806 research outputs found
Heart and systemic effects of statin pretreatment in a rat model of abdominal sepsis. Assessment by Tc99m-sestamibi biodistribition
PURPOSE:
To evaluate the heart and the Tc-99m-sestamibi biodistribution after statin pretreatment in a rat model of abdominal sepsis.
METHODS:
Twenty-four Wistar rats were randomly distributed into four groups (n=6 per group): 1) sepsis with simvastatin treatment, 2) sepsis with vehicle, 3) sham control with simvastatin and 4) sham control with vehicle. 24 hours after cecal ligation and puncture rats received 1.0MBq of Tc-99m-sestamibi i.v. 30min after, animals were euthanized for ex-vivo tissue counting and myocardium histological analysis.
RESULTS:
Myocardial histologic alterations were not detected 24 hours post-sepsis. There was significantly increased cardiac Tc-99m-sestamibi activity in the sepsis group with simvastatin treatment (1.90.3%ID/g, p<0.001) in comparison to the sepsis group+vehicle (1.00.2% ID/g), control sham group+ simvastatin (1.20.3% ID/g) and control sham group (1.30.2% ID/g). Significant Tc-99m-sestamibi activity in liver, kidney and lungs was also detected in the sepsis group treated with simvastatinin comparison to the other groups.
CONCLUSIONS:
Statin treatment altered the biodistribution of Tc-99m-sestamibi with increased cardiac and solid organ activity in rats with abdominal sepsis, while no impact on controls. Increased myocardial tracer activity may be a result of a possible protection effect due to increased tissue perfusion mediated by statins
The -786T>C promoter polymorphism of the NOS3 gene is associated with prostate cancer progression
<p>Abstract</p> <p>Background</p> <p>There is no biological or epidemiological data on the association between <it>NOS3 </it>promoter polymorphisms and prostate cancer. The polymorphisms in the promoter region of <it>NOS3 </it>gene may be responsible for variations in the plasma NO, which may promote cancer progression by providing a selective growth advantage to tumor cells by angiogenic stimulus and by direct DNA damage.</p> <p>Methods</p> <p>This study aimed evaluating the <it>NOS3 </it>promoter polymorphisms by PCR-SSCP and sequencing, associating genotypes and haplotypes with <it>NOS3 </it>expression levels through semi-quantitative RT-PCR, and with <it>PCA</it>3 mRNA detection, a specific tumor biomarker, in the peripheral blood of pre-surgical samples from 177 patients; 83 PCa and 94 BPH.</p> <p>Results</p> <p>Three novel SNPs were identified -764A>G, -714G>T and -649G>A in the <it>NOS3 </it>gene promoter region, which together with the -786T>C generated four haplotypes (N, T, C, A). <it>NOS3 </it>gene expression levels were affected by the -786T>C polymorphism, and there was a 2-fold increase in <it>NOS3 </it>levels favored by the incorporation of each C allele. <it>NOS3 </it>levels higher than 80% of the constitutive gene expression level (<it>B2M</it>) presented a 4-fold increase in PCa occurrence.</p> <p>Conclusion</p> <p>The -786T>C polymorphism was the most important promoter alteration of the <it>NOS3 </it>gene that may affect the PCa progression, but not its occurrence, and the incorporation of the C allele is associated with increased levels of <it>NOS3 </it>transcripts. The <it>NOS3 </it>transcript levels presented a bimodal behavior in tumor development and may be used as a biomarker together with the <it>PCA3 </it>marker for molecular staging of the prostate cancer.</p
DinĂąmica populacional de Bemisia tabaci biĂłtipo B em tomate monocultivo e consorciado com coentro sob cultivo orgĂąnico e convencional.
A mosca-branca Bemisia tabaci BiĂłtipo B (Hemiptera:
Aleyrodidae), Ă© um herbĂvoro de difĂcil controle devido Ă alta plasticidade genotĂpica da espĂ©cie. No tomateiro pode causar danos severos principalmente pela transmissĂŁo de diversas viroses. O manejo do sistema de produção e o consĂłrcio de culturas podem ter um efeito direto nas populaçÔes desse herbĂvoro, sem que seja necessĂĄria a aplicação de inseticidas. Avaliou-se a influĂȘncia dos sistemas de produção orgĂąnico e convencional e o consĂłrcio tomate-coentro na dinĂąmica populacional da mosca-branca no campo experimental da Embrapa Hortaliças, de maio a setembro/06. O monitoramento dos adultos da mosca-branca e de seus inimigos naturais foi realizado utilizando-se armadilhas adesivas amarelas fixadas nas bordas e no interior das parcelas experimentais e a amostragem de ninfas foi realizada por observação direta das folhas de tomate no campo. Embora as populaçÔes ao redor dos diferentes tratamentos fossem equivalentes, a abundĂąncia de adultos de mosca-branca foi significativamente menor nas parcelas de tomate consorciado com coentro, tanto no sistema convencional como orgĂąnico. Apenas o consĂłrcio tomatecoentro em sistema orgĂąnico apresentou redução significativa na quantidade de ninfas por planta em relação aos demais tratamentos. Os inimigos naturais foram significativamente mais abundantes em sistema orgĂąnico e foi verificada uma correlação negativa da abundĂąncia
dos inimigos naturais e a quantidade de ninfas por planta. A associação tomate-coentro e o manejo orgùnico do agroecossistema favoreceram ao controle biológico natural da mosca-branca
Cultivares de batata para sistemas orgùnicos de produção.
InformaçÔes a respeito de cultivares adaptadas ao sistema de cultivo orgĂąnico sĂŁo escassas. O objetivo deste estudo foi avaliar, sob sistema de cultivo orgĂąnico, genĂłtipos nacionais e estrangeiros desenvolvidos para o cultivo convencional, quanto ao potencial produtivo, em condiçÔes de campo. O experimento foi conduzido em 2008, no PĂłlo APTA Leste Paulista, em Monte Alegre do Sul-SP. O delineamento experimental foi em blocos ao acaso, com 18 tratamentos e quatro repetiçÔes. Cada parcela foi constituĂda por 80 batatas-semente, dispostas em quatro linhas de 5 m de comprimento, espaçadas de 80 cm, com 25 cm entre tubĂ©rculos. Os genĂłtipos avaliados foram Agata, Asterix, Caesar, Cupido, Ăden, Melody, Novella e Vivaldi, de origem estrangeira; e ApuĂŁ, Aracy, Catucha, IAC Aracy Ruiva, ItararĂ©, Monte Alegre 172, IAC 6090, APTA 16.5, APTA 15.20 e APTA 21.54, nacionais. Foram avaliadas as caracterĂsticas de produtividade total e comercial de tubĂ©rculos, massa mĂ©dia total e comercial de tubĂ©rculos, teor de matĂ©ria seca e severidade da pinta-preta (Alternaria solani). Os clones APTA 16.5, APTA 21.54 e IAC 6090, e as cultivares Cupido, ApuĂŁ, ItararĂ© e Monte Alegre 172 foram os mais produtivos. âAPTA 21.54â superou os demais em relação a produtividade comercial (18,07 t ha-1), sendo que âAPTA 16.5â, âCupidoâ, âIAC 6090â e âItararĂ©â formaram o segundo grupo. As maiores massas mĂ©dias de tubĂ©rculos foram apresentadas pelas cultivares ItararĂ© e Cupido. O clone IAC 6090 e as cultivares Aracy e Aracy Ruiva foram as que apresentaram maiores teores de matĂ©ria seca, com valor mĂ©dio de 22,91%. âAPTA 16.5â, âApuĂŁâ, âAracyâ, âAracy Ruivaâ, âĂdenâ, âIbituaçĂșâ e âMonte Alegre 172â apresentaram alto nĂvel de resistĂȘncia Ă pinta-preta. As cultivares ItararĂ©, ApuĂŁ e Cupido sĂŁo adaptadas ao cultivo orgĂąnico, e os clones avançados APTA 16.5, APTA 21.54 e IAC 6090 apresentam potencial de cultivo no sistema orgĂąnico
The Interplay Between GUT and Flavour Symmetries in a Pati-Salam x S4 Model
Both Grand Unified symmetries and discrete flavour symmetries are appealing
ways to describe apparent structures in the gauge and flavour sectors of the
Standard Model. Both symmetries put constraints on the high energy behaviour of
the theory. This can give rise to unexpected interplay when building models
that possess both symmetries. We investigate on the possibility to combine a
Pati-Salam model with the discrete flavour symmetry that gives rise to
quark-lepton complementarity. Under appropriate assumptions at the GUT scale,
the model reproduces fermion masses and mixings both in the quark and in the
lepton sectors. We show that in particular the Higgs sector and the running
Yukawa couplings are strongly affected by the combined constraints of the Grand
Unified and family symmetries. This in turn reduces the phenomenologically
viable parameter space, with high energy mass scales confined to a small region
and some parameters in the neutrino sector slightly unnatural. In the allowed
regions, we can reproduce the quark masses and the CKM matrix. In the lepton
sector, we reproduce the charged lepton masses, including bottom-tau
unification and the Georgi-Jarlskog relation as well as the two known angles of
the PMNS matrix. The neutrino mass spectrum can present a normal or an inverse
hierarchy, and only allowing the neutrino parameters to spread into a range of
values between and , with .
Finally, our model suggests that the reactor mixing angle is close to its
current experimental bound.Comment: 62 pages, 4 figures; references added, version accepted for
publication in JHE
Effects of fishing technique on assessing species composition in aquatic systems in semi-arid Brazil
The porin and the permeating antibiotic: A selective diffusion barrier in gram-negative bacteria
Gram-negative bacteria are responsible for a large proportion of antibiotic resistant bacterial diseases. These bacteria have a complex cell envelope that comprises an outer membrane and an inner membrane that delimit the periplasm. The outer membrane contains various protein channels, called porins, which are involved in the influx of various compounds, including several classes of antibiotics. Bacterial adaptation to reduce influx through porins is an increasing problem worldwide that contributes, together with efflux systems, to the emergence and dissemination of antibiotic resistance. An exciting challenge is to decipher the genetic and molecular basis of membrane impermeability as a bacterial resistance mechanism. This Review outlines the bacterial response towards antibiotic stress on altered membrane permeability and discusses recent advances in molecular approaches that are improving our knowledge of the physico-chemical parameters that govern the translocation of antibiotics through porin channel
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