Human Osteoarthritic Cartilage Matrix Vesicles Generate Both Calcium Pyrophosphate Dihydrate and ApatiteIn Vitro

Calcium crystals in osteoarthritic (OA) joints promote enzymatic degradation of articular tissues. Matrix vesicles provide a nidus for calcium crystal formation in chick epiphyseal and mature porcine articular cartilage. In order to examine a potential role for matrix vesicles from OA cartilage in generating pathologic crystals, we sought to determine whether vesicles derived from human OA cartilage (OAMV) could mineralize; and we characterized the resultant mineral species. OAMV were isolated and examined for alkaline phosphatase (AP) and nucleoside triphosphate pyrophosphohydrolase (NTPPPH) activity. OAMV ATP-dependent and independent mineralization were measured in a radiometric biomineralization assay, and newly formed OAMV crystals were examined using Fourier transform infrared spectroscopy (FTIR) and compensated polarized light microscopy. The mean specific activity of OAMV AP was approximately 6 times higher and NTPPPH activity 11 times lower than that of previously characterized, mature, porcine, articular cartilage vesicles. OAMV progressively precipitated ⁴⁵Ca over time both in the presence and absence of ATP. The FTIR spectra of mineral formed in ATP-dependent assays most closely resembled the standard spectrum for calcium pyrophosphate dihydrate (CPPD). The FTIR spectra of OAMV mineral formed in the absence of ATP closely resembled apatite. These data support the hypothesis that OAMV may form mineral phases of two key crystals found in degenerating cartilage and provide further evidence for the role of matrix vesicles in pathologic articular cartilage biomineralization.     

A morphometric study of the inferior orbital fissure using three‐dimensional anatomical landmarks: Application to orbital surgery

The inferior orbital fissure (IOF) is an important structure during orbital surgery, however, neither its anatomical features nor the procedures necessary to expose the IOF have been examined in detail. A morphometric analysis of the IOF was performed on 232 orbits using computer software. The longest and shortest borders of the IOF were 18.2 ± 4.9 and 1.9 ± 1.3 mm, respectively. The outer and the inner angles were 138.9 ± 32.7° and 38.4 ± 24.7°, respectively. The perimeter of the IOF was 50.6 ± 13.5 mm and its area was 61.3 ± 39.1 mm². Eight types of IOF were observed. Type 1 IOF was observed in 42.2% and the Type 2 IOF was identified in 15.9%. A statistically significant relation was found between the longest edge and area and the widest edge and area of the IOF. The findings of our study suggest that the removal of the lateral wall should begin inferiorly, just lateral to the IOF and extended superolaterally. These data may be useful during surgical approaches to the orbit. Clin. Anat. 22:649–654, 2009. © 2009 Wiley‐Liss, Inc.     

义眼台取出的原因分析

目的分析义眼台取出的原因。方法回顾本科2001年9月至2004年8月期间收治的义眼台取出22例。结果义眼台暴露20例，义眼台感染10例，无纤维血管化4例。结论义眼台暴露，感染及无纤维血管化等是义眼台取出的常见原因。     

羟基磷灰石复合体在牙周骨缺损中的应用

骨形成蛋白（bone morphogenetic protein，BMP）作为一种高效骨诱导物质，对促进骨缺损的修复具有显著的效果。以羟基磷灰（hydroxylapatite，HA）微粒，胶原（collagen，Co）与牛骨形成蛋白（bBMP）合成的一种具有高生物诱导活性的新型复合人工骨材料即HA-bBMP-Co，可用于牙周病所致骨缺损的修复。我科用此种生物材料已治疗完成46例共46牙，并与经牙周基础治疗的患牙进行比较，经临床观察，疗效满意，现报道如下。     

眼眶炎性假瘤的治疗进展

眼眶炎性假瘤是一种常见的眼眶疾病,病因不明,治疗方法主要包括糖皮质激素治疗、放射治疗、免疫抑制剂治疗及手术治疗等。近年来开始应用生物治疗。本文旨在概述眼眶炎性假瘤的现代治疗方法。     

Evidence of hydroxyl-ion deficiency in bone apatites: an inelastic neutron-scattering study

The novelty of very large neutron-scattering intensity from the nuclear-spin incoherence in hydrogen has permitted the determination of atomic motion of hydrogen in synthetic hydroxyapatite and in deproteinated isolated apatite crystals of bovine and rat bone without the interference of vibrational modes from other structural units. From an inelastic neutron-scattering experiment, we found no sharp excitations characteristic of the vibrational mode and stretch vibrations of OH ions around 80 and 450 meV (645 and 3630 cm⁻¹), respectively, in the isolated, deproteinated crystals of bone apatites; such salient features were clearly seen in micron- and nanometer-size crystals of pure hydroxyapatite powders. Thus, the data provide additional definitive evidence for the lack of OH⁻ ions in the crystals of bone apatite. Weak features at 160–180 and 376 meV, which are clearly observed in the apatite crystals of rat bone and possibly in adult mature bovine bone, but to a much lesser degree, but not in the synthetic hydroxyapatite, are assigned to the deformation and stretch modes of OH ions belonging to HPO₄-like species.     

Unusual facet cyst containing struvite and hydroxyapatite

This case report describes a patient with severe back pain and radiculopathy. She was found to have a facet cyst within the lumbar spine that appeared to contain calcium on MRI and CT. Upon aspiration the cyst was found to contain calcium ammonium phosphate (struvite) and calcium phosphate (hydroxyapatite). Ammonia production in the presence of urease-producing bacteria is responsible for the production of struvite in the human body. We postulate that there was a prior infection of the facet with urease-producing bacteria, thus accounting for the production of the struvite within the facet cyst. Received: 29 June 2000 Revision requested: 18 August 2000 Revision received: 27 September 2000 Accepted: 27 September 2000     

Metastatic Renal Cell Carcinoma to the Eye and Adnexae: A Report of Three Cases and Review of the Literature

Three cases of metastatic renal cell carcinoma to the ocular structures are presented. Each of these tumors clinically simulated a more common ocular entity, thus causing diagnostic difficulty. The first patient had a metastatic tumor to the eyelid that clinically simulated a large chalazion. The second patient had a choroidal tumor with clinical features and ancillary studies strongly suggestive of a primary choroidal melanoma. The third patient presented with unilateral proptosis secondary to an orbital mass that was clinically believed to be a cavernous hemangioma of the orbit. In each case, there was a long interval between the initial diagnosis (15 months, 9 years, and 15 years respectively), and the ocular metastasis, which represented the first sign of metastatic disease.     

Evolution of an in vivo bioreactor.

The ideal bone graft substitute requires osteoconductive, osteoinductive, and osteogenic components. This study introduces an "in vivo bioreactor," a model in which pluripotent cells are recruited from circulating blood to a vascularized coralline scaffold supplemented with bone morphogenetic protein-2 (BMP-2). The bioreactor generates new, ectopic host bone with the capability of vascularized tissue transfer. More importantly, bone is reproducibly formed in a closed and malleable environment. In a rat model, the superficial inferior epigastric vessels were isolated, ligated, and then threaded through a prefabricated coral cylinder (hydroxyapatite, ProOsteon 500). Experimental groups were characterized by the following variables: (1) with/without incorporation of vascular pedicle; (2) with/without addition of BMP-2 (0.02 mg/cm3). Scaffolds were harvested 6 weeks after implantation, embedded and sectioned. Tissue samples were decalcified, fixed, and stained with H&E, trichrome green, and CD31/PECAM-1 (a marker of endothelial cells). Vascularized coral scaffolds supplemented with BMP-2 presumably recruited circulating mesenchymal stem cells to generate bone. Bone formation was quantified through histological analysis, and reported as a percentage, area bone/area cross section scaffold x 100. Mean bone formation was 11.30%+/-1.19. All scaffolds supplied by the vascular pedicle, regardless of BMP-2 supplementation, demonstrated neo-vascular ingrowth. Scaffolds lacking a pedicle showed no evidence of vascular ingrowth or bone formation. This paper introduces a model of a novel "in vivo bioreactor" that has future clinical and research applications. The tissue engineering applications of the "bioreactor" include treatment of skeletal defects (nonunion, tumor post-resection reconstruction). The bioreactor also may serve as a unique model in which to study primary and metastatic cancers of bone.