Search results for "Microscopy"
showing 10 items of 3390 documents
PSCDGs of mouse multipotent adult germline stem cells can enter and progress through meiosis to form haploid male germ cells in vitro
2010
Spermatogonial stem cells (SSCs) provide the basis for spermatogenesis throughout adult life by undergoing self-renewal and differentiation into sperm. SSC-derived cell lines called multipotent adult germline stem cells (maGSCs) were recently shown to be pluripotent and to have the same potential as embryonic stem cells (ESCs). In a differentiation protocol using retinoic acid (RA) and based on a double selection strategy, we have shown that ESCs are able to undergo meiosis and produce haploid male germ cells in vitro. Using this differentiation protocol we have now succeeded to generate haploid male germ cells from maGSCs in vitro. maGSCs derived from a Stra8-EGFP transgenic mouse line wer…
Synaptic vesicle alterations in rod photoreceptors of synaptophysin-deficient mice.
2001
Abstract The abundance of the integral membrane protein synaptophysin in synaptic vesicles and its multiple possible functional contributions to transmitter exocytosis and synaptic vesicle formation stand in sharp contrast to the observed lack of defects in synaptophysin knockout mice. Assuming that deficiencies are compensated by the often coexpressed synaptophysin isoform synaptoporin, we now show that retinal rod photoreceptors, which do not synthesize synaptoporin either in wild-type or in knockout mice, are affected by the loss of synaptophysin. Multiple pale-appearing photoreceptors, as seen by electron microscopy, possess reduced cytoplasmic electron density, swollen mitochondria, an…
Neuroprotection of lipoic acid treatment promotes angiogenesis and reduces the glial scar formation after brain injury
2012
After trauma brain injury, a large number of cells die, releasing neurotoxic chemicals into the extracellular medium, decreasing cellular glutathione levels and increasing reactive oxygen species that affect cell survival and provoke an enlargement of the initial lesion. Alpha-lipoic acid is a potent antioxidant commonly used as a treatment of many degenerative diseases such as multiple sclerosis or diabetic neuropathy. Herein, the antioxidant effects of lipoic acid treatment after brain cryo-injury in rat have been studied, as well as cell survival, proliferation in the injured area, gliogenesis and angiogenesis. Thus, it is shown that newborn cells, mostly corresponded with blood vessels …
2-Hydroxyoleate, a nontoxic membrane binding anticancer drug, induces glioma cell differentiation and autophagy
2012
Despite recent advances in the development of new cancer therapies, the treatment options for glioma remain limited, and the survival rate of patients has changed little over the past three decades. Here, we show that 2-hydroxyoleic acid (2OHOA) induces differentiation and autophagy of human glioma cells. Compared to the current reference drug for this condition, temozolomide (TMZ), 2OHOA combated glioma more efficiently and, unlike TMZ, tumor relapse was not observed following 2OHOA treatment. The novel mechanism of action of 2OHOA is associated with important changes in membrane-lipid composition, primarily a recovery of sphingomyelin (SM) levels, which is markedly low in glioma cells bef…
Transport of the major myelin proteolipid protein is directed by VAMP3 and VAMP7.
2011
CNS myelination by oligodendrocytes requires directed transport of myelin membrane components and a timely and spatially controlled membrane expansion. In this study, we show the functional involvement of the R-solubleN-ethylmaleimide-sensitive factor attachment protein receptor (R-SNARE) proteins VAMP3/cellubrevin and VAMP7/TI-VAMP in myelin membrane trafficking. VAMP3 and VAMP7 colocalize with the major myelin proteolipid protein (PLP) in recycling endosomes and late endosomes/lysosomes, respectively. Interference with VAMP3 or VAMP7 function using small interfering RNA-mediated silencing and exogenous expression of dominant-negative proteins diminished transport of PLP to the oligodendro…
Aircraft noise exposure drives the activation of white blood cells and induces microvascular dysfunction in mice
2021
Epidemiological studies showed that traffic noise has a dose-dependent association with increased cardiovascular morbidity and mortality. Whether microvascular dysfunction contributes significantly to the cardiovascular health effects by noise exposure remains to be established. The connection of inflammation and immune cell interaction with microvascular damage and functional impairment is also not well characterized. Male C57BL/6J mice or gp91phox−/y mice with genetic deletion of the phagocytic NADPH oxidase catalytic subunit (gp91phox or NOX-2) were used at the age of 8 weeks, randomly instrumented with dorsal skinfold chambers and exposed or not exposed to aircraft noise for 4 days. Pro…
The study of Positive and Negative Affect in children and adolescents: New advances in a Spanish version of the PANAS
2019
The study of affective disorders among young population has become increasingly relevant in the last years. The PANAS is a widely used questionnaire devoted to assess positive and negative affect. The main purpose of the current study was to examine the psychometric properties of the Spanish version of the PANAS for children (PANAS). The sample consisted of 1032 children and adolescents aged between 10 and 15 years. The ESEM two factor model (Positive Affect and Negative Affect) was found as the most suitable model. The PANAS scores also showed acceptable internal consistency. The ESEM two factor model was invariant across gender and educational level. Results showed statistically significa…
Vessel painting of the microcirculation using fluorescent lipophilic tracers
2005
Flexible approaches to defining microvessel morphometry are useful in the study of both acute and chronic structural changes of the microcirculation. In this report, we examined the utility of the intravascular infusion of lipophilic carbocyanine tracers in the structural assessment of the retina, skin, lung, and colon microcirculation. The microvessel labeling technique, here termed fluorescent vessel painting, involved the intravascular injection of sulfonated lipophilic carbocyanine tracers. The utility of vessel painting in morphometry was assessed using morphometric comparisons with corrosion casting and 2-dimensional and 3-dimensional scanning electron microscopy. The comparisons demo…
Remodeling of alveolar septa after murine pneumonectomy
2015
In most mammals, removing one lung (pneumonectomy) results in the compensatory growth of the remaining lung. In mice, stereological observations have demonstrated an increase in the number of mature alveoli; however, anatomic evidence of the early phases of alveolar growth has remained elusive. To identify changes in the lung microstructure associated with neoalveolarization, we used tissue histology, electron microscopy, and synchrotron imaging to examine the configuration of the alveolar duct after murine pneumonectomy. Systematic histological examination of the cardiac lobe demonstrated no change in the relative frequency of dihedral angle components (Ends, Bends, and Junctions) ( P >…
Aprotinin inhibits leukocyte–endothelial cell interactions after hemorrhage and reperfusion
2003
Background. The serine protease inhibitor aprotinin has been successfully used to reduce blood loss in patients undergoing cardiac operations. We studied aprotinin for its ability to modulate leukocyte– endothelial cell interactions after ischemia and reperfusion. Methods. The effects of aprotinin on leukocyte– endothelial cell interactions were observed by intravital microscopy in the rat mesenteric microcirculation and immunohistochemical analysis. The inflammatory cascade (leukocyte rolling, firm adherence, and transmigration) was studied after thrombin stimulation and after hemorrhage and reperfusion. Results. Intravenous bolus administration of aprotinin treatment (20,000 U/kg) signifi…