方格星虫酶解物成分分析及其抗氧化作用

用木瓜蛋白酶对方格星虫（Sipunculus nudus）进行酶促水解,并对酶解物冻干粉的成分进行了分析,其中粗蛋白质量分数为69.02%,多肽质量分数为60.60%,肽的平均链长为3.73个氨基酸残基,肽分子的平均相对分子质量为447.6;游离氨基酸占5.27%。氨基酸分析结果显示,方格星虫酶解物含有17种氨基酸（色氨酸未测）,其中人体必需氨基酸含量较高,占总氨基酸数的30.62%。方格星虫酶解物中还含有P、Fe、Mg、Mn、Zn、Cu、Se等至少12种矿质元素,以及含有抗氧化作用的营养成分,并通过动物试验证明了方格星虫酶解物具有显著的抗氧化作用。方格星虫酶解物可用于食品添加或用作功能性食品。     

聚—（羟丙基、丙基）—天冬酰胺材料体外酶解及植入小鼠体内的观察

目的：观察4种不同摩尔比的聚－（羟丙基、丙基）－天冬酰胺材料在体外酶解和植入小鼠体内后的变化。方法;用木瓜蛋白酶和胰酶对材料作了体外酶解试验,用凝胶色谱法对降解物碎片作了测定;用光镜、扫描电镜、透射电镜等对材料在埋植部位、肝、肾组织内的降解碎片进行观察;对材料植入小鼠体内后的生化指标（血红蛋白、白细胞、谷丙转氨酶、肌酐作了测定。结果：聚－（羟丙基、丙基）－天冬酰胺材料在体外能被逐步酶解。在植入小鼠体内的5周内,在埋植部位、肝、肾组织内能观察到材料的碎片。结论：聚－（羟丙基、丙基）－天冬酰胺材料能在体内、外逐步降解,植入小鼠体内后对动物的血象、肝、肾功能无明显的影响,具有生物相容性。     

Hemorrhagic activity of Bothrops venoms determined by two different methods and relationship with proteolytic activity on gelatin and lethality

The changes in hemorrhagic activity, proteolytic activity on gelatin and the lethal potency of four Bothrops venoms treated at different pH values or with EDTA were studied. Venoms from B. alternatus, B. jararaca, B. moojeni and B. neuwiedii of Argentina were preincubated at pH 5.8, 5.1 or 3.8 or with EDTA and the hemorrhagic activity expressed as size of the hemorrhagic lesion or as the amount of hemoglobin extracted, the proteolytic activity on gelatin and the lethal potency were determined. Although the MHDs recorded in rats were 19–56 fold higher than those recorded in mice, the A₅₅₀ extracted per gram of hemorrhagic haloes was very similar in rats or mice independent of the venom dose. Inhibition of proteolytic activity after preincubation at pH 5.1 or 3.8, agrees with the decreased amount of hemoglobin extracted from the hemorrhagic haloes, and with the increase in mean survival time after the i.p. injection to mice. Preincubation with EDTA resulted in 80% inhibition of hemorrhagic activity of B. jararaca venom and complete inhibition with the other Bothrops venoms tested. Measurement of the amount of hemoglobin extracted gives significant information in comparative studies, not available by measurement of the size of hemorrhagic haloes.     

Streptokinase may play role in expanding non-operative management of infected walled off pancreatic necrosis: Preliminary results

Goals and backgroundWe evaluated ex and in vivo effect of streptokinase on pancreatic necrosum to improve the success rate of pigtail catheter drainage and irrigation in infected walled off pancreatic necrosis using step up approach and also looked at potential risk of bleeding.Experiment and clinical cases1000 IU/ml of streptokinase was added to 10 g. of intra-operatively obtained fresh tissue of peripancreatic necrosis and results compared to treatment with saline. Mixture was incubated for 12 h in thermostat at 37.5 °C and subjected to histopathology. Subsequently streptokinase (50,000 units thrice a day for 5 days through PCD) was used in two patients with walled off pancreatic necrosis (WOPN) not responding to step up approach and who were being considered for surgery.Grossly there was fragmentation of necrosum in streptokinase treated tissue. Microscopically complete loss of supportive collagenous framework was noted in streptokinase treated necrosum with clumping of necrotic tissue into structure-less mass. No such changes were discernible in saline treated tissue. In two patients with WOPN there was clearance of debris after streptokinase instillation. None of the patients was on thromboprophylaxis and bleeding was not noticed in any of the patients.ConclusionBased on ex vivo effect of streptokinase in dissolution of necrosum at periphery, we believe that in patients with walled off pancreatic necrosis (WOPN) not responding to pigtail catheter drainage and saline irrigation; streptokinase may prove to be useful adjunct.     

响应面法优化广金钱草中总黄酮的酶法提取工艺

目的 采用响应面法优化广金钱草中总黄酮的酶法提取工艺.方法 在单因素试验的基础上,根据Box-Behnken设计原理,采用四因素三水平响应面分析方法,考察酶解时间、温度、酶用量和pH值对总黄酮得率的影响,建立二次多项式回归方程的预测模型,绘制以总黄酮含量为响应值的等高线图和响应曲面,讨论各因素间的交互作用.结果 确定了酶法提取工艺的最佳参数为:以60％乙醇提取、料液比为1∶50、0.23％纤维素酶、酶解1.49 h、酶解温度为30.55℃、pH5.52;实际测得总黄酮的得率为6.560 mg·g-1,与预测值6.481 mg·g-1相近.结论 酶法提取广金钱草中总黄酮的反应条件温和,可避免破坏有效成分的结构;优选的工艺稳定可行,提高了提取效率.     

Enzymatic glycosylation of oleanane-type triterpenoids

Abstract

Glycosylation is an effective approach to improve the druggability of natural products by increasing their water solubility. In this work, we report the glycosylation of oleanane-type triterpenoids by a recombinant microbial glycosyltransferase YjiC1. A preliminary screening test indicated YjiC1 exhibited robust capabilities for O-glycosylation of triterpenoids, based on LC/MS analysis. Among the products, two new compounds (2a and 3a), together with a known one (1a), were isolated and characterized. These products exhibited improved water solubility, and 3a showed moderate anti-HIV activities at 100 μM. This reaction provides a facile and efficient approach to synthesize the glucosides of triterpenoids.     

A novel rapid and selective enzymatic debridement agent for burn wound management: A multi-center RCT

Objectives

Excisional debridement followed by autografting is the standard of care (SOC) for deep burns, but is associated with serious potential complications. Conservative, non-surgical and current enzymatic debridement methods are inefficiently slow. We determined whether a non-surgical option of rapid enzymatic debridement with the debriding enzyme NexoBrid™ (NXB) would reduce need for surgery while achieving similar esthetic and functional outcomes as SOC.

Methods

We conducted a multi-center, open-label, randomized, controlled clinical trial including patients aged 4-55 years with deep partial and full thickness burns covering 5-30% of their total body surface area (TBSA). Patients were randomly assigned to burn debridement with NXB (applied for 4 h) or SOC, which included surgical excisional or non-surgical debridement.

Results

NXB significantly reduced the time from injury to complete débridement (2.2 vs. 8.7 days, P < 0.0001), need for surgery (24.5% vs. 70.0%, P < 0.0001), the area of burns excised (13.1% vs. 56.7%, P < 0.0001) and the need for autografting (17.9% vs. 34.1%, P = 0.01). Scar quality and quality of life scores were similar in both study groups as were the rates of adverse events.

Conclusions

Enzymatic débridement with NXB resulted in reduced need for and extent of surgery compared with SOC while achieving comparable long-term results in patients with deep burns.

Trial registration

: Clinical Trials.gov NCT00324311.     

In vitro and in vivo characteristics of stem cells from human exfoliated deciduous teeth obtained by enzymatic disaggregation and outgrowth

Objective

Stem cells from human exfoliated deciduous teeth (SHED) are a good source of dental tissue for regeneration therapy, and can be obtained using different primary culture methods. The aim of this study was to determine the differences in the in vitro and in vivo characteristics between SHED isolated via enzymatic disaggregation (e-SHED) and outgrowth (o-SHED) primary culture methods.

Design

Dental pulp stem cells were isolated from 14 exfoliated deciduous teeth by enzymatic disaggregation (n = 7) and outgrowth (n = 7). Their proliferation potential and colony-forming ability were evaluated in vitro, as was their mesenchymal stem-cell-marker expression (using flow cytometry), and their differentiation was verified using quantitative real-time PCR (qPCR) and histochemical staining. In addition, the qualitative and quantitative characteristics of the hard tissue that was generated after in vivo transplantation were compared using haematoxylin and eosin staining, immunohistochemical staining, qPCR, and quantitative alkaline phosphatase analysis.

Results

The cell-proliferation potential, colony-forming ability, and Stro-1 and CD146 expression were higher in e-SHED than in o-SHED. While the in vitro adipogenic differentiation potential was greater in e-SHED than in o-SHED, the in vitro osteogenic differentiation did not differ significantly between the two cell types. Although in vivo hard tissue formation was greater following transplantation of o-SHED into mice, there was no difference in the quality of hard tissue generated by e-SHED and o-SHED.

Conclusion

The findings of this study indicate that e-SHED exhibit stronger stemness characteristics, but that o-SHED are more suitable for hard-tissue regeneration therapy in teeth.     

PTD-SOD融合蛋白的毕赤酵母表达载体的构建和表达

目的 PTD-SOD是含有PTD和SOD的融合蛋白,前人的研究表明它能跨膜进入细胞,具有比SOD更高的生物利用率.但至今为止的表达都是在大肠杆菌中完成的,得到的是没有活性的包涵体.本文将人工合成的PTD-SOD全基因插入含有AOX1基因启动子和分泌信号肽序列的毕赤酵母表达载体pPICZα中,重组载体转化进入毕赤酵母.结果 表明,经甲醇诱导,配合蛋白PTD-SOD成功得到分泌表达,表达量随诱导时间的延长而递增,诱导8d后活力达到最高,值为301.48U·mL-1.由于本文构建的毕赤酵母表达系统表达的PTD-SOD是有活性的分泌蛋白,这就为下游的工艺操作带来了极大的便利,为PTD-SOD的理化研究和工业化生产提供了物质基础.