乳杆菌DM9811代谢产物对种植体周围炎龈下菌群的影响

目的从维护种植体周围菌群平衡和种植体远期固持率的角度出发,观察乳杆菌DM9811代谢产物对种植体周围炎龈下菌群的影响,探索一种适用人群广泛、较少或无副作用、疗效好、复发率低的新型生态治疗药物。方法将16例符合种植体周围炎的病例随意分为试验组（乳杆菌代谢产物含漱组）和对照组（纯净水含漱组）,分别于含漱前、含漱后3d、7d、30d进行微生物学检查。结果治疗后试验组牙龈卟啉单胞菌（P．g）、中间普氏菌（P．i）显著低于对照组（P〈0．05）;口腔链球菌、变形链球菌显著高于对照组（P〈0．05）：乳杆菌差异无显著性。结论乳杆菌DM9811代谢产物有抑制P．g、P．i,扶植口腔链球菌,从而调节种植体周菌群平衡的作用。     

乳杆菌DM9811代谢产物脂肪酸组分对义齿性口炎患者口腔中白假丝酵母菌的抑制

目的从调整口腔菌群平衡的角度出发,观察乳杆菌DM9811代谢产物脂肪酸组分对义齿性口炎患者口腔菌群的影响。方法（1）体外试验：配制不同浓度乳杆菌DM9811代谢产物脂肪酸组分的沙包液体培养基,分别接种10^8CFU／ml白假丝酵母菌菌液,用CFU活菌记数法计数。（2）临床试验：符合义齿性口炎病例40例,随机分为试验组20例和对照组20例（阴性对照组和阳性对照组各10例）。分别给予乳杆菌DM9811代谢产物脂肪酸组分、纯净水、洗必泰含漱液。观察菌群变化。结果（1）体外试验：乳杆菌DM9811代谢产物脂肪酸组分在浓度为1．6、0．8和0．4mg／ml时对白假丝酵母菌的抑制作用分别为100％、98．11％和62．72％。（2）临床试验：试验组在治疗后口腔黏膜白假丝酵母菌数量明显降低,口腔链球菌数量升高,较治疗前差异均有显著性（P〈0．01）;停药后第21天较治疗7d差异无显著性（P〉0.05）。结论乳杆菌DM9811代谢产物脂肪酸组分对口腔白假丝酵母菌有明显的抑杀作用;对口腔链球菌有促进作用,可能有调整口腔菌群平衡的作用。     

枯草芽孢杆菌J-15抗大丽轮枝菌次生代谢产物对棉田土壤真菌多样性的影响

【背景】目前利用拮抗菌进行作物病害防治的研究较多,但拮抗菌次生代谢产物如何影响棉花根际土壤微生物群落相关的研究较少。【目的】探讨枯草芽孢杆菌J-15抗大丽轮枝菌次生代谢产物对棉田土壤真菌多样性的影响,为利用枯草芽孢杆菌J-15及其次生代谢产物防治棉花黄萎病的土壤微生物生态安全进行评估。【方法】以新疆北部玛纳斯地区棉田为土壤采样点,随机选取10个点进行采样后混合,经枯草芽孢杆菌J-15抗大丽轮枝菌次生代谢产物处理一定时间后,提取土样总DNA,利用Illumina HiSeq高通量技术,对样品中真菌ITS1-ITS2区进行高通量测序,分析J-15抗大丽轮枝菌次生代谢产物处理对土样真菌多样性的影响。【结果】在97%相似度水平下,处理10、30d后,样品中真菌的OTU数量、Chao1和ACE丰度指数均分别高于相同时间放置的未处理的对照组,而Simpson指数低于其对照组。从群落组成分析来看,与对照组相比,受J-15次生代谢产物处理的土壤样品,子囊菌门(Ascomycota)的盘菌属(Tricharina)和被孢霉门(Mortierellomycota)的被孢霉属(Mortierella)等优势真菌相对丰度提高,而丰度高于1%的2类病原真菌轮枝孢属(Verticillium)、镰孢霉属(Fusarmm)的丰度显著降低。【结论】J-15抗大丽轮枝菌次生代谢产物对棉田土壤真菌群落及丰度有显著影响,但不改变影响农业生产的土壤真菌群落的结构。     

乳杆菌DM9811代谢产物脂肪酸组分对义齿性口炎的临床应用研究

目的从口腔菌群平衡的角度观察乳杆菌DM9811代谢产物脂肪酸组分对义齿性口炎患者口腔细菌的影响。方法采取自身前后对照,24例义齿性口炎患者给予乳杆菌DM9811代谢产物脂肪酸组分制成的含漱液,每次20 ml,每日3次漱口。分别于用药前,用药后第7天、14天、28天以及停药后第60天采集标本培养,记录活菌数。结果24例患者中18例为有效病例。用药后7 d口腔白假丝酵母菌数量明显降低,口腔链球菌数量升高,较治疗前差异均有显著性（P〈0.01）,乳杆菌治疗前后差异无显著性（P〉0.05）;用药14 d、28 d及停药后60 d时,口腔内白假丝酵母菌、口腔链球菌、乳杆菌数量较7 d时差异均无显著性（P〉0.05）。结论乳杆菌DM9811代谢产物脂肪酸组分治疗义齿性口炎7 d时致病菌和优势菌即可达到相对平衡。乳杆菌DM9811代谢产物脂肪酸组分治疗义齿性口炎不会造成口腔菌群的失衡。     

芽孢杆菌制剂对养殖前期罗非鱼池塘微生物群落代谢功能的影响

采用BiologECO微平板法检测了4口养殖前期投放或不投放芽孢杆菌制剂的罗非鱼池塘水体及底泥微生物群落代谢功能的变化情况,研究芽孢杆菌制剂对养殖前期罗非鱼池塘微生物群落代谢功能的影响。结果表明:芽孢杆菌制剂对底泥微生物群落的代谢活性、功能多样性及6大类碳源的利用有明显的促进作用,而对水体微生物群落代谢活性和功能多样性的影响不明显,但促进了水体微生物对6大类碳源的利用。研究结果证实,在养殖前期投放芽孢杆菌制剂有利于改善罗非鱼养殖池塘微生物群落的代谢功能,主要体现在提高底泥微生物群落的代谢功能上。     

江苏盐城黑紫鸥（Larus saundersi）繁殖微生境的选择

1999～2001年春夏对江苏盐城国家级自然保护区黑嘴鸥的繁殖微生境进行了调查,黑嘴鸥的繁殖生境包括碱蓬群落（Suaeda glauca）、獐毛群落（Aeluropus littoralis）和大米草群落（Spartina anglica）,通过生境可获得性与可利用性分析,得知黑嘴鸥营巢对碱蓬生境具有正选择性,对獐毛和大米草生境具有负选择性。对繁殖微生境选择研究的结果表明,黑嘴鸥繁殖微生境具有以下特征：植被高度5～25cm,植被盖度20%～60%,底栖生物量大于300g/m^2,距水源距离500～1000m,距人类活动干扰距离大于500m,滩涂开发和人为活动是影响盐城地区黑嘴鸥繁殖微生境选择的重要因素。本文对黑嘴鸥繁殖栖息地的保护和管理提出了一些建议。     

芽胞杆菌对鱼池微生物群落代谢功能的影响

利用Biotog平板,以施用与不施用芽胞杆菌的鱼塘为研究对象,研究鱼塘水体与表泥不同空间的微生物群落代谢功能的差异。结果表明：芽胞杆菌提高了水体微生物群落代谢的平均活性,及对氨基酸类、胺类、羧酸类、聚合物及其它类碳源的利用能力,提高了水体微生物群落代谢的多样性（Shannon均度、Simpson指数、McIntosh均度差异显著）;两池表泥微生物群落代谢平均活性差异较小,对同一碳源的利用差异不大,芽胞杆菌显著提高了表泥的Simpson指数,但表泥的McIntosh指数显著低于对照池。总体而言,鱼塘施用芽胞杆菌,水体微生物群落代谢功能所受的影响大过表泥,芽胞杆菌通过提高水体微生物群落代谢活性,提高了水体微生物对有机污染物的降解能力,以此改善池塘的生态环境。     

贝莱斯芽孢杆菌生防次级代谢产物研究进展

贝莱斯芽孢杆菌（Bacillus velezensis）是生防芽孢杆菌中的重要代表,作为微生物农药的核心菌种,已被广泛应用于作物病害生物防治。贝莱斯芽孢杆菌具有植物内生性,其生防作用机制主要包括产生次级代谢产物对抗植物病原物;改善宿主植物根际微生物群落,促进宿主营养和生长;激发宿主植物产生防御反应,诱导植物获得系统抗性。其中,产生次级代谢产物是其最重要的生防作用机制。贝莱斯芽孢杆菌含有多个编码生物合成次级代谢产物的基因簇,其中包括编码聚酮化合物合酶（PKS）和非核糖体肽合成酶（NRPS）的基因簇,同时存在核糖体途径合成次级代谢产物基因簇。通过非核糖体途径可产生脂肽类化合物、聚酮类化合物、二肽和铁载体;通过核糖体途径产生小菌素、细菌素、羊毛硫抗生素。这些具有生物活性的次级代谢产物成为了天然新药和候选抗生素的储存库,对于解析生防菌作用机制具有重要意义。本文综述了贝莱斯芽孢杆菌的命名与更迭,产生次级代谢产物的类型、合成与调控基因以及靶标病原菌,以期为生防菌株的改良和生物农药的研发提供参考。     

半干旱黄土高原苜蓿草地撂荒过程土壤水分变化特征

土壤水分是黄土高原植被恢复和生态建设的主要限制因子,明确土壤水分随植被演替的变化规律是阐明黄土高原植被与水分相互作用机制的重要基础。以半干旱黄土高原小流域苜蓿草地撂荒过程为研究对象,通过对2016-2018年生长季苜蓿群落、苜蓿+赖草群落、赖草群落和长芒草群落四种草地群落0-1.8 m土壤水分进行动态监测以及0-5 m深度土壤水分测定,分析不同演替阶段苜蓿草地土壤水分的动态特征,探讨土壤水分对苜蓿草地撂荒过程的响应。结果表明：（1）在苜蓿草地撂荒演替过程中,土壤水分随群落恢复时间的延长呈先增加后降低的变化,降水的年际动态显著影响不同演替群落的土壤水分响应;（2）0-0.4 m土壤水分主要受降水影响,使得各草地群落在这一层次没有显著差异（P>0.05）,而1 m以下的土壤水分含量则主要受植被类型的影响,各草地群落之间存在显著差异（P<0.05）;（3）0-5 m深层土壤水分随群落的演替,1 m以下各土层土壤水分含量逐渐增加,表明撂荒过程中使土壤水分得到了一定程度的恢复。研究结果揭示了苜蓿草地撂荒过程土壤水分的变化规律,可为黄土高原生态恢复提供理论依据。     

乳杆菌DM9811代谢产物对固定正畸治疗患者口腔内主要致龋菌的影响

目的从维护口腔内菌群平衡的角度出发,观察乳杆菌DM9811代谢产物对固定正畸治疗患者口腔内主要致龋菌的影响及其临床效果,探索一种适用于固定正畸治疗患者,无副作用,效果好的新型微生态防龋药物。方法将20例接受固定正畸治疗的无龋病病例随机分为试验组和对照组,每组各10例。试验组给予乳杆菌代谢产物含漱液;对照组给予纯净水。2组病例分别与含漱前,含漱20、40和60 d进行改良菌斑指数(MPLI)、唾液pH的检测和口腔微生物学检查。以对照组为标准观察固定正畸治疗患者口腔内主要致龋菌数量的变化趋势和乳杆菌代谢产物含漱液对MPLI和唾液pH的影响。结果(1)乳杆菌DM9811代谢产物使固定正畸治疗患者的MPLI指数降低、唾液pH升高。(2)乳杆菌DM9811代谢产物使固定正畸治疗患者口腔内主要致龋菌数量下降。结论乳杆菌DM9811代谢产物对固定正畸治疗患者MPLI和唾液pH具有改善作用;对变形链球菌、乳杆菌有明显的杀菌抑菌作用,并对维持正畸治疗患者口腔内菌群平衡有重要作用。     

Raiding behavior of the dulotic antChalepoxenus muellerianus (Finzi) in the field (Hymenoptera: Formicidae,Myrmicinae)

Summary Little information is available regarding the raiding behavior in nature of dulotic ants belonging to the tribeLeptothoracini. Between July 17 and 24, 1991, several raids ofChalepoxenus muellerianus (Finzi) were observed in nature near Tignale/Lago di Garda, Italy. Apparently, this species raids frequently during its summer raiding season (5 raids were observed during 7 days spent observing 8 colonies). A singleChalepoxenus colony sometimes raids more than one host colony more or less simultaneously. Observations during which oneChalepoxenus colony raided another and captured slavemaker brood indicate that intraspecific raids can occur either accidentally, or as a result of competition or territoriality when there is a sufficient dense slavemaker population.     

Primate hemoglobins: Some sequences and some proposals concerning the character of evolution and mutation

During a multipurpose survey we examined electrophoretic mobilities of major (A, i.e., ₂₂) and minor (A₂, i.e., ₂₂) adult hemoglobins from populations of nine primate genera representing a total of 440 New World monkeys and apes. Sequences of hemoglobin chains were inferred from differences in amino acid composition between homologous tryptic peptides supplemented by detailed placement of more than 270 residues. Beta sequences were thus analyzed in five genera (Aotus, Ateles, Hylobates, Saimiri, and Saguinus) and sequences in seven (foregoing plus Gorilla and Pan). In most genera, sequences from several individuals, often from several species, were delineated. Fifteen kinds of intraspecies mutants were detected; 10 of these were precisely characterized. Five of the 15 mutants form electrophoretically detected genetic polymorphisms of ; none such occur in . Six electrophoretically detected mutants, four in and two in , are uncommon. One of these represents the complete absence of minor component. Three kinds of variants, two in and one in , are electrophoretically neutral and chance findings during sequence analysis of the equivalent of 38 allele products. Two of the neutral variants are not especially common; one may have polymorphic frequency. Several general conclusions stem from these and supplementary findings. First, comparisons of sequences suggest that and genes in all primates either arose from a single event in a common ancestor or from two approximately coincident events. Either assumption allows reconstruction of a reasonably accurate archetype sequence that is effectively common to all descendants. Second, there is a pancellular quantitative disproportion between major and minor hemoglobins ranging from 16:1 to 220:1 in species studied. Delta is consequently presumed to be functionally and adaptively less vital than . When these premises are adopted, is expected to be relatively invisible to natural selection, and, where darwinism is the principal arbiter of evolution and polymorphism, is expected to show fewer fixed changes and fewer genetic polymorphisms than . The opposite is observed. Delta exhibits as many or more changes from archetype than . This finding and the comparative abundance of polymorphism are attributed to nonadaptive factors which are thus considered the source of much evolutionary change. Third, particular sequence positions in various species are the site of recurrent mutations in both and . One such area is occupied by the majority of genetic polymorphisms found in man and other primates. The overall distribution of mutations arising in evolution is remarkably nonrandom in , , and a pool of both. These results are quite unlike most other observations in higher organisms. The sources of such nonrandomness are either selection and/or differential mutability. We rely on our prior assumption of relative selective invisibility for and, in part, ascribe the nonrandom distribution of changes to microzones of enhanced mutability. Fourth, the six uncommon electrophoretically detected mutants provide an estimate of heterozygosity (1/73) at hemoglobin loci that is tenfold greater than observed in man. Fifth, the unprecedented chance detection of three kinds of electrophoretically neutral intraspecies mutants among the equivalent of 38 characterized allele products suggests that neutral changes are as common as electrostatically active ones and at least tenfold more common than expected in extrapolation from human variant surveys. Sixth, analyses from three kinds of gibbon (Hylobates) hemoglobin suggest that one of these is a potentially unchanged relict of the ancient archetype and, further, indicate a degree of homozygous diversity within a species that nearly equals the difference between gibbon and man.This investigation received support from grants to S.H.B., HD-02508-04 and K3-GM-6308-03, from the National Institutes of Health.     

Kinetic comparison of seven strains of 2,4-dichlorophenoxyacetic acid-degrading bacteria.

Seven strains of 2,4-dichlorophenoxyacetic acid-degrading bacteria, including Pseudomonas, Alcaligenes, and Bordetella spp., were compared on the basis of growth kinetics. Estimates of maximum growth rate (mu max, k1) and half-saturation growth constant (Ks, k3) were obtained by fitting substrate depletion curves to a four-parameter version of the integrated Monod equation. Estimates of Ks ranged from 2.2 micrograms/ml (10 microM) to 33.8 micrograms/ml (154 microM), and estimates of mu max ranged from 0.20 h-1 (Td = 3.5 h) to 0.32 h-1 (Td = 2.2 h). Estimates of mu max, but not Ks, were affected by changes in initial inoculum density. Maximum growth rates (mu max) were also estimated from turbidity measurements. They ranged from 0.10 h-1 (Td = 6.9 h) to 1.0 h-1 (Td = 0.7 h). There was no correlation between estimates of mu max derived from substrate depletion curves and those derived from turbidity measurements (P = 0.20).     

Kinetic comparison of seven strains of 2,4-dichlorophenoxyacetic acid-degrading bacteria.

Seven strains of 2,4-dichlorophenoxyacetic acid-degrading bacteria, including Pseudomonas, Alcaligenes, and Bordetella spp., were compared on the basis of growth kinetics. Estimates of maximum growth rate (mu max, k1) and half-saturation growth constant (Ks, k3) were obtained by fitting substrate depletion curves to a four-parameter version of the integrated Monod equation. Estimates of Ks ranged from 2.2 micrograms/ml (10 microM) to 33.8 micrograms/ml (154 microM), and estimates of mu max ranged from 0.20 h-1 (Td = 3.5 h) to 0.32 h-1 (Td = 2.2 h). Estimates of mu max, but not Ks, were affected by changes in initial inoculum density. Maximum growth rates (mu max) were also estimated from turbidity measurements. They ranged from 0.10 h-1 (Td = 6.9 h) to 1.0 h-1 (Td = 0.7 h). There was no correlation between estimates of mu max derived from substrate depletion curves and those derived from turbidity measurements (P = 0.20).     

湿度和光照对桑白盾蚧种群生长的影响

本文分析了 4组不同湿度和 3组光照条件下桑白盾蚧 Pseudaulacapis pentagona(Targioni-Tozzetti)的种群生长状况 ,组建生命表。相对湿度在 55% ,77% ,80 % ,95%时 ,种群的内禀增长率分别为 :- 0 .0 0 57,0 .0 510 ,0 .0 50 8,0 .0 0 94 ;净增殖率分别为 :0 .6 92 0 ,2 7.2 10 0 ,2 7.6 6 80 ,1.86 0 6 ;后 3者世代增倍时间分别为 13.5910 ,13.6 4 4 6 ,73.7391天 ;光周期在 L∶D=14∶ 10 ,12∶ 12时 ,种群内禀增长率分别为 :0 .0 4 4 5,0 .0 334,净增殖率分别为 2 3.96 2 8,12 .156 2 ,增倍时间为 15.576 3,2 0 .752 0天 ,而 L∶D=10∶ 14时 ,净增殖率为 0 ,内禀增长率和增倍时间都不存在 ,种群将消亡。     

Optimal growth strategies when mortality and production rates are size-dependent

Summary Pontryagin's maximum principle from optimal control theory is used to find the optimal allocation of energy between growth and reproduction when lifespan may be finite and the trade-off between growth and reproduction is linear. Analyses of the optimal allocation problem to date have generally yielded bang-bang solutions, i.e. determinate growth: life-histories in which growth is followed by reproduction, with no intermediate phase of simultaneous reproduction and growth. Here we show that an intermediate strategy (indeterminate growth) can be selected for if the rates of production and mortality either both increase or both decrease with increasing body size, this arises as a singular solution to the problem. Our conclusion is that indeterminate growth is optimal in more cases than was previously realized. The relevance of our results to natural situations is discussed.     

Phenotypic and genetic differences between opaque and translucent colonies of Vibrio alginolyticus

Many pathogens undergo phase variation between rugose and smooth colony morphology or between opaque and translucent colony morphology, which is mainly due to the variation in the surface polysaccharides. In this study, Vibrio alginolyticus ZJ-51 displayed phase variation between opaque, rugose colonies (Op) and translucent, smooth colonies (Tr). Unlike the vibrios reported previously, Tr cells of ZJ-51 enhanced biofilm formation and motility, but they did not differ from Op cells in the quantity of surface polysaccharides produced. Real time PCR was used to analyze the expression of the genes involved in polysaccharide biosynthesis, flagellar synthesis, and the AI-2 quorum-sensing system. The results revealed that the K-antigen capsule gene cluster (which consists of homologs to the cpsA-K in Vibrio parahaemolyticus) and O-antigen polysaccharide gene cluster (which contains homologs to the wza-wzb-wzc) were significantly more transcribed in Tr cells. The AI-2 quorum-sensing genes showed enhanced expression in the Tr variant which also exhibited greater expression of genes associated with polar flagellar biosynthesis. These results suggest that colony phase variation might affect the virulence and survival ability in the stressful environment inhabited by V. alginolyticus.     

Das Geometrische Prinzip der „Moebiusringe“ im Chromosomenmechanismus der heterotypischen Mitose und seine Bedeutung für Vererbung und Geschwulstentstehung

Zusammenfassung Unter genauester Berücksichtigung der morphologischen Befunde dürfte also die vorliegende Untersuchung den Nachweis der Realisierung eines bemerkenswerten Torsionsprinzips (Moebius-Modus) in der heterotypischen Mitose erbracht haben, wodurch gleichzeitig eine einheitliche morphogenetische Erklärung für die so verschiedenartigen und teilweise sich sogar anscheinend widersprechenden Befunde und Chromosomenbilder dieser Mitoseform gegeben ist. An Hand spezieller und allgemeiner Befunde und Erfahrungen der Vererbungs- und Geschwulstlehre konnte weiterhin gezeigt werden, daß die Kenntnis des genannten Modus (Moebius-Modus) auch für diese Gebiete von größtem Interesse ist.     

Sialidase of swine influenza A viruses: variation of the recognition specificities for sialyl linkages and for the molecular species of sialic acid with the year of isolation

The sialidase of swine influenza A viruses of N1 and N2 subtypes, isolated from 1930 to 1992, was studied for substrate specificity with ganglio-series, lacto-series type II and GM3 gangliosides containing Neu5Ac2-3Gal, Neu5Gc2-3Gal and Neu5Ac2-6Gal linkages. All viral sialidases tested showed that the activity for hydrolysing substrates with Neu5Ac2-3Gal was higher than the activities with Neu5Gc2-3Gal and Neu5Ac2-6Gal linkages. When GM1b, GM3 and sialylparagloboside were used as substrates, the earliest strain (A/Wisconsin/15/30 H1N1, isolated in 1930) showed the activity ratio of Neu5Ac2-6Gal to Neu5Ac2-3Gal to be 0.13:0.2, and the ratio Neu5Gc2-3Gal/Neu5Ac2-3Gal to be 0.19:0.37, while those strains isolated from 1978 to 1992 exhibited ratios of 0.29:0.58 for Neu5Ac2-6Gal/Neu5Ac2-3Gal and 0.51:0.76 for Neu5Gc2-3Gal/Neu5Ac2-3Gal. The above results indicate that the substrate specificities of sialidases from swine influenza A viruses towards sialyl linkages and the molecular species of sialic acid are related to the year of isolation, i.e. strains isolated after 1978 exhibited higher activity towards Neu5Ac2-6Gal and Neu5Gc2-3Gal linkages when compared with strains isolated in an earlier year, 1930.Abbreviation Neu5Ac 5-N-acetylneuraminic acid - Neu5Gc 5-N-glycolyneuraminic acid - Gal d-galactose - Glc d-glucose - Cer Ceramide - II³(Neu5Ac)Lac Neu5Ac2-3Gal1-4Glc - GM3(Neu5Ac2-3Gal) Neu5Ac2-3Gal1-4Glc1-Cer - GM3(Neu5Gc2-3Gal) Neu5Gc2-3Gal1-4Glc1-Cer - GM1b(Neu5Ac2-3Gal) Neu5Ac2-3Gal1-3GalNac1-4Gal1-4Glc1-Cer - GMlb(Neu5Gc2-3Gal) Neu5Gc2-3Gal1-3GalNAc1-4Gal1-4Glc1-Cer - IV³(Neu5Ac)nLc4Cer Neu5Ac2-3Gal1-3GlcNAc1-4Gal1-4Glc1-Cer - IV³(Neu5Gc)nLc4Cer Neu5Gc2-3Gal1-3GlcNAc1-4Gal1-4Glc1-Cer - IV⁶(Neu5Ac)nLc4Cer Neu5Ac2-6Gal1-3GlcNAc1-4Gal1-4Glc1-Cer - TDC taurodeoxycholate.     

Inter-rater reliability of muscle contractile property measurements using non-invasive tensiomyography

Tensiomyography (TMG) is a relatively novel technique to assess muscle mechanical response based on radial muscle belly displacement consecutive to a single electrical stimulus. Although intra-session reliability has been found to be good, inter-rater reliability and the influence of sensor repositioning and electrodes placement on TMG measurements is unknown. The purpose of this study was to analyze the inter-rater reliability of vastus medialis muscle contractile property measurements obtained with TMG as well as the effect of inter-electrode distance (IED). Five contractile parameters were analyzed from vastus medialis muscle belly displacement–time curves: maximal displacement (Dm), contraction time (Tc), sustain time (Ts), delay time (Td), and half-relaxation time (Tr). The inter-rater reliability and IED effect on these measurements were evaluated in 18 subjects. Intra-class correlation coefficients, standard errors of measurement, Bland and Altman systematic bias and random error as well as coefficient of variations were used as measures of reliability. Overall, a good to excellent inter-rater reliability was found for all contractile parameters, except Tr, which showed insufficient reliability. Alterations in IED significantly affected Dm with a trend for all the other parameters. The present results legitimate the use of TMG for the assessment of vastus medialis muscle contractile properties, particularly for Dm and Tc. It is recommended to avoid Tr quantification and IED modifications during multiple TMG measurements.