磁导航系统遥控导管消融治疗右心室流出道室性心动过速/室性早搏

目的：探讨应用磁导航遥控导管消融治疗右心室流出道起源的室性心动过速/室性早搏（ RVOT-VT/PVCs）的安全性和有效性。方法2008年11月至2009年11月,在南京医科大学第一附属医院心血管内科行体表心电图检查,诊断为RVOT-VT/PVCs的患者共16例[女12例,男4例,平均年龄（44±15）岁],结合应用非接触标测系统和起搏标测确定靶点,磁导航遥控磁导管实施消融术,消融失败者改为手控导管消融。结果10例（63%）患者使用磁导航消融成功,6例需手控导管消融,1例术后出现动静脉瘘。平均放电（3．9±1．6）次,放电时间（240±33） s,总手术时间为（190±42） min,总X线曝光时间为（4．8±2．6） min,术者X线曝光时间平均为（3．2±2．0） min,磁导航系统遥控导管X线曝光时间为（1．6±1．0） min。结论应用磁导航系统结合非接触标测系统可安全、有效地实施遥控导管消融治疗RVOT-VT/PVCs,并可减少术者和患者的X线曝光时间。     

In vivo anticancer activity of rhomboidal Pt(II) metallacycles

The development of novel antitumor agents that have high efficacy in suppressing tumor growth, have low toxicity to nontumor tissues, and exhibit rapid localization in the targeted tumor sites is an ongoing avenue of research at the interface of chemistry, cancer biology, and pharmacology. Supramolecular metal-based coordination complexes (SCCs) have well-defined shapes and geometries, and upon their internalization, SCCs could affect multiple oncogenic signaling pathways in cells and tissues. We investigated the uptake, intracellular localization, and antitumor activity of two rhomboidal Pt(II)-based SCCs. Laser-scanning confocal microscopy in A549 and HeLa cells was used to determine the uptake and localization of the assemblies within cells and their effect on tumor growth was investigated in mouse s.c. tumor xenograft models. The SCCs are soluble in cell culture media within the entire range of studied concentrations (1 nM–5 µM), are nontoxic, and showed efficacy in reducing the rate of tumor growth in s.c. mouse tumor xenografts. These properties reveal the potential of Pt(II)-based SCCs for future biomedical applications as therapeutic agents.Molecular assemblies of nanoscale-size and well-defined geometries have recently emerged as an interesting new paradigm in drug design and drug delivery. To date, liposomes, the self-assembled lipid nanoparticles held together by weak interactions, are among the most widely studied and clinically successful nanoparticle-based drug carriers. Their use allows the drug to achieve sustained plasma levels while encapsulated, with the size preventing the fast clearance by the kidneys that often occurs with the free drug. However, liposomes themselves do not produce a therapeutic effect and their application as drug carriers for medical purposes has often been hindered by poor loading capacity (<5 wt %) and the inability to pass through biological barriers (1, 2). Inorganic and hybrid porous materials, such as molecular organic frameworks (MOFs), have also shown promise due to their higher loading capacities (>25 wt %) (3–5), but MOFs have poor hydrolytic stability (6, 7). Recent studies on materials from Institut Lavoisier (MIL)-100(Cr) and MIL-100(Fe), however, suggest that MOFs can persist in biologically relevant environments and can act as vehicles for some anticancer and antiviral agents (8–10). These early findings have prompted further investigations into the biomedical applications of supramolecular coordination complexes (SCCs) (11–24). SCCs preserve the attractive properties of MOFs, such as building block modularity (22, 23, 25), yet afford an increased solubility in the biological milieu and lend themselves to small-molecule characterization techniques due to their well-defined structure.Although development of SCCs for biomedical applications is in its infancy, some SCCs, such as trigonal prisms self-assembled from p-cymene and ruthenium-based metal fragments with pyridyl donors, have shown the ability to act as effective carriers of some chemotherapeutic agents (26–28). Moreover, a library of cytotoxic to cancer cells p-cymene ruthenium-based polygons and cages has also been developed (11). For biomedical applications, the information about the cellular uptake, delivery of a guest, and metabolism of the drug delivery vehicle is critical, although currently the fate of SCCs in biological environments is not well understood. In a rare report, a systematic investigation of the structural stability of a water-soluble, hexacationic ruthenium-based trigonal prism was performed; however, it was determined that the ruthenium-based trigonal prisms decompose in the presence of amino acids histidine, lysine, and arginine (29).An intriguing approach is the design of tumor-targeted modalities that combine detection and treatment through the self-assembly of emissive, metal-based coordination complexes. Such modalities can be especially valuable as they often do not require photoexcitation to elicit cytotoxicity. Recently Gray, Gross, and Medina-Kauwe and coworkers reported HerGa, a self-assembled tumor-targeted particle that bears the Ga(III)-metalated derivative of the sulfonated corrole (30, 31). The particle, which contained Ga(III)-corrole noncovalently bound to the tumor-targeting cell penetration protein HerPBK10, provided both tumor detection and elimination. Systemic injection of this protein–corrole complex resulted in tumor accumulation, which can be visualized in vivo due to the red corrole fluorescence. Cytotoxic and cytostatic properties of these targeted Ga(III) corroles were found to be cell-line dependent, with the ability to induce late M-phase arrest in several cancer cell lines (32).Despite the well-known cytotoxic properties of mono- and multinuclear platinum complexes (33–35), studies of the antitumor properties of platinum-based SCCs are rare (17, 36). Moreover, recent reports have demonstrated that platinum-based SCCs can act as effective hosts for guests and have interesting photophysical properties (37–42). In particular, highly emissive rhomboids based on aniline-containing donors and Pt-based metal acceptors have been developed that display different photophysical properties from those of their constituent subunits (40). These assemblies are interesting targets to investigate the cytotoxicity of organoplatinum SCCs, whereas their emission spectra could be used for interrogating the structural integrity in vitro. Here, for the first time to our knowledge, we report the uptake of SCCs in vitro in cell-based assays, determined by using laser-scanning confocal microscopy, and an in vivo assessment of the anticancer activity of SCCs in mouse s.c. tumor xenograft models.     

Silver carbene complexes: An emerging class of anticancer agents

Cancer is a major global health problem with large therapeutic challenges. Although substantial progress has been made in cancer therapy, there still remains a need to develop novel and effective treatment strategies to treat several relapsed and refractory cancers. Recently, there has been growing demand for considering organometallics as antineoplastic agents. This review is focused on a group of organometallics, silver N-heterocyclic carbene complexes (SCCs) and their anticancer efficacy in targeting multiple pathways in various in vitro cancer model systems. However, the precise molecular mechanism of SCCs anticancer properties remains unclear. Here, we discuss the SCCs chemistry, potential molecular targets, possible molecular mechanism of action, and their application in cancer therapies.     

The expanding spectrum of low-penetrance TNFRSF1A gene variants in adults presenting with recurrent inflammatory attacks: Clinical manifestations and long-term follow-up

Objective

To analyze the clinical manifestations and response to treatment in a cohort of adult patients presenting with recurrent inflammatory attacks and carrying low-penetrance TNFRSF1A variants, as well as to provide data on their long-term follow-up.

Methods

We performed a retrospective chart review of 36 patients carrying low-penetrance TNFRSF1A variants. Moreover, 60 genetically negative patients treated for recurrent inflammatory attacks and 13 patients with structural TNFRSF1A mutations were also analyzed. Detailed demographic and clinical data were collected at the time of molecular screening and at each follow-up visit. Treatments and markers of inflammation were also assessed.

Results

Individuals with low-penetrance TNFRSF1A variants have a lower family history for inflammatory attacks and present with a later disease onset compared with patients with structural mutations, but do not differ, in this respect, with genetically negative individuals. Moreover, low-penetrance variants are less frequently associated with a chronic disease course, with clinical manifestations such as abdominal pain and myalgia, and with amyloidosis. A distinctive clinical feature is a higher rate of pericarditis. Interestingly, mutation-negative patients were found to present with a significant history of recurrent pharyngitis during childhood. Patients with low-penetrance variants are mostly managed with short courses of steroids or non-steroidal anti-inflammatory drugs on attacks. Although the need for a biological treatment is significantly lower compared with patients with structural mutations, still approximately 20% of individuals with recurrent inflammatory attacks carrying low-penetrance variants ultimately require these therapies.

Conclusions

Our study confirms that low-penetrance TNFRSF1A variants can be associated with an autoinflammatory phenotype. Although a chronic disease course is rarely observed, some patients ultimately benefit from a biological treatment.     

Monogenic autoinflammatory disorders: beyond the periodic fever

The past two decades have seen an exponential increase in the number of monogenic autoinflammatory disorders described, coinciding with improved genetic sequencing techniques. This group of disorders has evolved to be heterogeneous and certainly more complex than the original four ‘periodic fever syndromes’ caused by innate immune over‐activation. This review aims to provide an update on the classic periodic fever syndromes as well as introducing the broadening spectrum of clinical features seen in more recently described conditions.     

Optimizing ring assembly reveals the strength of weak interactions

Most cellular processes rely on large multiprotein complexes that must assemble into a well-defined quaternary structure in order to function. A number of prominent examples, including the 20S core particle of the proteasome and the AAA+ family of ATPases, contain ring-like structures. Developing an understanding of the complex assembly pathways employed by ring-like structures requires a characterization of the problems these pathways have had to overcome as they evolved. In this work, we use computational models to uncover one such problem: a deadlocked plateau in the assembly dynamics. When the molecular interactions between subunits are too strong, this plateau leads to significant delays in assembly and a reduction in steady-state yield. Conversely, if the interactions are too weak, assembly delays are caused by the instability of crucial intermediates. Intermediate affinities thus maximize the efficiency of assembly for homomeric ring-like structures. In the case of heteromeric rings, we find that rings including at least one weak interaction can assemble efficiently and robustly. Estimation of affinities from solved structures of ring-like complexes indicates that heteromeric rings tend to contain a weak interaction, confirming our prediction. In addition to providing an evolutionary rationale for structural features of rings, our work forms the basis for understanding the complex assembly pathways of stacked rings like the proteasome and suggests principles that would aid in the design of synthetic ring-like structures that self-assemble efficiently.     

Splitting CO2 into CO and O2 by a single catalyst

The metal complex [(tpy)(Mebim-py)Ru^II(S)]²⁺ (tpy = 2,2^′ : 6^′,2^′′-terpyridine; Mebim-py = 3-methyl-1-pyridylbenzimidazol-2-ylidene; S = solvent) is a robust, reactive electrocatalyst toward both water oxidation to oxygen and carbon dioxide reduction to carbon monoxide. Here we describe its use as a single electrocatalyst for CO₂ splitting, CO₂ → CO + 1/2 O₂, in a two-compartment electrochemical cell.     

破裂型椎间盘突出动物模型中自身免疫反应的实验研究

目的:从动物实验的角度探讨破裂型椎间盘突出动物模型中的自身免疫反应.方法:20只SD大鼠分为两组,实验组采用自体髓核移植于坐骨神经旁的方法建立破裂型椎间盘突出动物模型(坐骨神经痛模型);对照组大鼠手术方法同实验组,但不放置髓核.术前及术后1、2、3周时采用爬坡实验及后肢机械缩爪阈值测定评估大鼠造模前后后肢运动能力及痛觉过敏的变化.术后3周时处死动物应用透射比浊法检测大鼠血清中免疫球蛋白IgG、IgM的含量,ELISA法测定血清中TNF-α、IL-6、IL-12的含量;采用免疫组化染色观察移植髓核中抗原抗体复合物沉积情况;应用BCA蛋白定量法观察坐骨神经中磷脂酶A2(PLA2)的活性.结果:所有大鼠模型建立前爬坡试验结果均为Ⅳ级,造模后对照组爬坡试验仍为Ⅳ级,实验组在造模后1、2及3周时爬坡试验均为Ⅲ级.实验组大鼠造模后1、2、3周时的后肢机械缩爪阈值分别为67.2±8.4、41.3±5.2及40.7±5.3mmHg,较术前(90.4±5.0mmHg)及对照组明显降低(P＜0.01),出现较为明显的痛觉过敏.术后3周实验组大鼠血清中IgG含量4.98±0.96g/L及IgM含量1.45±0.37g/L较对照组(4.31±0.77g/L及0.79±0.35g/L)明显上升(P＜0.05);血清中TNF-α、IL-6、IL-12的含量(205.77±46.32pg/L,186.4±87.3pg/L,69.23±27.46pg/L)较对照组(11.01±2.53pg/L,85.0± 13.2pg/L,21.65±11.93pg/L)均明显升高(P＜0.05).实验组大鼠移植髓核中出现抗原抗体复合物阳性沉积,阳性率为80％,明显高于对照组(P＜0.01);其坐骨神经中PLA2活性为0.0766±0.0039μmoL/(min·L),较对照组0.0006±0.0010μmoL/(min·L)明显升高(P＜0.05).结论:破裂型椎间盘突出动物模型中存在着由移植髓核引起的全身及局部异常的自身免疫反应,这可能是导致其疼痛的主要原因.