钙敏感受体激动剂的临床研究进展

继发性甲状旁腺功能亢进症(SHPT)是慢性肾脏病(CKD)常见的并发症,慢性肾脏病导致患者矿物质和骨代谢异常,其严重性主要是导致心血管钙化,与透析患者的生存预后密切相关.活性维生素D类药物用于临床治疗继发性甲状旁腺功能亢进症常常伴发高血钙、高血磷而增加心血管钙化的危险.多数药物治疗无效的继发性甲状旁腺功能亢进症患者只能接受甲状旁腺切除术治疗.钙敏感受体激动剂的问世改变了继发性甲状旁腺功能亢进症药物治疗的难题,使多数重症继发性甲状旁腺功能亢进症患者避免了手术风险.我们对钙敏感受体激动剂的临床应用作一介绍.     

活性维生素D临床应用

活性维生素D在临床上应用广泛。对于肝、肾功能逐渐衰退,伴有肌少症和/或神经功能损害的老年骨质疏松症(osteoporosis,OP)患者,妊娠/哺乳相关的OP及骨密度(bone mineral density,BMD)下降患者,均可适当补充。活性维生素D联合钙剂是甲状旁腺功能减退症和骨软化症的首选治疗方案,同时也是慢性肾脏病-矿物质和骨异常患者预防和治疗继发性甲状旁腺功能亢进症的主要措施之一。活性维生素D治疗窗相对狭窄,用药期间需要定期监测安全性指标,如血钙磷、尿钙磷及全段甲状旁腺素等。     

活性维生素D在慢性肾脏病-矿物质和骨异常中的应用

矿物质和骨异常(mineral and bone disorder,MBD)是慢性肾脏病(chronic kidney disease,CKD)的常见并发症之一,是CKD患者致残和致死的重要原因之一。维生素D缺乏是CKD-MBD发生、发展的重要原因。合理应用活性维生素D(包括骨化三醇或其他维生素D类似物),使血钙、磷和全段甲状旁腺素(intact parathyroid hormone,iPTH)维持在理想范围,可有效防治继发性甲状旁腺功能亢进症、血管钙化、肾性骨营养不良和骨质疏松等,改善CKD患者的生存质量,降低发病率和病死率。     

维生素D缺乏继发甲状旁腺功能亢进症患者的临床特点

目的分析3例严重维生素D缺乏继发甲状旁腺功能亢进症患者的临床特点及治疗策略。方法收集确诊为维生素D缺乏继发甲状旁腺功能亢进患者3例,对其进行详细的病史采集和体格检查,生物化学指标测定及影像学检查。结果患者1、2起病隐匿,临床症状不典型;患者3有长期双下肢乏力,全身疼痛,进行性加重的活动障碍及身高变矮。实验室检查结果:血25羟维生素D (25 hydroxyvitamin D,25OHD)低于检测值下限(8. 0μg/L),甲状旁腺素(parathyroid hormone,PTH)水平升高,碱性磷酸酶(alkaline phosohatase,ALP)及Ⅰ型胶原C端肽(C-terminal telopeptide of type 1 collagen,β-CTX)升高。双能X线吸收检测仪(dual energy X-ray absorptiometry,DXA)检测骨密度,提示骨密度显著降低。给予维生素D联合钙剂治疗3个月后,患者临床症状好转,随着25OHD水平升高,血PTH及骨转换标志物水平均下降,骨密度检查可见骨量增加。结论维生素D缺乏在人群中普遍存在,由于早期缺乏临床症状易被忽视,但当其引起继发性甲状旁腺功能亢进时,会对骨骼产生严重影响,导致骨转换增加,骨量流失加快,摔倒及骨折风险增加等。因此,应重视维生素D缺乏的早期防治,避免发生继发性甲状旁腺功能亢进。     

维持性血液透析患者骨质疏松的诊治

随着血液透析技术的发展,透析患者的数量明显增加,透析患者的生活质量特别是肾性骨病所引起的骨健康问题备受关注。骨质疏松症是一种以骨量下降、骨微结构损害、骨脆性增加、易发生骨折为特征的全身性骨病。透析患者由于继发性甲状旁腺机能亢进(SHPT)、骨代谢异常、营养不良、维生素D缺乏、骨矿物质流失等原因易导致骨质疏松。随着透析患者透析龄的增加,骨质疏松的患病率呈现增高趋势,脆性骨折的致残率、病死率高,已成为影响其生活质量和生存率的重要因素。     

维生素D治疗慢性肾脏疾病继发性甲状旁腺功能亢进症的进展

继发性甲状旁腺功能亢进症(SHPT)是慢性肾脏疾病(CKD)最常见的并发症之一.维生素D及其类似物是治疗SHPT的常用药物,充分了解低维生素D状态对CKD患者的危害,维生素D制剂治疗SHPT的药理机制及治疗过程中应该注意的问题,有助于临床医师合理应用此类药物,延缓SHPT发展为三发性甲状旁腺功能亢进症.     

维生素D与骨质疏松症

骨质疏松症(osteoporosis,OP)是患病率显著上升、危害严重的骨骼疾病,在其发病机制中,维生素D缺乏是引起负钙平衡、骨丢失加快、继发性甲状旁腺功能亢进、跌倒增加、骨折风险升高的重要危险因素。我国人群中维生素D缺乏广泛存在,建议在OP防治工作中,重视评估患者的维生素D营养状况,并给予患者合理的、个体化的维生素D治疗。     

维生素D缺乏与骨质疏松

维生素D对骨骼最主要的作用之一是为骨质矿化提供合适的微环境。尽管部分食物中强化维生素D,或额外补充维生素D,但人群中维生素D缺乏仍很普遍。维生素D缺乏可导致甲状旁腺功能亢进、骨转换增加和骨丢失,引起骨折风险增加。维生素D和钙剂补充是防治骨质疏松症的基本措施。研究表明补充足量维生素D能增加骨量、肌肉容量,和肌肉协调功能,有助于预防骨质疏松及其骨折。     

原发性醛固酮增多症与骨质疏松症的相关性

继发性骨质疏松症是由于疾病、药物、器官移植等原因所致的骨量低下,骨微结构损坏,骨脆性增加和易发生骨折的代谢性骨病。积极寻找骨质疏松症的病因,对有效治疗继发性骨质疏松症具有重要意义。在临床工作中,笔者发现,原发性醛固酮增多症患者骨量减少/骨质疏松症甚至脆性骨折的发生率高于普通人群。近年来,研究显示,原发性醛固酮增多症及高醛固酮血症动物模型及患者体内普遍存在矿物质代谢异常,骨量减少/骨质疏松症甚至脆性骨折风险。本文从继发性甲状旁腺功能亢进症、骨质疏松症相关基因、盐皮质激素受体、氧化应激、上皮钠离子通道方面对原发性醛固酮增多症引起骨质疏松症的发病机制研究进展进行综述,探讨原发性醛固酮增多症与骨质疏松症的关系,为继发性骨质疏松症的预防及诊治提供依据和方法。     

维生素D不足、矿物质代谢异常对慢性肾病心血管系统的影响及处理

1,25-二羟维生素D3合成减少、肾脏对磷廓清不足、血钙失调、继发性甲状旁腺功能亢进和骨病是慢性肾脏疾病的特征,临床观察性研究证实维生素D及维生素D受体激活剂治疗与血液透析患者的生存率获益有关,并独立于甲状旁腺激素、血钙和磷,可能的解释是维生素D及维生素D受体激活剂对心血管系统产生了有利影响。现就矿物质代谢紊乱、维生素D不足对慢性肾脏疾病患者心血管系统的影响及相关处理进行简要综述。     

State of knowledge of helminth fauna of freshwater fishes of Poland

A total 89 fish and lamprey species has been recorded from Polish freshwater habitats. Twenty-seven of them (30.3%) have not been surveyed for parasitic helminthes. Some of the latter fishes are either rare or not easily accessible. Other live only in specific habitats in scattered localities. An important obstacle for studying parasite faunas of some fishes may be their status on an endangered species. Among the non-surveyed fishes, are those which have been relatively recently introduced to Poland or migrated there on their own. The present paper attempts to review all hitherto not studied helminthologically fish species, their habitats, localities and current protection status.     

Inhibition of intimal thickening of the carotid artery of rabbits and of outgrowth of explants of aorta by probucol.

The effect of administration of probucol in preventing intimal thickening of rabbit carotid artery after balloon catheter injury and the mechanism of action of the drug were studied. Groups of 6 male New Zealand-White rabbits were given normal diet (Group I), high cholesterol diet (Group II) or high cholesterol diet plus probucol (Group III) for 4 weeks. Balloon catheter injury was made in week 2 and animals were killed in week 4. No significant differences in the total cholesterol levels in Groups II and III were found in week 4. The medians of areas of the intimal layer in cross-sections of the carotid arteries of Groups I, II and III were 0.237, 0.475 and 0.309 mm2, respectively. Thus high-cholesterol diet increased the thickness of the intimal layer and probucol reduced its effect. There were no significant differences in the areas of the medial layers in these 3 groups. For the examination of the mechanism of the effect of probucol, rabbits were given chow containing 0.5% cholesterol with and without 0.5% probucol (7 rabbits each) and then the numbers of explants from their aortas showing outgrowth were compared. The plasma total cholesterol levels of these two groups were the same. The probucol concentrations in the plasma and aorta of the former group were 18.6 +/- 13.2 micrograms/ml and 7.3 +/- 5.4 micrograms/g wet tissue, respectively. The number of explants showing outgrowth on day 14 was suppressed by 34% in the probucol-treated group.(ABSTRACT TRUNCATED AT 250 WORDS)