Controlling septation in fission yeast: finding the middle, and timing it right

The fission yeast Schizosaccharomyces pombe provides a simple eukaryotic model for the study of cytokinesis. S. pombe cells are rod-shaped, grow mainly by elongation at their tips, and divide by binary fission after forming a centrally placed division septum. Analysis of mutants has begun to shed light upon how septum formation and cytokinesis are regulated both spatially and temporally. Some of the proteins involved in these events have been functionally conserved throughout eukaryotic evolution, suggesting that aspects of this control will be common to all eukaryotic cells. Received: 16 December 1998 / 10 March 1999     

动脉粥样硬化斑块形成时血管平滑肌细胞增生相关基因的cDNA全长克隆及其功能的初步探讨

目的　克隆动脉粥样硬化斑块形成时血管平滑肌细胞（ＳＭＣ） 增生相关基因的ｃＤＮＡ 全长,并对其功能进行初步探讨。方法　选用氧化低密度脂蛋白（ｏｘＬＤＬ） 作为刺激物作用于培养的人主动脉ＳＭＣ,利用减除杂交技术构建减除文库,克隆相关基因片段,在全长文库构建的基础上筛选相关基因的ｃＤＮＡ全长。并进行原核系统内蛋白表达及量效关系检测。结果　发现了４ 个新基因片段,克隆了一个新基因ｃＤＮＡ 全长,该基因在原核系统内有大约相对分子质量为４４ ０００ 的蛋白表达,其高表达可能与ＳＭＣ增生有关。结论　筛选克隆的新基因ＰＳＭＣＨ１ 在动脉粥样硬化斑块形成时可能有较重要的生物学作用。     

Water and solute secretion by the choroid plexus

The cerebrospinal fluid (CSF) provides mechanical and chemical protection of the brain and spinal cord. This review focusses on the contribution of the choroid plexus epithelium to the water and salt homeostasis of the CSF, i.e. the secretory processes involved in CSF formation. The choroid plexus epithelium is situated in the ventricular system and is believed to be the major site of CSF production. Numerous studies have identified transport processes involved in this secretion, and recently, the underlying molecular background for some of the mechanisms have emerged. The nascent CSF consists mainly of NaCl and NaHCO₃, and the production rate is strictly coupled to the rate of Na⁺ secretion. In contrast to other secreting epithelia, Na⁺ is actively pumped across the luminal surface by the Na⁺,K⁺-ATPase with possible contributions by other Na⁺ transporters, e.g. the luminal Na⁺,K⁺,2Cl⁻ cotransporter. The Cl⁻ and HCO₃ ⁻ ions are likely transported by a luminal cAMP activated inward rectified anion conductance, although the responsible proteins have not been identified. Whereas Cl⁻ most likely enters the cells through anion exchange, the functional as well as the molecular basis for the basolateral Na⁺ entry are not yet well-defined. Water molecules follow across the epithelium mainly through the water channel, AQP1, driven by the created ionic gradient. In this article, the implications of the recent findings for the current model of CSF secretion are discussed. Finally, the clinical implications and the prospects of future advances in understanding CSF production are briefly outlined.     

PLGA based drug delivery systems: Promising carriers for wound healing activity

Wound treatment remains one of the most prevalent and economically burdensome healthcare issues in the world. Current treatment options are limited and require repeated administrations which led to the development of new therapeutics to satisfy the unmet clinical needs. Many potent wound healing agents were discovered but most of them are fragile and/or sensitive to in vivo conditions. Poly(lactic‐co‐glycolic acid) (PLGA) is a widely used biodegradable polymer approved by food and drug administration and European medicines agency as an excipient for parenteral administrations. It is a well‐established drug delivery system in various medical applications. The aim of the current review is to elaborate the applications of PLGA based drug delivery systems carrying different wound healing agents and also present PLGA itself as a wound healing promoter. PLGA carriers encapsulating drugs such as antibiotics, anti‐inflammatory drugs, proteins/peptides, and nucleic acids targeting various phases/signaling cycles of wound healing, are discussed with examples. The combined therapeutic effects of PLGA and a loaded drug on wound healing are also mentioned.     

Insulinotropic action of L-rhamnose in isolated rat islets

Summary L-Rhamnose at different concentrations stimulated incorporation of³H-leucine both into islet (pro)insulin and that released into the medium. Maximum isotope incorporation with either glucose or rhamnose was seen at a concentration of 16.7 mM, although the glucose-induced effect was significantly greater. Like glucose, rhamnose also enhanced the activities of acid phosphatase and cathepsin B in isolated rat islets.Communication No. 2759.     

Modifications of the organic and mineral fractions of dental tissues following conditioning by self-etching adhesives

Objectives

Our objective was to analyse the acid strengths and concentrations in contemporary self-etch adhesives and test whether the adhesion/decalcification concept functions the same way for all products.

Methods

The self-etching adhesives were dissolved in a 50% water-ethanol solvent, these were reacted with biological apatite (HA) in the form of powder of human dentine in order to quantify calcium release and study the reaction products as a function of acid strengths and concentrations. The four self-etching adhesives investigated were AdheSE One (Ivoclar Vivadent, Schaan, Liechtenstein), Adper Easy Bond (3 M ESPE, St Paul, MN, USA), Optibond All-In-One (KERR, Orange, CA, USA), Xeno V (Dentsply De Trey, Konstanz, Germany).

Results

Acid concentrations were found to span the range from 1 to 2 mmol/l, and the acid dissociation constants varied between apparent pKa values of 3.4 and 4.2. The pH values changed with time from values near 2.8 to 3.6, confirming the buffering action of HA. The stronger acids dissolved more calcium ions but left less organic matter attached to the tissue particles. Thermogravimetric and infrared analysis demonstrated that the weaker acids tended to bind to HA surfaces and increased significantly the organic to mineral ratios of the powders.

Conclusion

Self-etching adhesives can be differentiated and classified in two types: weak acids attach to the mineral phase and leach little calcium; strong acids bind to the calcium ions, demineralize more and tend to debond from the dentinal hard tissues by forming more soluble calcium salts.     

Influence of fluoride concentration and ethanol pre-treatment on the reduction of the acid susceptibility of enamel

Objective

To determine the association between KOH-soluble and structurally bound fluoride uptake and the erosion resistance of enamel, respectively. Additionally, the effect of enamel pre-treatment with ethanol before fluoridation was assessed.

Methods

Sixty bovine incisors (4 specimens/tooth) were randomly allocated to six groups (A-F). Samples 1 and 2 remained untreated, serving as control at baseline. Pre-treatment of the samples was performed for 5 min with 99% ethanol (groups A, B and C) or physiologic saline (groups D, E and F). Samples 3 and 4 were treated either with 0.5% (groups A and D), 1.0% (groups B and E) or 1.5% (groups C and F) fluoride solution. In samples 1 and 3, uptake of KOH-soluble and structurally bound fluoride was determined. Samples 2 and 4 were used for the determination of acid susceptibility by immersion in 1 ml HCl for 30 s. Calcium release into HCl was assessed by atomic absorption spectroscopy. Differences between the groups were calculated by unpaired t-tests (p < 0.05).

Results

Mode of pre-treatment showed no influence on fluoride acquisition. KOH-soluble and structurally fluoride uptake increased with increasing fluoride concentrations. Highest acid resistance was observed after treatment with 1% fluoride solution for both kinds of pre-treatment followed by 1.5% and 0.5% fluoride solution.

Conclusion

Dose-dependency was observed for enamel fluoride acquisition but not for acid resistance.     

甲钴胺联合叶酸治疗2型糖尿病肾病伴高血清同型半胱氨酸血症患者临床疗效及安全性

目的 探究甲钴胺联合叶酸治疗2型糖尿病肾病（DN）伴高血清同型半胱氨酸（Hcy）血症患者的临床疗效及安全性。方法 回顾性分析2015年8月至2016年7月期间本院收治的70例2型DN伴高Hcy血症患者分为两组,各35例。对照组采用常规西药综合治疗（短效注射胰岛素、盐酸贝那普利片、缬沙坦分散片）,观察组在此基础上辅以甲钴胺联合叶酸治疗,两组均连续治疗52周,对比两组临床疗效及两组治疗前后24 h尿蛋白定量（24 h Pro）、血Hcy水平,并记录两组治疗安全性。结果 观察组总有效率为88.6%（31/35）,高于对照组的77.1%（27/35）（P<0.05）。观察组治疗后12、20、36、52周的24 h Pro均低于同期对照组（P<0.05）。观察组治疗后12、20、36、52周的血Hcy均分别低于同期对照组（P<0.05）。两组均未发生严重药物不良反应。结论 对DN伴高Hcy血症患者加用甲钴胺、叶酸治疗的临床疗效确切,有助于降低血Hcy水平,以减少尿蛋白排泄,且治疗安全可靠。     

血液透析对患者血清碱性磷酸酶、骨硬化蛋白与骨代谢的影响

目的血液透析对患者血清碱性磷酸酶(ALP)、骨硬化蛋白(SOST)与骨代谢等指标的影响。方法选取本院2016年1月至2019年1月期间收治的血液透析患者116例为研究对象纳入观察组,另选同期在本院进行体检的50例健康受试者为对照组。采用酶联免疫吸附试验法对两组患者入院时的ALP、SOST、骨代谢指标:血清骨钙素(OC)、β胶原蛋白(β-CTX)、I型前胶原氨基末端前肽(PINP)指标水平,并进行组间对比。对观察组患者进行维持性的血液透析治疗,并检测比较在患者透析治疗前、透析治疗1、6、12个月的各项指标水平。采用Pearson检验对观察组患者的ALP、SOST与骨代谢指标的相关性进行分析。结果与对照组比较,观察组患者血液透析治疗前ALP、SOST、OC、β-CTX、PINP等指标均低于对照组受试者各项指标水平,组间比较差异有统计学意义(P<0.05)。观察组患者中随着透析治疗时间的延长,患者的ALP、SOST、OC、β-CTX、PINP等指标水平均明显上升,各时间点间比较差异有统计学意义(P<0.05)。经Pearson检验分析,血液透析患者的ALP、SOST与骨代谢指标OC、β-CTX、PINP呈正相关性。结论血液透析患体内的ALP、SOST、骨代谢指标均呈现异常降低,经持续性血液透析治疗患者的ALP、SOST、骨代谢指标均有改善,且ALP、SOST与骨代谢指标OC、β-CTX、PINP呈正相关性。