医疗器械市场现状、潜力与对策探讨

通过对国内外医疗器械市场现状的描述,分析国内医疗器械市场巨大潜力,从而引发国外医疗器械公司在成功抢占高档医疗器械市场后,又将目光锁定中国医疗器械企业赖依生存的中低档医疗器械和潜在市场。本文只是从经营决策的三个不同角度,即合作对付竞争、再生产品活动,目标市场战略来探讨国内医疗器械企业应对竞争的方法。     

对动物源性医疗器械免疫原性评价的思考

近年来,动物源性医疗器械产品的咨询和申报数量明显上升。本文对动物源性医疗器械申报现状进行了介绍,并结合技术审评的情况,对该类产品免疫原性的评价进行思考,以期对该类产品的申报注册有所帮助。     

透视我国医疗器械市场

医疗器械行业属于新兴的朝阳行业 ,但行业监管严格 ,进入壁垒较高 ;同时 ,医疗器械产品的差异性大 ,因而种类也非常繁多 ,细分行业差异性极强 ,产品系列盈利能力差距显著。目前 ,随着计算机技术的发展 ,一批尖端精密医疗仪器设备迅速得到广泛的应用 ,推动了整个医疗器械行业的发展 ,因而近 2 0年来世界医疗器械行业的增长十分迅速。据 HIMA(美国医疗卫生工业制造商协会 )预测 ,到 2 0 0 6年 ,全球医疗器械销售额将达到 2 60 0亿美元左右。我国的医疗器械工业总产值 2 0世纪 90年代以来一直保持快速增长 ,平均增幅一直保持在 1 2 %～1 5%的…     

四项医械重点监管

为加强医疗器械生产企业的日常监督管理,根据《医疗器械生产企业日常监督调度管理规定(试行)》,结合生产企业监督管理的实际情况,国家食品药品监督管理局决定在2002年公布的《国家重点监     

新法规体系下体外诊断设备产品说明书编写的几点思考

结合新发布的《医疗器械说明书和标签管理规定》,对体外诊断设备产品说明书编写要求进行了介绍,对体外诊断设备产品说明书的常见问题进行了分析,为体外诊断设备生产企业编写产品说明书提出意见和建议。     

医疗器械特色图书馆开展企业竞争情报服务初探

阐述医疗器械竞争情报的概念与类型;分析了我国医疗器械行业竞争情报工作的现状和医疗器械特色图书馆开展竞争情报服务的优势及存在问题;提出竞争情报服务的模式和内容。     

信息

未来医疗器械发展的热点展望在当前经济环境下,无论从哪个方面来看,医疗器械行业都比其他行业发展态势要好。例如,美国每年销售到国外市场的医疗设备一直维持在40亿～50亿美元的贸易顺差。今年二月,著名的Frost&Sullivan市场调查公司进行了一次调查,展望了一下“2013年医疗器械行业将是怎样”,预测未来这个行业发展的热点。据Frost&Sullivan公司行业经理CharlieWhelan说,心血管产品、整形外科产品(如重建性的植入物、脊椎关节等)将仍然是医疗器械行业内主要的领域,竞争激烈、变化迅速,继续得到显著的增长。随着微创手术成为治疗的标准方…     

对胶原基创面修复材料安全性评价的思考

近年来,胶原基创面修复类医疗器械产品的咨询和申报数量明显上升。本文对胶原基创面修复材料现状进行了介绍,并结合技术审评的情况,对其安全性的评价进行思考,以期对该类产品的申报注册有所帮助。     

我国医疗器械监管中条形码技术应用现状及建议

条形码作为一种可印制的计算机语言,在普通商品流通领域已经得到广泛应用,如食品、日用品包装上的条形码除了用于防伪外,还可以应用于产品出入库等物流环节的信息管理,提高了物流的工作效率,更能使有质量问题的产品得到快速控制和召回。近年来,国家食品药品监督管理总局在药品生产包装时给其加印统一标准和规范的药品条形码(即电子监管码),当药品在流通使用过程中,只需对其进行扫描操作,就能将该药品的相关信息录入国家药品电子监管网,实现对其流向的即时监控,在药品监管中发挥了重要作用。同样,在医疗器械监管中,各地对条形码的应用方面也做了尝试,如:天津的骨科内固定产品标识管理系统、安徽的医疗器械行政许可网络查询软件系统、青岛的医疗器械生产企业片组监管信息平台和上海的植入性医疗器械监管系统等[1]。通过对医疗器械产品的条形码进行扫描操作,实现医疗器械的相关信息快速录入、查询、管理等功能。但是,目前我国医疗器械使用的条形码仍存在着标准不统一、信息不完整、应用不完全等一系列问题。     

谈谈“医疗器械新产品研制管理程序”

随着我国经济体制改革的不断深入和对外开放、对内搞活政策的逐步实施,商品经济的竞争、企业之间的竞争,将越来越激烈。以质量求生存,以品种求发展,这将是每个企业生死攸关的首要任务。企业必须使产品质量精益求精和不断推出适销对路的新产品,才能在竞争中立于不败之地。反之,则将被淘汰。医疗器械虽是特殊商品,它要讲经济效益,亦要讲社会效益。但是,它既属商品,因而也回避不了商品经济竞争的规律。近几年来,我们行业经过企业管理的整顿和推行全面质量管理,总结了新产品研制管理方面的一般规律,又根据医疗器械产品批量小、更新快的特点,制订了“医疗器械新产品研制管理程序”。通过三年来的实践,     

Role of protein kinase C in phospholemman mediated regulation of α₂β₁ isozyme of Na⁺/K⁺-ATPase in caveolae of pulmonary artery smooth muscle cells

We have recently reported that α(2)β(1) and α(1)β(1) isozymes of Na(+)/K(+)-ATPase (NKA) are localized in the caveolae whereas only the α(1)β(1) isozyme of NKA is localized in the non-caveolae fraction of pulmonary artery smooth muscle cell membrane. It is well known that different isoforms of NKA are regulated differentially by PKA and PKC, but the mechanism is not known in the caveolae of pulmonary artery smooth muscle cells. Herein, we examined whether this regulation occurs through phospholemman (PLM) in the caveolae. Our results suggest that PKC mediated phosphorylation of PLM occurs only when it is associated with the α(2) isoform of NKA, whereas phosphorylation of PLM by PKA occurs when it is associated with the α(1) isoform of NKA. To investigate the mechanism of regulation of α(2) isoform of NKA by PKC-mediated phosphorylation of PLM, we have purified PLM from the caveolae and reconstituted into the liposomes. Our result revealed that (i) in the reconstituted liposomes phosphorylated PLM (PKC mediated) stimulate NKA activity, which appears to be due to an increase in the turnover number of the enzyme; (ii) phosphorylated PLM did not change the affinity of the pump for Na(+); and (iii) even after phosphorylation by PKC, PLM still remains associated with the α(2) isoform of NKA.     

Phosphomimetic mutations enhance oligomerization of phospholemman and modulate its interaction with the Na/K-ATPase

Na/K-ATPase (NKA) activity is dynamically regulated by an inhibitory interaction with a small transmembrane protein, phospholemman (PLM). Inhibition is relieved upon PLM phosphorylation. Phosphorylation may alter how PLM interacts with NKA and/or itself, but details of these interactions are unknown. To address this, we quantified FRET between PLM and its regulatory target NKA in live cells. Phosphorylation of PLM was mimicked by mutation S63E (PKC site), S68E (PKA/PKC site), or S63E/S68E. The dependence of FRET on protein expression in live cells yielded information about the structure and binding affinity of the PLM-NKA regulatory complex. PLM phosphomimetic mutations altered the quaternary structure of the regulatory complex and reduced the apparent affinity of the PLM-NKA interaction. The latter effect was likely due to increased oligomerization of PLM phosphomimetic mutants, as suggested by PLM-PLM FRET measurements. Distance constraints obtained by FRET suggest that phosphomimetic mutations slightly alter the oligomer quaternary conformation. Photon-counting histogram measurements revealed that the major PLM oligomeric species is a tetramer. We conclude that phosphorylation of PLM increases its oligomerization into tetramers, decreases its binding to NKA, and alters the structures of both the tetramer and NKA regulatory complex.     

Interaction of furosemide with lipid membranes

Summary The interaction of furosemide with different phospholipids was investigated. Its influence on the lipid structure was inferred from its effect on the phase transition properties of lipids and on the conductance of planar bilayer membranes. The thermotropic properties of dipalmitoyl phosphatidylcholine, phosphatidylethanolamine (natural), dipalmitoyl phosphatidylethanolamine, brain sphingomyelin, brain cerebrosides and phosphatidylserine in the presence and absence of furosemide were investigated by differential scanning calorimetry,. The modifying effect of furosemide seems to be strongest on phosphatidylethanolamine (natural) and sphingomyelin bilayers. The propensity of furosemide to decrease the electrical resistance of planar lipid membranes was also studied and it is shown that the drug facilitates the transport of ions. Partition coefficients of furosemide between lipid bilayers and water were measured.Abbreviations DSC differential scanning calorimetry - PLM planar lipid membranes - DPPC dipalmitoyl phosphatidylcholine - DMPC dimyristoyl phosphatidylcholine - PE phosphatidyl ethanol     

Phospholemman is a substrate for myotonic dystrophy protein kinase

The genetic abnormality in myotonic muscular dystrophy, multiple CTG repeats lie upstream of a gene that encodes a novel protein kinase, myotonic dystrophy protein kinase (DMPK). Phospholemman (PLM), a major membrane substrate for phosphorylation by protein kinases A and C, induces Cl currents (I(Cl(PLM))) when expressed in Xenopus oocytes. To test the idea that PLM is a substrate for DMPK, we measured in vitro phosphorylation of purified PLM by DMPK. To assess the functional effects of PLM phosphorylation we compared I(Cl(PLM)) in Xenopus oocytes expressing PLM alone to currents in oocytes co-expressing DMPK, and examined the effect of DMPK on oocyte membrane PLM expression. We found that PLM is indeed a good substrate for DMPK in vitro. Co-expression of DMPK with PLM in oocytes resulted in a reduction in I(Cl(PLM)). This was most likely a specific effect of phosphorylation of PLM by DMPK, as the effect was not present in oocytes expressing a phos(-) PLM mutant in which all potential phosphorylation had been disabled by Ser --> Ala substitution. The biophysical characteristics of I(Cl(PLM)) were not changed by DMPK or by the phos(-) mutation. Co-expression of DMPK reduced the expression of PLM in oocyte membranes, suggesting a possible mechanism for the observed reduction in I(Cl(PLM)) amplitude. These data show that PLM is a substrate for phosphorylation by DMPK and provide functional evidence for modulation of PLM function by phosphorylation.     

Bcl-XL as a fusion protein for the high-level expression of membrane-associated proteins

An Escherichia coli plasmid vector for the high-level expression of hydrophobic membrane proteins is described. The plasmid, pBCL, directs the expression of a target polypeptide fused to the C terminus of a mutant form of the anti-apoptotic Bcl-2 family protein, Bcl-XL, where the hydrophobic C terminus has been deleted, and Met residues have been mutated to Leu to facilitate CNBr cleavage after a single Met inserted at the beginning of the target sequence. Fusion protein expression is in inclusion bodies, simplifying the protein purification steps. Here we report the high-level production of PLM, a membrane protein that is a member of the FXYD family of tissue-specific and physiological-state-specific auxiliary subunits of the Na,K-ATPase, expressed abundantly in heart and skeletal muscle. We demonstrate that milligram quantities of pure, isotopically labeled protein can be obtained easily and in little time with this system.     

Lambda red-mediated synthesis of plasmid linear multimers in Escherichia coli K12

Summary Expression of the red ⁺ and gam ⁺ genes of bacteriophage in plasmids cloned in Escherichia coli wild-type cells leads to plasmid linear multimer (PLM) formation. In mutants that lack exonuclease I (sbcB sbcC), either of these functions mediates PLM formation. In order to determine whether PLM formation in sbcB sbcC mutants occurs by conservative (break-join) recombination of circular plasmids or by de novo DNA synthesis, thyA sbcB sbcC mutants were transferred from thymine- to 5-bromo-2-deoxyuridine (BUDR)-supplemented medium, concurrently with induction of red ⁺ or gam ⁺ expression, and the density distribution of plasmid molecular species was analyzed. After a period of less than one generation in the BUDR-supplemented medium, most PLM were of heavy/heavy density. Circular plasmids, as well as chromosomal DNA, were of light/light or light/heavy density. These results indicate that Red or Gam activities mediate de novo synthesis of PLM in sbcB sbcC mutants. Examination of plasmid DNA preparations from sbcB sbcC mutants expressing gam ⁺ or red ⁺ reveals the presence of two molecular species that may represent intermediates in the PLM biosynthesis pathway: single-branched circles (-structures) and PLM with single-stranded DNA tails. While Gam-mediated PLM synthesis in sbcB mutants depends on the activity of the RecF pathway genes, Red-mediated PLM synthesis, like Red-mediated recombination, is independent of recA and recF activities. One of the red ⁺ products, protein, suppresses RecA deficiency in plasmid recombination and PLM synthesis in RecBCD^– Exol^– cells. The dependence of PLM synthesis on the RecE, RecF or Red recombination pathways and the dependence of plasmid recombination by these pathways on activities that are required for plasmid replication support the proposal that PLM synthesis and recombination by these pathways are mutually dependent. We propose the hypothesis that DNA double-stranded ends, which are produced in the process of PLM synthesis, are involved in plasmid recombination by the RecE, RecF and Red pathways. Conversely, recombination-dependent priming of DNA synthesis at 3 singles-tranded DNA ends is hypothesized to initiate PLM synthesis on circular plasmid DNA templates.Abbreviations PLM plasmid linear multimers - BUDR 5-bromo-2-deoxyuridine - bp base pair     

Characterization of the phospholemman knockout mouse heart: depressed left ventricular function with increased Na-K-ATPase activity

Phospholemman (PLM, FXYD1), abundantly expressed in the heart, is the primary cardiac sarcolemmal substrate for PKA and PKC. Evidence supports the hypothesis that PLM is part of the cardiac Na-K pump complex and provides the link between kinase activity and pump modulation. PLM has also been proposed to modulate Na/Ca exchanger activity and may be involved in cell volume regulation. This study characterized the phenotype of the PLM knockout (KO) mouse heart to further our understanding of PLM function in the heart. PLM KO mice were bred on a congenic C57/BL6 background. In vivo conductance catheter measurements exhibited a mildly depressed cardiac contractile function in PLM KO mice, which was exacerbated when hearts were isolated and Langendorff perfused. There were no significant differences in action potential morphology in paced Langendorff-perfused hearts. Depressed contractile function was associated with a mild cardiac hypertrophy in PLM KO mice. Biochemical analysis of crude ventricular homogenates showed a significant increase in Na-K-ATPase activity in PLM KO hearts compared with wild-type controls. SDS-PAGE and Western blot analysis of ventricular homogenates revealed small, nonsignificant changes in Na- K-ATPase subunit expression, with two-dimensional gel (isoelectric focusing, SDS-PAGE) analysis revealing minimal changes in ventricular protein expression, indicating that deletion of PLM was the primary reason for the observed PLM KO phenotype. These studies demonstrate that PLM plays an important role in the contractile function of the normoxic mouse heart. Data are consistent with the hypothesis that PLM modulates Na-K-ATPase activity, indirectly affecting intracellular Ca and hence contractile function.     

G2 chromosomal radiosensitivity in Fanconi's anemia

Both the peripheral lymphocytes from 4 patients affected with the inherited disease Fanconi's anemia (FA), and tissue-culture fibroblasts from skin biopsies from 3 patients similarly affected were found to be about twice as sensitive to the induction of chromatid-type chromosomal aberrations by X-rays administratered in the G2 phase of the cell cycle as cells from normal controls. Using tritiated thymidine labelling of peripheral lymphocytes and of cultured fibroblasts, it was determined that 3 affected patients and 3 normal controls all had similar percent labeled mitoses (PLM) curves, so the increased induced aberration yields seen in the FA cells do not appear to be simply a consequences of a longer than normal G2 phase of the cell cycle.     

A study of the membrane association and regulatory effect of the phospholemman cytoplasmic domain

Phospholemman (PLM) is a single-span transmembrane protein belonging to the FXYD family of proteins. PLM (or FXYD1) regulates the Na,K-ATPase (NKA) ion pump by altering its affinity for K(+) and Na(+) and by reducing its hydrolytic activity. Structural studies of PLM in anionic detergent micelles have suggested that the cytoplasmic domain, which alone can regulate NKA, forms a partial helix which is stabilized by interactions with the charged membrane surface. This work examines the membrane affinity and regulatory function of a 35-amino acid peptide (PLM(38-72)) representing the PLM cytoplasmic domain. Isothermal titration calorimetry and solid-state NMR measurements confirm that PLM(38-72) associates strongly with highly anionic phospholipid membranes, but the association is weakened substantially when the negative surface charge is reduced to a more physiologically relevant environment. Membrane interactions are also weakened when the peptide is phosphorylated at S68, one of the substrate sites for protein kinases. PLM(38-72) also lowers the maximal velocity of ATP hydrolysis (V(max)) by NKA, and phosphorylation of the peptide at S68 gives rise to a partial recovery of V(max). These results suggest that the PLM cytoplasmic domain populates NKA-associated and membrane-associated states in dynamic equilibrium and that phosphorylation may alter the position of the equilibrium. Interestingly, peptides representing the cytoplasmic domains of two other FXYD proteins, Mat-8 (FXYD3) and CHIF (FXYD4), have little or no interaction with highly anionic phospholipid membranes and have no effect on NKA function. This suggests that the functional and physical properties of PLM are not conserved across the entire FXYD family.     

Identification of a Cytoskeleton-bound Form of Phospholemman with Unique C-Terminal Immunoreactivity

Phospholemman (PLM) is a 72-amino acid transmembrane protein thought to function in Na,K-ATPase regulation or assembly, similar to other members of the FXYD family of proteins. Unique to PLM among these regulatory proteins are sites for C-terminal phosphorylation by PKA and PKC, although a role for phosphorylation in PLM function remains unclear. To study PLM phosphorylation, we used PLM phosphopeptides to generate antibodies to specifically detect phosphorylated PLM. Peptide affinity chromatography isolated two populations of antibodies: one reacting with standard PLM, a collection of closely-spaced 15-kDa protein bands by SDS-PAGE. About 20% of PLM antibodies reacted specifically with a single distinct form of PLM. Levels of this second immunological form (PLM-b) were increased with overexpression of PLM cDNA, and also reacted with a monoclonal antibody against the PLM N-terminus. In complete contrast to standard PLM, however, PLM-b was quantitatively insoluble in nonionic detergents and was released from tight binding by colchicine. Antibodies to PLM-b were present in two different antisera raised to the phosphorylated C-terminal peptide (residues 57-70), but not in antiserum raised to the non-phosphorylated C-terminal peptide. Despite an apparent relationship between PLM-b and phosphorylated PLM, PLM-b levels were not affected by treatment of heart cells with isoproterenol. PLM-b appears to represent a cytoskeleton-attached detergent-insoluble form of PLM with distinctive C-terminal immunoreactivity that might have implications for PLM structure and function.