正常黄韧带中胶原的实验研究

目的研究人正常黄韧带中Ⅰ型和Ⅱ型胶原含量,探讨临床意义。方法用盐析法对34个正常黄韧带标本中的Ⅰ型和Ⅱ型胶原含量进行测定,并用SDS-PAGE法进行胶原的分型确定。结果正常黄韧带中Ⅰ型胶原含量为8.89±1.13(g/100g湿重黄韧带),Ⅱ型胶原含量为0.51±0.12(g/100g湿重黄韧带),二者有显著差异,P<0.01。结论正常黄韧带中主要胶原为Ⅰ型胶原,Ⅰ型胶原在黄韧带中主要维持其抗张力性能和刚性。     

Specificity of urinary excretion of cross-linked N-telopeptides of type I collagen as a marker of bone turnover

Urinary excretion of cross-linked N-telopeptide of type I collagen (NTX) has been reported to be a specific indicator of bone resorption. We studied the utility of a new immunoassay for NTX as an indicator of changes in bone resorption caused by treatment with pamidronate (APD) followed by T₃. Twenty-two male subjects received either placebo (Group 1) or APD on study days 1–2 (Group 2). One week later all subjects received T₃ 100 g/day (days 8–15). Urinary NTX, pyridinoline (PYD), hydroxyproline (HYP), and creatinine (cr) were measured on 2-hour fasting urine samples at baseline (day 1), after APD/placebo (day 8), after T₃ (day 16), and at days 30 and 58. NTX/cr excretion fell 85% after treatment with APD (P<0.001 versus baseline), but not after placebo. The fall in mean urinary NTX after receiving APD was greater than the fall in PYD (25%) or HYP (31%) (P<0.001 NTX versus PYD and HYP). After treatment with APD, NTX excretion remained suppressed below baseline until day 58, whereas PYD and HYP excretion returned to baseline by study day 16. Persistence of APD's effect on bone until day 58 was suggested by the fact that serum calcium and parathyroid hormone levels had not returned to baseline by day 58. On day 16, after all subjects were treated with T₃, urinary NTX/cr rose significantly (P<0.01) in Group 1 (-bisphosphonate) but not in Group 2 (+bisphosphonate). We conclude that urinary NTX is responsive to acute thyroid hormone-induced increases and bisphosphonate-induced decreases in bone resorption, and may reflect these changes more accurately than PYD or HYP.Portions of the data presented here were presented at the Fifteenth Annual Meeting of the American Society for Bone and Mineral Research, Tampa, Florida, September 18–22, 1993.     

The dynamics of β1 integrin expression during peripheral nerve regeneration

The aim of the present study was to examine the expression of 1 integrin subunit after peripheral nerve transection. After sciatic nerve transection two experimental procedures were used; changes in the freely regenerating rat sciatic nerve were compared to a situation in which spontaneous regeneration was prevented by suturing both ends of the nerve to the muscle next to the point of transection. Specimens for morphological analysis were collected 6 h, 1, 3, 5, 7 days and 2, 4, 6 and 8 weeks after the axotomy. Sections from the proximal (two zones) and distal (three zones) stumps next to the point of transection were stained with antibodies against 1 integrin subunit, macrophages, collagen types I and III, and S-100 protein. The control nerves showed 1 integrin-stained cells in the perineurium and vasa nervorum but the endoncurium was negative. Positively stained endoneurial fibroblast-like cells could be seen in the proximal part of the nerve already at 24 h after transection. The number of these positively stained cells increased steadily; they were most numerous 4 weeks after transection in the distal zone 2. Subsequently, the number of positively stained endoneural cells declined sharply and 8 weeks after transection no positively stained cells could be found. The morphological appearance and the immunohistochemical properties of the cells suggest that the majority of 1 integrin-positive cells are endoneurial fibroblast-like cells. Thus, the process appeared to be dynamic, starting from the proximal part and continuing to the distal parts, and was similar in both experimental groups. The positive staining in perineurial cells indicate that 1 integrin, which is an important mediator of the cell-matrix interaction, may have an essential role in the formation and strengthening of the normal peripheral nerve structures. Furthermore, 1 integrin seems to have an active role in reactions which occur during the early phases of peripheral nerve regeneration.     

血清Ⅳ型胶原测定在肾移植中的意义

目的：探讨血清Ⅳ型胶原（Ⅳ－Ｃ）动态变化在肾移植术后监测中的意义。方法：检测６１例肾移植患者血清Ⅳ－Ｃ浓度,观察不同病情状况时血清Ⅳ－Ｃ浓度的改变。结果显示：肾移植术前及术后动态测定血清Ⅳ－Ｃ浓度有助于早期诊断和鉴别诊断急性排斥反应（ＡＲ）、急性肾小管坏死（ＡＴＮ）和感染,可作为肾移植监测的一个辅助指标。     

Improved Bone Biomechanical Properties in Rats after Oral Xylitol Administration

The effects of 5, 10, and 20% dietary xylitol supplementations on the biomechanical properties, histological architecture, and the contents of collagen, pyridinoline, and deoxypyridinoline in long bones of rats were studied. Tibiae were used for the three-point bending test, and femurs were used for the torsion and loading test of the femoral neck. The 10 and 20% oral xylitol administrations caused a significant increase of tibial stress, femoral shear stress, and stress of the femoral neck as compared with the controls. Parallel, but not significant, effects were also seen in the 5% xylitol supplementation group. No significant differences in strain or Young's modulus of the tibiae were detected between the groups. An increased shear modulus of elasticity in femurs was detected in the 20% supplementation group as compared with the controls. The histomorphometrical data for the secondary spongiosa of the proximal tibia revealed that trabecular bone volume was significantly greater in all dietary xylitol supplementation groups as compared with the controls. The bone volume increased along with increasing xylitol content. No significant differences between the groups were detected concerning the amount of collagen per dry weight of organic matrix, the concentrations of pyridinoline or deoxypyridinoline in collagen, or the ratio of these crosslinks. This suggests no xylitol-dependent selective changes in these structures of bone collagen. In conclusion, dietary xylitol supplementation in rats improves the biomechanical properties of bone and increases the trabecular bone volume dose dependently. Received: 30 January 1997 / Accepted: 1 October 1998     

乙型肝炎病毒前C区变异患者血清Ⅳ型胶原/层粘连蛋白和一氧化氮的分析

目的：分析乙型肝炎病毒（ＨＢＶ）前Ｃ区基因变异在肝纤维化形成中的作用,探讨肝纤维化与一氧化氮的关系。方法：利用错配ＰＣＲ限制片段多态性分析,检测ＨＢＶ前Ｃ区１８９６位点突变,并检测慢性乙肝患者血清Ⅳ型胶原／层粘连蛋白（ＣⅣ／ＬＮ）和ＮＯ。结果：Ａ组３１例前Ｃ区变异或变异优势患者ＣⅣ（１２７．３５±２４．３３）μｇ／Ｌ,ＬＮ（１６９．１０±２８．２３）μｇ／Ｌ明显高于Ｂ组３０例无前Ｃ区基因变异患者ＣⅣ（８６．８４±１２．６６）μｇ／Ｌ,ＬＮ（９４．２０±１５．２９）μｇ／Ｌ（Ｐ＜０．００１）,且Ａ组ＮＯ－２／ＮＯ－３（４８．５５±４．０３）μｍｏｌ／Ｌ明显高于Ｂ组ＮＯ－２／ＮＯ－３（３６．６０±４．０２）μｍｏｌ／Ｌ（Ｐ＜０．００１）。结论：ＨＢＶ前Ｃ区变异与肝纤维化、肝硬化发生发展有关系,且血清ＮＯ随ＣⅣ和ＬＮ增高而增高。     

Collagen production by human smooth muscle cells isolated during intestinal organogenesis

Summary The extracellular matrix influences organogenesis by modulating cell behavior. In humans, collagen is the major matrix constituent of the adult intestinal wall and is synthesized by smooth muscle cells. The objective of the current study was to examine collagen production by fetal human intestinal smooth muscle cells isolated during intestinal morphogenesis. Techniques were developed for the isolation and culture of human fetal intestinal smooth muscle cells. The cultured cells were confirmed as muscle by immunohistochemical stains for cytoskeletal filaments and documentation of contractile behavior. In culture, these cells stained for mesenchymal and muscle cytoskeletal proteins: vimentin, actin, and desmin, and did not stain for neural or epithelial markers. The muscle cells contracted in response to acetylcholine, in contrast to human fetal dermal fibroblasts which did not contract appreciably. Collagen production was assayed by the uptake of [³H]-proline into collagenase-digestible protein. Collagen production was greatest at 11 weeks gestation, the youngest age studied. By 20 weeks gestation, collagen production had decreased to adult levels. However, when compared to another matrix-producing fetal mesenchymal cell, the dermal fibroblast, intestinal smooth muscle cells produced twice as much collagen. Collagen types were determined by polyacrylamide slab gel electrophoresis. Smooth muscle cells predominantly produced types I and III collagen chains. Therefore, collagen production is a significant function of human fetal intestinal smooth muscle cells, and probably plays a major role in the development of intestinal structure. The in vitro model presented here provides a means of studying the regulation of this collagen production throughout intestinal organogenesis.     

抗纤软肝冲剂对肝星状细胞胶原降解相关基因表达的影响

目的 从细胞分子水平研究抗纤软肝冲剂对肝星状细胞(HSC)胶原降解的影响。方法 抗纤软肝冲剂药物血清温育传一代HSC，以生理盐水和秋水仙碱为对照。ELISA法测定细胞上清I型胶原，并测定细胞层总蛋白以校正胶原含量；半定量RT—PCR法检测间质胶原酶(MMN)和金属蛋白酶组织抑制因子-1(TIMP-1）的mRNA表达。结果 抗纤软肝冲剂组细胞上清中的I型胶原含量明显低于其他两组(P＜0．05或P＜0．01)；明显促进细胞MMN的mRNA表达(P＜0．05或P＜0.01)，显著抑制细胞TIMP-1的mRNA表达(P＜0．05或P＜0．01)。结论 抗纤软肝冲剂能促进MMN基因表达，抑制TIMP-1基因表达，从而促进胶原降解，这可能是该方抗肝纤维化的细胞分子学机制之一。     

黄芪注射液对病毒性心肌炎患者血清胶原前肽的影响

目的研究黄芪注射液对心肌炎患者心脏胶原代谢的影响。方法83例临床心肌炎患者与20例健康志愿者作为研究对象,心肌炎患者予黄芪注射液治疗2周,在治疗前、后以ELISA法分别检查其血清中I型胶原羧基末端肘(ICTP)和Ⅲ型前胶原氨基末端肽(PⅢNP)浓度。健康志愿者不予用药作为空白对照。结果心肌炎患者血清胶原前肽水平较健康志愿者明显增高。经连续2周黄芪注射液治疗后,心肌炎患者ICTP和PIIINP血清浓度均下降,其中ICTP接近正常水平。结论黄芪注射液治疗心肌炎疗效可靠,黄芪注射液可能通过干预胶原代谢,抑制胶原过度增生而改善患者预后,减少并发症的发生。     

The Effect of Carboxyl-Terminal Propeptide of Type I Collagen (c-Propeptide) on Collagen Synthesis of Preosteoblasts and Osteoblasts

Recently we found that the carboxyl-terminal propeptide of type I collagen (c-propeptide) is a major secretory protein of osteoblasts. Mature osteoblasts secreted 64 nM c-propeptide, and it was reported that 40 nM c-propeptide inhibited collagen synthesis at 80% of the control level. In this study, we investigated the effect of c-propeptide on collagen synthesis of preosteoblasts and osteoblasts, and found that preosteoblasts downregulated collagen synthesis by 40 nM c-propeptide, but osteoblasts were not affected by the same condition. When the binding activities of c-propeptide for preosteoblasts and osteoblasts were compared, osteoblasts showed weak affinity to c-propeptide compared with preosteoblasts, and the number of receptors for c-propeptide decreased in osteoblasts. These results imply that a decrease of receptors in osteoblasts might reduce the sensitivity of osteoblasts to c-propeptide. Received: 6 August 1999 / Accepted: 9 May 2000 / Online publication: 22 September 2000