Search results for "cell survival"
showing 10 items of 870 documents
Neuroglobin mRNA expression after transient global brain ischemia and prolonged hypoxia in cell culture.
2006
Abstract Neuroglobin is a nerve-specific respiratory protein that has been proposed to play an important role in the protection of brain neurons from ischemic and hypoxic injuries. Here, we investigated the regulation of neuroglobin expression after transient global ischemia in the rat brain using mRNA in situ hybridization and under hypoxic stress in cultured neuronal cell lines (PC12, HN33) by quantitative RT-PCR. While neuroglobin mRNA expression was significantly enhanced in cell culture after severe prolonged hypoxia (0–1% O 2 for 24 h), we did not find any significant increases in neuroglobin mRNA levels in the rat brain after transient global ischemia. Vegf and Glut1 mRNAs showed inc…
Circadian variation in shedding of the oocysts of Isospora turdi (Apicomplexa) in blackbirds (Turdus merula): an adaptative trait against desiccation…
2009
5 pages; International audience; Many parasite species spend part of their life cycle in the external environment waiting for a new host. Emergence of parasites often occurs once a day, which may help to minimise mortality in an inhospitable environment and increase transition rates. Many intestinal parasites in birds are released in faeces only in the late afternoon. However, the adaptative significance of this pattern is unclear. One hypothesis is that a particular time of emergence may prevent parasite desiccation and therefore increase the parasite's life expectancy in the external environment. We tested this hypothesis experimentally using the blackbird (Turdus merula) infected with Is…
Hsp60 expression, new locations, functions and perspectives for cancer diagnosis and therapy.
2008
Hsp60 in eukaryotes is considered typically a mitochondrial chaperone (also called Cpn60) but in the last few years it has become clear that it also occurs in the cytosol, the cell surface, the extracellular space, and in the peripheral blood. Studies with prokaryotic models have shown that Hsp60 plays a role in assisting nascent polypeptides to reach a native conformation, and that it interacts with Hsp10 (which also resides in the mitochondria and is also named Cpn10). In addition to its role in polypeptide folding in association with Hsp10, other functions and interacting molecules have been identified for Hsp60 in the last several years. Some of these newly identified functions are asso…
Characteristics of the spermathecal contents of old and young honeybee queens.
2009
Sperm are often stored, for a long time after mating, in females of various animal species. In case of the queen honeybee (Apis mellifera), sperm remain fertile for several years in the spermatheca. Little information is available regarding the effect of long-term storage of sperm on its fertility. To evaluate this, enzymes and/or sperm have been analysed from the spermatheca of 75 queens of various ages (0 year Y0, n=14; one year Y1, n=14; two years Y2, n=7; virgin queen VQ, n=40) and semen samples have been taken from 46 drones. The sperm from the spermatheca of older queens move more slowly (F=11.45, P < 0.0001) and show different movement patterns (Chi2=90.0, P < 0.0001) from those of t…
Metabolic activity of fresh and cryopreserved cynomolgus monkey (Macaca fascicularis) hepatocytes
2000
1. The effect of cryopreservation on the metabolic capacity of monkey hepatocytes over 4 h in suspension and 24 h in culture was determined. Hepatocytes were diluted in a buffer containing 10% DMSO and frozen in a computer-controlled chamber. 2. Initial ethoxyresorufin and ethoxycoumarin O-deethylase (ECOD) activities were the same in fresh and cryopreserved (CP) hepatocytes. ECOD activity in suspensions declined over 4 h but was the same in fresh and CP hepatocytes. 3. The formation of testosterone hydroxy (OHT) metabolites (namely 6beta-OHT, 2beta-OHT, 16beta-OHT, 16alpha-OHT, 15beta-OHT, 2alpha-OHT and 6beta-OHT) was unaffected by cryopreservation. The loss of OHT activities over 4 h in …
Learning to learn: Theta oscillations predict new learning, which enhances related learning and neurogenesis
2011
Animals in the natural world continuously encounter learning experiences of varying degrees of novelty. New neurons in the hippocampus are especially responsive to learning associations between novel events and more cells survive if a novel and challenging task is learned. One might wonder whether new neurons would be rescued from death upon each new learning experience or whether there is an internal control system that limits the number of cells that are retained as a function of learning. In this experiment, it was hypothesized that learning a task that was similar in content to one already learned previously would not increase cell survival. We further hypothesized that in situations in…
Synergistic effect of peplomycin in combination with bleomycin on L5178y mouse lymphoma cells in vivo.
1984
Studying the treatment of NMRI mice with ip injections of bleomycin (BLM) for 5 days we found an approximate LD50 of 35 mg/kg; the toxicity of peplomycin (PEP) was slightly higher (LD50: approximately 25 mg/kg). The effect of the two drugs on growth of L5178y mouse lymphoma cells in NMRI mice was examined. BLM alone caused at a concentration of 2.5 mg/kg an almost complete inhibition of tumor cell growth; the same effect was determined with 1 mg PEP/kg. At these concentrations the drugs caused an increase of the survival time of 110% (BLM) or 104% (PEP). Given in combination, one-sixth of the optimal doses yielded an 100% increase of the median survival time. These results indicate a signif…
Haploinsufficiency of ATP1A2 encoding the Na+/K+ pump alpha2 subunit associated with familial hemiplegic migraine type 2.
2003
Headache attacks and autonomic dysfunctions characterize migraine, a very common, disabling disorder with a prevalence of 12% in the general population of Western countries(1,2). About 20% of individuals affected with migraine experience aura, a visual or sensory-motor neurological dysfunction that usually precedes or accompanies the headache(3). Although the mode of transmission is controversial(4), population-based and twin studies have implicated genetic factors, especially in migraine with aura(5,6). Familial hemiplegic migraine is a hereditary form of migraine characterized by aura and some hemiparesis. Here we show that mutations in the gene ATP1A2 that encodes the alpha2 subunit of t…
Chemo-radiotherapy induced oral mucositis during IMRT for head and neck cancer: an assessment
2014
Background This study is conducted mainly to evaluate the changes in quality and quantity of oral epithelial cells during the course of IMRT. Material and Methods 30 Patients undergoing chemo-radiotherapy were followed through course of treatment. They were compared with a group of age- and sex-matched healthy individuals. The procedure involved WHO clinical scoring, collection of oral washings and preparation of buccal smears from both study group and control group. The changes occurred were recorded as a way of assessing the severity of oral mucositis. Results Revealed a significant occurrence of oral mucositis in almost all patients during weekly follow up. There was a significant increa…
Novel antihypertensive hexa- and heptapeptides with ACE-inhibiting properties: From the in vitro ACE assay to the spontaneously hypertensive rat
2011
Bioactive ACE inhibiting peptides are gaining interest in hypertension treatment. We have designed and screened six synthetic heptapeptides (PACEI48 to PACEI53) based on two hexapeptide leads (PACEI32 and PACEI34) to improve ACE inhibitory properties and assess their antihypertensive effects. ACE activity was assayed in vitro and ex vivo. Selected peptides were administered to spontaneously hypertensive rats (SHRs) and normotensive Wistar-Kyoto (WKY) rats. In vitro cytotoxicity was assessed with the MTT reduction test. The six heptapeptides at low micromolar concentration produced different degrees of in vitro inhibition of ACE activity using the synthetic substrate HHL or the natural subst…