硫酸软骨素酶ABC和环磷酸腺苷缓释组织工程 支架的构建

目的:制备一种可生物降解有效安全的硫酸软骨素酶ABC(ChABC)和环磷酸腺苷(cAMP)缓释组织工程支架,使药物缓慢稳定释放,降低局部应用时对神经的刺激,促进中枢神经系统损伤后神经的修复和轴突的再生。方法:应用电纺丝技术制作的含ChABC及cAMP的聚碳酸亚丙酯及壳聚糖缓释组织工程支架,分析支架直径、载药量、包封率等参数,然后以磷酸盐缓冲液为体外释药介质观察组织工程支架的药物释放速度、药物的失活率及支架的降解速度。结果:ChABC和cAMP缓释组织工程支架在聚碳酸亚内酯质量浓度为8%、电压为10～15 kV、距离为15～20 cm时可以纺出纤维直径约3μm的平滑支架,单纯聚碳酸盐内酯纤维光滑,直径均一,壳聚糖微球光滑,聚碳酸亚内酯与壳聚糖混合后电纺丝形成的支架呈串珠样结构,其能缓慢持续释放有活性ChABC和cAMP,12 d后支架降解失重率约7%。结论:应用电纺丝方法成功制备含ChABC及cAMP的聚碳酸盐内酯及壳聚糖组织工程支架,其药物稳定释放,局部应用无神经刺激,可生物降解。     

鲑鱼降钙素联合钙剂治疗骨质疏松的疗效及对骨代谢相关指标的影响观察

目的:观察鲑鱼降钙素联合钙剂治疗骨质疏松的临床疗效,及对患者骨代谢指标的影响。方法:骨质疏松患者360例随机分为观察组和对照组各180例,对照组给予复方碳酸钙片1粒,po,qd,观察组在对照组基础上加用鲑鱼降钙素注射液50 IU,im,qd。治疗两个月后,比较两组患者治疗前后的疼痛评分、骨密度、骨代谢相关指标等变化情况,观察两组临床疗效与药品不良反应。结果:治疗后两组疼痛评分均较前降低(P<0.01),且观察组的疼痛评分显著低于对照组(P<0.01)。治疗后两组各骨密度指标比较,差异无统计学意义(P>0.05)。治疗后两组血清BGP、β-CTX、PTH、BNALP、25OHVit D等骨代谢指标均较治疗前有明显改善(P<0.01),且观察组改善情况明显优于对照组(P<0.01)。观察组药品不良反应发生率明显高于对照组(P<0.01)。结论:鲑鱼降钙素联合钙剂治疗骨质疏松能明显改善患者的疼痛评分和骨代谢相关指标,显著优于单用钙剂治疗,但不良反应明显增多。     

Long-term renal and cardiovascular effects of antihypertensive treatment regimens based upon isradipine, perindopril and thiazide

The aim of this study was to describe the renal function (renal hemodynamics, water and sodium handling) and its relation to cardiovascular structural changes in a population of essential hypertensive patients before and after antihypertensive treatment. Glomerular filtration rate and renal plasma flow were measured by a constant infusion technique. The reference substances used were [¹³¹I]iodohippurate (Hippuran) and [¹²⁵I]iothalamate. The lithium clearance method was used for measuring renal water and sodium handling. Microalbuminuria was measured. A subcutaneous gluteal biopsy was taken and the media thickness to lumen diameter ratio of small resistance vessels was determined. Left ventricular mass index was determined by echocardiography. Thirty-seven patients with newly diagnosed or poorly controlled essential hypertension were randomized to treatment with regimens based upon either isradipine, perindopril or hydrochlorothiazide-amiloride. Atenolol and hydralazine were added as secondary and tertiary drugs, respectively, when needed for normalization of diastolic blood pressure. Investigations were performed before and after 9 months of normalization of blood pressure. Renal function in untreated hypertensive patients was characterized by increased renal vascular resistance, decreased renal blood flow, normal glomerular filtration fraction and normal serum creatinine. No association was found between peripheral resistance vessel structure in subcutaneous vessels and renal hemodynamic parameters. Patients with severe left ventricular hypertrophy (left ventricular mass >360 g) had lower glomerular filtration fraction, greater renal vascular resistance, lower renal blood flow and increased microalbuminuria in comparison with patients with less pronounced cardiac changes. After 1 year of treatment, which had a profound effect on heart and vessel structure, renal hemodynamics were unchanged in patients receiving antihypertensive treatment regimens based on the ACE inhibitor perindopril or the Ca-antagonist isradipine, whereas renal plasma flow was reduced, glomerular filtration rate preserved and filtration fraction significantly increased in those treated with a regimen based on diuretics. The serum creatinine concentration was decreased in the former group, whereas it was unchanged in the latter two. Significantly detrimental effect on uric acid homeostasis was only found in patients treated with a regimen based on diuretics.     

慢性肾脏病继发性甲旁亢治疗进展（综述）

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。近年研究发现,新型的磷结合剂碳酸镧,能有效降低血清磷水平,并不引起继发骨损害和高钙血症,是一种相对较安全的磷结合剂,西那卡塞是被称为拟钙剂(calcimimetics)的新一类化合物中的第一个药物,能激活甲状旁腺中的钙受体,从而降低甲状旁腺素的分泌。尤其适用于慢性肾衰竭患者顽固性、继发性甲状旁腺功能亢进伴有高磷血症的短期治疗。     

ICP-AES法同时测定碳酸锂原料药中6种杂质元素

目的：建立电感耦合等离子体发射光谱（ICP-AES)同时测定碳酸锂原料药中6种杂质元素（钙、钠、钾、镁、铁和铝）的分析方法,并分析不同厂商碳酸锂原料药的杂质含量。方法：用硝酸溶解样品, ICP-AES法分析样品中6种杂质元素的含量。结果：6种元素标准曲线的相关系数均高于0.999,加标回收率为93%～99%,检出限为0.0003～0.1275μg·mL-1,RSD值均小于2%;利用本法对5个厂家使用的碳酸锂原料药进行测定,结果表明C厂的原料药中钙、钠、镁、铁和铝元素含量均高于其余4个厂家,其中钠超出了药典规定限度。结论：与《中国药典》中碳酸锂原料药杂质测定方法进行比对,本试验所建立的方法测定结果与药典方法一致,且方法专属性强、灵敏度高、操作简单,可以用于碳酸锂原料药中6种杂质元素的测定。     

Lithium-associated hyperparathyroidism and hypercalcaemia: A case-control cross-sectional study

Background

Lithium is recommended as a first-line treatment for Bipolar Disorder (BD). Thyroid and renal alterations are well known lithium side-effects, while effects on parathyroids are less studied. The aim of this case-control cross-sectional study is to compare parathyroid hormone (PTH) and calcium levels in lithium-exposed bipolar patients and in subjects who had never been exposed to lithium.

Methods

112 BD patients were enrolled, 58 on lithium since at least 1 month (mean exposure 60.8±74.8 months) and 54 in the control group. Blood exams included complete blood count, PTH, total and ionized calcium, TSH, T3 and T4, creatinine, urea, sodium and potassium, and lithium serum levels. The Student's t-test and the Pearson's Chi-square test were used for bivariate analyses. A linear regression model was used to analyze the relationship between the duration of exposure to lithium and PTH and calcium levels.

Results

PTH and ionized calcium levels were significantly higher in lithium-exposed patients; the proportions of subjects with hyperparathyroidism (8.6%) and hypercalcaemia (24.1%) were significantly greater in lithium-exposed patients. The linear regression analyses showed a significant effect of exposure to lithium in months on ionized calcium levels but not on PTH levels.

Limitations

Given the cross-sectional design of the study we could not identify the exact time of occurrence of hyperparathyroidism.

Conclusions

Our results indicate that lithium-associated stimulation of parathyroid function is more common than assumed to date. Among parameters to be evaluated prior to lithium implementation and during long-term lithium maintenance, calcium (and eventually PTH) should be added.     

Cognitive effects of the GSK-3 inhibitor “lithium” in LPS/chronic mild stress rat model of depression: Hippocampal and cortical neuroinflammation and tauopathy

Low-dose repeated lipopolysaccharide pre-challenge followed by chronic mild stress (LPS/CMS) protocol has been introduced as a rodent model of depression combining the roles of immune activation and chronic psychological stress. However, the impact of this paradigm on cognitive functioning has not been investigated hitherto.MethodsThis study evaluated LPS/CMS-induced cognitive effects and the role of glycogen synthase kinase-3β (GSK-3β) activation with subsequent neuroinflammation and pathological tau deposition in the pathogenesis of these effects using lithium (Li) as a tool for GSK-3 inhibition.ResultsLPS pre-challenge reduced CMS-induced neuroinflammation, depressive-like behavior and cognitive inflexibility. It also improved spatial learning but increased GSK-3β expression and exaggerated hyperphosphorylated tau accumulation in hippocampus and prefrontal cortex. Li ameliorated CMS and LPS/CMS-induced depressive and cognitive deficits, reduced GSK-3β over-expression and tau hyperphosphorylation, impeded neuroinflammation and enhanced neuronal survival.ConclusionThis study draws attention to LPS/CMS-triggered cognitive changes and highlights how prior low-dose immune challenge could develop an adaptive capacity to buffer inflammatory damage and maintain the cognitive abilities necessary to withstand threats. This work also underscores the favorable effect of Li (as a GSK-3β inhibitor) in impeding exaggerated tauopathy and neuroinflammation, rescuing neuronal survival and preserving cognitive functions. Yet, further in-depth studies utilizing different low-dose LPS challenge schedules are needed to elucidate the complex interactions between immune activation and chronic stress exposure.     

In vitro biocompatibility evaluation of bioresorbable copolymers prepared from l-lactide, 1, 3-trimethylene carbonate,and glycolide for cardiovascular applications

PLLA-TMC-GA terpolymer was prepared by ring-opening polymerization of l-lactide, 1, 3-trimethylene carbonate (TMC), and glycolide (GA). The biocompatibility of terpolymer was evaluated in comparison with PLLA and PLLA-TMC with the aim of assessing their potential in the development of bioresorbable cardiovascular stents. Various aspects of in vitro biocompatibility were considered, including MTT assay, hemolytic test, dynamic clotting time, platelet adhesion, platelet activation, protein adsorption, plasma recalcification time and release of cytokines. The results revealed that the terpolymer presents good cytocompatibility and hemocompatibility. Moreover, no significant increase in the release of cytokines was detected. It is thus concluded that these polymers, in particular PLLA-TMC-GA terpolymer present good biocompatibility for cardiovascular applications.     

Mechanical behavior of nano-hybrid composite in comparison to lithium disilicate as posterior cement-retained implant-supported crowns restoring different abutments

ObjectiveResin-based materials are gaining popularity in implant dentistry due to their shock absorption capacity. Therefore, the aim of this study was to evaluate the fracture strength and failure mode of resilient materials for both crowns and abutments and compare them to the most widely used materials in different combinations after subjection to long-term fatigue loading.MethodsForty-eight cement-retained implant-restorations were assembled on titanium implants. Identical custom-made CAD/CAM abutments were milled out of 3 different materials (n = 16); T: titanium, Z: zirconia and P: ceramic-reinforced PEEK. Each group was subdivided, according to the restorative crown material, into two subgroups (n = 8); C: nano-hybrid composite and L: Lithium disilicate. Specimens were subjected to dynamic load of 98 N for 1,200,000 cycles with integrated thermal cycling. The surviving specimens were subjected to quasi-static loading until failure. Shapiro–Wilk test was used to test for normality. One-way ANOVA followed by Tukey’s post-hoc test was used to detect statistically significant differences between groups.ResultsAll specimens withstood 1,200,000 load cycles. The fracture strength values varied from a minimum of 1639 ± 205 N for group PL to a maximum of 2949 ± 478 N for group ZL.SignificanceThe abutment material influenced the fracture strength and failure mode of the restoration. A combination of zirconia abutments and nano-hybrid composite showed the most favorable mode of failure within the test groups. Therefore, this combination might be recommended as an alternative for restoring single implants in the posterior area.