均大于0.05)。Ag/MSN组吸水率分别与MSN组和Ag/MSN-Chi组比较，差异均无统计学意义(t＝0.482、1.159，P值均大于0.05)。经检测，Ag/MSN-Chi组、Ag/MSN组、MSN组和空白对照组的PT比较，差异无统计学意义(F＝10.28，P>0.05)；Ag/MSN-Chi组、Ag/MSN组、MSN组和空白对照组APTT分别为(20.9±2.1)、(28.5±3.4)、(31.4±2.6)、(38.7±2.5) s，4组比较差异有统计学意义(F＝8.70，P<0.05)；Ag/MSN-Chi组、Ag/MSN组、MSN组APTT分别与空白对照组比较，差异均有统计学意义(t＝9.443、4.186、3.506，P值均小于0.05)；Ag/MSN-Chi组APTT与Ag/MSN组比较，差异有统计学意义(t＝3.294，P<0.05)。MSN组在培养0.5、2、4、6、24 h 5个时间点抑菌率比较差异无统计学意义(F＝5.437，P>0.05)；培养0.5 h，Ag/MSN组和Ag/MSN-Chi组抑菌率分别为(99.7±5.2)%、(97.1±5.4)%，与培养0.5 h MSN组抑菌率(11.2±5.8)%比较，差异均有统计学意义(t＝19.678、18.775, P值均小于0.05)；培养24 h，Ag/MSN组和Ag/MSN-Chi组抑菌率分别为(73.2±5.1)%和(72.9±6.9)%，与MSN组(11.8±5.7)%比较，差异均有统计学意义(t＝13.904、11.825, P值均小于0.05)。Ag/MSN-Chi组、Ag/MSN组和对照组止血时间分别为(12.3±1.5)、(17.2±3.4)、(28.1±3.8) s，3组比较差异有统计学意义(F＝5.892，P<0.05)；Ag/MSN-Chi组和Ag/MSN组止血时间分别与对照组比较，差异均有统计学意义(t＝9.473、5.236, P值均小于0.05)；且Ag/MSN-Chi组与Ag/MSN组止血时间比较，差异有统计学意义(t＝3.230，P<0.05)。 结论Ag/MSN-Chi在不增加细胞毒性的基础上具有有较好的吸水性能、止血性能及抗菌性能。     

TGFβ1基因对血管内皮细胞细胞外基质表达及与基质黏附的影响

了解TGFβ1基因对血管内皮细胞表达细胞外基质蛋白及与基质黏附力的影响。用DOTAP脂质体转染p MAMneo TGFβ1于原代培养的脐静脉内皮细胞,经G4 18筛选,TGFβ1表达经免疫荧光鉴定。Western blot确定 型胶原、纤黏连蛋白的表达,微管吸吮系统确定内皮细胞与基质的黏附力。结果表明生理情况下的内皮细胞能表达少量的TGFβ1及胶原、纤黏连蛋白。经G4 18筛选,外源性TGFβ1在血管内皮细胞中稳定表达,能显著提高胶原、纤黏连蛋白纤维的表达及细胞与基质的黏附。说明TGFβ1在血管组织工程中促进内皮细胞的黏附具有一定的应用价值。     

Induction of a cytotoxic T cell response by co-injection of a T helper peptide and a cytotoxic T lymphocyte peptide in incomplete Freund's adjuvant (IFA): Further enhancement by pre-injection of IFA alone

We have previously demonstrated that it is possible to induce a consistent and strong cytolytic T lymphocyte (CTL) response to synthetic peptides, corresponding to poorly immunogenic malaria CTL epitopes, by co-injecting them with peptides representing defined T helper (Th) epitopes in incomplete Freund's adjuvant (IFA). In this study we have tested different immunization protocols to improve further the elicitation of the CTL response. We show that the CTL response to a mixture of Th + CTL peptides administered in IFA was further enhanced by a previous injection of the Th epitope peptide in IFA. Moreover, we found that the response could be significantly augmented by a pre-injection of IFA alone. This enhancement was observed only if the Th epitope was also present in the second injection. The number of lymph node cells recovered was 2–3-fold higher in mice pre-injected with IFA, but the increase in specific CTL activity, expressed as lytic units per animal, by pre-injection of IFA was at least 10–20-fold. Thus, pre-injection of IFA clearly increases the magnitude of a subsequent CTL response.     

Reversible blockade of experience-dependent plasticity by calcineurin in mouse visual cortex

Numerous protein kinases have been implicated in visual cortex plasticity, but the role of serine/threonine protein phosphatases has not yet been established. Calcineurin, the only known Ca2+/calmodulin-activated protein phosphatase in the brain, has been identified as a molecular constraint on synaptic plasticity in the hippocampus and on memory. Using transgenic mice overexpressing calcineurin inducibly in forebrain neurons, we now provide evidence that calcineurin is also involved in ocular dominance plasticity. A transient increase in calcineurin activity is found to prevent the shift of responsiveness in the visual cortex following monocular deprivation, and this effect is reversible. These results imply that the balance between protein kinases and phosphatases is critical for visual cortex plasticity.     

领导干部心理健康量表的初步编制

目的编制一套适用于领导干部群体的心理健康量表。方法通过文献研究、个案分析、问卷调查等,确立测验结构并编制成预测量表,通过对127位被试施测结果进行条目分析等形成正式量表,并进行因子分析等考察量表的信度和效度。结果编制成一个含3个量表:心理症状量表、自我概念量表、外界适应量表,共计93个项目的测评系统。项目与其所在量表的题总相关系数在0.445～0.855之间(P<0.001),各条目决断值(CR值)均具有显著性;对自我概念量表和外界适应量表探索性因素分析分别提取4个和3个公因子,累计解释总变异量分别为54.842%,48.365%,因子载荷在0.427～0.814和0.434～0.796之间;各量表的Cronbach'sα系数分别为0.775,0.860,0.952。结论初步研究显示量表的信效度均达到心理学测量标准,具有较好的信效度。     

1 MHz腔内射频加热辐射器在体模和犬颈段食管中的热场分布

目的 在肌肉等效体模及Beagle犬颈段食管中测定ZRL—Ⅱ型食管腔内加热辐射器的温度分布，探讨其热场分布能否满足食管癌加热治疗的临床需要。方法 ①在肌肉等效体模中测定ZRL—Ⅱ型食管腔内射频加热辐射器的温度分布，②Beagle犬用氯胺酮麻醉、固定。将腔内加热辐射器插入食管腔内，加热45min后分层解剖犬的颈部，同时测量食管外壁、气管、食管周围软组织中的温度。结果 ①在肌肉等效体模中距离导管囊表面1cm的环形体内的温度在43．2℃～43．6℃之间；在距离导管囊表面2cm的环形体内的温度在42．6℃～43．3℃之间，在距离导管囊表面3cm的环形体内的温度在42．6℃～42．8℃之间。②测得Beagle犬颈段食管腔内和外壁的温度为43．5℃，气管内为38．0℃，主动脉旁38．0℃，距食管外壁1cm处的软组织温度为40-3℃，距食管外壁2cm处的软组织温度为39．0℃，而颈部皮下的温度是37．5℃。结论 ①ZRL-Ⅱ型射频食管腔内加热辐射器的热场分布满足临床食管腔内加热的需要，②体模测定与活体动物测定，热场分布存在一定差异，需进一步研究。     

Significance of cytogenetic and fluorescence in situ hybridization analysis in evaluating antichronic myeloid leukemia efficacy of different immune effector cells

We report on the antileukemia effect of interleukin 2 (IL2) on different immune cells from 22 patients with chronic myeloid leukemia (CML). Bone marrow cells from these patients were first cultured in modified long-term bone marrow culture medium for several days, then separately cultured with lymphokine activated killer cells (LAK), cytokine-induced killer cells (CIK), and dendritic cell cocultured CIK (DC-CIK) for another 1-2 days. They were then detected for presence of the Philadelphia chromosome (Ph) by cytogenetic analysis and fluorescence in situ hybridization (FISH). The percentage of Ph-chromosome-positive cells in the bone marrow mononuclear cells after culturing with CIK and DC-CIK was significantly lower than that after culturing with IL2 or LAK. Our results demonstrate that cytogenetics and FISH are useful techniques for the evaluation of the anti-CML effect of immune cells and that CIK or DC-CIK can be appropriate candidates for adoptive immune cell therapy in vivo or for leukemia cell purging ex vivo.     

Molecular cloning and expression of a novel alternative splice variant of BRDT gene

In this study, a human adult testis cDNA microarray was constructed and hybridized with (33)P-labeled human adult testis, embryo testis and sperm cDNA probes, respectively. A novel alternative splice variant of BRDT gene, named BRDT-NY, presumably involved in testicular function was cloned. It was expressed 3.96-fold more in human adult than embryo testis and also expressed in human spermatozoa. Similarly, RT-PCR revealed a differential expression pattern of this gene in human adult testes and fetal testes. The full length of BRDT-NY was 3438 bp and contained a 2883 bp open reading frame, encoding a 960-amino-acid protein. Sequence analysis showed that it has two bromodomains in N-terminal of the protein. Multiple tissue RT-PCR results showed that BRDT-NY was exclusively expressed in testis. mRNA expression of BRDT-NY gene was deleted in some azoospermic patients' testes. These experiments suggested that BRDT-NY gene may have an important role in the process of spermatogenesis and may be correlated with male infertility.     

Rothmund-Thomson syndrome associated with trisomy 8 mosaicism.

This report describes a boy with Rothmund-Thomson syndrome associated with trisomy 8 mosaicism. The patient presented with typical features of Rothmund-Thomson syndrome but some of the features often seen in trisomy 8 mosaics were also observed in him. The possibility that the two disorders might share a common pathogenesis is postulated.