The prevention and reversibility of tissue non-enzymatic glycosylation in diabetes

The time course of non-enzymatic glycosylation (NEG) of liver, kidney, tail collagen, and haemoglobin was studied in diabetic rats. Increased NEG of liver, kidney, and collagen was detectable within 4 weeks of diabetes. The abnormal NEG of liver, kidney, and haemoglobin present after 4 weeks of untreated diabetes could be normalized by 4-8 weeks of intensive insulin therapy given by continuous subcutaneous infusion. However, the same treatment was ineffective in reversing the abnormal NEG and thermal stability of tail collagen. The differences in the development and reversibility of these tissue changes may be due to different tissue turnover rates. Insulin therapy, given from the onset of diabetes, was effective in preventing the development of collagen abnormalities. This suggests that early and vigorous treatment of diabetes is necessary to prevent collagen changes which are potentially irreversible.     

硅凝胶乳房假体包膜组织学研究

目的　通过动物实验 ,以了解硅凝胶乳房假体包膜中胶原组织学特点。方法　 30只大白兔 ,每只大白兔背部两侧肌层下随机各置入 10ml硅凝胶假体 1个。 3周、1、2、3、6、12个月时分别将包膜和假体完整地取出 ,在光学显微镜下测量包膜厚度 ,取包膜样本做成石蜡切片 ,进行HE染色、James染色、维多利亚蓝、丽春红复合染色和天狼猩红染色 ,光学显微镜下观察比较包膜特点 ,其余包膜样本进行胶原分型和含量测定。结果　⑴假体组织学特点 :大致可分为两层 ,包膜外层为疏松结缔组织 ,内层为致密结缔组织。包膜厚度在 3个月前逐渐增加 (P <0 .0 1) ;置入时间越长 ,假体包膜胶原成分越多、细胞成分越少 ,包膜越厚 (P <0 .0 1) ;3个月后 ,趋于稳定 (P >0 .0 5 )。⑵包膜胶原总量在 3个月前逐渐增高(P <0 .0 1) ;3个月后趋于稳定 (P >0 .0 5 )。⑶ 3个月前 ,包膜中胶原纤维最多 ,网状纤维次之 ,弹力纤维最少甚至无 ;,3个月后趋于稳定。⑷ 3个月前 ,包膜Ⅲ型胶原有减少趋势 ,Ⅰ型胶原有增多趋势 ;3个月后 ,均趋于稳定。结论　假体包膜在组织学上与瘢痕类似 ,是假体周围创面愈合的必然产物     

Immunofluorescent localization of structural collagen types in endochondral fracture repair

A nonimmobilized rat tibial fracture model of endochondral osseous repair was examined for the unique localizations of specific collagen genetic types. At various stages of the healing process, the demineralized callus was reacted with immunofluorescent antibodies directed against the type specific forms of matrix collagen. Type III collagen rapidly appeared (day 8-10) and remained in the primitive mesenchymal callus until remodeled. It was particularly prominent in the highly vasoformative regions and the pericallus encapsulation but not present in preexisting cortical and neoformed lamellar bone. The type II collagen, a marker of cartilage, was uniquely located only in areas of chondroid differentiation and calcification. Type II collagen was absent from all bone and was not identified beneath the repairing intact periosteum. The differentiating chondrocytes synthesized type II collagen on an underlayer of type III collagen already within the mesenchymal matrix. From these studies of genetically unique collagen markers, it appears that only in areas of motion or anoxia does an intermediate of chondroid tissue appear. The utilization of specific type II and type III collagen immunofluorescent antibodies has facilitated the understanding of the fracture repair process and has acted as an indicator for unique matrix components.     

胶原基纳米骨修复兔下颌骨缺损的实验研究

目的 研究胶原基纳米骨(nHAC)修复下颌骨缺损的效果,以期为临床提供一种理想的骨替代材料。方法 在32只成年兔双侧下颌骨形成0.8 mm×0.6mm全层骨膜骨质缺损,每一缺损作为一个实验单位。术后4、5、6、8、10、11、12周取材,行大体标本、X线片、组织学和扫描电镜观察。结果 nHAC与CPC相比同期成骨量大。8周时nHAC成骨情况尚不如Bio-Oss。而12周时已接近Bio-Oss成骨水平。空白缺损则未能修复。结论 nHAC生物相容性好,效果较好于CPC,远期与Bio-Oss相似,是一种较为理想的骨替代材料。     

Recombinant human insulin-like growth factor-I stimulates in vitro matrix synthesis and cell proliferation in rabbit flexor tendon

Flexor tendons have an intrinsic ability for repair, with a capacity to metabolize matrix components and to proliferate. To identify factors with the potential of affecting those abilities, the effects of recombinant human insulin-like growth factor (rhIGF-I), insulin and fetal calf serum (FCS) on the synthesis of proteoglycan, collagen, and non-collagen protein and cell proliferation were investigated in short-term explant cultures of the deep flexor tendon of the rabbit. Matrix synthesis and cell proliferation were stimulated dose dependently by rhIGF-I at doses between 10 and 250 and at 10-100 ng/ml, respectively, by insulin at 250-5,000 ng/ml, and by FCS at 2-15%. Estimated maximal stimulation (Emax) of up to three times the control value was observed with rhIGF-I at 250 ng/ml. Maximal stimulation was observed at 5,000 ng/ml with insulin, and FCS at 15%. rhIGF-I was more potent than insulin in stimulating protein synthesis and cell proliferation. The Emax of stimulation of proteoglycan and collagen synthesis by rhIGF-I were two times that of FCS, and the Emax of cell proliferation by FCS was twice that of rhIGF-I. Growth factors thus have the ability to stimulate matrix synthesis and cell proliferation in rabbit flexor tendon. This provides a rationale for further studies on the role of growth factors in flexor tendon healing in humans.     

Localization of collagen in the rat lung: biochemical quantitation of types I and III collagen in small airways,vessels, and parenchyma

The marked insolubility of pulmonary collagen has limited its accurate biochemical quantitation in small samples of lung and other tissues. We have recently developed a microassay based on radioisotope dilution techniques that we have used for the accurate determination of types I and III collagen in extremely small tissue samples. By applying this method to carefully dissected small airways and vessels and samples of parenchymal tissue of rat lungs, we have localized and quantitated biochemically the type I and III structural collagens of the lung. Large pulmonary arteries are the units richest in these interstitial collagen types on the basis of dried tissue weight (50 μg/100 μg dried tissue). Amounts of both types I and III collagen are considerably lower in the alveolar domain than in vessels and airways of the rat lung. The proportion of tissue composed of these collagen types decreases centripetally in rat pulmonary arteries, but increases in the bronchial tree. The relative proportions of type I and type III remain constant in all the structures tested. The higher total amount of collagen in the nonalveolar domain has implications for biochemical studies based on whole lung samples.     

Activity of rheumatoid arthritis and levels of collagen antibodies: a prospective study

Summary Thirty-seven patients with classical or definite rheumatoid arthritis (RA) were studied prospectively over a period of 12 months to assess whether there was a relationship between disease activity and raised levels of antibodies to native or denatured type II collagen. Nineteen patients had inactive RA according to ARA criteria for disease remission and 18 had active RA throughout the study. At the beginning of the study the levels of collagen antibodies were comparable in each group. After 1 year, antibodies to denatured type II collagen in patients with inactive RA had declined to significantly lower levels whereas in patients with active RA the levels of antibodies fluctuated during the period of study and were not significantly different at the end. There was no relationship between levels of antibodies to type II collagen and any specific index of disease activity, severity of X-ray changes in the hands and feet, or progression over 1 year in X-ray changes. The finding of a decline in levels of antibodies to denatured type II collagen in inactive RA suggests that the anticollagen response is an integral component of the rheumatoid process and could have a primary or secondary role in pathogenesis.     

实验性肝硬化形成过程中肝脏糖胺多糖和胶原含量的变化

采用四氯化碳、高胆固醇饮食等复合致病因子所致肝硬化大鼠模型，检测了肝硬化发生发展过程中肝脏胶原及己糖胺、透明质酸含量的变化。结果表明：随着肝硬化的发生发展肝脏胶原含量呈进行性增加，肝脏透明质酸、己糖胺含量亦相应增加，且在肝脏纤维间隔形成阶段（实验第四、六周）其胶原含量与己糖胺水平呈显著正相关。     

Allograft Airway Fibrosis in the Pulmonary Milieu: A Disorder of Tissue Remodeling

Obliterative bronchiolitis (OB) is thought to be a form of chronic allograft rejection. However, immunosuppressive therapy is not effective once fibrosis has developed. We hypothesize that disordered tissue remodeling is a mechanism for the pathogenesis of OB. We examined allograft airway fibrosis in an intrapulmonary tracheal transplant model of OB. Allograft airways were completely obliterated at day 21 by fibrotic tissue; however, tissue remodeling continued thereafter, as demonstrated by the change of collagen deposition density, shift from type I to type III collagen, shift from fibroblasts to myofibroblasts and shift of expression profiles and activities of matrix metalloproteinases (MMPs). We then used a broad-spectrum MMP inhibitor, SC080, to attempt to manipulate tissue remodeling. Administration of the MMP inhibitor from day 0 to day 28 reduced airway obliteration, without inhibiting T-cell activation. MMP inhibition from day 14 to day 28 showed similar effects on airway obliteration. MMP inhibition from day 21 to day 35 did not reverse the airway obliteration, but significantly reduced the collagen deposition, type III collagen and myofibroblasts in the lumen. We conclude that tissue remodeling plays a critical role in the development and maintenance of fibrosis after transplantation.     

The value of injectable collagen in vocal and glottic rehabilitation

Summary In 1962, Arnold used injectable Teflon to reintroduce Brünings' technique for rehabilitating the paralysed vocal cord. Although Teflon would not appear to be carcinogenic, the technique is not entirely trouble-free. Injectable collagen as a biological implant seems to be an attractive alternative since it is a component part of the extracellular protein matrix. In actual clinical use, the collagen is easily injectable, is well-tolerated by patients, and is only subject to limited resorption. It also undergoes some transformation into living connective tissue with neovascularization. Our study was carried out on 14 patients: 13 had vocal cord paralyses from various causes and 1 had vocal cord atrophy as a sequel to traumatic injury. The therapeutic indication for correction in all of these patients was dysphonia for which speech therapy had failed to produce an adequate result. One patient was found to suffer from symptomatic aspiration as well. The actual technique of surgery involved the injection of a mean quantity of 1.5 cc collagen into the submucosal tissue of the affected cord during direct laryngoscopy. Postoperatively, all of our patients showed improved dysphonia without secondary effects occurring from the collagen. We also found lessened aspiration in our patient so affected. Our period of follow-up to date ranges from 3–12 months.Read in part before the XIII World Congress of Otolaryngology, Miami Beach, Florida, May 26–31, 1985