Uncalcified Synovial Chondromatosis in the Pisotriquetral Joint

Synovial chondromatosis is a rare lesion in the wrist, but some cases in the distal radioulnar joint have been reported and previous case reports emphasize joint calcifications, shown on preoperative plain radiographs. We report an extremely uncommon case of synovial chondromatosis in the pisotriquetral joint, in which radiographs and magnetic resonance imaging did not demonstrate apparent calcified bodies. In our case, for the accurate diagnosis and treatment, surgical exploration of the joint and synovectomy with removal of loose bodies was performed.     

Rapidly growing calcified cerebellar astrocytoma in infants

We report the case of an infant with a cerebellar astrocytoma that showed marked calcification within only 6 months. In general, only slow-growing tumors tend to calcify. To our knowledge, no other case of such rapid calcification in cerebellar astrocytoma has been reported.     

儿童颈椎间盘钙化的诊断和治疗

儿童颈椎间盘钙化症（cervical incervertebral dise calcification in children）是一种少见的疾病。1924年Baron首先报道本病．国内1982年至今陆续报道，迄今仅百余例。作者经治儿童颈椎间盘钙化症5例．结合文献对其诊断和治疗加以讨论。     

大脑中动脉钙化的CT与经颅多普勒超声对照研究

目的探讨大脑中动脉（middle cerebral artery,MCA）水平段（M1）钙化的量化指标与血流动力学的关系。资料与方法搜集经头颅CT确诊M1段钙化且行经颅多普勒超声（transcranial Doppler,TCD）检查者41例,按有无钙化分为钙化组和无钙化组。分析MCA钙化组血流动力学参数与钙化量化指标是否有相关性;检验钙化组与无钙化组血流动力学参数及狭窄发生率的差异。结果MCA搏动指数（pulsatility index,PI）与钙化体积以及积分值呈线性相关;钙化组与无钙化组PI差异有统计学意义（P〈0.05）,但狭窄发生率差异无统计学意义（P〉0.05）。结论MCA钙化程度与TCD反映血管弹性的PI相关,但与反映狭窄程度的血流速度无相关性。     

Effect of ultrafilterable fragments from chondroitinase and protease-treated aggrecan on calcium phosphate precipitation in liposomal suspensions

A liposome-centered endogenous precipitation method was used to investigate the effect of ultrafilterable fragments from the enzymatic digestion of rat chondrosarcoma aggrecan on the formation of insoluble calcium phosphate salts in buffered solutions at pH 7.4 and 22°C. Unlike the intact aggrecan and its major chondroitin sulfate and core protein components, disaccharide units from chondroitinase degradation of the aggrecan and small (<3kg/mol molecular weight) fragments from protease digestion of the core structure were found to be only weakly inhibitory toward mineral formation. Corresponding reductions in Ca²⁺-binding indicate that these fragments were unable to adsorb to active sites on the apatite surface for long enough periods to significantly hinder crystal growth. The data suggest that controlled enzymatic breakdown of aggrecan may be one possible mechanism by which the calcification of growth plate cartilage is allowed to advance in vivo.The commercial materials and equipment identified in this paper do not imply recommendation or endorsement by the National Institute of Standards and Technology nor is the material and equipment necessarily the best available for the purpose.     

Fine structure and mineral components of fibrous stonelike masses obtained from the human mesenteries

We investigated the fine structure and mineral components of 29 stonelike masses obtained from the mesenteries of four adult cadavers, using optical microscopy, backscattered electron imaging, scanning electron microscopy, energy-dispersive X-ray microanalysis, and X-ray diffraction. Although the overall appearance of the stonelike masses measuring about 5–20mm in diameter and 0.06–3.1g in dry weight was roughly grouped into smooth bulb- and uneven bulk-shaped types, all the calcified masses basically consisted of core and mantle regions. The smooth bulb-shaped masses had a broad mantle with many concentric rings, whereas the uneven bulk-shaped masses contained a large core. In their core regions, spherulitic and short bundle-shaped deposits composed of needle-shaped apatite crystals were mainly found among loose collagen fibers. Their mantle regions, on the other hand, showed the concentric structures of dense collagen fibers in the intra- and/or extrafibrous calcification with fine sandy grain-shaped deposits. The mineral elements were mainly Ca and P, and the major crystals were hydroxyapatite. Hexahedral whitlockite containing Mg was a minor component. The fiber-rich mantle regions showed lower calcification and lesser crystallization than the fiber-poor core region. When necrotic or some tumor adipose tissues and necrotic lymphoid tissues that might have been caused by some digestive diseases are recognized as foreign matter, their tissues occasionally will be calcified and grow into stonelike masses. These stonelike masses tend to occur more often in women than in men.     

Angiotensin-(1-7)对血管平滑肌细胞钙化的影响及信号转导通路

目的:在钙化大鼠主动脉血管平滑肌细胞上观察血管紧张素-(1-7)[Angiotensin-(1-7)]对钙化的影响及其信号通道。方法:用β-磷酸甘油制备钙化的大鼠血管平滑肌细胞,再以血管紧张素-(1-7)、血管紧张素Ⅱ、血管紧张素Ⅱ 血管紧张素-(1-7)、选择性蛋白激酶A(PKA)或蛋白激酶C(PKC)抑制剂等干预,通过Von Kossa染色及检测钙含量、碱性磷酸酶活性、骨钙素浓度和Cbfa1 mRNA表达来探讨血管紧张素Ⅱ对钙化的影响及其信号通道。结果:血管紧张素-(1-7)抑制钙化大鼠血管平滑肌细胞的钙含量、碱性磷酸酶活性(P>0.05)、骨钙素浓度和Cbfa1 mRNA表达(P<0.05),也抑制血管紧张素Ⅱ对血管平滑肌细胞的钙含量、碱性磷酸酶活性、骨钙素浓度和Cbfa1 mRNA表达的促进作用(P<0.05);血管紧张素-(1-7)提高血管平滑肌细胞内cAMP浓度(P<0.05),PKA抑制剂可阻断血管紧张素-(1-7)对钙化血管平滑肌细胞的钙含量、碱性磷酸酶活性、骨钙素浓度和Cbfa1 mRNA表达的抑制作用(P<0.05)。结论:血管紧张素-(1-7)可抑制β-磷酸甘油诱导的血管平滑肌细胞钙化,并拮抗血管紧张素Ⅱ促进的血管平滑肌细胞钙化;这些效应与cAMP-PKA-Cbfa1信号途径有关。     

心血管组织钙化时内源性硫化氢系统下调

目的：观察心血管组织钙化时内源性硫化氢生成系统(CSE/H2S)的变化，以探讨内源性硫化氢在心血管组织钙化中的作用及血管钙化的细胞分子机制。方法：在维生素D3 (Vit D3)和尼古丁(nicotine)诱导大鼠血管钙化模型上，测定钙含量、［45Ca2+］沉积及碱性磷酸酶（ALP）活性判断心血管钙化程度,采用生化法测定血浆、心肌组织和主动脉H2S含量及CSE活性，半定量RT-PCR方法测定心血管组织CSE mRNA水平。结果：钙化组大鼠心肌组织钙含量较对照组高3.8倍,主动脉钙含量、［45Ca2+］ 沉积及ALP 活性分别较对照组高6.8倍、1.4倍和 1.9倍（P＜0.01）；钙化组大鼠血浆H2S含量较对照组低39%（P<0.01），心肌和主动脉组织的 H2S含量也分别较对照组低39%和31%，CSE mRNA表达也分别低28％和36％（P<0.01），CSE活性分别低56%和53%(P<0.01)。结论：钙化心血管组织CSE/H2S通路受抑制，内源性H2S生成减少。     

Amyloid deposits in aortic and mitral valves

Summary The material from 100 consecutive aortic and mitral valve operations has been studied histologically with particular reference to the presence of amyloid deposits. Sixty seven per cent were positive (aortic 88%, mitral 45%).The simultaneous occurrence of calcification of the valves and amyloid degeneration as well as of calcification and hyalinization was significant. Similarly there was significantly more amyloid in the older age groups, as well as a significant correlation between the degree of hyalinization of the valve and amyloid.]Thirty-two patients had previously suffered from rheumatic fever. The heart valves of these patients did not differ histologically from the others, whereas significantly more amyloid was observed in the stenotic mitral valves than in the mitral valves which were insufficient.     

Ectopic Calcification and Hypophosphatemic Rickets: Natural History of ENPP1 and ABCC6 Deficiencies

Generalized arterial calcification of infancy (GACI) is a rare disorder caused by ENPP1 or ABCC6 variants. GACI is characterized by low pyrophosphate, arterial calcification, and high mortality during the first year of life, but the natural course and possible differences between the causative genes remain unknown. In all, 247 individual records for patients with GACI (from birth to 58.3 years of age) across 19 countries were reviewed. Overall mortality was 54.7% (13.4% in utero or stillborn), with a 50.4% probability of death before the age of 6 months (critical period). Contrary to previous publications, we found that bisphosphonate treatment had no survival benefit based on a start-time matched analysis and inconclusive results when initiated within 2 weeks of birth. Despite a similar prevalence of GACI phenotypes between ENPP1 and ABCC6 deficiencies, including arterial calcification (77.2% and 89.5%, respectively), organ calcification (65.8% and 84.2%, respectively), and cardiovascular complications (58.4% and 78.9%, respectively), mortality was higher for ENPP1 versus ABCC6 variants (40.5% versus 10.5%, respectively; p = 0.0157). Higher prevalence of rickets was reported in 70.8% of surviving affected individuals with ENPP1 compared with that of ABCC6 (11.8%; p = 0.0001). Eleven affected individuals presenting with rickets and without a GACI diagnosis, termed autosomal recessive hypophosphatemic rickets type 2 (ARHR2), all had confirmed ENPP1 variants. Approximately 70% of these patients demonstrated evidence of ectopic calcification or complications similar to those seen in individuals with GACI, which shows that ARHR2 is not a distinct condition from GACI but represents part of the spectrum of ENPP1 deficiency. Overall, this study identified an early mortality risk in GACI patients despite attempts to treat with bisphosphonates, high prevalence of rickets almost exclusive to ENPP1 deficiency, and a spectrum of heterogenous calcification and multiple organ complications with both ENPP1 and ABCC6 variants, which suggests an overlapping pathology. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR). This article has been contributed to by US Government employees and their work is in the public domain in the USA.