Relations between Meckel's cartilage and the morphogenesis of the mandible in the human embryo

Summary Based on a series of human embryos classified in stages [28], the authors studied the evolution of Meckel's cartilage in its ventral portion and its relations to the morphogenesis of the mandible. Three stages appeared particularly important: stage 16, appearance of Meckel's cartilage; stage 20, beginning of membranous ossification; and stage 23, end of the embryonic period (8th week). The primitive bony nodule which develops from the embryonic mesenchyme appears as a double bony layer forming a groove containing the neurovascular bundle, into which the dental lamina is also invaginated.

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Relations entre le cartilage de Meckel et la morphogénèse de la mandibule chez l'embryon humain

Résumé A partir d'une série d'embryons humains classés en stades [28], les auteurs étudient l'évolution du cartilage de Meckel dans sa portion ventrale et ses relations avec la morphogénèse de la mandibule. Trois stades apparaissent comme particulièrement importants : Stade 16 : Apparition du cartilage de Meckel ; Stade 20 : Début de l'ossification membraneuse. Stade 23 : Fin de la période embryonnaire (8ème semaine). Le nodule osseux primitif, qui s'est formé aux dépens du mésenchyme embryonnaire, se présente sous l'aspect d'une double lame osseuse formant une gouttière, lit du paquet vasculo-nerveux, dans laquelle vient également s'invaginer la lame dentaire.

     

Antiangiogenic and antimetastatic properties of Neovastat (Æ-941), an orally active extract derived from cartilage tissue

A novel naturally occurring antiangiogenic agent isolated from cartilage, referred to as Neovastat (AE-941), was examined for its efficacy against tumor neovascularization and progression. Exposure to Neovastat results in ex ovo antiangiogenic properties in the chorioallantoid membrane of chicken embryo (71% decrease in the angiogenic index as compared to the basic fibroblast growth factor (bFGF) treated control embryos, P < 0.0001). Oral administration of Neovastat inhibits bFGF-induced angiogenesis in the Matrigel mouse model (87.5% decrease in hemoglobin as compared to the bFGF-treated control implants, P < 0.0001). Neovastat also induces a dose response decrease of lung metastases in the Lewis lung carcinoma model (oral administration; 69.1% of inhibition obtained at the maximal dose of 0.5 ml/day, P < 0.0001). Combined with a sub-optimal dose of cisplatinum (2 mg/kg, i.p.), Neovastat (0.5 ml/day) improved the therapeutic index by increasing the antimetastatic efficacy and by exerting a protective activity against cisplatinum-induced body weight loss and myelosuppression. In summary, our experimental data provide evidence of antiangiogenic and antimetastatic properties of Neovastat, following oral administration.     

Contrasting in vitro effects of retinol and mononuclear cell factor on young and old human cartilage

Studies with young animal cartilage have shown that retinol and mononuclear cell-factor (MCF) cause in vitro breakdown of the cartilage, mediated by the living chondrocyte (indirect degradation). We studied the effects of retinol and MCF on healthy human articular cartilage of different ages, measuring the effects on proteoglycan (PG) content of the cartilage, and on PG synthesis during 8 days of culture. This study shows: Retinol and MCF induce indirect degradation of young, but not of old human cartilage of the humeral head; Both retinol and MCF suppress PG synthesis of young and stimulate PG synthesis of old cartilage; The effects of retinol and MCF on cartilage PG content and on PG synthesis are related to the metabolic state of the chondrocyte; Therefore mononuclear cell-factor may have a destructive or beneficial effect on cartilage depending on whether proteoglycan synthesizing activity is high or low, respectively.     

The role of cartilage canals in endochondral and perichondral bone formation: are there similarities between these two processes?

We investigated the development of cartilage canals to clarify their function in the process of bone formation. Cartilage canals are tubes containing vessels that are found in the hyaline cartilage prior to the formation of a secondary ossification centre (SOC). Their exact role is still controversial and it is unclear whether they contribute to endochondral bone formation when an SOC appears. We examined the cartilage canals of the chicken femur in different developmental stages (E20, D2, 5, 7, 8, 10 and 13). To obtain a detailed picture of the cellular and molecular events within and around the canals the femur was investigated by means of three-dimensional reconstruction, light microscopy, electron microscopy, histochemistry and immunohistochemistry [vascular endothelial growth factor (VEGF), type I and II collagen]. An SOC was visible for the first time on the last embryonic day (E20). Cartilage canals were an extension of the vascularized perichondrium and its mesenchymal stem cell layers into the hyaline cartilage. The canals formed a complex network within the epiphysis and some of them penetrated into the SOC were they ended blind. The growth of the canals into the SOC was promoted by VEGF. As the development progressed the SOC increased in size and adjacent canals were incorporated into it. The canals contained chondroclasts, which opened the lacunae of hypertrophic chondrocytes, and this was followed by invasion of mesenchymal cells into the empty lacunae and formation of an osteoid layer. In older stages this layer mineralized and increased in thickness by addition of further cells. Outside the SOC cartilage canals are surrounded by osteoid, which is formed by the process of perichondral bone formation. We conclude that cartilage canals contribute to both perichondral and endochondral bone formation and that osteoblasts have the same origin in both processes.     

Evaluation of human knee meniscus biopsies with near-infrared, reflectance confocal microscopy. A pilot study

Knee cartilage biopsy is used to confirm the pathology in both clinical and experimental conditions and often guides diagnosis and therapeutic strategies. Current histopathological techniques are time consuming, induce tissue artefacts and often prevent further evaluation, once the tissue has been fixed. Hence, there is a potential need for a fast and nondestructive imaging technique for unfixed tissue. Near-infrared, reflectance confocal microscopy (CM) allows real-time, virtual sectioning of unstained, bulk tissue samples. This pilot study evaluates the use of CM in the assessment of meniscus histopathology in a series of 26 freshly-excised human meniscus samples compared to standard light microscopy of stained sections. CM images of the meniscus show cell and matrix detail, depicting morphologic features of collagen and elastic fibres, vessels and nerve endings. In addition, crystal deposits of gout and pseudogout are also demonstrable. Thus, CM is a novel imaging technique that could enable the pathologist to make a rapid microscopic evaluation of cartilage in a fresh and unfixed fashion.     

肩锁关节及关节盘的相关解剖学特征

背景:目前临床上多数认为,肩部疾病如肩锁关节脱位、肩峰下撞击综合征等与肩锁关节的解剖形态有很大的关系,但国内外文献很少有关于肩锁关节的形态学数据支持,特别对于肩锁关节关节盘的解剖学研究。同时肩锁关节属于微动关节,参与肩关节的联合运动,现临床上有关肩锁关节脱位的手术方式繁多,较流行的手术方式多为刚性固定,并未保留其微动特点以及锁骨和肩胛骨的运动特点,其中关节盘的取舍目前国内外并无大样本多中心对照研究。目的:对肩锁关节及关节盘行相关解剖学研究,用于更好地指导肩部疾病的诊治。方法:对58具肩锁关节尸体标本(同济大学解剖教研室提供)进行形态学及组织结构研究,共获得58个肩峰、58个锁骨和36个关节盘(包括完全型和不完全型)。采用BIGLIANI肩峰形态分型、DEPALMA锁骨形态分型、EMURA肩锁关节盘分型,获得各肩峰与锁骨组合下关节盘出现的频率并行苏木精-伊红染色(上海市普陀区人民医院提供)。结果与结论:①在58个肩锁关节尸体中,肩锁关节盘type1型共15例,所占比例最高,为25.9%;type3a型共4例,所占比例最少,为6.9%。②Ⅰ型肩峰32个,所占比例最高,为55.2%;Ⅲ型肩峰3个,所占比例最低,为5.2%。③Ⅰ型锁骨27个,所占比例最高,为46.6%;Ⅲ型锁骨9个,所占比例最低,为15.5%。④以Ⅰ型及Ⅱ型肩峰与Ⅰ型锁骨组合所占比例较大,分别为24.1%和22.4%,以Ⅲ型肩峰对Ⅰ型锁骨所占比例最小,为0%。⑤而在Ⅰ型肩峰与Ⅰ型锁骨组合下type1型和type2b型关节盘所占比例最大,分别为35.7%和28.6%;Ⅱ型肩峰与Ⅰ型锁骨组合下type2a型和type1型关节盘所占比例最大,分别为38.5%和23.1%。⑥苏木精-伊红染色在组织切片中可以发现,关节盘中的细胞外基质清晰可辨,细胞形态饱满,含有丰富的细胞质,提示为软骨细胞,即形成纤维软骨的主要成分。此外,从关节囊顶端和底端两侧可见部分骨膜纤维层移行至关节盘内侧,考虑共同组成关节盘结构,即关节盘由近骨面的软骨细胞及远离骨面的纤维层共同构成。     

Differentiation of extracellular matrix in the cellular cartilage ("Zellknorpel") of the mouse pinna

Summary Differentiation of cellular cartilage was studied in the mouse pinna with particular reference to matrix material. Fixation of glycosaminoglycans was performed by the use of acridine orange and elastin was identified by staining thin sections with tannic acid and uranyl acetate.Condensation of mesenchymal cells (prechondroblasts) initiates the formation of a blastema of cartilaginous tissue at postnatal day 4. The synthesis of acidic glycosaminoglycans begins at postnatal day 8 when prechondroblasts transform to chondroblasts. Glycosaminoglycans can be detected within secretory vesicles of chondroblasts at postnatal day 8, in the extracellular space at postnatal day 13. Delicate collagen fibrils and elastic fiber microfibrils are seen between prechondroblasts and chondroblasts. Deposition of elastin begins at postnatal day 11. A network of elastic fibers and lamellae is formed, which replaces both collagen fibrils and elastic fiber microfibrils. In the interstice of mature cellular cartilage only elastin and proteoglycans are present (postnatal day 21).These findings indicate that cellular cartilage represents an independent kind of supporting tissue, which may serve as a progenitor of hyaline or elastic cartilage (transitional cellular cartilage) but does not differentiate from hyalin cartilage.With financial support from the Hochschuljubiläumsstiftung der Stadt Wien. Part of this work has been presented at the 3. Arbeitstagung der Anatomischen Gesellschaft, Würzburg, 6.-8. 10. 1982     

Morphological characteristics of the life cycle of resting cartilage cells in mouse rib investigated in intrasplenic isografts

Summary Resting cartilages taken from 2-day-old mouse ribs were transplanted into spleens in order to carry out morphological investigations of the life cycles of their chondrocytes. The explants were isografted for periods of up to 60 days and examined at light and electron microscopic levels, using von Kossa's reaction or osmium-potassium ferrocyanide (OPF) fixation. By day 3 after transplantation, resting cartilage containing immature chondrocytes was well adapted to splenic tissue and by 7 days after transplantation these chondrocytes had changed into early hypertrophic chondrocytes containing large vacuoles, glycogen aggregates and abundant secretory organelles. It was also demonstrated by von Kossa's reaction that the initial calcification occurred in the territorial matrix during this period. In spite of the hypertrophic chondrocytes in the central zone being surrounded by an extensively calcified matrix during days 14–21 after transplantation, these cells had well-preserved organized organelles, except that Golgi-associated elements and endoplasmic reticulum revealed a tendency toward degenerative changes. With increased duration of the grafting period, from 30–60 days, the calcification zone progressed gradually, and the number of hypertrophic chondrocytes embedded in the calcified matrix decreased considerably. By day 60, degenerating hypertrophic chondrocytes of two types were distinguished: flattened cells containing large vacuoles, poorly developed Golgi apparatuses, and rough endoplasmic reticulum; and shrunken dark cells displaying terminal hypertrophy. During the present study, we observed no vascular invasion into the calcified matrix, or appearance of bone-related cells, and the morphological changes from the resting chondrocytes to cellular hypertrophy accompanied by the formation of a calcified matrix were observed at day 60. These findings indicate that resting cartilage cells of the mouse have the capacity for terminal differentiation when transplanted into the spleen.     

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。     

终板蛋白多糖的变化对颈椎间盘力学性能的影响

目的:通过测定退变颈椎间盘压缩性能的改变,同时观测软骨终板基质蛋白多糖(proteoglycan PG)的变化,为退变的椎间盘显现异常力学特性作一分子机制上的探讨。方法:将24只家兔随机分为对照组和模型组,模型组家兔保持45°低屈曲住5小时/次·天,取C5-6椎间盘进行生物力学测定;同时生化测定椎间盘终板糖胺多糖(glycosaminoglycan,GAG)总量、硫酸软骨素(chongdroitin sulphate,CS)和硫酸角质素(keratan sulphate,KS)比值和透明质酸(hyaluronic acid,HA)含量;总结分析颈椎间盘退变时基质各成分的系统变化及其对椎间盘力学性能的影响。结果:模型组终板抗压强度、断裂时的最大形变、终板基质蛋白多糖总含量、硫酸软骨素/硫酸角质素比值、透明质酸含量都低于对照组(P<0.05),并随造模进程的深入而减小。结论:长时间的应力不均状态,造成椎间盘终板材料力学特性改变;颈椎间盘基质蛋白多糖含量和成分改变是颈椎间盘生物力学性能减退的主要原因之一。