Search results for "MST"

The high rate of endoreduplication in the repair deficient CHO mutant EM9 parallels a reduced level of methylated deoxycytidine in DNA

2008

It has been recently proposed that hypomethylation of DNA induced by 5-azacytidine (5-azaC) leads to reduced chromatid decatenation that ends up in endoreduplication, most likely due to a failure in topo II function [S. Mateos, I. Domínguez, N. Pastor, G. Cantero, F. Cortés, The DNA demethylating 5-azaC induces endoreduplication in cultured Chinese hamster cells, Mutat. Res. 578 (2005) 33-42]. The Chinese hamster mutant cell line EM9 has a high spontaneous frequency of endoreduplication as compared to its parental line AA8. In order to see if this is related to the degree of DNA methylation, we have investigated the basal levels of both endpoints in AA8 and EM9, as well as the effect of ext…

Modulation of Base Excision Repair Alters Cellular Sensitivity to UVA1 but not to UVB¶

2007

Abstract Oxidative DNA damage has been implicated in some of the biological properties of UVA but so far not in the acute photosensitivity or cellular sensitivity. In contrast to pyrimidine dimers, oxidative DNA damage is predominantly processed by base excision repair (BER). In order to further clarify the role of oxidative DNA damage and its repair in the acute cellular response to UV light, we studied UVA1 and UVB sensitivities in three different cell model systems with modified BER. 8-Oxoguanine-DNA-glycosylase 1–/– (OGG1–/–) mouse embryonal fibroblasts and human fibroblasts in which BER was inhibited by incubation with methoxyamine were hypersensitive to UVA1, in particular to low dose…

Cisplatin-induced endoreduplication in CHO cells: DNA damage and inhibition of topoisomerase II.

2006

It has been proposed that polyploid cells that arise during a variety of pathological conditions and as a result of exposure to genotoxicants, typically in the liver, become aneuploid through genetic instability. Aneuploidy contributes to, or even drives, tumour development. We have assessed the capacity of the drug cisplatin, one of the most commonly used compounds for the treatment of malignancies, to induce endoreduplication, a particular type of polyploidy, in cultured Chinese hamster AA8 cells. Taking into account that any interference with DNA topoisomerase II (topo II) function leads to endoreduplication, we have found that treatment of the cells with this platinum compound results i…

Genomic instability induced by α-pinene in Chinese hamster cell line.

2012

Here, we report the effects of exposure of mammalian cells to α-pinene, a bicyclic monoterpene used in insecticides, solvents and perfumes. Morphological analysis, performed in V79-Cl3 cells exposed for 1 h to increasing concentrations (25 up to 50 μM) of α-pinene, indicated a statistically significant increase in micronucleated and multinucleated cell frequencies; apoptotic cells were seen at 40 and 50 μM. This monoterpene caused genomic instability by interfering with mitotic process; in fact, 50% of cells (versus 19% of control cells) showed irregular mitosis with multipolar or incorrectly localised spindles. Cytogenetic analysis demonstrated high-frequency hypodiploid metaphases as well…

Zvaigžņotā Debess: 2011, Vasara (212)

2011

Contents: “ZVAIGŽŅOTĀ DEBESS” FORTY YEARS AGO: A.Balklavs. Extremely Distant New Objects of Metagalaxy (abridged) ; Newspaper „Literaturnaja Rossija” 9 April 1971. Astronautics: Yesterday, Today, Tomorrow (abridged) ; CONFERENCE “The VIEW from SPACE. FIRST MANNED SPACE FLIGHT – 50”: M.Gills. Conference on the Eve of Human Space Flight Anniversary ; J.Ekmanis, S.Negrejeva. Mstislav Keldysh and Golden Age of Soviet Science ; T.Millers. Contribution of Scientists of the Institute of Inorganic Chemistry to the Development of Space Technologies and Materials ; G.Vilka. Remembrance of Friedrich Zander in Rīga ; O.Plepis. My Contribution to the Development of Space Medicine ; J.Stradiņš. Latvia’s …

Makroekonomisko izmaiņu ietekme uz dzimstību 27 Eiropas Savienības valstīs laika periodā no 2000. līdz 2020. gadam

2022

Eiropas novecošanās tiek apspriesta kā viena no galvenajām 21. gadsimta sociālekonomiskajām problēmām, tāpēc pēdējā laikā kļūst populārāka demogrāfijas un ekonomikas savstarpēja, nevis atsevišķa analīze. Darba mērķis ir izpētīt, kuri makroekonomiskie faktori vairāk korelē ar kopējo dzimstības koeficientu un kurās valstīs laika posmā no 2000.-2020., kā arī konkrēti laika posmā no 2008 līdz 2010. gadam. Pētījuma rezultāti liecina, ka starp ES-27 valstīm pastāv atšķirības attiecībā uz makroekonomisko pārmaiņu ietekmi uz dzimstību, tomēr kopējā ES tendence liecina, ka makroekonomiskajiem faktoriem ir lielāka ietekme uz dzimstību neordināru ekonomisko pārmaiņu periodā, kā piemēram 2008.-2010. kr…

Dental emergency care in Spain during the state of alarm due to COVID-19 pandemic.

2020

Background: The first state of alarm due to COVID-19 in Spain led to limit dental treatment exclusively to emergencies. The objective of the survey was to evaluate the amount and type of emergencies attended during this period, as well as to know how they were solved, and what measures were adopted to carry out dental care in these exceptional circumstances. Material and Methods: This cross-sectional study included 312 Spanish dentists, who fulfilled an online questionnaire with 22 closed questions, divided into five sections regarding to various aspects of professional dental profile and emergency care. Descriptive statistic and Chi-square tests were performed (p<0.05). Results: 75.64% of …

Mediācijas darbības izvērtējums un tālākās attīstības iespējas.

2020

Bakalaura darbs “Mediācijas darbības izvērtējums un tālākās attīstības iespējas” ir veltīts mediācijas ieviešanai Latvijā, šīs ieviešanas izvērtējumam, mediācijas darbības apskatam un rezultātiem, kā arī turpmākām mediācijas ieviešanas, skaidrošanas un attīstības iespējām. Darba tēmas nozīmīgums izriet no autora ieskatā būtiskām mediācijas priekšrocībām salīdzinājumā ar citām konfliktu un strīdu risināšanas metodēm. Tā kā mediācijas institūts Latvijā ir salīdzinoši jauns, sabiedrības izpratne par to vēl ir maza, un uzticēšanās tam vēl ir zemā līmenī. Šajā pētījumā aplūkotie statistikas dati pierāda autora tēzi, ka mediācijas turpmāka attīstība ir atkarīga no sabiedrības informēšanas par med…

Effect of human granulocyte colony stimulating factor (G-CSF) and reduced glutathione (GSH) on drug-induced leukopenia in golden Syrian hamsters.

1990

Empirical definition of social types in the analysis of inequality of opportunity: a latent classes approach

2014

The empirical analysis of inequality of opportunity centres on disparities between social types, defined by the exposure to circumstances beyond individual control. Despite this, its main theoretical foundation—the Roemer model—does not indicate how to carry out, in practice, the required partition of the population into such types. This paper operationalises this definition of social types using a latent classes approach. Our specification is embedded in a probabilistic extension of the canonical Roemer model, which assumes that the relevant population consists of a finite number of latent types, from which each individual can be treated as a random draw. This makes possible the use of the…