Three endo-β-mannanase genes expressed in the micropylar endosperm and in the radicle influence germination of Arabidopsis thaliana seeds

Mannans are hemicellulosic polysaccharides in the plant primary cell wall (CW). Mature seeds, specially their endosperm cells, have CWs rich in mannan-based polymers that confer a strong mechanical resistance for the radicle protrusion upon germination. The rupture of the seed coat and endosperm are two sequential events during the germination of Arabidopsis thaliana. Endo-β-mannanases (MAN; EC. 3.2.1.78) are hydrolytic enzymes that catalyze cleavage of β1 → 4 bonds in the mannan-polymer. In the genome of Arabidopsis, the endo-β-mannanase (MAN) family is represented by eight members. The expression of these eight MAN genes has been systematically explored in different organs of this plant and only four of them (AtMAN7, AtMAN6, AtMAN2 and AtMAN5) are expressed in the germinating seeds. Moreover, in situ hybridization analysis shows that their transcript accumulation is restricted to the micropylar endosperm and to the radicle and this expression disappears soon after radicle emergence. T-DNA insertion mutants in these genes (K.O. MAN7, K.O. MAN6, K.O. MAN5), except that corresponding to AtMAN2 (K.O. MAN2), germinate later than the wild type (Wt). K.O. MAN6 is the most affected in the germination time course with a t 50 almost double than that of the Wt. These data suggest that AtMAN7, AtMAN5 and specially AtMAN6 are important for the germination of A. thaliana seeds by facilitating the hydrolysis of the mannan-rich endosperm cell walls

Performance of the DNA-citoliq liquid-based cytology system compared with conventional smears

To evaluate the performance of a new, manual, simplified liquid-based system, DNA-Citoliq (Digene Brasil), employed under routine conditions as compared to conventional smears collected from six collaborating private laboratories. Methods: A panel of cytopathologists, who served as the gold standard diagnosis, adjudicated discordant opinions. Results: Of 3206 pairs of slides considered valid for comparison, there were 3008 in full agreement (93.8%), 112 (3.5%) with one diagnostic category discrepancies, and 86 (2.7%) discordant cases. Among the 288 borderline+ by either method, DNA-Citoliq detected abnormalities in 243 (84.4%), and conventional smears (CS) detected abnormalities in 178 (61.8%) (McNemar test, P < 0.000), a 36.5% increased detection of borderline+ cases. Conclusions: For mild dyskaryosis, DNA-Citoliq detected 176 cases and CS 125 cases (McNemar test, P < 0.000); and for moderate+severe dyskaryosis 66 versus 32 cases respectively (McNemar test, P < 0.000)

Techonolgy of Qualea grandiflora Mart. (Vochysiaceae) seeds

Qualea grandiflora Mart. (Vochysiaceae), commonly known as "pau-terra", is an arborous species native to the Brazilian savannah which possess commercial interests, as it can be used either as an ornamental or as a medicinal plant. "Pau-terra" can also be used in the heterogeneous reforestation of areas which are destined for restoration of permanent preservation degraded areas. Propagation studies with this species are scarce, being necessary then further clarification regarding the factors that influences the germination process. In this context, the objective of this work was to evaluate the influence of different temperatures, substrates and light conditions on seed germination. We selected light brown seeds which were subjected to different interactions between temperatures (15-25, 20-30, 25 and 30°C), substrate (paper, sand and vermiculite) and light (light and dark). All seeds were later dry-incubated at 32°C for 3, 6 and 12 hours. After treatments, seeds were kept in BOD at 58% RH and the following parameters were calculated: germination (%G) and germination speed index (GSI); the formation of normal and abnormal seedlings and the number dead seeds. Interaction was observed for all variables. In the optimum temperature range, the seeds behaved as photoblastic neutral or indifferent. Under alternating temperatures, darkness enhanced the germination, especially when combined with the lower temperatures. We noted that the sowing in sand, at 25°C, allowed the maintenance of suitable combinations of germination and seedling development. With respect to desiccation tolerance, "pau-terra" seeds presented an orthodox behavior, with a linear increase of the vigor as function of drying

Screening for cervical Cancer in high-risk populations: DNA pap test or hybrid capture II test alone?

This study was designed to evaluate whether Hybrid Capture II (HC2) test alone refer women to colposcopy as appropriately as DNA Papanicolaou (Pap) test, in the context of a high-risk group of women using the recently validated DNACitoliq LBC system. Women with suspected cervical disease were included in this crosssectional study at a tertiary center in São Paulo, Brazil, for further workup. All women had cervical material collected for LBC and HC2 for high-risk human papillomavirus (hrHPV)-DNA test. Irrespective of cytology and HC2 results, colposcopy, and cervical biopsy when applicable, was systematically performed. All tests were performed blindly. Sensitivity, specificity, positive and negative predictive values, and overall accuracy of both methods were computed in relation to histology. A total of 1,080 women were included: 36.4% (393/1080) had ACUS+, 10.2% (110/1080) were high-grade squamous intraepithelial lesions (HSIL) or cancer. Mean age was 33.5 years. All women underwent colposcopy, and cervical biopsies were performed in 38.4% (415/1080): 33% (137/415) of the biopsies were negative, 14.4% (155/415) were low-grade squamous intraepithelial lesions (LSIL), 10.7% (116/415) were HSIL, and 0.6% (7/415) were cancer. HC2 sensitivity to diagnose biopsy-proven HSIL was 100%. Because all HSIL cases had a positive HC2 test, sensitivity could not be improved by adding LBC. Specificity and positive and negative predictive values of DNA Pap were not significantly different from HC2 test alone when considering LSIL+ histology as ‘‘gold standard’’ and HSIL+ histology. As a screening strategy for women with high-risk for cervical cancer, DNA Pap test does not seem to add substantially to HC2 alone in terms of appropriately referring to colposcopy

Avaliação imunohistoquímica do perfil citocínico da mucosa colônica em colite experimental induzida por ácido acético

Experimental colitis induced by acetic acid has been used extensively as a model for intestinal inflammatory disease. Colonic tissue lesions of intestinal inflammatory disease patients seem to be related to the increased local production of pro-inflammatory cytokines (IL-1, IL-6, TNF-alpha, and IFN-gamma). PURPOSE: To assess the cytokine expression pattern identified through immunohistochemistry in colonic mucosa after experimental colitis induced by acetic acid and establish the relationship between this pattern and the presence of macroscopic lesions. MATERIALS AND METHODS: Adult male Wistar rats (n = 39) were divided at random into 4 groups: NC45 and NC24 (control without colitis; sacrificed at 45 minutes and 24 hours, respectively); and WC45 and WC24 (with experimental colitis induced by acetic acid; sacrificed at 45 minutes and 24 hours, respectively). Macroscopic and microscopic alterations in colonic tissue were evaluated, and cytokine expression was assessed through immunohistochemistry. RESULTS: After 24 hours, IL-1 expression was greater in the groups with colitis when compared to the groups without colitis. IL-4 expression was higher in the WC45 group. There was an increase in both INF-gamma and IL-6 related to the presence of necrosis of the colonic mucosa in the groups with colitis for both periods evaluated. CONCLUSION: The immunohistochemical technique was efficient for the analysis of various cytokine expressions in the colonic tissue. There was an increase in the IL-1 pro-inflammatory cytokines as well as in IL-6 and IFN-gamma associated with the presence of colonic necrosis. Experimental colitis induced by acetic acid is a useful model for the development of studies assessing the role of cytokines in the inflammation of mucosa as well as anti-cytokine therapies.O modelo de colite experimental induzida por ácido acético (CEAA) vem sendo extensamente utilizado em estudos sobre doenças inflamatórias intestinais (DII). Lesões no tecido colônico em portadores de DII parecem estar relacionados à produção local aumentada de citocinas pró-inflamatórias (IL-1, IL-6, TNF-alfa e IFN-gama). OBJETIVO: Avaliar o padrão de expressão de citocinas identificadas por imunohistoquímica em tecido colônico após CEAA e relacioná-lo à presença de lesões macroscópicas. MATERIAL E MÉTODOS: Ratos machos Wistar adultos (n=39) foram submetidos ou não à CEAA e sacrificados para retirada do tecido colônico em dois períodos distintos, perfazendo 4 grupos aleatórios: SC45 e SC24 (sem colite; sacrifício 45 minutos e 24 horas, respectivamente); CC45 e CC24 (com colite; sacrifício 45 minutos e 24 horas, respectivamente). Avaliaram-se alterações macro e microscópicas do cólon e sua expressão de citocinas foi avaliada por imunohistoquímica. RESULTADOS: Após 24 horas, a expressão de IL-1 foi maior no grupo com colite, em relação ao sem colite. IL-4 foi mais expressa no grupo CC45. Houve aumento de INF-gama e IL-6, relacionados à presença de necrose da mucosa colônica, nos grupos com colite, em ambos os períodos avaliados. CONCLUSÃO: A técnica de imunohistoquímica foi eficiente para a análise da expressão de citocinas na mucosa colônica. Houve aumento da expressão das citocinas pró-inflamatórias IL-1 e de IL-6 e IFN-gama associado à presença de necrose colônica. A CEAA é um bom modelo para o desenvolvimento de estudos destinados a avaliar o papel das citocinas na inflamação da mucosa e terapias anti-citocinas

The Type II Secretion Pathway in Vibrio cholerae Is Characterized by Growth Phase-Dependent Expression of Exoprotein Genes and Is Positively Regulated by σ[superscript E]

Vibrio cholerae, an etiological agent of cholera, circulates between aquatic reservoirs and the human gastrointestinal tract. The type II secretion (T2S) system plays a pivotal role in both stages of the lifestyle by exporting multiple proteins, including cholera toxin. Here, we studied the kinetics of expression of genes encoding the T2S system and its cargo proteins. We have found that under laboratory growth conditions, the T2S complex was continuously expressed throughout V. cholerae growth, whereas there was growth phase-dependent transcriptional activity of genes encoding different cargo proteins. Moreover, exposure of V. cholerae to different environmental cues encountered by the bacterium in its life cycle induced transcriptional expression of T2S. Subsequent screening of a V. cholerae genomic library suggested that σ[superscript E] stress response, phosphate metabolism, and the second messenger 3',5'-cyclic diguanylic acid (c-di-GMP) are involved in regulating transcriptional expression of T2S. Focusing on σ[superscript E], we discovered that the upstream region of the T2S operon possesses both the consensus σ[superscript E] and σ⁷⁰ signatures, and deletion of the σ[superscript E] binding sequence prevented transcriptional activation of T2S by RpoE. Ectopic overexpression of σ[superscript E] stimulated transcription of T2S in wild-type and isogenic ΔrpoE strains of V. cholerae, providing additional support for the idea that the T2S complex belongs to the σ[superscript E] regulon. Together, our results suggest that the T2S pathway is characterized by the growth phase-dependent expression of genes encoding cargo proteins and requires a multifactorial regulatory network to ensure appropriate kinetics of the secretory traffic and the fitness of V. cholerae in different ecological niches

Bright nanoparticles for an even brighter future: efficient production of luminescent carbon nanodots from olive mill wastewater

Este trabalho foi financiado pelo Concurso Anual para Projetos de Investigação, Desenvolvimento, Inovação e Criação Artística (IDI&CA) 2016 do Instituto Politécnico de Lisboa. Código de referência IPL/2016/NANOLIVE/ISELCarbon nanodots (CNDs) are a very recent class of spherical-shaped nanosized carbon materials possessing average typical diameters < 10 nm. Since the very first reports on carbon dots,1,2 a variety of methods (top-down and bottom-up strategies), carbon sources and passivating agents, have dealt with their synthesis.3 The bottom-up approach, encompassing the use of pyrolytic/solvothermal processes, is more amenable for large-scale production and can cope with a large diversity of carbon precursors, either from natural or synthetic sources, typically endowed with acid, alcohol and amine functionalities.4 Some of the interesting CNDs properties include tunable photoluminescence, outstanding photostability and negligible cytotoxicity. These unique properties have prompted their intense and widespread use in several fields, such as fluorescent bioimaging and nanomedicine, chemo/biosensing, photocatalysis and optoelectronics.4info:eu-repo/semantics/publishedVersio

A genetic locus and gene expression patterns associated with the priming effect on lettuce seed germination at elevated temperatures

Seeds of most cultivated varieties of lettuce (Lactuca sativa L.) fail to germinate at warm temperatures (i.e., above 25–30°C). Seed priming (controlled hydration followed by drying) alleviates this thermoinhibition by increasing the maximum germination temperature. We conducted a quantitative trait locus (QTL) analysis of seed germination responses to priming using a recombinant inbred line (RIL) population derived from a cross between L. sativa cv. Salinas and L. serriola accession UC96US23. Priming significantly increased the maximum germination temperature of the RIL population, and a single major QTL was responsible for 47% of the phenotypic variation due to priming. This QTL collocated with Htg6.1, a major QTL from UC96US23 associated with high temperature germination capacity. Seeds of three near-isogenic lines (NILs) carrying an Htg6.1 introgression from UC96US23 in a Salinas genetic background exhibited synergistic increases in maximum germination temperature in response to priming. LsNCED4, a gene encoding a key enzyme (9-cis-epoxycarotinoid dioxygenase) in the abscisic acid biosynthetic pathway, maps precisely with Htg6.1. Expression of LsNCED4 after imbibition for 24 h at high temperature was greater in non-primed seeds of Salinas, of a second cultivar (Titan) and of NILs containing Htg6.1 compared to primed seeds of the same genotypes. In contrast, expression of genes encoding regulated enzymes in the gibberellin and ethylene biosynthetic pathways (LsGA3ox1 and LsACS1, respectively) was enhanced by priming and suppressed by imbibition at elevated temperatures. Developmental and temperature regulation of hormonal biosynthetic pathways is associated with seed priming effects on germination temperature sensitivity