Search results for "Capillarie"
showing 10 items of 86 documents
Capillaries within human skeletal muscle fibers.
1991
Internalized capillaries, i.e. capillaries within muscle fibers, represent a rare myopathological feature. This was systematically studied in 923 muscle biopsy specimens and found in 24, chiefly in the gastrocnemius muscle, more rarely in the biceps and quadriceps muscles affecting males more often than females and most frequently associated with juvenile spinal muscular atrophy or Becker's muscular dystrophy. Internalized capillaries, often multiple, ran along the long axis of the muscle fiber within an "internalized" extracellular space and were almost exclusively seen in type I myofibers. Internalization seems to start at the site of fiber splitting while penetration through the intact s…
Anticancer activities of six selected natural compounds of some Cameroonian medicinal plants.
2011
BACKGROUND: Natural products are well recognized as sources of drugs in several human ailments. In the present work, we carried out a preliminary screening of six natural compounds, xanthone V(1) (1); 2-acetylfuro-1,4-naphthoquinone (2); physcion (3); bisvismiaquinone (4); vismiaquinone (5); 1,8-dihydroxy-3-geranyloxy-6-methylanthraquinone (6) against MiaPaCa-2 pancreatic and CCRF-CEM leukemia cells and their multidrug-resistant subline, CEM/ADR5000. Compounds 1 and 2 were then tested in several other cancer cells and their possible mode of action were investigated. METHODOLOGY/FINDINGS: The tested compounds were previously isolated from the Cameroonian medicinal plants Vismia laurentii (1,…
Role of oxoproline in the regulation of neutral amino acid transport across the blood-brain barrier.
1996
Regulation of neutral amino acid transport was studied using isolated plasma membrane vesicles derived from the bovine blood-brain barrier. Neutral amino acids cross the blood-brain barrier by facilitative transport system L1, which may allow both desirable and undesirable amino acids to enter the brain. The sodium-dependent amino acid systems A and Bo,+ are located exclusively on abluminal membranes, in a position to pump unwanted amino acids out. gamma-Glutamyl transpeptidase, the first enzyme of the gamma-glutamyl cycle, is an integral protein of the luminal membrane of the blood-brain barrier. We demonstrate that oxoproline, an intracellular product of the gamma-glutamyl cycle, stimulat…
Role of geometry and anisotropic diffusion for modelling PO2 profiles in working red muscle
1990
A 3-dimensional analytical model of O2 diffusion in heavily working muscle is proposed which considers anisotropic, myoglobin (Mb)-facilitated O2 diffusion inside the muscle fiber and a carrier-free layer separating erythrocytes and fiber. The model is used to study the effects of some commonly applied simplifying assumptions (reduced dimensionality, neglected anisotropy) on the resulting PO2 distributions: (1) In order not to underestimate PO2 drops near erythrocytes, modelling O2 transport in 3 dimensions is important. (2) For a capillary-to-fiber ratio of 1, the results from the 2-dimensional version of the present model and from a Krogh-type model which incorporates a carrier-free layer…
Particulate Matter Contamination of Intravenous Antibiotics Aggravates Loss of Functional Capillary Density in Postischemic Striated Muscle
2002
Through the increased use of less expensive and counterfeit medicines, the contamination of parenteral fluids and drugs by particulate matter poses an increasing health hazard worldwide. However, the mechanism of action of such contamination has never been conclusively demonstrated. We have systemically injected the particles contained in three different 1-g preparations of the antibiotic cefotaxime into hamsters and visualized the functional capillary density in striated skin muscle, using intravital fluorescence microscopy. Injection of particles from either of the three preparations did not affect capillary perfusion in normal muscle (n = 3 hamsters, each). However, injection of particle…
Factors contributing to the variability in muscle ageing
2012
a b s t r a c t Ageing is accompanied with a progressive loss of muscle mass and force generating capacity. Ultimately, the muscle wasting and weakness may dramatically impact on mobility and the quality of life, where the elderly has increasing problems with performing activities of daily life, such as rising from a chair or climbing stairs. The rate of structural and functional deterioration of muscle appears to vary considerably between people. Part of the variation in the 'rate of muscle ageing' is attributable to genetic factors, the timing of changes in circulating hormones and the presence or absence of chronic low-grade systemic inflammation. Where an individual cannot change much i…
The pre-vascularisation of a collagen-chondroitin sulphate scaffold using human amniotic fluid-derived stem cells to enhance and stabilise endothelia…
2015
Abstract A major problem in tissue engineering (TE) is graft failure in vivo due to core degradation in in vitro engineered constructs designed to regenerate thick tissues such as bone. The integration of constructs post-implantation relies on the rapid formation of functional vasculature. A recent approach to overcome core degradation focuses on the creation of cell-based, pre-engineered vasculature formed within the TE construct in vitro , prior to implantation in vivo . The primary objective of this study was to investigate whether an amniotic fluid-derived stem cell (AFSC)–human umbilical vein endothelial cell (HUVEC) co-culture could be used to engineer in vitro vasculature in a collag…
Ovine Carotid Artery-Derived Cells as an Optimized Supportive Cell Layer in 2-D Capillary Network Assays
2014
PLoS one 9(3), e91664 (2014). doi:10.1371/journal.pone.0091664
Capillary enlargement, not sprouting angiogenesis, determines beneficial therapeutic effects and side effects of angiogenic gene therapy.
2010
Aims Currently, it is still unclear which mechanisms drive metabolic benefits after angiogenic gene therapy. The side-effect profile of efficient angiogenic gene therapy is also currently incompletely understood. In this study, the effects of increasing doses of adenoviral (Ad) vascular endothelial growth factor-A (VEGF-A) were evaluated on vascular growth, metabolic benefits, and systemic side effects. Methods and results Adenoviral vascular endothelial growth factor-A or AdLacZ control was injected intramuscularly (109–1011 vp/mL) or intra-arterially (5 × 1011 vp/mL) into rabbit ( n = 102) hindlimb muscles and examined 6 or 14 days later. Blood flow, tissue oedema, metabolic benefits, and…
Sonic hedgehog promotes angiogenesis and osteogenesis in a coculture system consisting of primary osteoblasts and outgrowth endothelial cells.
2009
A number of previous studies documented the angiogenic potential of outgrowth endothelial cells in vitro and in vivo and provided evidence that therapeutic success could depend on coculture or coimplantation strategies. Thus, deeper insight into the molecular mechanisms underlying this pro-angiogenic effect of cocultures might provide new translational options for tissue engineering and regenerative medicine. One promising signaling pathway in bone repair involved in neoangiogenesis and bone formation is the sonic hedgehog (Shh) pathway. In this article, we focus on the effect of Shh on the formation of microvessel-like structures and osteoblastic differentiation in cocultures of primary os…