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101.
Tightly regulated control of over-expression is often necessary to study one aspect or time point of gene function and, in transgenesis, may help to avoid lethal effects and complications caused by ubiquitous over-expression. We have utilized the benefits of an optimized tet-on system and a modified muscle creatine kinase (MCK) promoter to generate a skeletal muscle-specific, doxycycline (Dox) controlled over-expression system in transgenic mice. A DNA construct was generated in which the codon optimized reverse tetracycline transactivator (rtTA) was placed under control of a skeletal muscle-specific version of the mouse MCK promoter. Transgenic mice containing this construct expressed rtTA almost exclusively in skeletal muscles. These mice were crossed to a second transgenic line containing a bi-directional promoter centered on a tet responder element driving both a luciferase reporter gene and a tagged gene of interest; in this case the calpain inhibitor calpastatin. Compound hemizygous mice showed high level, Dox dependent muscle-specific luciferase activity often exceeding 10,000-fold over non-muscle tissues of the same mouse. Western and immunocytochemical analysis demonstrated similar Dox dependent muscle-specific induction of the tagged calpastatin protein. These findings demonstrate the effectiveness and flexibility of the tet-on system to provide a tightly regulated over-expression system in adult skeletal muscle. The MCKrtTA transgenic lines can be combined with other transgenic responder lines for skeletal muscle-specific over-expression of any target gene of interest. 相似文献
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Chazaud B Sonnet C Lafuste P Bassez G Rimaniol AC Poron F Authier FJ Dreyfus PA Gherardi RK 《The Journal of cell biology》2003,163(5):1133-1143
Once escaped from the quiescence niche, precursor cells interact with stromal components that support their survival, proliferation, and differentiation. We examined interplays between human myogenic precursor cells (mpc) and monocyte/macrophages (MP), the main stromal cell type observed at site of muscle regeneration. mpc selectively and specifically attracted monocytes in vitro after their release from quiescence, chemotaxis declining with differentiation. A DNA macroarray-based strategy identified five chemotactic factors accounting for 77% of chemotaxis: MP-derived chemokine, monocyte chemoattractant protein-1, fractalkine, VEGF, and the urokinase system. MP showed lower constitutive chemotactic activity than mpc, but attracted monocytes much strongly than mpc upon cross-stimulation, suggesting mpc-induced and predominantly MP-supported amplification of monocyte recruitment. Determination of [3H]thymidine incorporation, oligosomal DNA levels and annexin-V binding showed that MP stimulate mpc proliferation by soluble factors, and rescue mpc from apoptosis by direct contacts. We conclude that once activated, mpc, which are located close by capillaries, initiate monocyte recruitment and interplay with MP to amplify chemotaxis and enhance muscle growth. 相似文献
104.
The aim of this article is to briefly present the Galler Collection, a little-known historic Swiss bone reference series of high value for paleopathological research. The Galler Collection consists of approximately 600 mostly dry-bone specimens of many major bone diseases dating from the late 19th and early 20th centuries. Clinical information and autopsy reports are available for the majority of specimens. Rarely documented conditions represented in the collection include: severe forms of myositis ossificans progressiva, kyphoscoliosis, endemic cretinism, hypo- and hyperparathyroidism, and phosphorus-induced bone necrosis. At present, the Galler Collection is located at the National History Museum in Basel (Augustinergasse 2, 4001 Basel, Switzerland, Telephone: +41612665500, Fax: +41612665546). 相似文献
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106.
睫状神经营养因子对大鼠去神经骨骼肌的营养作用 总被引:6,自引:0,他引:6
目的:了解睫状神经营养因子(CNTF)对去神经引起的肌肉萎缩的治疗作用。方法:离断SD大鼠一侧坐骨神经,连续给予CNTF20d,观察肌肉湿重、蛋白含量、肌纤维横截面积、收缩性能和残肢程度。结果:①给予0.2mg/kg的CNTF,可使损务侧肌纤维横截面积增加35%,肌肉湿重增加38%,胫前肌总蛋白含量增加24%,腓长肌强直收缩强度提高40%,显著改善肢残程度;②0.2mg/kg的CNTF作用明显强于0.05mg/kg的CNTF;③此目鱼肌(慢肌)比伸趾长肌(快肌)对CNTF更敏感。结论:CNTF能显著改善成年大鼠坐骨神经离断后骨骼肌的萎缩和功能丧失,该效应的强弱与用药剂量和肌肉类型有关。 相似文献
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109.
A revised method for estimating adult age at death using the auricular surface of the ilium has been developed. It is based on the existing auricular surface aging method of Lovejoy et al. ([1985] Am. J. Phys. Anthropol. 68:15-28), but the revised technique is easier to apply, and has low levels of inter- and intraobserver error. The new method records age-related stages for different features of the auricular surface, which are then combined to provide a composite score from which an estimate of age at death is obtained. Blind tests of the method were carried out on a known-age skeletal collection from Christ Church, Spitalfields, London. These tests showed that the dispersion of age at death for a given morphological stage was large, particularly after the first decade of adult life. Statistical analysis showed that the age-related changes in auricular surface are not significantly different for males and females. The scores from the revised method have a slightly higher correlation with age than do the Suchey-Brooks pubic symphysis stages. Considering the higher survival rates of the auricular surface compared with the pubic symphysis, this method promises to be useful for biological anthropology and forensic science. 相似文献
110.
Zorbas YG Kakurin VJ Denogradov SD Luzhkov SH Neofitov AC 《Biological trace element research》2002,90(1-3):155-173
Hypokinesia (diminished movement) induces muscle mineral depletion. However, the mechanism of muscle mineral depletion during
hypokinesia (HK) remains unknown. Measuring electrolyte retention and electrolyte values in muscle, plasma, and urine during
and after HK, the aim of this study was to discover if HK could depress mineral retention and lead to muscle mineral depletion.
Studies were done on 204 13-wk-old male Wistar rats (370–390 g) during 10 d pre-HK period, 98 d HK period, and 15 d post-HK
period. Rats were equally divided into two groups: vivarium control rats (VCR) and hypokinetic rats (HKR). All hypokinetic
rats were kept for 98 d in small individual cages, which restricted their movements in all directions without hindering food
and water intakes. All control rats were housed for 98 d in individual cages under vivarium control conditions. Both groups
of rats were pair-fed.
During the HK period skeletal muscle sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), and water content and electrolyte
retention decreased significantly (p < 0.05), while urinary and plasma electrolyte levels increased significantly (p < 0.05) in HKR compared with their pre-HK values and their respective VCR. During the initial days of the post-HK period,
mineral retention increased significantly (p < 0.05), plasma and urinary electrolyte level decreased significantly (p < 0.05), while muscle electrolyte and water content remained significantly (p < 0.05) depressed in HKR compared with VCR. Muscle mineral and water content, electrolyte retention, plasma, and urinary
electrolyte values did not change in VCR compared with their pre-HK values.
It was concluded that during HK decreased muscle mineral content may suggest muscle mineral depletion, while increased urinary
electrolyte loss and muscle mineral depletion may demonstrate reduced mineral retention. Reduced electrolyte excretion and
depressed muscle mineral content during post-HK may indicate skeletal muscle mineral depletion during HK. Dissociation between
electrolyte retention and muscle mineral depletion may demonstrate the presence of decreased electrolyte retention as the
mechanism of muscle electrolyte depletion during prolonged HK. 相似文献