Advances in treatment of hyperkalemia in chronic kidney disease

Introduction: Hyperkalemia is a frequent electrolyte disorder associated with life-threatening cardiac arrhythmias and sudden death. Patients prone to hyperkalemia have chronic kidney disease (CKD) either alone or in conjunction with diabetes or heart failure (HF). Although agents inhibiting the renin–angiotensin–aldosterone–system (RAAS) are currently the first-line treatments toward cardio- and nephroprotection, their administration often leads to potassium elevation in such patients and results in high rates of treatment discontinuation.

Areas covered: This article provides an overview of factors interfering with potassium homeostasis and discusses emerging potassium-lowering therapies for long-term management of hyperkalemia.

Expert opinion: In recent randomized clinical studies, two new oral potassium-exchanging compounds, patiromer and sodium zirconium cyclosilicate, were shown to effectively normalize elevated serum potassium and chronically maintain potassium homeostasis in hyperkalemic patients treated with RAAS blockers. Both agents exhibit good tolerability and were not associated with serious adverse effects. Although additional research is required, these drugs are promising for lowering the risk of incident hyperkalemia associated with RAAS blockade use in people with diabetes or HF who have CKD. They also provide the opportunity to test whether patients who could not previously receive RAAS blockade may benefit from their cardio- and renoprotective effects.     

Laser-assisted Zr/ZrO2 coating on Ti for load-bearing implants

Oxidized Zr alloys have been shown to exhibit lower friction and superior wear properties, suggesting that they could be used in hip and knee implants. However, conventional oxidation of Zr alloys above 500 °C, in dry air, for several hours has been shown to have detrimental effects on the substrate’s properties. In this work, we deposited pure Zr on Ti, then oxidized the coating using a continuous-wave Nd:YAG laser, which facilitated localized heating to elevated temperatures without affecting the substrate. Laser-assisted oxidation resulted in a 7 μm thick fully dense ZrO₂ layer on Zr in which an increase in oxidation kinetics was evident due to an increase in the laser power and/or the oxygen partial pressure. Due to its high surface energy and wettability, the wear rate of laser-oxidized Zr was two orders of magnitude less compared to that of as-deposited Zr. The oxidized coatings showed comparable in vitro biocompatibility to that of pure Ti and excellent in vitro cell–material interactions. This article reports the processing of Zr/ZrO₂ coatings on Ti using lasers, and the influence of laser parameters and oxygen partial pressure on the coating’s mechanical, microstructural, wear and in vitro biological properties using human osteoblast cells.     

Primary renal candidiasis: Fungal mycetomas in the kidney

Fungal infections of the urinary tract have a predilection for drainage structures rather than for the renal parenchyma. Of the causal factors, diabetes mellitus, immunosupressed states, AIDS and prematurity are those most commonly encountered. The case of a young, diabetic man whose chief clinical presentation was dysuria is described. On further examination he was found to harbour fungal balls in the right kidney. Radiological manifestations of acute pyelonephritis were also present. Although primary renal candidiasis is often commensurate with systemic fungaemia, he displayed none of the clinical features of disseminate infection and, hence, was treated conservatively with oral antifungal agents. Fortuitously, spontaneous passage of fungal particulate matter in urine was later reported.     

The longest use of liposomal amphotericin B and 5-fluorocytosine in neonatal renal candidiasis

Bilateral fungal obstruction of the renal collecting system is rare in infancy. Treatment options include medical or surgical procedures. Reports of successful medical treatment with liposomal amphotericin B have been published but the duration of treatment is controversial. We report a 3-week-old preterm baby with myelomeningocele who had experienced acute renal failure related to bilateral renal fungus balls, which improved with percutaneous nephrostomy and 12 weeks of liposomal amphotericin B intravenously combined with 5-fluorocytosine orally for 9 weeks.     

全解剖式氧化锆冠牙体预备原则的研究进展

全冠修复是大面积牙体缺损最常用的修复方式。随着材料的发展,氧化锆陶瓷的出现解决了口腔传统全瓷材料强度不足的问题。全解剖式氧化锆冠（以下简称全锆冠）的机械性能比起传统玻璃陶瓷全冠已经有了很大的进步,但在临床应用时仍沿用烤瓷冠或传统全瓷冠的牙体预备原则。已有研究表明,咬合面厚度为0.5 mm的全锆冠可以满足临床需求;但轴面预备量、牙合向聚合度、颈缘形态和宽度等方面相关文献报道有限且结论尚不统一。此外,随着透明氧化锆的快速发展,其牙体预备原则更缺乏统一的标准。因此,该文通过综述全锆冠的牙体预备原则的研究进展,为全锆冠的临床牙体预备提供参考。     

氧化锆牙种植体材料的毒理学研究

目的 研究氧化锆增韧陶瓷(一种新型的牙种植体材料)的临床使用安全。方法 采用急性全身毒性、皮内刺激试验、溶血试验、Ames试验、细胞毒性试验。结果 急性全身毒性试验动物表现未见异常;皮内刺激试验中试验组与阴性对照组无差别;溶血试验的溶血度<5％;Ames试验结果为阴性;细胞毒性试验结果表明该物质无细胞毒性。结论 氧化锆牙种植体材料属无毒、无刺激物质,也不能诱发溶血反应,无致突变作用,并且无细胞毒性,可以安全使用。