FT-IR study for hydroxyapatite/collagen nanocomposite cross-linked by glutaraldehyde

FT-IR analysis was performed for the hydroxyapatite (HAp)/collagen (COL) nanocomposite cross-linked by glutaraldehyde (GA). The amide bands I, II and III from COL matrix, and phosphate and carbonate bands from HAp were identified. The amide B band arising from C–H stretching mode showed a sensitive conformation by the degree of cross-linking. The amide I band showed a complicate conformational change by the degree of cross-linking. The characteristic amide I band at 1685 cm⁻¹, which is known as an aging parameter in the biological bone, did not show a monotonous tendency by the degree of cross-linking. The relative contents of the organics in the cross-linked HAp/COL nanocomposite were evaluated as an integration ratio between the amide I band at 1600–1700 cm⁻¹ and PO₄³⁻ band at 900–1200 cm⁻¹. The increase of the organics content by the cross-linking is enabled by the further organization of Ca²⁺ ions of HAp crystals in HAp/COL nanocomposite. The complicate conformational behavior in the amide I, II and III bands seems to be affected by the cross-linking induced directional arrangement of HAp/COL nanocomposite fibrils.     

Scanning electron microscopic studies of reticular framework in the rat mesenteric lymph node

Background: The reticular framework in the lymph node has in the past been studied mainly by light microscopy of silver-impregnated specimens. The aim of the present study is to understand three-dimensionally the ultrastructure and organization of the reticular framework better than before. Methods: The mesenteric lymph nodes of the rat were prepared either an alkali-water maceration method or a conventional method and were observed in a scanning electron microscope (SEM). Results: The SEM study of alkali-water macerated tissues visualized directly the reticular fiber network in the lymph node. The reticular fibers consisted of thin bundles of collagem fibrils. They were continuous with the collagen fibriliar sheaths of blood vessels and lymphatic sinuses as well as with the fibrous capusule, thus acting as a skeleton of the lymph node. The arrangement of the reticulum was variable, depending on individual compartments. The SEM study of conventionally treated tissues, on the other hand, clarified the shape of reticular cells and their relationship with the reticular fibers. The sinus reticular cells connected with the sinus lining cells but separated from the parenchymal reticular cells, indicating that the former two originate from lymphatic endothelial cells. The parenchymal reticular cells varied in shape depending on their locations but essentially shared features with fibroblasts. Conclusions: The arrangements of the reticular fibers in the parenchyma were closely related to the associated reticular cells, showing the possibility that the reticular cells maintain the shape of the reticular framework suitable for each compartment of the lymph node. © 1995 Wiley-Liss, Inc.     

Age- and training-related changes in the collagen metabolism of rat skeletal muscle

Summary The effects of ageing and life-long endurance training on the collagen metabolism of skeletal muscle were evaluated in a longitudinal study. Wistar rats performed treadmill running 5 days a week for 2 years. The activities of collagen biosynthesis enzymes, prolyl-4-hydroxylase and galactosylhydroxylysyl glucosyltransferase, were highest in the muscles of the youngest animals, decreased up to the age of 2 months and from then on remained virtually unchanged. The enzyme activity in young animals was higher in the slow collagenous soleus muscle than in the rectus femoris muscle. The enzyme activity in the soleus muscle was higher for older trained rats than older untrained rats. The relative proportion of type I collagen increased and that of type III collagen decreased with age, suggesting a more marked contribution by type I collagen to the agerelated accumulation of total muscular collagen. The results show that collagen biosynthesis decreases with maturation and that life-long endurance training maintains a higher level of biosynthesis in slow muscles.     

血栓性脑血管疾病患者治疗前后血小板活化膜表面糖蛋白检测及临床意义

目的 :探讨血栓性脑血管疾病患者治疗前后血小板活化标记物CD62 P,GPⅡb/Ⅲa的表达及其临床应用价值。方法 :采用流式细胞仪 (FCM )检测治疗前后血小板活化标记物CD62 P、GPⅡb/Ⅲa的表达。结果 :血栓性脑血管疾病患者治疗前血小板活化标志物CD62 P、GPⅡb/Ⅲa分别为CD62 P5 2 .19± 12 .3 7% ,GPⅡb/Ⅲa 77.98± 14 .2 2 % ,较正常对照组有显著性升高 (P <0 .0 1) ;治疗后CD62 P3 1.16± 17.43 % ,GPⅡb/Ⅲa 40 .71± 11.64 %较治疗前有显著性下降 (P<0 .0 1) ,但仍高于正常对照组 (P <0 .0 1)。结论 :血小板活化标志物CD62 P、GPⅡb/Ⅲa对血栓性脑血管疾病的诊断具有重要价值 ,为临床症状缓解后患者长期药物预防提供理论依据     

中药赤芍对球囊损伤术后血管重构的干预研究

目的 观察中药赤芍防止球囊损伤术后血管重构作用。方法 新西兰白兔随机分为对照组、单纯高脂组、赤芍高剂量组、低剂量组。高脂喂养6周建立动脉粥样硬化模型,行颈动脉球囊损伤术,8周时取材作病理形态学检查。结果(1)与高脂组比较,赤芍高、低剂量组增生内膜面积、中层面积,内膜、中膜、外膜PCNA阳性着色均显著减少(P<0.05或P<0.01)。(2)各组内皮增生成分主要为平滑肌细胞;巨噬细胞阳性着色主要分布在外膜,与高脂组比较,赤芍高、低剂量组阳性着色较少。(3)高脂组动脉损伤侧外膜Ⅰ型胶原增多,赤芍组Ⅰ型胶原增加较少。结论 赤芍对高脂喂养兔颈动脉球囊损伤术后血管重构有显著防止作用。     

类风湿性关节炎患者关节滑膜液浸润的T细胞表达特性

目的 :为研究类风湿性关节炎 (RA)患者关节滑膜液浸润的淋巴细胞介导自身免疫病的特性 ,分析了 2 2例RA患者滑膜液中淋巴细胞的免疫表型、对II型胶原的反应频率及IL 10、IL 12的分泌格局。方法 :用流式细胞术分别测定滑膜液和外周血淋巴细胞表型 ,并采用国际标准半有限稀释法分析了关节滑膜液中浸润的淋巴细胞对II型胶原 (CII)的反应频率 ,同时用ELISA方法检测了滑膜液与外周血中IL 10与IL 12含量。结果 :滑膜液中的T淋巴细胞的表型分别为CD4 (39 6 %±10 5 % )和CD8细胞 (36 4 %± 16 4 % ) ,CD4 CD8细胞比值显著低于外周血 ,且同时表达CD16和CD5 6的活化NK细胞占15 5 %± 11 1%。T细胞受体谱取用表明仍以αβTCR为主 (6 9 6 %± 15 7% )。有意义的是 :滑膜液中的T细胞对CII的反应频率为 15 2× 10 - 6 ,远远高于外周血 (4 0× 10 - 6 )。IL 12含量为 (4 19 9± 89 2 )pg ml,IL 10含量为 (187 7± 34 5 )pg ml,与外周血中这 2种细胞因子的含量〔分别为IL 12 :(6 5 32± 34 2 )pg ml和IL 10 :(85± 12 7)pg ml〕比较 ,具有显著的统计学差异。结论 :上述实验结果表明这种具有表达特性的浸润T细胞介导了RA患者关节滑膜组织的免疫损伤。     

Functional associations between collagen fibre orientation and locomotor strain direction in cortical bone of the equine radius

A novel technique for determining the collagen fibre orientation pattern of cross-sections of cortical bone was used to study mid-diaphyseal sections from the equine radius. Several in vivo strain gauge studies have demonstrated that this bone is loaded in bending during locomotion in such a way that the cranial cortex is consistently subjected to longitudinal tensile strains and the caudal cortex to longitudinal compressive strains. Twenty-three radii from 17 horses were studied. All the bones obtained from adult horses exhibited a consistent pattern of collagen fibre orientation across the cortex. The cranial cortex, subjected to intermittent tension, and the lateral and medial cortices, through which the neutral axis passes, contained predominantly longitudinally oriented collagen fibres. The caudal cortex, subjected to longitudinal compression during life, contained predominantly oblique/transverse collagen. This pattern was less evident in bones from foals. Microscopic analysis of the bones studied showed that primary lamellar bone was composed of predominantly longitudinal collagen fibres, irrespective of cortex. However, there was a strong relationship between cortical location and fibre orientation within remodelled bone. Secondary osteons which formed in the caudal (compressive) cortex contained predominantly oblique/transverse collagen, while those which formed elsewhere contained longitudinal collagen. This observation explained the developmental appearance of the characteristic macroscopic pattern of collagen fibre orientation across the whole cortex in the adult. These findings provide evidence for the existence of a relationship between the mechanical function of a bone with its architecture, and now demonstrate that it extends to the molecular level.     

氨基葡萄糖胶囊干预膝骨关节炎患者外周血单个核细胞中软骨代谢相关基因的表达

背景:目前关于氨基葡萄糖的研究多集中于对膝骨关节炎的治疗作用,但关于其对膝骨关节炎患者外周血中软骨代谢相关基因影响的研究有限。目的:观察氨基葡萄糖胶囊对膝骨关节炎的治疗效果及对软骨代谢相关基因表达的影响。方法:选取2017年3月至2019年2月郑州大学附属郑州中心医院收治的90例膝骨关节炎患者,另选取同期医院体检中心收入的40例健康受试者,检测并对比健康受试者与膝骨关节炎患者治疗前外周血单个核细胞中软骨寡聚基质蛋白、Ⅱ型胶原纤维α1、聚糖蛋白、特异性组织抑制物3基因表达水平。采用随机数表法将膝骨关节炎患者分为常规组和研究组,分别给予双氯芬酸钠缓释片、双氯芬酸钠缓释片+氨基葡萄糖胶囊治疗12周,对比治疗前后2组外周血单个核细胞中各基因表达水平、Lequesne指数,统计治疗期间2组不良反应发生情况。结果与结论:①与健康受试者比较,膝骨关节炎患者外周血单个核细胞中软骨寡聚基质蛋白、特异性组织抑制物3 mRNA相对表达量升高(P<0.05),Ⅱ型胶原纤维α1、聚糖蛋白mRNA相对表达量降低(P<0.05);②治疗前研究组和常规组外周血单个核细胞中各基因表达水平比较,差异均无显著性意义(P>0.05);治疗后2组外周血单个核细胞中软骨寡聚基质蛋白、特异性组织抑制物3 mRNA相对表达量均低于治疗前,且研究组低于常规组(P<0.05);治疗后2组外周血单个核细胞中Ⅱ型胶原纤维α1、聚糖蛋白mRNA相对表达量均高于治疗前,且研究组高于常规组(P<0.05);③治疗前研究组和常规组Lequesne指数比较,差异均无显著性意义(P>0.05);治疗后2组Lequesne指数均低于治疗前,且研究组低于常规组(P<0.05);④研究组和常规组不良反应发生率比较,差异均无显著性意义(P>0.05);⑤结果表明,氨基葡萄糖胶囊可有效改善膝骨关节炎患者临床症状且安全可靠,可能通过抑制软骨寡聚基质蛋白、特异性组织抑制物3基因表达,促进Ⅱ型胶原纤维α1、聚糖蛋白基因表达实现的。     

血管紧张素Ⅱ对心房颤动患者外向钾电流的作用

目的：研究血管紧张素Ⅱ(AngⅡ)对心房颤动(AF)患者心房肌外向钾电流的作用及其受体机制。方法: 采用急性酶解法获取游离心房肌细胞，应用膜片钳全细胞技术记录外向钾电流。结果: (1) 在钳制电位-10 mV~+50 mV时, AF组瞬时外向钾电流(I_to1)密度明显低于窦性心律(SR)组（P<0.01），而持续性外向钾电流（I_sus）密度与SR组无明显差异。(2) 以0.1 μmol/L AngⅡ灌流后，在钳制电位0 mV~+50 mV时，SR患者的Ito1密度明显低于灌流前（P<0.01），其动力学特性没有改变，AngⅡ对AF组I_to1的抑制作用明显低于SR组 (P<0.01)。0.1 μmol/L AngⅡ对两组I_sus没有影响。(3) AngⅡ对Ito1的抑制作用可逆，10 μmol/L缬沙坦（valsartan）以及1 μmol/L沙拉新(saralasin)均能完全消除0.1 μmol/L AngⅡ对Ito1的抑制，以10 μmol/L valsartan灌流后，膜电位+50 mV时I_to1的电流密度增加（22.46±4.30）%。结论: AngⅡ通过Ⅰ型受体（AT₁R）介导，明显抑制心房肌细胞膜I_to1，是AF患者心房肌瞬时外向钾通道电重构的机制之一。     

内外源性结缔组织生长因子对肾小管上皮细胞胶原合成的比较研究

目的：探讨内外源性结缔组织生长因子（CTGF）对人肾小管上皮细胞（HK2）胶原合成的作用。方法：将HK2细胞分为5组：（1）对照组；（2）TGF-β₁ 5 μg/L刺激组；（3）CTGF 5 μg/L刺激组；（4）TGF-β₁ 5 μg/L刺激＋CTGF反义ODN 3 mmol/L干预组；（5）TGF-β₁ 5 μg/L刺激＋CTGF正义ODN 3 mmol/L干预组。采用 RT-PCR 和Western blotting检测胶原Iα₁（Col Iα₁）、胶原IVα₁（Col IVα₁） mRNA水平和蛋白水平表达。 结果：TGF-β₁刺激可使HK2细胞Col Iα₁、Col IVα₁ mRNA和蛋白表达显著升高，而CTGF刺激则无此作用，CTGF反义ODN可拮抗TGF-β₁刺激引起Col Iα₁、Col IVα₁ mRNA和蛋白表达升高，正义ODN无拮抗作用。 结论：内源性CTGF介导了TGF-β₁刺激引起的HK2细胞胶原合成，外源性CTGF对HK2细胞胶原合成无影响。