Abstract:
:Activity of telomerase, the enzyme that synthesizes the telomere ends of linear eukaryotic chromosomes, is repressed in most normal human somatic cells but induced in most human cancers. Normal human cells that lack telomerase activity progressively lose telomere sequences. In contrast, most immortalized cell lines and malignant human tumors appear to maintain constant telomere length via telomerase activity. Telomerase is composed of at least two subunits, an RNA subunit that templates telomere synthesis, and a catalytic protein subunit. The gene encoding the catalytic protein subunit of telomerase has recently been identified, first in yeast and ciliates and then in humans. This catalytic subunit belongs to the reverse transcriptase family. Studies of telomerase subunits further define a role for telomerase in the control of mammalian cell lifespan. The expression of the human telomerase catalytic subunit gene, hTERT, is induced in immortalized cells and primary tumors. When hTERT is ectopically expressed in hitherto telomerase-negative cells, telomerase enzyme activity appears, and an extended lifespan has been observed in some cells. In contrast, disruption of the mouse telomerase RNA subunit gene, mTERC, results in a delayed failure of cell proliferation. Telomerase activity therefore appears to be necessary for the prolonged survival of mammalian cells.
journal_name
Toxicol Lettjournal_title
Toxicology lettersauthors
Meyerson Mdoi
10.1016/s0378-4274(98)00278-1keywords:
subject
Has Abstractpub_date
1998-12-28 00:00:00pages
41-5eissn
0378-4274issn
1879-3169pii
S0378-4274(98)00278-1journal_volume
102-103pub_type
杂志文章,评审abstract::A multi-unit, dynamic flow, inhalation exposure system which is capable of accommodating 12 mice per unit has been described. Components of the system include a mixing board, one or more glass distributing tubes, and detachable glass chamber tubes. The flow of a specified concentration of test gas exits from the mixin...
journal_title:Toxicology letters
pub_type: 杂志文章
doi:10.1016/0378-4274(85)90055-4
更新日期:1985-02-01 00:00:00
abstract::The prevention of renal diseases induced by chemicals requires the use of tests with which adverse renal effects can be detected at a stage when removal from exposure to the offending agent(s) may lead to complete recovery or may at least prevent an accelerated decline in renal function. The screening tests used in cl...
journal_title:Toxicology letters
pub_type: 杂志文章,评审
doi:10.1016/0378-4274(89)90113-6
更新日期:1989-03-01 00:00:00
abstract::The possible embryotoxic effects of cyclohexylamine hydrochloride doses (expressed as free base) of 10, 30 and 100 mg/kg of body weight per day administered orally in water to mice and rats from the 6th to 15th day post-coitum were investigated. Treatment with daily doses of up to 100 mg/kg of body weight to mice and ...
journal_title:Toxicology letters
pub_type: 杂志文章
doi:10.1016/0378-4274(83)90049-8
更新日期:1983-06-01 00:00:00
abstract::The skin is highly sensitive to the chemical warfare agent in mustard gas, sulfur mustard (SM) that initiates a delayed injury response characterized by erythema, inflammation and severe vesication (blistering). Although SM poses a continuing threat, used as recently as in the Syrian conflict, no mechanism-based antid...
journal_title:Toxicology letters
pub_type: 杂志文章
doi:10.1016/j.toxlet.2018.03.007
更新日期:2018-09-01 00:00:00
abstract:OBJECTIVES:Reactivation of inhibited acetylcholinesterase (AChE) with oximes is a causal therapy of intoxication with organophosphorus compounds (OPs). Maximal oxime effects are expected when effective doses are administered as soon as possible and as long as reactivation can be anticipated. An obidoxime plasma level i...
journal_title:Toxicology letters
pub_type: 杂志文章
doi:10.1016/j.toxlet.2010.06.005
更新日期:2010-09-01 00:00:00
abstract::Furan, a potential human carcinogen, is formed during heat-treatment of food. Previous studies of the genotoxicity of furan have given disparate results. Hence, there is a need for complementary data to clarify the mechanism behind the carcinogenicity of furan. In this study, we have used the flow cytometer-based micr...
journal_title:Toxicology letters
pub_type: 杂志文章
doi:10.1016/j.toxlet.2006.08.020
更新日期:2007-02-28 00:00:00
abstract::The cyanobacterial non-proteinogenic amino acid β-N-methylamino-l-alanine (BMAA) is proposed to be involved in the etiology of amyotrophic lateral sclerosis/parkinsonism dementia complex. When administered as single doses to neonatal rats, BMAA gives rise to cognitive and neurodegenerative impairments in the adult ani...
journal_title:Toxicology letters
pub_type: 杂志文章
doi:10.1016/j.toxlet.2016.06.015
更新日期:2016-09-06 00:00:00
abstract::When pregnant mice were exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), the average time to eye opening in the offspring was shortened by about a day. How acceleration of eye opening by TCDD occurs remains unknown. To reveal the underlying mechanisms of the accelerated eye opening, pregnant mice were intraperit...
journal_title:Toxicology letters
pub_type: 杂志文章
doi:10.1016/j.toxlet.2010.04.001
更新日期:2010-07-01 00:00:00
abstract::Several studies have demonstrated that bisphenol A (BPA) exhibited weak estrogenic activity in the 3-day uterotrophic assay using ovariectomized (OVX) and immature rats (Toxicol. Lett. 115 (2000) 231; Regul. Toxicol. Pharmacol. 32 (2000) 118; J. Toxicol. Sci. 26 (2001) 111) and BPA also possessed anti-androgenic activ...
journal_title:Toxicology letters
pub_type: 杂志文章
doi:10.1016/s0378-4274(02)00130-3
更新日期:2002-09-05 00:00:00
abstract::When considering the state of the art in toxicology from an analytical perspective, the key developments relate to three major areas. (1) Forensic horizon: Today forensic analysis has broadened its scope dramatically, to include workplace toxicology, drug abuse testing, drugs and driving, doping, environmental and vet...
journal_title:Toxicology letters
pub_type: 杂志文章,评审
doi:10.1016/s0378-4274(98)00293-8
更新日期:1998-12-28 00:00:00
abstract::Monosodium glutamate (MSG) was administered to adult male mice for 6 d at dose levels of 2, 4 and 8 mg/g b.w. Dose levels of 4 and 8 mg/g MSG resulted in significant changes in serum total lipids, triglycerides, phospholipids, free fatty acids and blood glucose 31 d after cessation of exposure. Administration of 2 mg/...
journal_title:Toxicology letters
pub_type: 杂志文章
doi:10.1016/0378-4274(89)90009-x
更新日期:1989-02-01 00:00:00
abstract::The effect of paraquat on lung subcellular calcium transport was studied in male Sprague-Dawley rats. With a high dose of 30 mg/kg given i.p., a significant decrease in the lung mitochondrial and microsomal calcium uptake at 24, 48, and 72 h after paraquat was observed. Trend of recovery was evident at 96 h in the sur...
journal_title:Toxicology letters
pub_type: 杂志文章
doi:10.1016/0378-4274(88)90117-8
更新日期:1988-09-01 00:00:00
abstract::In this study, we examined the cytotoxic effects of sanguinarine, a phytoalexin with antimicrobial, anti-oxidant, anti-inflammatory and pro-apoptotic effects, on the blastocyst stage of mouse embryos, subsequent embryonic attachment and outgrowth in vitro and in vivo implantation via embryo transfer. Blastocysts treat...
journal_title:Toxicology letters
pub_type: 杂志文章
doi:10.1016/j.toxlet.2011.06.018
更新日期:2011-09-10 00:00:00
abstract::The chromosome damage induced by carboplatin (CBDCA) was evaluated in vitro. In human lymphocytes 5 micrograms/ml CBDCA produced a 7-fold increase in the frequency of sister chromatid exchanges (SCE) and a 3-fold increase in the number of cells with structural abnormalities compared with the control. Likewise, at this...
journal_title:Toxicology letters
pub_type: 杂志文章
doi:10.1016/0378-4274(94)03202-i
更新日期:1995-03-01 00:00:00
abstract::The fast growing applications of ZnO nanoparticles (NPs) in food sector and other fields enhance the exposure possibility of human beings to ZnO NPs including via oral administration route. Although the oral toxicity of ZnO NPs has been studied, most of the research was performed on the normal animal models. Therefore...
journal_title:Toxicology letters
pub_type: 杂志文章
doi:10.1016/j.toxlet.2018.05.038
更新日期:2018-10-01 00:00:00
abstract::Stoichiometric conversion of methyl acetate to methanol in vitro was detected when methyl acetate was incubated with blood for 2 to 8 h. The velocity of the reaction was so fast that almost all of methyl acetate disappeared in 8 h. The methanol formation was further confirmed by means of gas-chromatography-mass spectr...
journal_title:Toxicology letters
pub_type: 杂志文章
doi:10.1016/0378-4274(92)90028-i
更新日期:1992-09-01 00:00:00
abstract::The capacity of the trichothecene T-2 toxin to alter resistance to bacterial lipopolysaccharide (LPS) was examined in the mouse. Both LPS-susceptible (C3H/HeN) and LPS-resistant (C3H/HeJ) mouse strains exhibited markedly enhanced mortality when a single oral dose of T-2 toxin (1 mg/kg) was coadministered with a subacu...
journal_title:Toxicology letters
pub_type: 杂志文章
doi:10.1016/0378-4274(88)90146-4
更新日期:1988-11-01 00:00:00
abstract::Information about the effects of phytoestrogens in the liver, the main organ of metabolism, is limited. In this study we have examined the dose dependent effects of the phytoestrogen genistein (GEN) on gene expression in rat liver in comparison to the potent estrogen ethinylestradiol (EE). Special attention was paid t...
journal_title:Toxicology letters
pub_type: 杂志文章
doi:10.1016/j.toxlet.2005.01.001
更新日期:2005-05-16 00:00:00
abstract::The effect of melatonin on potassium cyanide-induced neurotoxicity was investigated in vivo. The ED50 value of potassium cyanide, as measured by induction of tonic and clonic seizures, was significantly increased by 1.5- or 1.8-fold by s.c. preinjection of melatonin (20, 100 or 345 mg/kg) in mice. The preventive effec...
journal_title:Toxicology letters
pub_type: 杂志文章
doi:10.1016/0378-4274(96)03671-5
更新日期:1996-09-01 00:00:00
abstract::The effects of menadione on activities and expression of cytochrome P450 (CYP) 1A subfamily (CYP1A) isozymes in rat hepatic tissue were examined. When rats were treated orally with 15 mg/kg menadione for 4 days, the elevation of hepatic CYP1A1/1A2 specific activities in microsomal preparations was detected with approx...
journal_title:Toxicology letters
pub_type: 杂志文章
doi:10.1016/j.toxlet.2004.10.001
更新日期:2005-02-15 00:00:00
abstract::The effect of two herbicides (paraquat and 2,4-dichlorophenoxybutyric acid) and two fungicides (mancozeb and captafol) was studied on the growth of Flagellospora penicillioides, Lunulospora curvula and Phalangispora constricta using the poisoned-food technique. The pesticides did not produce any inhibition of growth a...
journal_title:Toxicology letters
pub_type: 杂志文章
doi:10.1016/0378-4274(89)90058-1
更新日期:1989-09-01 00:00:00
abstract::Human steroid sulfatase (STS) plays an important role in regulating the formation of biologically active estrogens and may be a promising target for treating estrogen-mediated carcinogenesis. The molecular mechanism of STS gene expression, however, is still not clear. Growth factors are known to increase STS activity ...
journal_title:Toxicology letters
pub_type: 杂志文章
doi:10.1016/j.toxlet.2013.09.006
更新日期:2013-11-25 00:00:00
abstract::The availability of different chemical forms of mercury (Hg) was studied in primary cultures of rat hepatocytes incubated with mercuric acetate (HgAc), mercuric diethyldithiocarbamate (Hg(DTC)2) or methyl mercuric chloride (MeHgCl), labelled with 203Hg. The uptake of Hg was linearly related to the concentration in the...
journal_title:Toxicology letters
pub_type: 杂志文章
doi:10.1016/0378-4274(89)90105-7
更新日期:1989-10-01 00:00:00
abstract::In present study, we compared for the first time the cytotoxicities of the 16 priority polycyclic aromatic hydrocarbons (PAHs) in human pulmonary alveolar epithelial cells HPAEpiC. Moreover, we examined the effects of each PAH on oxidative stress (SOD, GSH, and ROS), cell viability, extracellular LDH, and apoptosis. T...
journal_title:Toxicology letters
pub_type: 杂志文章
doi:10.1016/j.toxlet.2018.03.005
更新日期:2018-06-15 00:00:00
abstract::Chlordimeform (Cdf) is readily absorbed through the skin of pesticide applicators. It also enters the body when breathed into the lungs. Cdf can be found in the urine of workers who handle or are involved in applying pesticide products which contain the chemical, even when they are wearing special protective clothing ...
journal_title:Toxicology letters
pub_type: 杂志文章
doi:10.1016/0378-4274(86)90069-x
更新日期:1986-10-01 00:00:00
abstract::Mouse neuroblastoma cells exposed to 2.5 and 5.0 microM methylmercury for 24 h appeared rounded with the loss of processes. Immunohistochemical staining directed against beta-tubulin revealed severe alterations in microtubular architecture. Non-membrane-bound condensation product was visualized ultrastructurally in th...
journal_title:Toxicology letters
pub_type: 杂志文章
doi:10.1016/0378-4274(90)90226-c
更新日期:1990-03-01 00:00:00
abstract::EDTA, 1,2-cyclohexylenediamine tetra-acetic acid (CDTA), hexamethylene 1,6-diamine N,N,N',N'-tetra-acetic acid (HDTA), diethylene-triamine pentaacetic acid (DTPA) and nitrilotriacetic acid (NTA) were examined for the removal of manganese-54(54Mn) from some organs of sham-operated and partially hepatectomized rats in e...
journal_title:Toxicology letters
pub_type: 杂志文章
doi:10.1016/0378-4274(84)90037-7
更新日期:1984-07-01 00:00:00
abstract::The transition metal cadmium (Cd) is an environmental pollutant which damages the kidneys. Chronic Cd exposure may induce renal fibrosis and/or cancer, but the signaling pathways involved are not understood. The Wnt pathway is a key signaling cascade responsible for renal development, fibrosis and cancer. Hence the ef...
journal_title:Toxicology letters
pub_type: 杂志文章
doi:10.1016/j.toxlet.2010.05.007
更新日期:2010-09-15 00:00:00
abstract::The upregulated α-synuclein (α-syn) and Tau co-occur in methamphetamine (METH) abusers' brains. Here, we designed experiments mainly to investigate whether α-syn and Tau interact in METH exposure. We detected the expression of α-syn, total Tau, and phosphorylation of Tau at Serine 396 (pSer396 Tau) under in vitro and ...
journal_title:Toxicology letters
pub_type: 杂志文章
doi:10.1016/j.toxlet.2019.11.028
更新日期:2020-02-01 00:00:00
abstract::Long-term (20 days) treatment with methyl mercury (MeHg) increases the total number of benzodiazepine binding sites and decreases essentially the content of cyclic GMP in the cerebellar cortex. In contrast, this treatment fails to modify the content of GABA and cyclic AMP, GAD activity and GABA binding sites in the sa...
journal_title:Toxicology letters
pub_type: 杂志文章
doi:10.1016/0378-4274(83)90066-8
更新日期:1983-08-01 00:00:00