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61.
62.
The purpose of this study was to examine whether prediction of antagonist moment (M(flx)) of the hamstrings using clinically applicable models depends on the muscles examined. Nine healthy males performed maximal isometric knee extension and flexion contractions at 0 degrees , 45 degrees and 90 degrees angles. Calibration knee flexion efforts were also performed at different levels of intensity. The resulting electromyographic (EMG) - moment curves were fitted using polynomial equations which were then used to estimate M(flx) from the antagonist EMG. Analysis of variance designs showed that the M(flx) predicted using the biceps femoris EMG was not significantly different compared with those predicted using the semitendinosus EMG data (p>0.05). Further, prediction of M(flx) using the EMG of both muscles or a combination of EMGs and architectural properties reduced estimation error but did not provide significantly different predicted values compared with the simpler single-muscle EMG - moment models (p<0.05). It appears that M(flx) prediction using the present EMG - moment model is not muscle specific. Prediction using models which combine EMG data and anatomic parameters of the hamstring muscle components yielded more accurate estimates and therefore their use to examine co-contraction levels is recommended. 相似文献
63.
Hollenberg MD Oikonomopoulou K Hansen KK Saifeddine M Ramachandran R Diamandis EP 《Biological chemistry》2008,389(6):643-651
Proteinases such as thrombin and trypsin can affect tissues by activating a novel family of G protein-coupled proteinase-activated receptors (PARs 1-4) by exposing a 'tethered' receptor-triggering ligand (TL). Work with synthetic TL-derived PAR peptide sequences (PAR-APs) that stimulate PARs 1, 2 and 4 has shown that PAR activation can play a role in many tissues, including the gastrointestinal tract, kidney, muscle, nerve, lung and the central and peripheral nervous systems, and can promote tumor growth and invasion. PARs may play roles in many settings, including cancer, arthritis, asthma, inflammatory bowel disease, neurodegeneration and cardiovascular disease, as well as in pathogen-induced inflammation. In addition to activating or disarming PARs, proteinases can also cause hormone-like effects via PAR-independent mechanisms, such as activation of the insulin receptor. In addition to proteinases of the coagulation cascade, recent data suggest that members of the family of kallikrein-related peptidases (KLKs) represent endogenous PAR regulators. In summary: (1) proteinases are like hormones, signaling in a paracrine and endocrine manner via PARs or other mechanisms; (2) KLKs must now be seen as potential hormone-like PAR regulators in vivo; and (3) PAR-regulating proteinases, their target PARs, and their associated signaling pathways appear to be novel therapeutic targets. 相似文献
64.
65.
Bone morphogenetic proteins (BMPs) are expressed during osteogenesis and their action is regulated by corresponding BMP inhibitors.
Chordin (a well recognized BMP inhibitor) and BMP-2 are expressed during osteogenic differentiation of human mesenchymal stem
cells. Chordin inhibition induces human mesenchymal stem cell differentiation and reduces their proliferation by increasing
BMP-2 bioavailability. The potential of suppressing BMP inhibitors is emerging as a biological therapeutic target in bone
tissue engineering, because it results in an unopposed synergy between the various growth factors that are involved in osteogenesis,
within their physiological milieu. 相似文献
66.
Background
In marine mussels of the genus Mytilus there are two mitochondrial genomes. One is transmitted through the female parent, which is the normal transmission route in animals, and the other is transmitted through the male parent which is an unusual phenomenon. In males the germ cell line is dominated by the paternal mitochondrial genome and the somatic cell line by the maternal. Research to date has not allowed a clear answer to the question of whether inheritance of the paternal genome is causally related to maleness.Methodology/Principal Findings
Here we present results from hybrid crosses, from triploid mussels and from observations of sperm mitochondria in fertilized eggs which clearly show that maleness and presence of the paternal mitochondrial genome can be decoupled. These same results show that the female mussel has exclusive control of whether her progeny will inherit the mitochondrial genome of the male parent.Conclusions/Significance
These findings are important in our efforts to understand the mechanistic basis of this unusual mode of mitochondrial DNA inheritance that is common among bivalves. 相似文献67.
68.
Venetis C Theologidis I Zouros E Rodakis GC 《Proceedings. Biological sciences / The Royal Society》2006,273(1600):2483-2489
Species of the mussel family Mytilidae have a special mitochondrial DNA (mtDNA) transmission system, known as doubly uniparental inheritance (DUI), which consists of a maternally inherited (F) and a paternally inherited (M) mitochondrial genome. Females are normally homoplasmic for the F genome and males are heteroplasmic mosaics, with their somatic tissues dominated by the maternal and their gonads dominated by the paternal genome. Several studies have indicated that the maternal genome may often be present in the male germ line. Here we report the results from the examination of mtDNA in pure sperm from more than 30 males of Mytilus galloprovincialis. In all cases, except one, we detected only the M genome. In the sperm of one male, we detected a paternal genome with an F-like primary sequence that was different from the sequence of the maternal genome in the animal's somatic tissues. We conclude that the male germ line is protected against invasion by the maternal genome. This is important because fidelity of gamete-specific transmission of the two mitochondrial genomes is a basic requirement for the stability of DUI. 相似文献
69.
Fotini G. Skiada Katerina Grigoriadou Eleftherios P. Eleftheriou 《Central European Journal of Biology》2010,5(6):839-852
The effects of six basal media on in vitro shoot proliferation of the greek grapevines Vitis vinifera L. cv. ‘Malagouzia’ and ‘Xinomavro’ were investigated. Galzy and Zlenco proved to be the most effective for ‘Malagouzia’
and ‘Xinomavro’, respectively. If only BA was present in the medium, shoot development was poor and the plantlets were chlorotic.
When the medium was supplemented with BA and NAA, growth was enhanced. The best ratio (in μM) of growth regulators was 0.5/0.3
for ‘Malagouzia’, and 0.1/0.03 for ‘Xinomavro’, which resulted in the highest number of microshoots per explant and greatest
proliferation rate. The development of ‘Malagouzia’ and ‘Xinomavro’ explants at 21±2 and 26±2°C was also investigated, revealing
the higher temperature to be more effective. Regarding rooting, 0.5 μM IBA improved root formation at 26°C for ‘Malagouzia’
and 0.5 μM IBA at 21°C for ‘Xinomavro’. Moreover, 0.5 μM IBA resulted in a higher rooting percentage (>95%) and proved to
be more beneficial for the overall morphological appearance of the plantlets of ‘Malagouzia’. After acclimatization, survival
of microshoots cultivated in media with IBA was higher than those in NAA. 相似文献
70.
Daniela Cretu Ioannis Prassas Punit Saraon Ihor Batruch Rajiv Gandhi Eleftherios P Diamandis Vinod Chandran 《Clinical proteomics》2014,11(1):27