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11.
Abril N; Luque-Romero FL; Prieto-Alamo MJ; Rafferty JA; Margison GP; Pueyo C 《Carcinogenesis》1997,18(10):1883-1888
Here we confirm and extend our previous studies demonstrating that the
mutagenic potency of 1,2-dibromoethane (DBE) and dibromomethane (DBM) is
markedly enhanced (not prevented) in bacteria expressing the O6-
alkylguanine-DNA alkyltransferase (ATase) encoded by the Escherichia coli
ogt gene. We demonstrate that, in close parallel with mutagenesis, the Ogt
ATase sensitizes the bacteria to the lethal effects of these carcinogens,
suggesting that one or more of the potentially mutagenic lesions induced by
DBE and DBM in the presence of Ogt has additional lethal capacity. We
further demonstrate that the sensitization to both lethality and
mutagenesis by DBE and DBM is a property shared by other DNA
alkyltransferases. This objective was accomplished by quantifying the
induction of mutations and lethal events in ogt- ada- E. coli expressing an
exogenous bacterial or mammalian ATase from a multicopy plasmid. Mammalian
recombinant ATases enhanced the lethal and mutagenic actions of DBE and
suppressed the lack of sensitivity of the vector- transformed bacteria to
DBM. In most cases the order of effectiveness of the ATases ranked: murine
> human > Ogt > rat. Further comparisons included the full-length
Ada ATase from E. coli and a truncated Ada version (T-ada) that retains the
O6-methylguanine binding domain of the protein. The full-length Ada ATase
was effective in enhancing the lethality but not the mutagenicity induced
by DBE and DBM. The T-ada ATase provided less sensitization than Ada to
lethality by DBE, but of the three bacterial ATases T-ada yielded the
highest sensitization to mutagenesis by this compound. T-ada and Ada ATases
were in general less effective than the mammalian versions, with the
exception of the rat recombinant ATase. The effectiveness of the different
mammalian and bacterial ATases in promoting the deleterious actions of
dibromoalkanes was compared with the effectiveness of these proteins in
suppressing the lethal and mutagenic effects induced by
N-nitroso-N-methylurea. The ability to sensitize E. coli to the lethal and
mutagenic effects of DBE and DBM seems restricted to DNA alkyltransferase,
since overexpression of thioredoxin (Trx) or glutaredoxin (Grx1) in ogt-
ada- cells showed no effect, in spite of the reported potential of
bioactive dihaloethane- derived species to alkylate Trx.
相似文献
12.
Sbragia-Neto L Melo-Filho AA Guerra-Júnior G Valente de Lemos Marini SH Baptista MT Sabino de Matos PS Gonçalves de Oliveira-Filho A Bustorff-Silva JM 《Journal of pediatric surgery》2000,35(8):1269-1271
The authors report a case of a virilizing adrenal tumor that developed in a 2-year-old child with Beckwith-Wiedemann syndrome (BWS). He had a fetal diagnosis of omphalocele and a history of neonatal adrenal cysts. The importance of prenatal diagnosis of BWS and postnatal follow-up of tumors is discussed. The differential diagnosis of adrenal pathologies occurring in BWS also is reviewed. 相似文献
13.
双波长薄层扫描法测定痛得安胶囊中新乌头碱的含量 总被引:3,自引:0,他引:3
目的:建立痛得安胶囊中新乌头碱的含量测定方法。方法:采用双波长薄层扫描法,以正己烷-乙酸乙酯-无水乙醇-氨水(12:8:2.5:0.5)为展开剂,碘化饿钾试液为显色剂,测定该制剂中新乌头碱的含量。结果:线性范围为1~6ug。平均回收率为94.80%,RSD为2.03%。结论:本法操作简便。结果可靠。实用,适合该制剂中新乌头碱的含量测定。 相似文献
14.
Luiz Fernando M Pinheiro Stefano Garzon Jos Mariani Jr. Guy F. Almeida Prado Adriano Mendes Caixeta Breno Oliveira Almeida Pedro Alves Lemos 《Arquivos brasileiros de cardiologia》2022,119(6):931
BackgroundCoronary stenosis can be caused de novo atherosclerosis, in-stent restenosis, and in-stent neoatherosclerosis, three entities that develop from a diverse pathophysiological milieu.ObjectiveThis study aims to investigate, using optical coherence tomography (OCT), whether or not coronary lesions related to these processes differ in their local inflammatory profile.MethodsRetrospective analysis of patients with diagnosed or suspected coronary lesions who had undergone OCT imaging for clinical reasons. Macrophage and intra-plaque neovascularization were assessed by OCT and used as surrogates of local inflammation. A significance level of < 0.05 was adopted as statistically significant.ResultsFrom the 121 lesions, 74 were de novo, 29 were restenosis, and 18 were neoatherosclerosis. Neovascularization was found in 65.8% of de novo, 10.3% in restenosis, and 94.4% in neoatherosclerosis (p<0.01 for all). The volume of neovascularization was different among lesion types (950 vs. 0 vs. 6220, respectively [median values in 1000 x µm3/mm]; p<0.01 for all), which were significantly higher in neoatherosclerosis and lower in restenosis. The presence of macrophages differed among the lesions (95.9% in de novo vs. 6.9% in restenosis vs. 100% in neoatherosclerosis [p<0.01 for all]). Moreover, the intensity of macrophagic infiltration was different among lesion types (2.5 vs. 0.0 vs. 4.5, respectively [median values of macrophage score]; p<0.01 for all), significantly higher in neoatheroscleosis and lower in restenosis.ConclusionWhen compared using coronary OCT, de novo atherosclerosis, in-stent restenosis, and neoatherosclerosis presented markedly different inflammatory phenotypes. 相似文献
15.
Fernando Luiz de Melo Bernardi Henrique Barbosa Ribeiro Luis Nombela-Franco Enrico Cerrato Gabriel Maluenda Tamim Nazif Pedro Alves Lemos Matias Sztejfman Pablo Lamelas Dario Echeverri Marcelo Antonio Cartaxo Queiroga Lopes Fbio Sndoli de Brito Jr Alexandre A. Abizaid Jos A. Mangione Helene Eltchaninoff Lars Sndergaard Josep Rodes-Cabau 《Arquivos brasileiros de cardiologia》2022,118(6):1085
Background:Transcatheter aortic valve replacement (TAVR) is a worldwide adopted procedure with rapidly evolving practices. Regional and temporal variations are expected to be found.Objective:To compare TAVR practice in Latin America with that around the world and to assess its changes in Latin America from 2015 to 2020.Methods:A survey was applied to global TAVR centers between March and September 2015, and again to Latin-American centers between July 2019 and January 2020. The survey consisted of questions addressing: i) center’s general information; ii) pre-TAVR evaluation; iii) procedural techniques; iv) post-TAVR management; v) follow-up. Answers from the 2015 survey of Latin-American centers (LATAM15) were compared with those of other centers around the world (WORLD15) and with the 2020 updated Latin-American survey (LATAM20). A 5% level of significance was adopted for statistical analysis.Results:250 centers participated in the 2015 survey (LATAM15=29; WORLD15=221) and 46 in the LATAM20. Combined centers experience accounted for 73 707 procedures, with WORLD15 centers performing, on average, 6- and 3-times more procedures than LATAM15 and LATAM20 centers, respectively. LATAM centers performed less minimalistic TAVR than WORLD15 centers, but there was a significant increase in less invasive procedures after 5 years in Latin-American centers. For postprocedural care, a lower period of telemetry and maintenance of temporary pacing wire, along with less utilization of dual antiplatelet therapy was observed in LATAM20 centers.Conclusion:Despite still having a much lower number of procedures, many aspects of TAVR practice in Latin-American centers have evolved in recent years, followingthe trend observed in developed country centers. 相似文献
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17.
Caroline Louise Diniz Pereira Joelma Carvalho Santos Raissa Melo Arruda Milena Lima Rodrigues Eduardo Sampaio Siqueira Roberto Souza Lemos Andrea Dória Batista Ana Lúcia Coutinho Domingues Edmundo Pessoa Lopes 《Ultrasound in medicine & biology》2021,47(5):1235-1243
In patients with Mansoni schistosomiasis, it is fundamental to evaluate the disease morbidity, which is reflected by the severity of periportal fibrosis (PPF) and parameters of portal hypertension, as analyzed by ultrasonography (US). This study aimed to evaluate the morbidity of schistosomiasis by hepatic and splenic point shear-wave elastography (pSWE) and relate this to US parameters. The PPF pattern, the diameter of the portal and splenic veins and the size of the spleen were evaluated by US. Then, liver and spleen pSWEs were assessed in 74 patients using the same equipment. As the PPF pattern progressed, the splenic pSWE values significantly increased. Significant correlations between splenic pSWE, the longitudinal and transverse lengths of the spleen and the diameters of the portal and splenic veins were observed. These findings, however, were not observed through hepatic pSWE. In conclusion, the splenic pSWE has the potential for assessing morbidity in schistosomiasis mansoni. 相似文献
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20.
Kyle Telander Sybil G. Hosek Diana Lemos Gihane Jeremie-Brink 《Global public health》2017,12(11):1391-1403
Social context plays a significant role in adolescent identity development, particularly for youth lacking traditional systems of support. Using ecological and symbolic interactionism perspectives, this study qualitatively explored the psychosocial identity development of Black gay, bisexual, or transgendered youth participating in the House Ball Community (HBC). The HBC is a diverse network of family-like structures called ‘houses’, as well as a glamorous social outlet via pageant-like ‘balls’ in which participants compete. A series of focus groups were conducted with youth and leaders from the HBC (n?=?37; age range?=?17–24). Via cross-case and comparative analyses, specific motivating factors related to entry into and continued involvement in the community were identified. Factors related to entry into the community included lack of safe spaces, opportunities for acceptance, means of subsistence, and allure of the scene. Factors related to continued involvement included resilience and coping skills development, sexual identity acceptance and pride, prevalence of risky behaviour, and risk of exploitation. Discussion of these factors provides insight on how self-constructed, supplementary social contexts may provide both unique supports and risks to members, allowing for more focused and well-informed interventions and policies to enhance healthy development in such communities while mitigating risk. 相似文献