Detection of liver fibrosis with magnetic cross-relaxation

The utility of MRI using magnetization transfer (MT) enhanced pulse sequences to diagnose hepatic cirrhosis in a rat model was investigated. Hepatic T₁ was measured with and without MT off-resonance RF pulses in 17 treated and six control rats. The livers were evaluated histologically, and the hydroxyproline content quantitatively measured. We did not find a statistically significant linear correlation between the MR relaxation times and the degree of tissue injury. However, the MR measurements performed with MT were superior to those without differentiating the treated and control groups. Specifically, the T₁ times were 695 ±76 ms for the treated group, versus 748 ± 61 ms in the controls; P= 0.095. The T_1sat times were also lower in the treated group, with statistical significance: 367 ± 51 ms versus 421 ± 38 ms, P = 0.016. Finally, the change in the relaxation rates (the inverse of the relaxation times) with and without saturation were 1.31 ± 0.22 s^?1 (treated group) versus 1.05 ± 0.12 s^?1 (controls), which differed significantly, P= 0.001.     

Region-specific constitutive gene expression in the adult porcine meniscus.

The knee meniscus exhibits extensive spatial variations in native healing capacity, biochemical composition, and cell morphology that suggest the existence of distinct phenotypes for meniscus cells. Constitutive gene expression levels of appropriate extracellular matrix proteins may serve as useful molecular markers of cellular phenotypes; however, relatively little is known of variations in the gene expression for meniscus cells of different regions of the tissue. The objective of the present study was to evaluate constitutive differences between radial inner and outer regions in gene expression for extracellular matrix proteins relevant to the meniscus. A secondary objective was to determine if these region-specific differences in gene expression are maintained after periods of monolayer culture. The innermost regions of the meniscus were found to constitutively express higher mRNA levels for proteins highly expressed in articular cartilage, including aggrecan, type II collagen, and NOS2. In contrast, the outer meniscus was found to contain higher gene expression for proteins associated with fibrous tissues including type I collagen, and the proteases MMP2 and MMP3. Isolated inner and outer meniscus cells maintained these region-specific gene expression patterns for collagens and proteoglycans during short-term monolayer culture. The results provide new information that suggests the utility of constitutive gene expression levels as molecular markers to distinguish tissue and cells of the inner and outer meniscus.     

老化皮肤的胶原与弹性组织变化研究

目的：探讨光曝露情况及年龄因素对皮肤中弹性组织、Ⅰ/Ⅲ型胶原及基底膜Ⅳ型胶原的影响,进而探索皱纹形成的组织学原因。方法：对80例取自不同年龄志愿者的曝光部位（眶周/前额、面颊）及非曝光部位（腹部/臀部）的皮肤组织进行HE染色、Weigert染色、苦味酸天狼猩红染色及免疫组化处理,采用显微形态观察和半定量分析。结果：各部位皮肤基底膜内Ⅳ型胶原的含量无差异;随着曝光时间增加,前额/眶周皮肤中Ⅰ型胶原减少率最大,弹性变性物质增加率最大。结论：前额/眶周皮肤的胶原显著减少和弹性变性物质明显增生,是该部位皮肤皱纹早发的重要原因。     

新型神经支架材料的构建及其与骨髓基质干细胞复合的实验研究

[目的]研制出一种可用于修复周围神经缺损的组织工程支架材料,并观察体外培养的骨髓基质干细胞在支架材料中的生长情况。[方法]以I型胶原蛋白和明胶通过冷冻干燥技术制备胶原蛋白支架材料。扫描电镜观察内部结构的排列规律及走行,测量其孔径大小、孔隙率等指标。将骨髓基质干细胞复合到胶原蛋白支架材料中共培养5 d后,扫描电镜下观察其在材料内部的生长情况。[结果]构建的材料均为圆柱状,内部为孔径均匀且平行排列的微管结构,体外培养的骨髓基质干细胞成功种植在支架材料上,在材料内部生长良好。[结论]构建的支架材料具有良好的三维空间构形和生物相容性,为神经损伤的修复提供了一种新型的支架材料。     

A clinical procedure to predict the value of temporary occlusion therapy in keratoconjunctivitis sicca

PURPOSE: To evaluate the effects of dissolvable collagen punctal plugs on the symptoms, tear stability and volume in aqueous deficient dry eyes. METHODS: Sixty-two aqueous deficient dry eye patients of mixed aetiology underwent lacrimal punctal occlusion with dissolvable collagen plugs. The subjects were randomly allocated to one of two treatment groups: group I (n = 36) had their lower puncta occluded and group II (n = 26) had both their upper and lower puncta occluded. The effectiveness of this treatment was clinically assessed by (1). scoring subject symptoms and (2). measuring the tear parameters of tear thinning time (TTT) and tear meniscus height (TMH) as indicators of tear stability and volume, respectively. Following baseline measurements, patients were reviewed at time intervals of 5 and 12 days post-occlusion. A group of age- and gender-matched normals (n = 45) was recruited for comparison (group III). RESULTS: Tear volume and stability were significantly higher in group III compared with I and II at baseline. In the treated groups on both days 5 and 12: (1). symptom score reduced significantly from a median value of 7 to 3 (p = <0.001); (2). tear stability increased significantly from a median value of 3 to 5 s by day 5 (p collagen plugs offers no practical beneficial gain compared with occluding just the lower punctum.     

胶原凝胶复合骨胶原基质(BCM)负载关节软骨细胞的实验研究

目的 探讨胶原凝胶包埋软骨细胞接种BCM支架的三维培养对软骨细胞生长及功能的影响.方法 将胶原凝胶包埋的关节软骨细胞接种BCM支架并在体外培养,应用倒置相差显微镜和扫描电镜观察软骨细胞的粘附、生长和增殖情况,培养14d,行苏木精-伊红、甲苯胺蓝染色观察软骨组织形成情况.结果 软骨细胞在支架上粘附、生长和增殖良好,体外培养14d能形成较成熟的软骨组织.结论 胶原凝胶复合BCM支架具有良好的细胞相容性,可作为负载生长因子的载体.     

应用人自体血清培养人口腔黏膜上皮的实验研究

目的 研究人自体血清培养人口腔黏膜移植生长的生物学特性，为组织工程化尿道提供新材料。方法 将人自体血清培养黏膜移植于裸鼠体内，分别于移植后2、3、4、6周观察培养黏膜生长与转归，应用anti—HLA免疫荧光鉴定成活黏膜组织属性，应用抗人Ⅳ型胶原及抗人层黏蛋白为基底膜形成指标。结果 裸鼠体内移植培养黏膜成活生长分化良好，anti—HLA免疫荧光证实为移植的培养人黏膜组织；免疫组化发现移植后3周开始形成基底膜，4周形成完整的基底膜。结论 自体血清培养的人口腔黏膜可形成功能完整的上皮组织。     

Human monocyte interactions with non-enzymatically glycated collagen

Summary We have previously shown that receptors for advanced glycation end products are expressed on activated human monocytes. We now report that activated human monocytes exhibit increased adhesion to non-enzymatically glycated collagen substrates (+32%±1, p<0.001), and the increased adhesion can be competitively inhibited with non-enzymatically glycated albumin. Non-activated monocytes, which do not express receptors for advanced glycation end products, exhibit decreased adhesion (-16%±1, p<0.001). Similar results were observed with substrates of fibronectin and endothelial cell matrix proteins. As the presence of glycation adducts on collagen interferes with the normal binding of monocytes/macrophages, one possible role for advanced glycation adduct receptors on activated monocytes is to counterbalance such decreased adherence. Overcompensation for long periods of time may lead to pathological changes. Additionally, such receptors may play a role in monocyte-mediated remodelling of glycated matrix proteins, as we have observed increased degradation of nonenzymatically glycated collagen substrates by activated human monocytes at 2 h (+52%±11, p=0.01), 3 h(+49% ±10, p=0.01), and 4 h (+36%±6, p<0.01) after adding activated monocytes to ¹²⁵I-labelled substrates.     

几丁糖预防腹膜粘连抑制胶原基因表达的实验研究

目的 :探讨几丁糖在胶原基因表达及预防大鼠腹膜粘连形成中的作用。方法 :制作大鼠回肠浆膜均一缺损的腹膜粘连模型 ,关腹前注入乳酸Ringer液或几丁糖 ,术后 14天进行粘连评分。采用半定量逆转录 -聚合酶链反应 (RT PCR)方法测定各粘连组织标本Ⅰ型胶原基因mRNA的表达 ;采用苦味酸天狼猩红染色 -偏振光法及计算机图像分析系统来观察和分析Ⅰ型和Ⅲ型胶原纤维在粘连组织中的分布及染色表达面积。结果 :与正常腹膜和乳酸Ringer’s液组相比 ,几丁糖组大鼠的粘连显著减轻 ,Ⅰ型胶原基因mRNA的表达减弱 ,Ⅰ型胶原形成减少 (P <0 .0 1) ,Ⅲ型胶原在各组间无差别 (P >0 .0 5 )。结论 :胶原基因的过度表达可能在粘连形成过程中有重要的作用 ,几丁糖能抑制Ⅰ型胶原基因的表达 ,减少Ⅰ型胶原的合成 ,从而减轻粘连的程度     

Serum markers for fibrosis and plasma transforming growth factor-β1 in patients with hepatocellular carcinoma in comparison with patients with liver cirrhosis

In order to elucidate collagen metabolism in hepatocellular carcinoma (HCC) tissue, we compared levels of different potential markers of collagen metabolism and plasma transforming growth factor-β₁ in patients with HCC and in patients with liver cirrhosis. Serum levels of prolyl hydroxylase and the tissue inhibitor of metalloproteinase-1 in patients with HCC were significantly higher than those in patients with liver cirrhosis and increased with the size of the HCC tumour, whereas the serum levels of procollagen type III propeptide and type IV collagen 7S domain were similar in the two groups. In HCC, the increased plasma transforming growth factor-β₁ levels were closely correlated with serum levels of prolyl hydroxylase and the tissue inhibitor of metalloproteinase-1. These findings suggest that, in HCC tissue, the intracellular biosynthesis of collagen is enhanced, whereas the secretion of procollagen is disturbed and the degradation of collagen is suppressed by the excess production of the tissue inhibitor of metalloproteinase-1. The results also suggest that plasma transforming growth factor-β₁ plays an important role in the altered metabolism of collagen in HCC.