胃癌组织中P16、Cyclin D1、Rb表达及其生物学行为的研究

目的研究P16、Cyclin、D1Rb基因在胃癌中的表达及其与胃癌生物学行为的关系.方法采用免疫组化方法检测10例正常胃黏膜、30例胃癌组织中P16、Cyclin D1、Rb蛋白的表达,并结合其临床资料进行分析.结果P16、Cyclin D1、Rb蛋白阳性表达,正常胃粘膜分别为90%、10%、90%;胃癌分别为36.67%、53.33%、50%,胃癌纽与正常对照组间差异均有显著性(P＜0.05),P16、Cyclin D1蛋白与胃癌分化程度、淋巴结转移与否、远处转移与否呈一定的相关性.结论P16、Cyclin D1、Rb基因与胃癌发生有关,P16、Cyclinp蛋白检测有助于胃癌预后的判断.     

Role of the vitamin D3 pathway in healthy and diseased skin – facts, contradictions and hypotheses

Abstract: Irradiation of human keratinocytes with UVB (280–320 nm) in vitro and in vivo activates the metabolism of 7‐dehydrocholesterol to hormonally active calcitriol. The production of calcitriol in the skin strongly depends on the photosynthesis of vitamin D₃ which is biologically inactive in the first instance. Vitamin D₃ serves as the starting substrate for two subsequent enzymatic hydroxylation steps in epidermal keratinocytes. Both the amount of vitamin D₃ and the activity of anabolic and catabolic vitamin D hydroxylases determine the cutaneous level of calcitriol. The hormonally active metabolite of vitamin D₃ regulates a huge number of genes in keratinocytes, and thus acts in an autocrine and/or paracrine manner. This local pathway of vitamin D₃ is unique, but its relevance for healthy and diseased skin is widely unknown, yet. Experimental findings implicate several questions: ( 1 ) Is UVB‐induced formation of calcitriol involved in regulation of growth and differentaition of epidermal cells as well as immunological and skin protective processes? ( 2 ) What endogenous and exogenous factors including drugs affect the cutaneous vitamin D₃ pathway? From a therapeutical point of view, it has been known for a long time that topical application of calcitriol and its analogs can improve hyperproliferative skin diseases like psoriasis. In spite of many encouraging studies in recent years, the fields of the routinely therapeutical application of calcitriol or vitamin D analogs in dermatology (e.g. treatment of immunological, inflammatory, malignancies and infectious skin diseases) have not been intensified. Why is that?     

蛋白质组学在皮肤科的研究进展

蛋白质组学是研究细胞内所有蛋白质及其动态变化规律的科学,近年来它被广泛应用于生命科学的各个领域.二维聚丙烯酰胺凝胶电泳法(2D PAGE)是蛋白质组学核心技术.就蛋白质组学在皮肤病学基础研究和临床皮肤病中的应用进行综述.     

A new strategy of delayed long-term prophylaxis could prevent cytomegalovirus disease in (D+/R−) solid organ transplant recipients

Abstract:  Long-term prophylaxis against cytomegalovirus (CMV) started immediately after transplantation in (D+/R−) poses a higher risk of late-onset CMV disease. Delayed CMV prophylaxis could allow a transitory exposure of the immune system to CMV, which would let the immune system mount an adequate CMV-specific cytotoxic response in (D+/R−) patients and confer protection against CMV disease. We included all (D+/R−) solid organ transplant recipients (SOT) performed at our institution (January 3/October 6) who received CMV prophylaxis (mainly with oral valganciclovir) during 100 d. In the first period (until December 4), prophylaxis was initiated immediately after transplantation (conventional prophylaxis: CP). Since January 5, it was initiated after 14 d (delayed prophylaxis: DP). Incidence and severity of CMV disease was compared between both groups. A total of 44 SOT recipients were included (CP: 26 and DP: 18). CMV disease was diagnosed in eight patients (18%), seven of 26 (27%) in the CP group, and one of 18 (5.5%) in the DP group (p = 0.07). CMV colitis was reported in five of 26 patients in the CP group (19%), whereas there were no cases of visceral CMV disease in the DP group (p = 0.048). A 14-d delay in the beginning of long-term prophylaxis against CMV in (D+/R−) is safe and could prevent the onset of late-CMV disease.     

维生素E琥珀酸酯对人肝癌细胞凋亡和侵袭性

目的研究维生素E琥珀酸酯（VES）诱导体外培养人肝癌细胞凋亡以及对肝癌细胞侵袭性的抑制作用。方法自2004年至2005年7月,体外培养SMMC7721人肝癌细胞系,在培养液中加入VES共育,用等量的生理盐水作为对照组。培养6、24、48h后采用流式细胞仪检测肝癌细胞的凋亡,小孔趋化试验检测肝癌细胞的体外侵袭性变化。结果在加入VES后肝癌细胞的凋亡率与对照组相比明显增加。在48h加入VES的实验组与对照组相比,肝癌细胞的小孔趋化试验明显受到抑制。结论VES具有体外诱导人肝癌细胞系凋亡以及抑制肝癌细胞体外侵袭性的作用,是潜在的抗肿瘤因子。     

Calcium absorption following small bowel resection in man. Evidence for an adaptive response

Seventeen patients who had undergone extensive small bowel resection were studied for calcium absorption (FACa) and plasma vitamin D metabolites. FACa was measured by a double radio-tracer technique and expressed as percentage of total oral dose. FACa was decreased compared with controls (34%, range: 3-46 v 65%, range: 57-73, P less than 0.01). A positive correlation (r = 0.49, P = 0.05) was found between FACa and the remaining length of small bowel (SBL). As wide variations in both SBL and duration after surgery were observed among the seventeen investigated patients, we were led to individualize less heterogeneous subgroups of patients. Better correlations were found when the patients were divided into two subgroups according to whether the time interval between the resection and the investigation was shorter (r = 0.75, n = 11, P less than 0.02) or longer (r = 0.89, n = 6, P = 0.05) than 2 years. In thirteen patients who had a SBL shorter than 100 cm, a positive correlation was observed between FACa and the time interval after surgery (months): r = 0.65, P less than 0.05. Plasma 1,25 (OH)2D was markedly reduced in the whole group (31 pmol l-1, range: 8-108) compared with controls (103 pmol-1, range: 59-134, P less than 0.01). The present study shows that in extensively small bowel resected patients, calcium absorption is reduced, the alteration being dependent both on the length of the remnant small bowel and on the time after surgery.(ABSTRACT TRUNCATED AT 250 WORDS)     

Increased plasma cathepsin D concentration in hepatic carcinoma and cirrhosis but not in breast cancer

Using a sandwich enzyme-linked immunoassay, plasma total cathepsin D concentration was assayed in 40 breast cancer patients and 84 patients with various liver diseases and compared to that of 52 normal subjects. There were no significant variations found in breast cancer patients related to tumor size, node invasiveness or metastases. In normal women, cathepsin D levels were slightly but not significantly increased in the luteal phase and in pregnancy. By contrast, plasma cathepsin D concentration was significantly increased in 70-75% of patients with liver disease (cirrhosis, hepatocarcinoma, hepatitis), but not in those with liver steatosis. Cathepsin D was independent of most of the plasma hepatic function tests and was correlated with alpha-fetoprotein in cirrhosis and with alpha-fucosidase in primary hepatocellular carcinoma. We conclude that plasma cathepsin D is not a useful marker in breast cancer. However, since the cellular level of this protease is associated with risk of metastasis in breast cancer, clinical follow-up will be required to test whether high cathepsin D plasma concentration has any prognostic value in liver cirrhosis and primary hepatocarcinoma.     

Role of retinol in protecting epithelial cell damage induced by Clostridium difficile toxin A

Vitamin A (retinol), a fat-soluble vitamin, is an essential nutrient for the normal functioning of the visual system, epithelial cell integrity and growth, immunity, and reproduction. Our group has investigated the effect of high doses of oral vitamin A on early childhood diarrhea in our prospective community-based studies from Northeast Brazil and found a beneficial role in reducing the mean duration but not incidence of diarrheal episodes. In this study, we explored the role of retinol supplementation in intestinal cell lines following Clostridium difficile toxin A (TxA) challenge. C. difficile is the most common anaerobic pathogen borne with antibiotic-borne diarrhea and pseudomembranous colitis. Since retinol is critical for the integrity of tight junctions and to modulate the cell cycle, we have focused on changes in transepithelial electrical resistance (TEER) in Caco-2, a more differentiated intestinal cell line, and on models of cell proliferation, migration and viability in IEC-6 cells, an undifferentiated crypt cell line, following TxA injury. In this model, retinol therapy reduced apoptosis, improved cell migration and proliferation, and prevented the reduction in TEER, following C. difficile TxA challenge in a glutamine-free medium. These results suggest the role of retinol in protecting intestinal epithelial barrier function from C. difficile TxA enterotoxic damage.     

Pin1和周期素D1在胰腺癌中的表达及其意义

目的:检测胰腺癌及癌旁组织中Pin1和周期素D1基因的表达,探讨Pin1在胰腺癌发病中所起的作用。方法:收集27例胰腺肿瘤组织及其相应的肿瘤旁组织标本,采用实时荧光定量逆转录聚合酶链反应法（RQ RT-PCR）检测胰腺良恶性肿瘤及肿瘤旁组织中Pin1和周期素D1 mRNA 的表达,运用Fisher精确概率分析两者之间的相关性及其与肿瘤临床分期和病理特征的关系。结果:7例胰腺囊腺瘤中周期素D1和Pin1的表达与肿瘤旁组织之间无显著性差异;而20例胰腺癌中周期素D1和Pin1的表达明显高于肿瘤旁组织［（2.78±1.02）vs.（4.36±1.27）和(5.48±1.69) vs. (9.97±1.86),P<0.05）］。Pin1和周期素D1与肿瘤的临床分期和病理分化程度无明显的相关（组间差异均为P>0.05）,但Pin1与周期素D1的表达有关（P<0.01）。 结论:胰腺癌中Pin1的过表达可促进周期素D1表达,由此诱导了肿瘤的发生;Pin1可能在胰腺癌中起着重要作用。     

去卵巢骨质疏松模鼠DPD及1,25-(OH)2D3与骨质量的相关性研究

目的：探讨雌性SD大鼠切除卵巢后机体尿DPD及血1，25-（0H）2D3变化与骨质量的相关性。方法：40X雌性SD大鼠随机分为卵巢切除组（OVX组）和假手术组（Sham组），分别于术后12、24周取材。运用双能X线骨密度仪测L1、股骨、股骨颈骨密度，ELISA法测尿DPD浓度，激素放免法测血1，25-（OH）2D3浓度，光测弹性仪测L1压缩强度极限、弹性模量及右侧股骨弯曲破坏栽荷，不脱钙骨切片技术观察胫骨上段骨组织形态结构并计量分析，对实验数据进行相关性分析。结果：术后OVX组除尿DPD／Cr明显升高外，其他检测指标均较Sham组低，且随术后时间推移持续下降，差异有统计学意义。相关分析显示：尿DPD／Cr与腰椎、股骨密度、椎体压缩强度极限、股骨弯曲破坏荷载和骨小梁面积均呈负相关。血清1，25-（OH）2D3水平与腰椎、股骨、股骨颈密度、骨小梁面积、椎体压缩强度极限和股骨弯曲破坏荷载呈正相关。结论：大鼠卵巢切除后尿DPD、血1，25-（0H）2D3水平变化与骨质量显著相关，可以通过检测尿DPD、血1，25-（0H）2D，水平变化预测骨质量。