Search results for "MICE"
showing 10 items of 6027 documents
Defective Postnatal Neurogenesis and Disorganization of the Rostral Migratory Stream in Absence of theVax1Homeobox Gene
2004
The subventricular zone (SVZ) is one of the sources of adult neural stem cells (ANSCs) in the mouse brain. Precursor cells proliferate in the SVZ and migrate through the rostral migratory stream (RMS) to the olfactory bulb (OB), where they differentiate into granule and periglomerular cells. Few transcription factors are known to be responsible for regulating NSC proliferation, migration, and differentiation processes; even fewer have been found to be responsible for the organization of the SVZ and RMS. For this reason, we studied the ventral anterior homeobox (Vax1) gene in NSC proliferation and in SVZ organization. We found thatVax1is strongly expressed in the SVZ and in the RMS and that,…
Sustained activation of mTOR pathway in embryonic neural stem cells leads to development of tuberous sclerosis complex-associated lesions
2011
SummaryTuberous Sclerosis Complex (TSC) is a multisystem genetic disorder characterized by hamartomatous neurological lesions that exhibit abnormal cell proliferation and differentiation. Hyperactivation of mTOR pathway by mutations in either the Tsc1 or Tsc2 gene underlies TSC pathogenesis, but involvement of specific neural cell populations in the formation of TSC-associated neurological lesions remains unclear. We deleted Tsc1 in Emx1-expressing embryonic telencephalic neural stem cells (NSCs) and found that mutant mice faithfully recapitulated TSC neuropathological lesions, such as cortical lamination defects and subependymal nodules (SENs). These alterations were caused by enhanced gen…
Glutathione regulates telomerase activity in 3T3 fibroblasts.
2004
Changes in telomerase activity have been associated either with cancer, when activity is increased, or with cell cycle arrest when it is decreased. We report that glutathione, a physiological antioxidant present at high intracellular concentrations, regulates telomerase activity in cells in culture. Telomerase activity increases in 3T3 fibroblasts before exponential cell growth. The peak of telomerase activity takes place 24 h after plating and coincides with the maximum levels of glutathione in the cells. When cells are treated with buthionine sulfoximine, which decreases glutathione levels in cells, telomerase activity decreases by 60%, and cell growth is delayed. Glutathione depletion in…
Telomere shortening and chromosomal instability abrogates proliferation of adult but not embryonic neural stem cells.
2004
Chromosome integrity is essential for cell viability and, therefore, highly proliferative cell types require active telomere elongation mechanisms to grow indefinitely. Consistently, deletion of telomerase activity in a genetically modified mouse strain results in growth impairments in all highly proliferative cell populations analyzed so far. We show that telomere attrition dramatically impairs the in vitro proliferation of adult neural stem cells (NSCs) isolated from the subventricular zone (SVZ) of telomerase-deficient adult mice. Reduced proliferation of postnatal neurogenic progenitors was also observed in vivo, in the absence of exogenous mitogenic stimulation. Strikingly, severe telo…
Expression of the genetic suppressor element 24.2 (GSE24.2) decreases DNA damage and oxidative stress in X-linked dyskeratosis congenita cells.
2014
This is an open-access article distributed under the terms of the Creative Commons Attribution License.-- et al.
Retinoic Acid Induces Apoptosis-Associated Neural Differentiation of a Murine Teratocarcinoma Cell Line
2002
Abstract: Incubation with all-trans retinoic acid (RA) induces PCC7-Mz1 embryonic carcinoma cells to cease proliferation and to develop into a tissue-like pattern of neuronal, astroglial, and fibroblast-like derivatives over a period of several days. Concomitant with the induction of differentiation by RA, a sizable fraction of the Mz1 stem cells detaches and dies, with the maximal level of cell death achieved after 10 h of RA treatment. This RA-induced cell death fulfills all criteria of apoptosis, including nuclear condensation, intranucleosomal DNA degradation, expression of cysteine aspases (caspases), and the formation of apoptotic bodies. Apoptosis could be suppressed by the pan-caspa…
Retention-structure relationship studies for some steroidal hormones in micellar liquid chromatography
2000
The retention behavior in a C18 column of fourteen steroidal hormones (clostebol acetate, dehydrotestosterone, dydrogesterone, medroxyprogesterone, medroxyprogesterone acetate, methandienone, methyltestosterone, nandrolone, nandrolone decanoate, progesterone, testosterone, testosterone enanthate, testosterone propionate and, stanozolol) with pure micellar mobile phases prepared from sodium dodecyl sulfate (SDS), and hybrid mobile phases comprising SDS-acetonitrile and SDS-pentanol, was correlated with their octanol-water partition coefficients. Similar correlations were found with retention data obtained by other authors in gas chromatography, conventional reversed-phase liquid chromatograp…
DETERMINATION OF STEROIDAL HORMONES IN URINE SAMPLES BY MICELLAR LIQUID CHROMATOGRAPHY FOLLOWING SOLID-PHASE EXTRACTION
2001
Steroidal hormones were determined in spiked urine samples using micellar mobile phases of sodium dodecyl sulphate (SDS)-pentanol, solid-phase extraction (SPE), and detection in the UV region. In the optimized procedure, a 10 mL aliquot of urine sample is loaded into a C18 cartridge and washed with 2 mL of 50:50 (v/v) methanol-water, followed by 200 μL of 70:30 (v/v) methanol-water. The retained steroids are eluted with 2 mL of methanol and the eluate evaporated to dryness under nitrogen at 50°C. The residue is redissolved with 200 μL of the micellar mobile phase used in the chromatographic separation and injected into the chromatograph. The performance of the procedure was checked for 13 s…
A research on the action of testosterone propionate and of ciproterone acetate on the mouse-killing behaviour of the adult rat.
1979
AbstractData demonstrate exactly that testosterone favour above all the killing behaviour of castrate males at birth in comparison with control males while ciproterone acetate turns out to be more effective in diminishing the killing behaviour of males having integral testicle and of androgenized females at birth in comparison with castrated males.The results point out that the killing behaviour of rats is affected by the presence of testosterone in the first days of life, and in the grown-up animal.
Effects of chronic treatment with testosterone propionate on aggression and hormonal levels in intact male mice.
1998
Effects of testosterone propionate, an anabolic-androgenic steroid (AAS), on aggression in gonadally intact male mice were examined. Animals were given weekly injections of 3.75, 7.5, 15, and 30 mg/kg of drug or sesame oil for 10 weeks. During the last 3 weeks, behavioral tests were conducted and at the end of the experiment, body, liver and testes weight and hormonal data were collected. The treatment had minimal behavioral and endocrine effects. It resulted in shorter latencies of 'threat' only in the last agonistic encounter, increases in testosterone levels and decreases in testes weight in a non-linear dose-dependant way. The action of treatment was different on threat and attack, the …