Timing and frequency of bowel activity in patients ingesting sodium picosulphate/magnesium citrate and adjuvant bisacodyl for colon cleansing before colonoscopy

BACKGROUND:

Despite the wealth of research investigating bowel cleansing efficacy, there are very little data on the timing or frequency of bowel movements after each agent is ingested.

OBJECTIVE:

To examine the effect of each component of a three-day combined sodium picosulphate/magnesium citrate (PSLX) and bisacodyl regimen on the timing and frequency of bowel activity in patients undergoing colonoscopy.

METHODS:

Outpatients booked for colonoscopy were asked to complete a diary of their bowel preparation that tracked the timing of bowel movements. Bowel preparation quality was assessed using the Ottawa Bowel Preparation Scale. Bowel activity was compared with baseline and correlated with colon cleansing. Subgroup analysis was performed examining the effect of timing of the procedure and split-dose regimens.

RESULTS:

One hundred patients undergoing colon cleansing received bisacodyl 10 mg at 17:00 three days and two days before the day of colonoscopy. In one group, both sachets of PSLX were given the night before colonoscopy, while the second group, whose colonoscopies were scheduled after 11:00, ingested one sachet the night before and the second sachet at 06:00 on the day of colonoscopy. Patients had a mean of 1.7 bowel movements per day in the seven days before starting the cleansing regimen. Both doses of bisacodyl tablets resulted in a significant increase in the mean number of bowel movements compared with baseline (3.3/day first dose; 3.8/day second dose [P=0.03 and 0.001, respectively]). Each dose of PSLX also resulted in a significant increase in bowel movement frequency compared with baseline, with means of 4.4, 6.3 and 4.5 bowel movements after each dose. The mean time to the final bowel movement following the second sachet of PSLX was 8.9 h when taken the night before, and 3.9 h when taken the morning of the procedure. Bowel preparation quality significantly correlated with bowel frequency when total bowel movements were considered and when only the effects of bisacodyl were accounted for (P<0.01 for each).

DISCUSSION:

These data demonstrate that the addition of bisacodyl before PSLX ingestion has a significant additive effect on bowel frequency and correlates with bowel cleansing quality. The timing of the resulting bowel movements have practical implications for sleep and travel times to endoscopy suites.     

Small molecule inhibitor of type I transforming growth factor-β receptor kinase ameliorates the inhibitory milieu in injured brain and promotes regeneration of nigrostriatal dopaminergic axons

Transforming growth factor-β (TGF-β), a multifunctional cytokine, plays a crucial role in wound healing in the damaged central nervous system. To examine effects of the TGF-β signaling inhibition on formation of scar tissue and axonal regeneration, the small molecule inhibitor of type I TGF-β receptor kinase LY-364947 was continuously infused in the lesion site of mouse brain after a unilateral transection of the nigrostriatal dopaminergic pathway. At 2 weeks after injury, the fibrotic scar comprising extracellular matrix molecules including fibronectin, type IV collagen, and chondroitin sulfate proteoglycans was formed in the lesion center, and reactive astrocytes were increased around the fibrotic scar. In the brain injured and infused with LY-364947, fibrotic scar formation was suppressed and decreased numbers of reactive astrocytes occupied the lesion site. Although leukocytes and serum IgG were observed within the fibrotic scar in the injured brain, they were almost absent in the injured and LY-364947-treated brain. At 2 weeks after injury, tyrosine hydroxylase (TH)-immunoreactive fibers barely extended beyond the fibrotic scar in the injured brain, but numerous TH-immunoreactive fibers regenerated over the lesion site in the LY-364947-treated brain. These results indicate that inhibition of TGF-β signaling suppresses formation of the fibrotic scar and creates a permissive environment for axonal regeneration.     

胶原蛋白硫酸肝素支架移植入猪脑后对其神经元凋亡的影响

本实验研究胶原蛋白硫酸肝素支架移植入猪脑后对其神经元凋亡的影响,测定体内试验中该支架和 猪脑组织的生物相容性。实验组通过微创手术将胶原蛋白硫酸肝素支架移植入猪的脑内。对照组行假手术。分别于术后1天、3天、7天、14天或者30天手术处死动物,取组织标本行组织学分析（包括免疫组织化学法检测Bax 和Bcl-2）。HE染色发现移植后随即出现轻度组织反应。通过末端脱氧核糖核苷酸转移酶介导的缺口末端标记分析法于术后第1、3、7、14天在两组动物脑组织中都发现小量凋亡细胞;但是Bax 和Bcl-2呈低表达。在术后3天和7天,实验组和对照组间有显著差异,但是在术后30天两组间差异不明显。该支架和猪的脑组织具有组织相容性,能作为生物学底物安全地用于中枢神经系统组织工程。     

硫酸镁在麻醉镇痛中的应用现状

由于Mg2+具有拮抗N-甲基-天门冬氨酸(N-methyl-D-aspartment,NMDA)受体,抑制运动神经末梢乙酰胆碱和肾上腺髓质及交感能神经末梢肾上腺素等介质的释放等作用,常用以辅助全身麻醉、术后镇痛等,可明显减少麻醉镇痛药的消耗.     

椎弓根螺钉固定结合硫酸钙椎体成形术治疗胸腰椎压缩性骨折的生物力学研究

目的探讨椎弓根螺钉固定结合硫酸钙椎体成形术治疗胸腰椎压缩性骨折的生物力学性能。方法15具新鲜雄性小牛胸腰椎标本制成11～L1脊柱功能单位,随机分为正常完整标本组（A组）、后路经椎弓根螺钉内固定组（B组）、椎弓根螺钉内固定结合硫酸钙椎体成形术组（C组）。3组标本在万能材料试验机上测试其生物力学性能,试验数据进行统计学处理,并进行组间比较。结果C组的椎体和椎间盘平均应变比B组低14％和12％,比A组低21％和13％;C组位移分别比B、A组减少25％和37％。胸腰椎椎体和椎间盘的强度：C组比B组高14％和24％,比A组高13％和20％;C组胸腰椎刚度比B、A分别高44％和53％。胸腰椎最大抗扭强度：C组分别比B、A组高18％和30％,扭转刚度C组分别比B、A组高30％和46％。以上数据经统计学处理,差异均有统计学意义（P〈0．05）。结论椎弓根螺钉固定结合硫酸钙椎体成形术治疗胸腰椎压缩性骨折的生物力学性能是优越的,不但强度、刚度大,而且术后的胸腰椎体稳定,有利于减轻内植物的应力负荷,进而降低螺钉的松动、折断发生率及术后椎体高度的丢失。     

硫酸钙对人骨髓基质干细胞向成骨细胞转化时基因表达的影响

目的 观察硫酸钙(CS)在人骨髓基质干细胞(BMSCs)向成骨细胞转化过程中对成骨基因表达的影响,探讨硫酸钙修复骨缺损可能的生物学机制.方法 制备硫酸钙浸提的成骨诱导液(实验组)与常规的成骨诱导液(对照组),分别加入人BMSCs培养瓶(各3例),使其向成骨细胞的诱导分化,注意观察细胞的分化和生长.培养至第7天时进行RNA的抽提、纯化和质量检测,并合成cDNA,采用成骨功能基因芯片分别检测实验组和对照组中各种成骨基因的变化.结果 实验组和对照组细胞均生长良好,缓慢增殖,但实验组向成骨细胞分化的趋势要明显较对照组好.成骨基因芯片共检测到89种基因,其中有23种基因表达改变显著(Fold change＞2,P＜0.05).表达上调超过2倍的基因包括:AMELY、BMP2、COL4A3、COMP、EGF、FLT1、IGF1、ITGA2、MMP10、MMP2、TGFB2、TGFBR1、VDR和VEGFA.表达下调超过2倍的有:COL2A1、COL15A1、COL1A1、COL1A2、COL5A1、CSF2、FGF1、ITGA3和MMP8.结论 硫酸钙促进了人BMSCs向成骨细胞转化的过程,这种作用与硫酸钙促进成骨基因表达上调、合成活性因子增加相关,说明硫酸钙具有潜在的骨诱导活性,可以作为良好的骨修复替代材料,促进细胞的骨修复能力.     

体外评估硫酸肝素-胶原蛋白生物支架与嗅鞘细胞生物相容性的研究

背景：中风和神经系统的外伤和卒中可导致神经功能缺损,同时伴随轴突受损,形成胶质瘢痕、空腔和裂隙。嗅鞘细胞作为自体移植最佳的候选细胞,可以分泌神经营养因子促进轴突的生长。并且生物支架具有多孔的三维立体结构,能够运载细胞填充和桥连这些空隙。因此移植支架联合种子细胞是一种修复神经组织重要的策略。 方法：硫酸肝素-胶原蛋白生物支架经过一系列的程序而制作成功。将硫酸肝素-胶原蛋白生物支架与嗅鞘细胞在体外共培养,在第1、3、5和7天时用MTT法检测细胞活性。数据分析采用重复测量设计的方差分析,当P < 0.05时被认为具有显著性差异。之后将嗅鞘细胞用CFSE标记,通过流式细胞仪检测标记率为99.8%。用CFSE标记后的嗅鞘细胞以适宜的浓度种植于支架上。细胞在支架上的粘附和生长可以通过荧光显微镜和扫描电镜直接追踪和观察。 结果：硫酸肝素-胶原蛋白生物支架具有稳定的三维立体结构,对于嗅鞘细胞无毒性（F= 0.14,P= 0.9330）。除此之外,细胞及其轴突也能够在该支架中很好的黏附和生长。 结论：本实验表明硫酸肝素-胶原蛋白生物支架与嗅鞘细胞在体外具有很好的生物相容性。因此,硫酸肝素-胶原蛋白生物支架可能可以作为一种载体,种植嗅鞘细胞后应用于神经组织工程。     

Pregnenolone sulfate enhances spontaneous glutamate release by inducing presynaptic Ca-induced Ca release

Pregnenolone sulfate (PS) acts as an excitatory neuromodulator and has a variety of neuropharmacological actions, such as memory enhancement and convulsant effects. In the present study, we investigated the effect of PS on glutamatergic spontaneous excitatory postsynaptic currents (sEPSCs) in acutely isolated dentate gyrus (DG) hilar neurons by use of a conventional whole-cell patch-clamp technique. PS significantly increased sEPSC frequency in a concentration-dependent manner without affecting the current amplitude, suggesting that PS acts presynaptically to increase the probability of spontaneous glutamate release. However, known molecular targets of PS, such as α7 nicotinic ACh, NMDA, σ1 receptors and voltage-dependent Ca²⁺ channels, were not responsible for the PS-induced increase in sEPSC frequency. In contrast, the PS-induced increase in sEPSC frequency was completely occluded in a Ca²⁺-free external solution, and was significantly reduced by either the depletion of presynaptic Ca²⁺ stores or the blockade of ryanodine receptors, suggesting that PS elicits Ca²⁺-induced Ca²⁺ release (CICR) within glutamatergic nerve terminals. In addition, the PS-induced increase in sEPSC frequency was completely occluded by transient receptor potential (TRP) channel blockers. These data suggest that PS increases spontaneous glutamate release onto acutely isolated hilar neurons via presynaptic CICR, which was triggered by the influx of Ca²⁺ through presynaptic TRP channels. The PS-induced modulation of excitatory transmission onto hilar neurons could have a broad impact on the excitability of hilar neurons and affect the pathophysiological functions mediated by the hippocampus.