骨髓间充质干细胞向胰岛素分泌细胞诱导分化的动态观察

目的:探讨体外诱导骨髓间充质干细胞向胰岛素分泌细胞分化的可能性,并观察其动态变化。方法:实验于2005-09/2007-03在山东大学齐鲁医院完成。①标本来源:骨髓标本15例来自山东大学齐鲁医院成人骨髓检查结果正常者,均签署捐献同意书。②实验方法:无菌条件下取骨髓2.0～5.0mL,采用percoll分离液和贴壁法获得纯化的成人骨髓间充质干细胞。③实验评估:流式细胞仪行细胞表面抗原检测,在适当的条件下诱导其分化为成骨细胞和脂肪细胞。采用两步法向胰岛素分泌细胞诱导,观察其在碱性成纤维细胞生长因子、活化素A、胰岛素样生长因子、尼克酰胺等因子刺激下向胰岛素分泌细胞分化的动态变化。双硫踪染色鉴定胰岛样细胞团,酶联免疫吸附试验检测细胞分泌胰岛素的情况,RT-PCR检测胰岛细胞特异基因的表达。结果:①骨髓间充质干细胞的生长特性及免疫表型:分离培养获得的贴壁细胞,呈形态均一的梭形,流式细胞仪检测CD34、CD45表达阴性,CD29、CD44表达阳性。②向成骨细胞和脂肪细胞的诱导分化:此类细胞经茜素红染色、油红O染色均呈阳性,可诱导分化为成骨细胞和脂肪细胞。③向胰岛素分泌细胞的诱导分化:第1步诱导后出现细胞簇,双硫腙染色不着色,胰岛素分泌量少,仅检测到PDX-1基因的表达,证实其为胰岛前体细胞。第2步诱导后细胞簇数目逐渐上升,至诱导14d大部分细胞簇经双硫腙染色都呈红色。④诱导后培养上清中胰岛素含量:诱导第3,7,14,21天的胰岛素分泌量分别为(15.3±4.9),(34.1±5.6),(40.4±5.3),(39.8±5.1)mU/L。⑤胰岛细胞特异基因的表达:诱导7d仅检测到PDX-1基因的表达,insulin1、insulin2和Glut2基因均不表达。诱导14,21d检测到insulin2、PDX-1基因表达,insulin1基因弱表达,Glut2基因不表达。结论:体外分离、纯化得到的骨髓间充质干细胞诱导7d可分化出胰岛前体细胞,不具功能性;诱导14d后可成功地分化出成熟的具有功能性的胰岛素分泌细胞。     

普通和呼气相压力释放持续正压通气对睡眠呼吸暂停患者呼吸中枢驱动的影响比较

持续正压通气(CPAP)是治疗有症状的OSAHS患者的主要方法,然而其治疗的有效性与患者对CPAP的依从性有关.CPAP治疗时吸气相和呼气相均为正压,吸气相正压帮助吸气,而呼气相气道内正压则成为呼气阻力,导致患者呼气不畅.     

乳腺癌组织NRF-1表达及其意义的探讨

目的:探讨乳腺癌组织中核呼吸因子-1(NRF-1)蛋白表达与乳腺癌发生、发展及临床病理特征的关系。方法:采用免疫组化EnVision二步法,对211例乳腺癌组织和50例乳腺良性病变组织中NRF-1蛋白表达进行检测。结果:NRF-1蛋白表达定位于细胞核,着色呈棕黄色,乳腺癌中阳性表达(82.7%)低于乳腺良性病变组织阳性表达(100%),χ2=100.288,P=0.000;高分化乳腺癌NRF-1阳性率明显高于中、低分化乳腺癌(χ2=16.242,P=0.001;χ2=72.802,P=0.000),中分化乳腺癌也明显高于低分化乳腺癌,χ2=30.190,P=0.000。乳腺癌淋巴结转移患者NRF-1蛋白阳性表达率明显低于未转移者,χ2=12.025,P=0.007;TNM分期中I期NRF-1蛋白阳性表达率明显高于Ⅱ、Ⅲ期,χ2=12.025,P=0.007。结论:NRF-1蛋白的表达可能与乳腺癌的发生发展密切相关,可作为乳腺癌患者疾病进展监控和预后观测的指标,具有临床应用价值。     

Quadriceps strength predicts mortality in patients with moderate to severe chronic obstructive pulmonary disease

BACKGROUND: Prognosis in chronic obstructive pulmonary disease (COPD) is poorly predicted by indices of air flow obstruction, because other factors that reflect the systemic nature of the disease also influence prognosis. OBJECTIVE: To test the hypothesis that a reduction in quadriceps maximal voluntary contraction force (QMVC) is a useful predictor of mortality in patients with COPD. METHODS: A mortality questionnaire was sent to the primary care physician of 184 patients with COPD who had undergone quadriceps strength measurement over the past 5 years. QMVC was expressed as a percentage of the patient's body mass index. The end point measured was death or lung transplantation, and median (range) follow-up was 38 (1-54) months. RESULTS: Data were obtained for 162 patients (108 men and 54 women) with a mean (SD) percentage of forced expiratory volume in 1 s (FEV1) predicted of 35.6 (16.2), giving a response rate of 88%. Transplant-free survival of the cohort was 93.5% at 1 year and 87.1% at 2 years. Cox regression models showed that the mortality risk increased with increasing age and with reducing QMVC. Only age (HR 1.72 (95% CI 1.14 to 2.6); p = 0.01) and QMVC (HR 0.91 (95% CI 0.83 to 0.99); p = 0.036) continued to be significant predictors of mortality when controlled for other variables in the multivariate analysis. CONCLUSION: QMVC is simple and provides more powerful prognostic information on COPD than that provided by age, body mass index and forced expiratory volume in 1 s.     

Psoriasis under the microscope

Histopathology is a major diagnostic tool in dermatology, particularly in psoriasiform diseases. Morphological studies showed that the initial event in psoriatic lesions is perivascular infiltrate, followed by dilatation of superficial papillary vessels. Proliferation of keratinocytes and neutrophil exocytosis are secondary events. Fully developed psoriasis has a very characteristic pattern, which includes elongation of rete ridges leading to regular acanthosis, oedema of the papillary dermis associated with tortuous dilated vessels, thinning of suprapapillar area, decreased thickness of granular layer, and exocytosis of neutrophils in the spinous layer (Kogoj's pustule) or in the cornified parakeratotic layer (Munro microabscesses). Pustular psoriasis is characterized by large or confluent intra‐epidermal multilocular pustules. Whatever the clinical variant of psoriasis, common morphological signs suggest that it is basically a unique pathological process, with many possible presentations according to various factors such as age, size and localization of lesions, or therapy. Similar microscopic elementary lesions indicate that Hallopeau's acrodermatitis continua, Reiter's disease and geographical tongue are variants of psoriasis. Because of the many faces of the disease, psoriasis can resemble many other squamous or pustular disorders. Differential diagnosis by microscopic analysis is based on pattern analysis, PAS (Periodic Acid Schiff) staining to rule out fungal infection, and immunohistochemistry to characterize lymphocytic infiltrate. Psoriasis is one of the most common inflammatory skin diseases. In its characteristic presentation, psoriasis comprises well‐circumscribed red scaly papules and plaques. In this form, the disease is generally easy to identify, especially when the elbows, knees and scalp are affected. Nevertheless, the term ‘psoriasis’ includes more clinical variants than any other inflammatory dermatosis: psoriasis vulgaris vs. pustular, localized vs. generalized, topographic variants, mucous membranes involvement, hair and nail lesions. Although some of these conditions might be extremely different from psoriasis vulgaris, common pathological findings can be identified in all of them. Microscopic analysis of psoriatic lesions may therefore help clinicians to make the diagnosis and to understand that, whatever the clinical presentation, signs and symptoms are mainly due to a unique pathological process.