925 resultados para Glucosephosphate Dehydrogenase
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花粉管是种子植物受精过程中的雄性生殖单位的载体,由于其生长依赖于胞内Ca2+梯度,并具有典型的顶端极性生长的特点,因而成为近年来研究植物细胞相互识别、胞内和胞外信号传导理想的模式系统。裸子植物花粉与被子植物相比具有萌发时间长、生长缓慢等特点。Ca2+在裸子植物花粉萌发和花粉管生长中的作用机制目前尚不明确。本研究以裸子植物白皮松(Pinus bungeana)的花粉为材料,运用不同浓度钙通道抑制剂Nifedipine(Nif)处理,对其花粉萌发和花粉管生长进行了细胞学研究和蛋白质组学分析,以探讨Ca2+对白皮松花粉生长的调控机制,为进一步揭示裸子植物花粉萌发和花粉管生长机理提供参考。 本论文首先研究了钙通道抑制剂Nif和Ca2+螯合剂EGTA对白皮松花粉萌发和花粉管生长的影响。结果表明,用Nif处理花粉后,花粉萌发和花粉管生长均受到明显抑制。经Ca2+荧光探针Fluo-3AM标记,对Nif处理后Ca2+在花粉管中的分布模式进行了观察,发现Ca2+在正常生长的花粉管中呈梯度分布,并在其顶端的荧光最强。与对照相比,处理后的花粉管荧光强度明显减弱,且顶端Ca2+梯度消失。通过EGTA漂洗后的花粉粒,在正常培养基上萌发率较高,但其生长速率受到抑制。由此说明了细胞壁钙库对花粉管生长的抑制效应显著高于对花粉萌发的影响,是花粉管生长的限速因子。同时外加钙调素还可逆转EGTA对其花粉萌发和花粉管生长的抑制。上述结果表明,白皮松花粉萌发及花粉管生长需要外源Ca2+的内流,以及胞内形成的Ca2+浓度梯度。 用FM4-64探针标记结果发现,正常花粉管中的胞吞作用主要发生在顶端和亚顶端区域,胞吞的小泡也集中分布在这两个区域。经Nif处理后,既不影响花粉管的胞吞过程,同时胞吞发生的位置也与对照相似,只是胞吞的小泡分散于整个花粉管中。电子显微镜观察表明,各种细胞器在白皮松正常生长的花粉管中分布与被子植物存在较大差异,例如前者无明显地分区现象,不具胼胝质塞。白皮松花粉管顶端和亚顶端的壁旁体与质膜融合现象频繁发生。花粉管经Nif处理后,线粒体出现不同程度的解体和液泡化,内质网液泡化和核糖体脱落,液泡大量聚集在花粉管顶端,壁旁体与膜融合现象减少,以及花粉管壁明显变薄等。此外,通过微丝特异性探针鬼笔环肽标记结果表明,正常生长花粉管的微丝呈长轴向排列, Nif处理后微丝断裂,其断裂程度与处理浓度有关。由此可见,外源Ca2+对花粉管的胞吞无明显抑制或促进作用,但对胞吞小泡重回收可能有影响。当胞内Ca2+梯度消失后,则明显抑制了微丝骨架的聚合,进而使胞吐作用减缓,高尔基体分泌小泡聚集,多种细胞器液泡化,引起花粉管顶端膨大,细胞壁变薄,继而抑制花粉管的正常生长。 运用免疫荧光标记技术显示,正常生长的花粉管壁含有纤维素、胼胝质、果胶质和阿拉伯半乳聚糖蛋白(AGPs),其中纤维素和胼胝质在细胞壁上呈均匀分布,而酸性果胶质只存在花粉管两侧壁上,酯化果胶分布于花粉管顶端。经过Nif处理后,胼胝质和酸性果胶质均在花粉管顶端累积,而AGPs和纤维素的分布却无明显变化。另外,傅里叶红外光谱分析结果也同样支持上述结论。通过花粉管壁蛋白的SDS-PAGE分析表明,Nif对细胞壁蛋白的合成也有较大的影响。 在花粉管的钙通道受到抑制后,应用蛋白质组学技术分析其蛋白质的表达图谱,通过双向电泳已分离出约1000个蛋白质斑点,经软件分析发现,除其中50个蛋白斑点外,大部分蛋白质的表达量均未发生变化。上述50个发生变化的蛋白斑点酶切后,再经过ESI-MS/MS鉴定和质谱数据库的搜索,共鉴定出28个蛋白,其中12个为上调蛋白,16个下调蛋白,根据其主要功能分为与代谢、细胞扩展、翻译后修饰以及信号相关的蛋白。经过Nif处理后,花粉管中碳水化合物代谢能力下降,ATP的产生受到抑制,参与细胞壁多糖合成及小泡运输的蛋白,如valosin containing protein(VCP)、reversibly glycolsylated polypeptide(RGP)、UDP-glucose dehydrogenase (UDPGDH)和α-tubulin表达下调。另外,通过上述方法还鉴定出与丝氨酸/苏氨酸激酶保守结构域同源的受体蛋白激酶等。 综上所述,白皮松花粉管钙通道受到抑制后,通过影响花粉管蛋白的表达,抑制微丝微管骨架的组装,致使胞吐速度变慢,花粉管壁酸性果胶质、胼胝质等多糖分布的变化及总多糖含量的减少,最终抑制了花粉管的正常生长。
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根质膜具有重要的生物学功能,它参与了根响应脱落酸(ABA)的一系列活动。尽管已经有很多有关ABA影响根的生长和发育的报道,但是在蛋白质组水平上研究参与ABA信号转导及相关活动的质膜蛋白质的报道还未见到。我们期望利用蛋白质组学技术平台研究外源ABA胁迫下水稻根质膜与ABA功能相关的蛋白质组的变化。 本论文通过双向电泳(2DE)结合质谱(MALDI-TOF MS 和 MALDI-TOF/TOF MS)分析的方法鉴定了102个质膜相关蛋白质。这些蛋白质功能涉及到跨膜运输(16.2%)、胁迫反应(14.3%)、物质运输(4.8%)、细胞骨架动态变化(5.7%)、细胞壁重建(3.8%)、碳代谢和能量循环(13.3%)、蛋白质代谢(14.3%)、信号转导(18.1%)和其他功能的蛋白质(4.8%),以及未知功能的蛋白质(2.9%)。其中大约30%的蛋白质以同工型的形式存在。在这些鉴定结果中,有10个斑点(代表10种蛋白质)已被报道为质膜特异的蛋白质;68个蛋白质斑点(代表58种蛋白质)是质膜相关蛋白质。其余54个蛋白质斑点(代表42种蛋白质)是首次在水稻根的质膜囊泡中被鉴定出来。 在ABA处理条件下,我们在2DE胶上发现了15个响应ABA调节的蛋白质斑点。9个上调的蛋白质斑点分别代表以下9种蛋白质:vacuolar proton-ATPase A subunit, vacuolar ATPase B subunit、patatin、 Salt-stress root protein RS1、谷氨酰氨合成酶(Glutamine synthetase,GS)、OSR40c1、H+-exporting ATPase (vacuolar ATPase E subunit)、甘油醛-3-磷酸脱氢酶I型(glyceraldehyde-3- phosphate dehydrogenase, type I,GADPH)和醛缩酶C-1(aldolase C-1)。6个下调的蛋白质斑点分别代表4种蛋白质:endosperm lumenal binding protein、remorin protein、富含脯氨酸蛋白质(glycine-rich protein,GRP)和蔗糖合成酶(sucrose synthase, SuSy)。其中,OSR40c1和endosperm lumenal binding protein与蛋白质合成相关,从它们与ABA的关系中可以看出,ABA可能抑制了细胞的蛋白质合成。而vacuolar proton-ATPase A subunit、vacuolar ATPase B subunit和 H+-exporting ATPase参与了细胞质pH的调控,ABA致使了细胞质pH的上升。甘油醛-3-磷酸脱氢酶I型、醛缩酶C-1和蔗糖合酶参与了细胞壁的生长发育,ABA的作用可能导致了细胞壁生长发育的延迟。ABA促使Patatin上升,其作用可能与质膜膜脂的降解有关。而ABA的刺激也使谷氨酰氨合成酶的表达显著上升,谷氨酰氨合成酶可以去除细胞内有害的游离NH+4。同时还有未知功能的富含脯氨酸蛋白质(glycine-rich protein,GRP)同样受到ABA的诱导,但具体的功能及其与ABA的关系还要进一步的实验证据。
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Six enzyme systems, namely acid phosphatase, leucine aminopeptidase, phosphoglucose isomerase, tetrazolium oxidase, esterases and malate dehydrogenase were studied electrophoretically in Arenicola marina from various localities in United Kingdom. Out of 13 presumed loci, ten were found monomorphic. The three loci which appeared to be polymorphic are LAP-1, EST-2 and TO-1. Due to small sample size allele frequencies and genetic identity were not calculated. However, results indicate genetic difference among the population of A. marina.
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本实验以菠菜叶片为材料,分离并纯化了甜菜碱醛脱氢酶(BADH,EC 1.2.1.8),并对其某些性质进行了研究。此外,还提取并纯化了poly (A)+RNA,并对其完整性进行了分析,主要结果如下: 1.菠菜甜菜碱醛脱氢酶存在于60%硫酸铵沉淀部分,70%硫酸铵沉淀部分未检出其活性。用层析法纯化该酶,使纯化倍数达到405.3倍。菠菜甜菜碱醛脱氢酶有两个同工酶。 2.菠菜甜菜碱醛脱氢酶主要定位于胞液中。其中,在过氧化物酶体及微粒体中有一定量活性存在,但在叶绿体中未检出其活性。 3.菠菜甜菜碱醛脱氢酶活性有较广的pH值范围,其最适pH范围为9.5左右。该酶以NAD作为特异性辅酶,其Km值为8.0×10-6M, Vmax为0.143nmol/min。该酶以甜菜碱醛作为特异性底物,其Km值为1.82×10-4M,Vmax为0.182nmol/min。该酶活性为0.125~1M的NaCl、KCl和脯氨酸所抑制,但0.125~1M的蔗糖及甜菜碱对其活性没有影响。 4.PCMB和Mersalyl抑制该酶的活性,DTT可逐步恢复被抑制的活性。稀土元素LaCl3对该酶活性没有影响,但CeCl则使其完全失活。另外,Mn2+和Mo6+离子对其活性没有影响,Mg2+离子可增加其活性。 5.菠菜叶片中有菠菜甜菜碱醛脱氢酶的抑制因子存在,该因子可能是一种小分子化合物。 6.应用酚-氯仿方法分离了菠菜叶片的poly (A)+RNA,并在-80℃低温下长期贮存。
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从菠菜中克隆甜菜碱醛脱氢酶( betaine aldehyde dehydrogenase,BADH)基因并转化烟草, 研究转基因烟草光合作用对高温和盐胁迫等环境胁迫的抗性机理,利用外源甜菜碱研究在正常条件下对植物光合作用的影响以及在盐胁迫下外源甜菜碱对玉米幼曲光合作刚的保护机理。主要结果如下: 转BADH基因烟草中能合成甘氨酸甜菜碱,合成的甜菜碱主要积累于叶绿体中。转BADH 基因烟草提高了对高温胁迫的抗性,在中度高温胁迫下,转基冈烟草生长利光合作用对高温 的抗性增强。中度高温胁迫下,转基冈烟草光合作用的维持是由于甜菜碱对Rubisco活化酶的保护作用。在中度高温胁迫下甜菜碱通过维持Rubisco活化酶的活化态以及阻止Rubisco 活化酶山可溶性问质向类囊体的聚集,从而维持了Rubisco活化酶的活性,进而维持了C02 的同化。在严重高温胁迫下,烟草光系统II受到影响,转BADH基冈烟草通过提高体内抗氧化酶系统的功能,减轻了高温胁迫对光合机构造成的活性氧伤害,高温胁迫下转基因烟草体内抗氧化酶如SOD、APX、GR等酶活性明显高于野生型。在高温胁迫下,证明了甜菜碱对光系统II的保护作用主要在氧化侧,严重高温胁迫下,转基因烟草维持较高的PSII活性。 转BADH基因烟草提高了对盐胁迫的抗性,盐胁迫下转基因烟草光合作用的维持与盐胁迫下转基因烟草较高的气孔导度和抗氧化酶活性的提高有关。 外源甜菜碱在正常的非胁迫条件下对植物的生长有促进作用,而这一作用与光合速率的提高有关。通过对气孔导度、光合碳同化关键酶以及叶绿素荧光分析证明,甜菜碱对光合作用的促进与气孔导度的提高有关,同时甜菜碱提高了光系统ll的实际光化学效率。 外源甜菜碱提高了盐胁迫条件下植物的抗性,抗盐性的提高与盐胁迫下甜菜碱对气孔导度的提高以及维持较高的光系统II光化学活性有关。
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Background: The emergence of agriculture about 10,000 years ago marks a dramatic change in human evolutionary history. The diet shift in agriculture societies might have a great impact on the genetic makeup of Neolithic human populations. The regionally restricted enrichment of the class I alcohol dehydrogenase sequence polymorphism (ADH1BArg47His) in southern China and the adjacent areas suggests Darwinian positive selection on this genetic locus during Neolithic time though the driving force is yet to be disclosed. Results: We studied a total of 38 populations (2,275 individuals) including Han Chinese, Tibetan and other ethnic populations across China. The geographic distribution of the ADH1B*47His allele in these populations indicates a clear east-to-west cline, and it is dominant in south-eastern populations but rare in Tibetan populations. The molecular dating suggests that the emergence of the ADH1B*47His allele occurred about 10,000 similar to 7,000 years ago. Conclusion: We present genetic evidence of selection on the ADH1BArg47His polymorphism caused by the emergence and expansion of rice domestication in East Asia. The geographic distribution of the ADH1B*47His allele in East Asia is consistent with the unearthed culture relic sites of rice domestication in China. The estimated origin time of ADH1B*47His allele in those populations coincides with the time of origin and expansion of Neolithic agriculture in southern China.
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:亚洲人群中普遍存在突变型的乙醛脱氢酶2 ( ALDH2 3 2) 。此酶突变后活性缺失,导致乙醛在肝脏内大量 累积使突变携带者在喝酒后会有脸红等不适反应,因此这可能影响他们的饮酒行为。由于ALDH2 3 2 等位基因 与饮酒行为相关,它也可能与酒精引起的肝脏损伤及某些癌症密切相关,而且,它在不同的亚洲人群中有不同的频 率分布。近年来对ALDH2 3 2 等位基因的序列结构、表达及其重要功能等有了更深入的了解,对ALDH2 的多态 性在研究方法、研究群体分布范围等都有很大进展。同时还讨论了不同地理分布、不同年龄结构、性别差异条件 下,中国人群中ALDH2 基因型频率与饮酒行为的关系。
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长蠹科昆虫严重危害林木和仓贮物品。该文应用非损伤性DNA测序技术测定了来自不同国家的长蠹科害虫的线粒体DNAND4基因的部分序列。在获得的 2 0 4bp的序列中 ,7种昆虫的序列变异丰富 ,多数变异发生在密码子的第 3位点上。将实验结果与形态学特征比较分析 ,探讨 7个种的形态差异与基因序列的差异 ;结果表明 ,7种昆虫不仅在外形特征上存在差异 ,而且在ND4基因序列上的差异程度也很显著 ,平均为 2 1 94%。这为分类鉴定提供了充分的证据。
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We examined protein polymorphism of 20 native pig breeds in China and 3 introduced pig breeds. Thirty loci have been investigated, among which six loci were found to be polymorphic. Especially, the polymorphism of malate dehydrogenase (MDH), adenylate kinase (AK), and two new alleles of adenosine deaminase (ADA) had not been reported in domestic pigs and wild pigs. The percentage of polymorphic loci (P), the mean heterozygosity (H), and the mean number of alleles (A) are 0.200, 0.065, and 1.300, respectively. The degree of genetic variability of Chinese pigs as a whole was higher than that of goats, lower than that of cattle and horses, and similar to that of sheep. Using the gene frequencies of the 30 loci, Nei's genetic distance among the 20 native breeds in China and 3 introduced pig breeds was calculated by the formula of Nei. The program NEIGHBOR in PHYLIP 3.5c was chosen to construct an UPGMA tree and a NJ tree. Our results show that, of the total genetic variation found in the native pig breeds in China, 31% (0.31) is ascribable to genetic differences among breeds. About 69% of the total genetic variation is found within breeds. Most breeds are in linkage disequilibrium. The patterns of genetic similarities between the Chinese native pig breeds were not in agreement with the proposed pig type classification.
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In this report, we studied on a homoplasmic T12338C change in mitochondrial DNA (mtDNA), which substituted methionine in the translational initiation codon of the NADH dehydrogenase subunit 5 gene (ND5) with threonine. This nucleotide change was originall
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The acute toxicity and effects of diazinon on some haematological parameters of kutum (Rutilus frisii kutum, Kamensky, 1901) weighing 613.33 g±157.06 g were studied under static water quality conditions at 15°C ± 2ºC in winter and spring 2009. The effective physical and chemical parameters of water were pH= 7-8.2, dh= 300mg/L (caco3), DO= 7 ppm and T= 15°C±2ºC. The first test was primarily to determine the effects of acute toxicity (LC5096 h) of the agricultural toxicant diazinon (emulsion 60%) on kutum male brood stocks. For this purpose, 4 treatments were used to test toxicity; each treatment was repeated in 3 tanks with 9 fish per treatment and with 180 litres water capacity. After obtaining the final results, the information was analysed statistically with Probit version 1.5 (USEPA, 1985), and we determined the LC10, LC50 and LC90 values at 24 hours, 48 hours, 72 hours and 96 hours; the maximum allowable concentration value (LC5096 h divided by 10) (TRC, 1984); and the degree of toxicity. The second stage of testing consists of four treatments: LC0= 0 as experimental treatment, treatment A with a concentration of LC1= 0.107 mg/L, treatment B with concentration of LC5= 0.157 mg/L, treatment C with concentration of MAC value= 0.04 mg/L. Male brood stocks of kutum were treated with these concentrations for 45 days. Experiments were carried out under static conditions based on the standard TRC, 1984 method over 45 days. Our results show that long-term exposure to diazinon causes a decrease in the erythrocyte count (RBC), haemoglobin (Hb), haematocrit (PCV), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), leucocyte count (WBC), lymphocyte, testosterone, iron (Fe), sodium (Na), lactate dehydrogenase (LDH), and cholinesterase (CHeS). In addition, diazinon also causes an increase in prolymphocyte, aspartate aminotransferase (AST), cholesterol, alkaline phosphatase (ALP) and adrenaline (P<0.05). There are no significant effects on monocyte, eosinophil, magnesium (Mg), chloride (Cl), glucose (BS), urea (BUN), uric acid (U.A), triglyceride (TG), calcium (Ca), albumin (Alb), total protein (TP), cortisol, noradrenaline and high density lipoprotein (HDL) levels in kutum male brood stocks (P>0.05). Pathology results showed toxin diazinon no effect on average weight and fish body length, the average weight of heart, brain, spleen, liver, kidney and liver index but caueses decrease of gonad weigth and gonad index and also, cause complications of tissue necrosis, vascular congestion, inflammation in the liver, a sharp reduction in the number of glomeruli, necrosis, vascular congestion and haemorage in the kidney, capsule thickening and fibrosis, atrophy, vascular congestion, macrophages release increased, increasing sediment Hemosiderine and thickening of artery walls in the spleen, atrophy, fibrosis and necrosis in testis , vascular congestion, increased distance between the myocardium and fibrous string in heart and neuronal loss, vascular congestion and edema in the brain of kutum male brood stocks.
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The Annual report presents activities carried out by the Organization during the period 1973. It presents scientific work of the Organization which include: Tissue specificity of malate dehydrogenase in Astatoreochromis and two species of haplochromis, report on LaKe Babati Fishery, Observations on Engraulicypris orgenteus (PELLEGRIN) 1904 from Lake Victoria, Commercial trawl fishing on Lake Victoria: Fisheries development and conservation, Lunar periodicity and the breeding of Tilapia nilotica in the Northern part of Lake Victoria.
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Ab levels in the genital tract may be important in fertility and in preventing sexually transmitted diseases, In this study, I-125-labeled polymer or monomer mAb IgA (C4pIgA or C4mIgA) and IgC2b (C4IgC) to murine lactate dehydrogenase C4 and a polymer mAb IgA (npIgA) not cross-reacting with mouse sperm were intravenously injected into BALB/c mice, and the relative distribution of these Abs was determined. Polymer IgA was transported much more efficiently into the genital tract, trachea, and duodenum of both sexes than C4IgG and C4 mIgA (p < 0.01), The transport of polymer IgA (C4pIgA and npIgA) into the male genital tract greatly increased following orchiectomy (p < 0.01); this change was not affected by testosterone, suggesting that the unknown regulatory factor(s) from the testis may suppress polymer IgA transport, However, the transport of polymer IgA into female genital tissues was significantly decreased by ovariectomy (p < 0.01); this decline can be rectified by P-estradiol but not progesterone treatment, suggesting that estradiol may stimulate polymer IgA transport, Furthermore, the transport of C4IgG into tissues of the Fallopian tubes and the uterus was significantly decreased by treatment with progesterone (p < 0.01). Together, these findings indicate that serum polymer IgA can be transported selectively into the genital tracts of both sexes, that this transport is strongly under the control of gonads, and that transport of Ige into the Fallopian tubes and uterus is downregulated by progesterone.
Resumo:
Beneficial effects on bone-implant bonding may accrue from ferromagnetic fiber networks on implants which can deform in vivo inducing controlled levels of mechanical strain directly in growing bone. This approach requires ferromagnetic fibers that can be implanted in vivo without stimulating undue inflammatory cell responses or cytotoxicity. This study examines the short-term in vitro responses, including attachment, viability, and inflammatory stimulation, of human peripheral blood monocytes to 444 ferritic stainless steel fiber networks. Two types of 444 networks, differing in fiber cross section and thus surface area, were considered alongside austenitic stainless steel fiber networks, made of 316L, a widely established implant material. Similar high percent seeding efficiencies were measured by CyQuant® on all fiber networks after 48 h of cell culture. Extensive cell attachment was confirmed by fluorescence and scanning electron microscopy, which showed round monocytes attached at various depths into the fiber networks. Medium concentrations of lactate dehydrogenase (LDH) and tumor necrosis factor alpha (TNF-α) were determined as indicators of viability and inflammatory responses, respectively. Percent LDH concentrations were similar for both 444 fiber networks at all time points, whereas significantly lower than those of 316L control networks at 24 h. All networks elicited low-level secretions of TNF-α, which were significantly lower than that of the positive control wells containing zymosan. Collectively, the results indicate that 444 networks produce comparable responses to medical implant grade 316L networks and are able to support human peripheral blood monocytes in short-term in vitro cultures without inducing significant inflammatory or cytotoxic effects.
Short-term cytotoxic and inflammatory responses of human monocytes to stainless steel fibre networks
Resumo:
The aim of the current work was to examine the human monocyte response to 444 ferritic stainless steel fibre networks. 316L austenitic fibre networks, of the same fibre volume fraction, were used as control surfaces. Fluorescence and scanning electron microscopies suggest that the cells exhibited a good degree of attachment and penetration throughout both networks. Lactate Dehydrogenase (LDH) and TNF-α releases were used as indicators of cytotoxicity and inflammatory responses respectively. LDH release indicated similar levels of monocyte viability when in contact with the 444 and 316L fibre networks. Both networks elicited a low level secretion of TNF-α, which was significantly lower than that of the positive control wells containing zymosan. Collectively, the results suggest that 444 ferritic and 316L austenitic networks induced similar cytotoxic and inflammatory responses from human monocytes. © 2012 Materials Research Society.