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排序方式: 共有336条查询结果,搜索用时 15 毫秒
1.
Jin Wei Mia Madel Alfajaro Peter C. DeWeirdt Ruth E. Hanna William J. Lu-Culligan Wesley L. Cai Madison S. Strine Shang-Min Zhang Vincent R. Graziano Cameron O. Schmitz Jennifer S. Chen Madeleine C. Mankowski Renata B. Filler Neal G. Ravindra Victor Gasque Fernando J. de Miguel Ajinkya Patil Huacui Chen Craig B. Wilen 《Cell》2021,184(1):76-91.e13
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When the picrosirius red technique was applied to cardiac muscle sections, intense yellow myocyte staining sometimes obscured thin collagenous septa. The picrosirius red technique was modified to include treatment of the sections in 0.2% (w/v) aqueous phosphomolybdic acid prior to staining. With 1-5 min treatment, cytoplasmic staining was eradicated; diminution of collagen staining occurred only with long treatments at much higher concentrations of phosphomolybdic acid. Using this phosphomolybdic acid-picrosirius red technique, collagenous septa as thin as 0.2-0.5 /im and fine collagen fibers making up the septa were clearly discernible. The technique also worked well on sections stained by other techniques and then destained. The phosphomolybdic acid-picrosirius red technique should be useful in experiments designed to investigate the effects of collagen distribution on the electrical and mechanical behavior of cardiac muscle. 相似文献
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Homoserine kinase is a potential control point in the biosynthetic pathway for threonine, isoleucine and methionine. The radish leaf enzyme was tested 相似文献
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In an in vitro muscle bath, the active tension generated by strips of canine tracheal smooth muscle responding to cumulative additions of either histamine (10(-8) to 10(-3) M) or acetylcholine (10(-9) to 10(-3) M) was measured in the absence and presence of prostaglandin E2 (PGE2) (10(-6) to 10(-5) M). When contractile responses of equal magnitude were compared, the contractions elicited by acetylcholine were resistant to the inhibitory effects of PGE2, relative to comparable contractions elicited by histamine. To assess the role of adenylate cyclase in determining the different responses to histamine and acetylcholine in the presence of PGE2, we assayed adenylate cyclase activity in membranes prepared from canine tracheal smooth muscle and found that acetylcholine, but not histamine, decreased PGE2-stimulated adenylate cyclase activity by 48 +/- 2% (mean +/- SE; n = 5). However, in other experiments, we found that even large pharmacological increases in tissue adenosine 3',5'-cyclic monophosphate (cAMP) content only partially inhibited muscarinic tone. Also, exogenously applied analogues of cyclic AMP inhibited contractions induced by histamine more effectively than comparable contractions induced by acetylcholine. We concluded that acetylcholine decreased adenylate cyclase activity in membranes prepared from canine tracheal smooth muscle and that this effect may have contributed to, but did not completely account for, the relative resistance of muscarinic contractions to the inhibitory effects of PGE2. 相似文献
7.
Joseph L. Roberts Mateo Golloshi Derek B. Harding Madison Conduah Guanglu Liu Hicham Drissi 《Aging cell》2023,22(4):e13786
Age-related delays in bone repair remains an important clinical issue that can prolong pain and suffering. It is now well established that inflammation increases with aging and that this exacerbated inflammatory response can influence skeletal regeneration. Recently, simple dietary supplementation with beneficial probiotic bacteria has been shown to influence fracture repair in young mice. However, the contribution of the gut microbiota to age-related impairments in fracture healing remains unknown. Here, we sought to determine whether supplementation with a single beneficial probiotic species, Bifidobacterium longum (B. longum), would promote fracture repair in aged (18-month-old) female mice. We found that B. longum supplementation accelerated bony callus formation which improved mechanical properties of the fractured limb. We attribute these pro-regenerative effects of B. longum to preservation of intestinal barrier, dampened systemic inflammation, and maintenance of the microbiota community structure. Moreover, B. longum attenuated many of the fracture-induced systemic pathologies. Our study provides evidence that targeting the gut microbiota using simple dietary approaches can improve fracture healing outcomes and minimize systemic pathologies in the context of aging. 相似文献
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W. H. H. Krueger G. E. Gonye D. L. Madison K. E. Murray M. Kumar N. Spoerel S. E. Pfeiffer 《Journal of neurochemistry》1997,69(4):1343-1355
Abstract: Although the myelin membrane contains only a small set of major proteins, more sensitive assays indicate the presence of a plethora of uncharacterized proteins. We have used an antibody perturbation approach to reversibly block the differentiation of prooligodendroblasts into myelinating cells, and, in combination with a differential screening procedure, identified novel mRNAs that are activated during this period. One cDNA, TPO1, recognizes a 5.5-kb mRNA that is strongly up-regulated in oligodendrocytes after release of the differentiation block and that is expressed at high levels in brain tissue during active myelination. This cDNA represents at least two mRNAs differing from each other in their 5'-termini. The TPO1 cDNA contains an open reading frame of 1,380 bp, encoding a protein of 51.8 kDa with a predicted pl of 9.1 that contains two regions homologous to nonclassic zinc finger motifs. Subcellular localization studies suggest the enriched presence of TPO1 in spherical structures along the major cytoplasmic processes of oligodendrocytes. TPO1, along with homologues expressed in testis, placenta, and PC12 cells, form a novel family of proteins with multiple hydrophobic domains possibly serving as membrane spanning regions. We postulate that in oligodendrocytes, TPO1 encodes a protein factor involved in myelin biogenesis. 相似文献
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D. C. Swartzendruber A. Manganaro K. C. Madison M. Kremer P. W. Wertz C. A. Squier 《Cell and tissue research》1995,279(2):271-276
Previous studies have demonstrated that the intercellular spaces of the stratum corneum contain multilamellar lipid sheets with variable ultrastructure in addition to desmosomes or desmosomal remnants. The intercellular lamellae are thought to provide a permeability barrier whereas the desmosomes are responsible for cell-cell cohesion. In this study, transmission electron microscopy of RuO4-fixed tissue was used to compare the proportions of the intercellular spaces in epidermal and palatal stratum corneum occupied by desmosomes and by different patterns of lamellae. Desmosomes are more abundant in palatal than in epidermal stratum corneum (46.9 vs 15.0% length of intercellular space). In epidermis the most frequent lamellar arrangements involve 3 (23.5%) or 6 (24.2%) lucent bands with an alternating broad-narrow-broad pattern, whereas the most frequent lamellar arrangements in palatal tissue are 2 (17.2%) or 4 (10.5%) lucent bands of uniform width. Most of the nondesmosomal portion of the intercellular space in palatal stratum corneum was dilated and had elongated lamellae at the periphery and short disorganized lamellae and amorphous electron-dense material in the interior. It is concluded that the multilamellar lipid sheets are less extensive in palatal than in epidermal stratum corneum, which could explain the greater permeability of the palate. 相似文献
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Male red-backed salamanders (Plethodon cinereus) were studied to determine the origin of the chemical cues allowing for individual odour recognition between conspecifics. Individual males showed a preference for substrates with their own faecal and cloacal odours rather than those marked by unfamiliar conspecific males. This discriminatory ability did not depend on recent differences in food consumed. These scent marks might be used to define breeding territories in the field. 相似文献