复合壳聚糖微球-丝素基载药α-磷酸三钙骨水泥的细胞相容性及毒性

背景：磷酸钙骨水泥具有良好的生物相容性和骨传导性,已被应用于临床,但其不良的力学性能和缺乏骨诱导性限制了其进一步发展和应用。目的：制备壳聚糖微球-丝素基载药α-磷酸三钙骨水泥,验证其细胞相容性及细胞毒性。方法：分别以含体积分数10%胎牛血清和1%双抗的α-MEM培养基、苯酚、100%及50%复合壳聚糖微球-丝素基载药α-磷酸三钙骨水泥材料的浸提液培养MC3T3-E1细胞,采用MTT法评估细胞生长增殖情况,采用乳酸脱氢酶活性检测法判断复合壳聚糖微球-丝素基载药α-磷酸三钙骨水泥材料的毒性。将MC3T3-E1细胞系与复合壳聚糖微球-丝素基载药α-磷酸三钙骨水泥材料共培养,扫描电镜观察细胞在材料表面的附着及生长。结果与结论：复合壳聚糖微球-丝素基载药α-磷酸三钙骨水泥材料浸提液对MC3T3-E1细胞的生长增殖无明显影响,无明显细胞毒性。MC3T3-E1细胞在复合壳聚糖微球-丝素基载药α-磷酸三钙骨水泥材料表面生长良好,伸展充分,在材料表面伸出伪足,与材料贴附紧密,表明壳聚糖微球-丝素基载药α-磷酸三钙骨水泥细胞相容性良好。     

Randomized Study Comparing Two Regimens of Oral Sodium Phosphates Solution Versus Low-Dose Polyethylene Glycol and Bisacodyl

Purpose Low-volume bowel preparation regimens for colonoscopy are reported to improve patient acceptance and compliance. We sought to compare the bowel cleansing efficacy, tolerability, and acceptability of three low-volume regimens: an oral sodium phosphates solution 45/45 ml (NaP-45/45), a reduced-dose oral sodium phosphates solution 45/30 ml (NaP-45/30), and polyethylene glycol plus bisacodyl (PEG-2L). Results A total of 121 patients were evaluated (mean age 55.2 ± 8.9 years). Bowel cleansings rated as excellent and good were significantly different among the groups: NaP-45/45 = 98%, NaP-45/30 = 88%, and PEG-2L = 76% (P < 0.04). Side effects were not significantly different except for greater thirst in the NaP-45/45 group (P = 0.001) and increased vomiting in females using PEG-2L (two-tailed interaction, P < 0.10). Willingness to retake the preparation was higher among the sodium phosphates regimens (88, 95, and 73%, respectively; P = 0.019). Conclusions Better cleansing and willingness to retake the regimen was achieved with the oral sodium phosphates solutions than with polyethylene glycol plus bisacodyl.

Acute Effects of Cell Isolation on InsP Profiles in Adult Rat Cardiomyocytes

The isolation and culture of adult rat cardiomyocytes was shown to cause major changes in the contents of [³H]-labeled inositol phosphates and inositol phospholipids. Undigested heart tissue contained high levels of [³H]Ins(1,4,5)P₃(5364±800 ct/min/g tissue, 80±12 ct/min/mg protein) and mass content averaged 13.8 nmol/g tissue or 208±36 pmol/mg protein (mean±s.e.m.,n=4). After collagenase digestion, [³H]Ins(1,4,5)P₃was undetectable and the mass content of Ins(1,4,5)P₃had decreased to 0.8±0.2 pmol/mg protein (mean±s.e.m.,n=4,P<0.01). [³H]Ins(1,4)P₂was reduced by 80% and [³H]PtdIns(4,5)P₂by 90%. These profiles remained essentially unchanged when the isolated cells were maintained in culture for up to 24 h, even though the inositol phosphate response remained sensitive to norepinephrine. Similar to findings in intact tissue, the inositol phosphate response to norepinephrine in these cells was inhibited by neither U-73122 (5μm) nor by neomycin (5 mm). By 48 h in culture, the relative levels of [³H]Ins(1,4,5)P₃and [³H]Ins(1,4)P₂had increased in relation to the total inositol phosphate content and responses appeared to better reflect intact tissue. However, while retaining insensitivity to neomycin, cells at 48 h were fully sensitive to U-73122 (5μm). These data demonstrate that altered inositol phosphate responses are observed in adult cardiomyocytes from the time of isolation and that while the profiles change over time in culture, a pattern similar to that in intact heart is not re-established.     

基于磷酸丙糖异构酶基因序列的蓝氏贾第鞭毛虫分子系统发育的研究

[目的 ]探讨蓝氏贾第鞭毛虫种内系统发育及遗传多样性。 [方法 ]对不同来源虫株的磷酸丙糖异构酶(tim)基因进行 PCR扩增、序列测定后 ,用简约法和 NJ法构建分子系统树进行系统学分析。 [结果 ]在所测序列中共有 12 4个位点存在变异 (2 3% ) ,且大多数为发生在第三密码子的同义突变 ,两种构树方法所得两树的分枝结构相似 ,均将受试的 16株蓝氏贾第鞭毛虫分为明显的两组。 [结论 ]tim基因可作为研究蓝氏贾第鞭毛虫群体遗传结构一个有效的遗传标记     

预分化脂肪干细胞与纤维蛋白胶和磷酸钙骨水泥自体异位构建血管化移植物

背景：预构骨皮瓣研究启发人们构建预构血管化骨进行游离移植来替代带血管蒂游离自体骨移植修复大段骨缺损的想法。目的：设计一种基于预分化脂肪干细胞、纤维蛋白胶和多孔磷酸钙骨水泥支架复合体的血管化移植物。方法：将体外分离培养的大鼠脂肪干细胞在条件培养基中进行血管内皮细胞定向分化,经鉴定活性后,复合至纤维蛋白胶和多孔磷酸钙骨水泥构建血管化组织工程支架。将血管化组织工程支架、纤维蛋白胶/多孔磷酸钙骨水泥支架及多孔磷酸钙骨水泥支架分别植入SD大鼠股四头肌肌袋内,植入后2,4周进行组织学检测、血管定量分析和Western blot检测。结果与结论：向血管内皮细胞分化的脂肪干细胞与纤维蛋白胶和多孔磷酸钙骨水泥共培养7 d,可见细胞密度适中,与支架组织结合较好。植入实验中,各组支架孔隙中充填有纤维血管组织和脂肪组织,血管化组织工程组支架孔隙中均长入大量血管,并有小动脉长入,不同时间点的血管直径和数量及血管内皮生长因子C的表达量均优于纤维蛋白胶/多孔磷酸钙骨水泥组和多孔磷酸钙骨水泥组（P〈0.01）。表明构建的血管化组织工程支架能够实现可靠迅速血管化。     

黄嘌呤氧化酶比色法测定血清无机磷

目的建立一种酶学分析法以测定血清无机磷的含量。方法血清无机磷与次黄嘌呤核苷在嘌呤核苷磷酸化酶（ＰＮＰ）的催化下，生成次黄嘌呤和核糖１磷酸，黄嘌呤氧化酶氧化次黄嘌呤生成尿酸和过氧化氢，过氧化氢与４氨基安替比林和２，４，６三溴３羟基苯甲酸在过氧化物酶的作用下，生成红色产物，在５０５ｎｍ有最大吸收。结果线性范围为０２５～５０ｍｍｏｌ／Ｌ，批内和批间平均变异分别为１１７％和２７９％，平均回收率为１０３４％，与紫外分光光度法比较，相关系数ｒ＝０９９８，Ｙ＝１０５６Ｘ－００５２。结论采用了２，４，６三溴３羟基苯甲酸的方法灵敏、准确、简便、快速、适合于半自动和全自动生化分析仪     

Pharmacological characterization of mitogen-activated protein kinase activation by recombinant human 5-HT<Subscript>2C</Subscript>, 5-HT<Subscript>2A</Subscript>, and 5-HT<Subscript>2B</Subscript> receptors

The type 2 serotonin (5-HT₂) receptor subfamily is known to couple to phosphoinositide hydrolysis (PI) and the subsequent mobilization of intracellular Ca²⁺, as well as the release of arachidonic acid (AA). Less is known of 5-HT₂-mediated activation of the mitogen-activated protein kinase (MAPK) or extracellular signal-regulated kinase (ERK1/2) signaling. The present study measured the relative efficacies and potencies of 5-HT agonists to activate ERK2 in non-neuronal cells expressing recombinant human 5-HT_2A, 5-HT_2B, and 5-HT_2C(ISV) receptors. 5-HT agonists stimulated ERK2 activity via all three 5-HT₂ subtypes. There were no meaningful differences in the potencies or relative efficacies of these agonists to affect ERK2 activity vs. PI accumulation or Ca²⁺ mobilization, suggesting that these pathways may be sequentially linked. Indeed, ERK2 activity was very sensitive to PKC inhibition and calcium chelation and insensitive to tyrosine kinase and PI-3-kinase inhibition. 5-HT₂ receptors efficiently couple to MAPK activation via sequential PI hydrolysis, and Ca²⁺ mobilization. This profile differs from reports of “agonist-directed trafficking of receptor stimulus” between PI/Ca²⁺ and AA pathways activated by 5-HT₂ receptors.     

Two repetition time saturation transfer (TwiST) with spill-over correction to measure creatine kinase reaction rates in human hearts

Background

Phosphorus saturation transfer (ST) magnetic resonance spectroscopy can measure the rate of ATP generated from phosphocreatine (PCr) via creatine kinase (CK) in the human heart. Recently, the triple-repetition time ST (TRiST) method was introduced to measure the CK pseudo-first-order rate constant k_f in three acquisitions. In TRiST, the longitudinal relaxation time of PCr while γ-ATP is saturated, T₁`, is measured for each subject, but suffers from low SNR because the PCr signal is reduced due to exchange with saturated γ-ATP, and the short repetition time of one of the acquisitions. Here, a two-repetition time ST (TwiST) method is presented. In TwiST, the acquisition with γ-ATP saturation and short repetition time is dropped. Instead of measuring T<sub>1</sub>`, an intrinsic relaxation time T₁ for PCr, T₁^intrinsic, is assumed. The objective was to validate TwiST measurements of CK kinetics in healthy subjects and patients with heart failure (HF).

Methods

Bloch equation simulations that included the effect of spillover irradiation on PCr were used to derive formulae for T₁^intrinsic and k_f measured by both TRiST and TwiST methods. Spillover was quantified from an unsaturated PCr measurement used in the current protocol for determining PCr and ATP concentrations. Cardiac TRiST and TwiST data were acquired at 3 T from 12 healthy and 17 HF patients.

Results

Simulations showed that both k_f measured by TwiST and T₁^intrinsic require spill-over corrections. In human heart at 3 T, the spill-over corrected T₁^intrinsic = 8.4 ± 1.4 s (mean ± SD) independent of study group. TwiST and TRiST k_f measurements were the same, but TwiST was 9 min faster. Spill-over corrected TwiST k_f was 0.33 ± 0.08 s⁻¹ vs. 0.20 ± 0.06 s⁻¹ in healthy vs HF hearts, respectively (p < 0.0001).

Conclusion

TwiST was validated against TRiST in the human heart at 3 T, generating the same results 9 min faster. TwiST detected significant reductions in CK k_f in HF compared to healthy subjects, consistent with prior 1.5 T studies using different methodology.

Electronic supplementary material

The online version of this article (doi:10.1186/s12968-015-0175-4) contains supplementary material, which is available to authorized users.     

生物全降解药物支架植入小型猪冠状动脉：安全性及组织相容性

背景：为解决聚左旋乳酸支架支撑力不足、代谢的酸性产物容易导致血管局部无菌性炎症等缺点,本课题组设计出新型支架,在聚左旋乳酸基础上融入无定型磷酸钙纳米颗粒。目的：评价新型生物全降解支架聚左旋乳酸/无定型磷酸钙纳米颗粒的安全性及组织相容性。方法：取16头健康西藏小型猪,随机选取左前降支、左回旋支或右冠状动脉支相同管腔大小的血管段,植入新型生物全降解支架1枚,于植入前、植入后1个月取股动脉血标本,行血液学检测。植入1,6个月后,复查冠状动脉造影后对支架段标本行苏木精-伊红染色,观察支架血管损伤、炎症及内皮化程度。结果与结论：支架植入前后血常规、血生化指标无明显变化。支架植入1,6个月后,冠状动脉造影提示冠状动脉通畅,无血栓形成,支架段血管与周围组织界限清楚,无组织粘连、坏死、贴壁不良等异常表现。与支架植入1个月时比较,植入6个月后的炎症积分降低（P 〈0.05）、内皮化积分增加（P 〈0.05）,植入部位损伤积分无明显变化;并且支架周围未见心肌梗死灶及炎性细胞浸润。结果表明新型生物全降解支架具有良好的安全性及组织相容性。     

Impaired cardiac work and oxygen uptake after reperfusion of regionally ischaemic myocardium.

Transient regional left ventricular ischaemia was produced in the isolated working perfused rat heart by ligation of the left main coronary artery and subsequent release of ligature after 15 min of acute regional myocardial ischaemia. Reperfusion restored coronary flow and the oxygen uptake to preligation values but cardiac output and peak left ventricular pressures remained impaired and tissue contents of ATP did not recover. Reperfusion also failed to restore the efficiency of the heart to pre-ligation values.