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.     

Corns and calluses in athletes’ feet: a cause for concern

The risk of suffering disorders of the skin and underlying tissue in the lower extremities is one of the few adverse effects of a physically active lifestyle. Engagement in a physically challenging sport, demanding and repetitive physical activity or high-impact exercising has particularly been linked to hyperkeratotic lesions such as corns and calluses. Corn and callus formation is the skin's natural attempt to compensate for prolonged or excessive pressure, friction and other forms of local irritation by increasing its thickness at sites of excessive mechanical stress. Initially this thickening of the skin is helpful, but over time it builds up and becomes a source of morbidity. Increased mass of the lesion results in increased pressure and discomfort. Thus, a vicious cycle develops which is only broken by decreasing the size of the hyperkeratotic growth and relieving or eliminating pressure on the affected area of the skin. Failure to treat these conditions appropriately and adequately may contribute to the development of serious and disabling skin pathology. This paper considers the incidence of corns and calluses pertaining to athletes’ feet, describes their clinical characteristics, outlines the underlying causes or etiology of their formation, provides an overview of the pathogenetic mechanism responsible for their development and addresses certain diagnostic procedures used to identify them. The therapeutic means available for the treatment of corns and calluses along with their potential complications are further presented and discussed.     

浓蜜贝母的组织培养条件及不同时期生物碱积累的研究

目的对浓蜜贝母Fritillaria mellea原种鳞茎进行组织培养,比较浓蜜贝母愈伤组织生长过程中不同时期的总生物碱含量.方法采用不同激素、温度、光照等方法,探索浓蜜贝母愈伤组织的最佳诱导率条件,并对其总生物碱含量进行测定.结果浓蜜贝母的最佳诱导条件为激素及浓度NAA 1 mg/L+6BA 6 mg/L;温度(22±1)℃;散射光照;愈伤组织形成后20 d左右时的总生物碱含量最高.结论浓蜜贝母愈伤组织的总生物碱含量高于原种鳞茎.     

干旱胁迫对管花肉苁蓉组织培养体系中苯乙醇苷类成分含量的影响

目的建立管花肉苁蓉Cistanche tubulosa组织培养体系,并考察干旱胁迫对其中苯乙醇苷类成分含量的影响。方法通过液质联用技术分析管花肉苁蓉愈伤组织与悬浮培养体系中的主要化学成分,绘制其生长曲线,并通过渗透压调节剂(NaCl、甘露醇和PEG6000)模拟干旱胁迫环境,考察组织培养体系中松果菊苷和毛蕊花糖苷含量的变化。结果管花肉苁蓉愈伤组织与悬浮培养细胞均能生成松果菊苷和毛蕊花糖苷;绘制管花肉苁蓉愈伤组织生长曲线,确定30d为最佳继代时间;NaCl和甘露醇所诱导的干旱胁迫不利于愈伤组织细胞的生长及其苯乙醇苷类成分的积累,而6%PEG6000能显著促进悬浮细胞中苯乙醇苷类化合物的生成,诱导15d后,松果菊苷和毛蕊花糖苷的生物量分别为(1.07±0.10)g/L和(0.12±0.01)g/L,分别可达细胞干质量的20.94%和2.27%,为对照组的1.29倍和1.19倍。结论 PEG6000介导的干旱胁迫对管花肉苁蓉悬浮细胞中松果菊苷和毛蕊花糖苷的积累有明显促进作用。     

性激素缺乏对大鼠骨折愈合的影响

目的初步探讨性激素缺乏对骨折后大鼠骨折愈合的影响.方法采用64只3月龄Wistar大鼠,通过切除性腺后立即行右胫骨人造骨折手术.建立雌雄大鼠的骨折模型,分别于术后2、4、6、8周处死大鼠,取材行各项指标测定.结果(1)在术后不同时间组之间血钙(F=9.12.P＜0.005)、血镁(F=3.46,P＜0.05)和AKP值(F=6.7,P＜0.005)有显著性差异.(2)在去势组与非去势组之间股骨近端(F=6.29,P＜0.05)、胫骨骨折区(F=6.03,P＜0.05)BMD均有显著性差异,去势组BMD相对较低.大鼠胫骨骨折区BMD值在骨折后不同时期(F=17.54,P＜0.005)有显著性差异,随着术后时间的增加BMD值逐渐增加.(3)放射学检查显示非去势组骨痂和股骨近端骨密度较去势组高.(4)组织学检查显示去势大鼠的骨痂骨密度低,局部及周围骨质疏松化,骨痂编织骨化、板层化延迟.结论性激素缺乏会导致骨形成吸收偶联失衡,从而影响骨折愈合.     

家兔骨延长术中固定刚度对骨愈合的影响

目的探讨家兔骨延长术中固定刚度对骨痂生长和骨愈合的作用效果,为临床骨延长术选择最佳固定刚度提供参考依据。方法在骨延长动物模型截骨愈合的过程中,对模型动物使用外固定架固定。通过改变克氏针的直径(1.0 mm和1.5 mm),获得不同的固定刚度。截骨愈合后获取骨痂的HE染色片、X线平片、患肢与健肢负重力比值等,用自主开发的软件计算患足的侧位X线片上最弱截面与最强截面的惯性矩比值,计算正位X线片的骨痂总面积,分析这些参数与所采取的固定刚度的关系,描述不同的固定刚度对于骨痂形成及骨愈合所产生的作用效果。结果截骨后,随着治疗时间的延续,患肢的侧位X片上最弱截面与最强截面的惯性矩比值先下降到0.15±0.10,随后逐渐上升到0.44±0.12;患肢与健肢负重力比值由0.49±0.04逐渐上升到0.81±0.06;正位X线片骨痂总面积由80.03 mm2±50.04mm2逐渐上升到134.81 mm2±39.73 mm2。上述三项指标,在1.0 mm和1.5 mm直径克氏针固定组之间的差异均没有统计学意义。两组动物X线片骨痂总面积测量结果显示,1.0 mm克氏针固定组骨痂面积稍大于1.5 mm克氏针固定组;两组动物的骨标本HE染色结果显示,1.0 mm克氏针固定组新生骨组织活跃程度比1.5 mm克氏针固定组稍强。结论使用1.0 mm和1.5 mm克氏针都能够使截骨端愈合;两种固定刚度对患肢的侧位X线片上最弱截面与最强截面的惯性矩比值、患肢与健肢负重力比值的影响没有统计学意义;使用1.0 mm克氏针固定可以使截骨端产生更多的骨痂,增强新生骨组织的活跃程度。     

提高芍药愈伤组织中芍药苷和芍药内酯苷的含有量

目的进一步优化芍药愈伤组织中积累芍药双苷(芍药苷和芍药内酯苷)的培养条件。方法以芍药愈伤组织中芍药双苷的量为响应值,采用Plackett-Burman实验设计对8个影响愈伤组织生长和芍药双苷积累的植物激素(NAA、2,4-D、6-BA、TDZ)的质量浓度、蔗糖的含有量、Ca2+量、NH4+∶NO3-的比例及光照中筛选出了3个关键因素,通过最陡爬坡逼近和响应面优化方法确定这些因素的最适水平。结果三个因素的最佳条件为:40.20 g/L蔗糖、0.33 mg/L 6-BA和1.08 mg/L NAA。结论在此最优培养条件下,芍药愈伤组织合成芍药双苷的能力比优化前提高了33%,芍药双苷占愈伤组织干重含有量达到37.60 mg/g。     

不同浓度外源激素对黄芩愈伤组织诱导影响

目的：运用植物组织培养技术选择适合黄芩愈伤组织诱导的生长素与细胞分裂素的配比及浓度。方法：以黄芩幼根、叶片和带节茎段为外植体,用不同浓度生长素和细胞分裂素对黄芩进行愈伤组织诱导试验。结果：6-BA1.0mg·L-1诱导形成的愈伤组织疏松,诱导率高。诱导黄芩愈伤组织最佳生长素与细胞分裂素的浓度配比为NAA0.5mg·L-1＋6-BA1.0mg·L-1。结论：生长素与细胞分裂素配合使用时,愈伤组织的诱导率明显高于单个激素的处理,诱导结果也有差异。     

骨折愈合过程中低氧诱导因子-1α的表达及其调节作用

目的 探讨骨折愈合过程中低氧诱导因子-1α(HIF-1α)的表达及其调节作用.方法 建立小鼠胫骨骨折模型,骨折后1、3、7、14、21、28 d取材,应用X线摄片、Micro-CT和四环素荧光双标记技术,观测骨痂组织的演变和新骨形成状况;采用RT-PCR、Western blotting和免疫组织化学方法 ,检测骨痂组织细胞HIF-1α、血管内皮生长因子(VEGF)和成骨性标志物(Runx2和ALP)的表达状况,分析HIF-1α与骨折愈合进程的关系.结果 在早期骨痂组织中,募集于骨折处的细胞以及由此演化的成骨细胞、软骨细胞及骨细胞在低氧环境中均表达HIF-1α.骨折后第7天,HIF-1α阳性细胞百分率达到峰值,持续高表达7 d后逐渐下降,骨折后第28天基本恢复至骨折前水平;细胞VEGF表达特征的变化与HIF-1α的表现相似;早期骨痂细胞的骨形成功能活跃,骨痂体积较大,至骨折后14 d达到峰值后随骨改建的发生而逐步减小,骨痂矿化沉积主要发生于骨折愈合的中晚期(14～28 d).结论 骨折愈合过程中,参与骨折愈合的细胞属低氧感应细胞并表达HIF-1α;HIF-1α可调节细胞自身的状态,通过调控早期骨痂细胞的功能和刺激血管新生而参与调节骨折的愈合.     

激素和外植体对黄芩短枝生根和愈伤诱导的影响

目的研究不同激素组合和外植体对黄芩短枝生根和愈伤诱导的影响,筛选出最佳的短枝生根和愈伤诱导及继代培养基。方法以1/2MS为基本培养基,添加不同浓度的萘乙酸(NAA),配制成5种短枝生根培养基;以MS为基本培养基,添加不同浓度BA和NAA或2,4-D,配制成5种培养基。将剪下的枝条用清水冲洗2~3 h,再用2%次氯酸钠溶液浸泡15 min,最后用无菌水冲洗4~5次,将带1个腋芽或不带腋芽的茎段和叶片接种到培养基中。结果1/2MS培养基是最佳的1年生和2年生短枝生长和生根培养基,生根率达100%,腋芽的增殖倍数高达3.1和3.4;诱导愈伤组织的最适培养基及愈伤最佳的继代培养基均为MS+BA2.0 mg/L+NAA0.1 mg/L。结论高浓度的生长素对黄芩短枝生长势和生根有抑制作用,高浓度BA配比较低浓度NAA适于愈伤诱导,1年生和2年生短枝生根时对生长素的反应有一定差异。