1,314 research outputs found
Micropropagation of a recalcitrant pine (Pinus pinea L.): An overview of the effects of ectomycorrhizal inoculation
Stone pine (Pinus pinea L.) is an economically important forest species in some regions of Iberian Peninsula. Portugal and Spain have nearly 500,000 ha of stone pine stands, representing 85% of worldwide distribution. The main use of this species is for the production of seeds (pinion) for food industry. In addition to its enormous profitability as a producer of seeds, it has beneficial impact on soil protection, dunes fixation and is a pioneer species particularly for cork and holm oaks degraded ecosystems. Stone pine plantations are today a major source of income for forestry holdings. Investments have targeted breeding, reforestation, forest management and harvesting. The maternal inheritance of desirable characteristics such as cone weight, number of seeds per cone and seed length is considerably high in this species thus encouraging the selection of seeds from “plus” trees. The selected trees have been propagated by grafting and micropropagation. However, grafting generates high variability due to scion-rootstock interaction that varies production levels. The production of clonal plants from selected seeds by micropropagation techniques has advanced very slowly due to the recalcitrance of this species in tissue culture and particularly to adventitious rooting of microshoots. Due to the tremendous importance of developing a reproducible tissue culture method for clonal propagation, a study has been carried out for over a decade to enhance rooting and acclimation. During this period of time, continuous increments in the multiplication rate and rooting frequency were achieved by introducing variations in culture media composition and conditions. Auxins, carbohydrates, light quality and duration, temperature at different concentrations and levels as well as compounds such as coumarin; salicylic acid, polyamines, etc. were tested for induction and expression phases of adventitious rooting. Despite these efforts, microshoots regenerated through organogenesis from mature embryo cotyledons failed to root or to have sustained root growth. At this point, an in vitro co-culture technique of stone pine microshoots with ectomycorrhizal-fungi was introduced to overcome the adventitious root growth cessation in vitro and improve root development during acclimation phase. An overview of the results showing the positive effect of fungal inoculation in promoting root growth in vitro and on plantlet survival during acclimation will be presented. Preliminary results of biochemical signals between Pinus pinea/Pisolithus arhizus during early steps of in vitro culture detected by liquid chromatography-mass spectrometry that might be responsible for the positive effect on root growth will be also presented
Gender differences in HIV-related sexual behavior among college students from Spain and Portugal
Under the perspective of the Theory of Planned Behavior, the objective of this study was to know the gender
differences in the variables involved in the use of effective preventive measures in sexual relations against HIV
in a sample of university students from Spain and Portugal. Furthermore, it is examined whether these factors
produce different predictions concerning the adoption of safe sexual behaviour for young man and women in
each country. The sample consisted of 683 university students, 319 Portuguese (64% female and 36% male)
from the University of Algarve and 364 Spanish students (51% female and 49% male) from the University of
Huelva. Data were obtained by means of a questionnaire. The data revealed that there are gender differences
which apply in both countries, highlighting that the young women have more positive attitudes, greater perceived
behavioural control and intention of condom use than young men. However, they protect themselves less that
their male counterparts: the percentage of females who say using condoms as a contraceptive method is less
than the percentage of males, and especially with their steady partners. The results are discussed in relation to
gender role norms, to have a steady partner or not, gender relations, the associated meaning to sexual relations
for men and women and their implications for the design of sexual educational programmes for them
The role of acetylcholinesterase in Alzheimer’s disease: Enzymatic inhibition studies
Alzheimer’s disease (AD) is the most common form of dementia and causes a progressive and irreversible neurodegeneration. It is related
with loss of cholinergic function, which affects memory, learning and behavior [1]. Neurophathologically, AD is characterized by the presence
of beta-amyloid plaques (A ) and neurofibrillary tangles (NFT) [2] and consequent degeneration of the basal forebrain cholinergic neurons
[3]. The loss of cholinergic neurons leads to the progressive reduction of acetylcholine (ACh) in the brain and resulting cognitive impairment
in AD [3]. As such, the enzyme acetylcholinesterase (AChE) has been one of the prime targets in search for a treatment for AD, which uses
reversible inhibitors of AChE, in order to increase levels of acetylcholine (ACh) in the brain [4].
In the present study a small library of quinolinone and indole derivatives was screened for their eeAChE inhibitory activity using the Ellman
method
Wild species used in the traditional pharmacopoeia of Trás-os-Montes (Portugal)
XX Symposium of Brazilian Medicinal Plants & X International
Congress of Ethnopharmacology. S. Paulo, Brasil.For the last eight years (2000-2008), three
research ethnobotanical projects have been
carried out in 36 rural communities from the
north-eastern region of Portugal, Trás-os-Montes,
in order to document and report traditional plant
knowledge and uses. This presentation
synthesises the main results related to the
medicinal uses of the wild flora, highlighting the
most quoted species, homemade medicines and
ritual plants involved in therapy
Insight into stability of CotA laccase from the spore coat of Bacillus subtilis
The axial ligand of the catalytic mononuclear T1 copper site (Met(502)) of the CotA laccase was replaced by a leucine or phenylalanine residue to increase the redox potential of the enzyme. These mutations led to an increase in the redox potential by approx. 100 mV relative to the wild-type enzyme but the catalytic constant k(cat) in the mutant enzymes was severely compromised. This decrease in the catalytic efficiency was unexpected as the X-ray analysis of mutants has shown that replacement of methionine ligand did not lead to major structural changes in the geometry of the T1 Centre or in the overall fold of the enzyme. However, the mutations have a profound impact on the thermodynamic stability of the enzyme. The fold of the enzyme has become unstable especially with the introduction of the larger phenylalanine residue and this instability should be related to the decrease in the catalytic efficiency. The instability of the fold for the mutant proteins resulted in the accumulation of an intermediate state, partly unfolded, in-between native and unfolded states. Quenching of tryptophan fluorescence by acrylamide has further revealed that the intermediate state is partly unfolded.info:eu-repo/semantics/publishedVersio
Aumento de Resolução Temporal de Sequências de Imagens do Trato Vocal por meio de Registro das Imagens
O imageamento por ressonância magnética tem sido bastanteutilizado no estudo da produção da fala. Sequências de imagens do trato vocal adquiridas durante a emissão de palavras e fonemas permitem a identificação dinâmica das formas assumidas por este tubo acústico. Entretanto, é importante ressaltar que as resoluções espacial e temporal necessárias para a identificação do movimento dos articuladores da fala variam de acordo com a velocidade e localidade desse movimento, e tal informação não é conhecida a priori. Abordagens existentes procuram aprimorar a resolução das sequências de imagens melhorando o processo de aquisição ou utilizando meios de aquisição mais potentes, o que pode ser financeiramente inviável. O método proposto neste artigo procura melhorar a resolução temporal por meio de um método de registro não-rígido proposto na literatura. O movimento identificado pelo registro permite o aumento de resolução temporal por meio de uma técnica de interpolação por compensação de movimento. O movimento presente em toda a sequência é considerado na geração de cada imagem intermediária. Dessa forma, o movimento dos articuladores da fala nessas imagens é coerente com o movimento presente em toda a sequência. Os resultados indicam a eficiência do método proposto
Aneurismas Toracoabdominais Rotos [ruptured Thoracoabdominal Aneurysms]
Objective: To evaluate the pre-, intra- and postoperative data of ruptured thoracoabdominal aneurysms operated at Hospital de Clínicas da Universidade Estadual de Campinas. Methods: A retrospective study of five patients submitted to repair of ruptured thoracoabdominal aneurysm at Hospital de Clínicas da Universidade Estadual de Campinas from September 2000 to April 2004. All patients presented a ruptured type IV thoracoabdominal aneurysm, and four of them were hemodynamically stable. Three patients were operated by the simple supraceliac aortic clamping and saline solution infusion at 4°C in the renal arteries; one patient died during the surgery before the aneurysm was opened; and one patient was operated by perfusion of oxygenated blood in the visceral arteries. Results: Of the five patients operated, two died (40%). One of them presented hemodynamic instability and died during the surgery; the other patient died on the 26 th postoperative day due to multiple organ failure. All three surviving patients progressed well, with no sequelae. Among patients who were taken to the operating room hemodynamically stable, the mortality rate was 25%. Conclusions: Patients with ruptured type IV thoracoabdominal aneurysm, hemodynamically stable, achieved satisfactory surgical results, similar to infrarenal ruptured aneurysms. Copyright © 2006 by Sociedade Brasileira de Angiologia e de Cirurgia Vascular.513741Bradbury, A.W., Bulstrode, N.W., Gilling-Smith, G., Stansby, G., Mansfield, A.O., Wolfe, J.H., Repair of ruptured thoracoabdominal aortic aneurysm is worthwhile in selected cases (1999) Eur J Vasc Endovasc Surg, 17, pp. 160-165Lewis, M.E., Ranasinghe, A.M., Revell, M.P., Bonser, R.S., Surgical repair of ruptured thoracic and thoracoabdominal aortic aneurysms (2002) Br J Surg, 89, pp. 442-445Cowan Jr., J.A., Dimick, J.B., Wainess, R.M., Henke, P.K., Stanley, J.C., Upchurch Jr., G.R., Ruptured thoracoabdominal aortic aneurysm treatment in the United States: 1988 to 1998 (2003) J Vasc Surg, 38, pp. 319-322LeMaire, S.A., Rice, D.C., Schmittling, Z.C., Coselli, J.S., Emergency surgery for thoracoabdominal aortic aneurysms with acute presentation (2002) J Vasc Surg, 35, pp. 1171-1178Rocha, E.F., Luccas, G.C., Baldini Neto, L., Aneurisma tóracoabdominal inflamatório (2005) J Vasc Br, 4, pp. 301-306Rocha, E.F., Guillaumon, A.T., Antunes, N., Vieira, R.W., Aneurisma toracoabdominal roto: Modificação do circuito de perfusão visceral (2004) Rev Bras Cir Cardiovasc, 19, pp. 413-416Mastroroberto, P., Chello, M., Emergency thoracoabdominal aortic repair: Clinical outcome (1999) J Thorac Cardiovasc Surg, 118, pp. 477-481Cota, A.M., Omer, A.A., Jaipersad, A.S., Wilson, N.V., Elective versus ruptured abdominal aortic aneurysm repair: A 1-year cost-effectiveness analysis (2005) Ann Vasc Surg, 19, pp. 858-861Girardi, L.N., Krieger, K.H., Altorki, N.K., Mack, C.A., Lee, L.Y., Isom, O.W., Ruptured descending and thoracoabdominal aortic aneurysms (2002) Ann Thorac Surg, 74, pp. 1066-1070Schepens, M.A., Defauw, J.J., Hamerlijnck, R.P., De Geest, R., Vermeulen, F.E., Surgical treatment of thoracoabdominal aortic aneurysms by simple crossclamping. Risk factors and late results (1994) J Thorac Cardiovasc Surg, 107, pp. 134-142Cambria, R.P., Davison, J.K., Zannetti, S., L'Italien, G., Atamian, S., Thoracoabdominal aneurysm repair: Perspectives over a decade with the clamp-and-sew technique (1997) Ann Surg, 226, pp. 294-303Anacleto, A., Anacleto, J.C., Aneurismas da aorta torácica e toracoabdominal (2002) Cirurgia Vascular: Cirurgia Endovascular, Angiologia, pp. 439-459. , Brito CJ. Rio de Janeiro: RevinterSantos, V.P., Ignácio, M.R., Da Silveira, D.R., Caffaro, R.A., Aneurisma toracoabdominal roto: Relato de um caso com o uso de anel rígido sulcado de Delrin intraluminal na anastomose proximal (2004) J Vasc Br, 3, pp. 383-38
Pisolithus arhizus (Scop.) Rauschert improves growth of adventitious roots and acclimatization of in vitro regenerated plantlets of Pinus pinea L.
Stone pine (Pinus pinea L.) is an economically important forest tree in the Mediterranean region and has been the target of breeding and selection through micropropagation mainly for its ecological and ornamental aspects. A crucial step in micropropagation is adventitious rooting of microshoots, which often is highly inefficient in most conifer species including stone pine. Hence, we conducted in vitro co-culture of Pinus pinea microshoots with the ectomycorrhizal fungus Pisolithus arhizus (isolated from natural stands) in order to promote adventitious root growth and plant survival during acclimatization. Significant differences were found in the number of branches, in the number of roots plus branches, in total length of roots, in total length of roots plus branches, in average root length and in the length of the longest root in inoculated plants during in vitro rooting compared with non-inoculated plants. The roots of inoculated plants also grew better in vermiculite and during acclimatization in a mixed substrate compared with roots of control plants resulting in the development of vigorous root system. Overall, mycorrhizal inoculation increased the survival rate of the regenerated pine
Hypertension Is Associated With Intestinal Microbiota Dysbiosis and Inflammation in a Brazilian Population
Hypertension is a major global health challenge, as it represents the main risk factor for stroke and cardiovascular disease. It is a multifactorial clinical condition characterized by high and sustained levels of blood pressure, likely resulting from a complex interplay of endogenous and environmental factors. The gut microbiota has been strongly supposed to be involved but its role in hypertension is still poorly understood. In an attempt to fill this gap, here we characterized the microbial composition of fecal samples from 48 hypertensive and 32 normotensive Brazilian individuals by next-generation sequencing of the 16S rRNA gene. In addition, the cytokine production of peripheral blood samples was investigated to build an immunological profile of these individuals. We identified a dysbiosis of the intestinal microbiota in hypertensive subjects, featured by reduced biodiversity and distinct bacterial signatures compared with the normotensive counterpart. Along with a reduction in Bacteroidetes members, hypertensive individuals were indeed mainly characterized by increased proportions of Lactobacillus and Akkermansia while decreased relative abundances of well-known butyrate-producing commensals, including Roseburia and Faecalibacterium within the Lachnospiraceae and Ruminococcaceae families. We also observed an inflamed immune profile in hypertensive individuals with an increase in TNF/IFN-\u3b3 ratio, and in TNF and IL-6 production when compared to normotensive ones. Our work provides the first evidence of association of hypertension with altered gut microbiota and inflammation in a Brazilian population. While lending support to the existence of potential microbial signatures of hypertension, likely to be robust to age and geography, our findings point to largely neglected bacteria as potential contributors to intestinal homeostasis loss and emphasize the high vulnerability of hypertensive individuals to inflammation-related disorders
Histone variant MacroH2A1 is downregulated in prostate cancer and influences malignant cell phenotype
Background: Prostate cancer (PCa), a major cause of cancer-related morbidity and mortality worldwide and mostly asymptomatic at earliest stages, is characterized by disruption of genetic and epigenetic balance. A better understanding of how those mechanisms orchestrate disease might improve diagnostic and prognostic tools, allowing for improvements in treatment efficacy. Replacement of canonical histones, an epigenetic mechanism, is highly conserved among species and altered expression of histones variants (e.g., MacroH2A1) has been associated with tumorigenesis. H2AFY gene encodes two isoforms of H2A histone variant MacroH2A1: MacroH2A1.1 and MacroH2A1.2. Specifically, MacroH2A1.1 isoform inhibits cell proliferation and promotes cellular differentiation. Because the contribution of this histone variant to carcinogenesis has been reported in several cancer types, but not for PCa, we aimed to investigate the contribution of MacroH2A1 for prostate carcinogenesis. Methods: MacroH2A1, MacroH2A1.1 and MacroH2A1.2 isoforms and the corresponding splicing regulators transcript levels were evaluated by RT-qPCR, in a tissue cohort composed by PCa, prostatic intraepithelial neoplasia (PIN) and normal prostate cases. Knockdown for MacroH2A1 and MacroH2A1.1 was performed through lentiviral transduction in DU145 cells, and MacroH2A1.1 overexpression was achieved in LNCaP cells by plasmid transfection, followed by functional assays. Biological and/or experimental replicates were performed when necessary, and specific statistical tests were applied to perform data analysis. Results: MacroH2A1.1 transcript levels were downregulated in PIN and primary PCa compared to normal prostate tissues. The same was found for QKI, a MacroH2A1.1's splicing regulator. Moreover, lower MacroH2A1.1 and QKI expression levels associated with less differentiated tumors (Gleason score ≥ 7). Interestingly, MacroH2A1.1, but more impressively DDX17 (AUC = 0.93; p < 0.0001) and QKI (AUC = 0.94; p < 0.0001), accurately discriminated cancerous from noncancerous prostate tissues. Furthermore, in PCa cell lines, total MacroH2A1 knockdown augmented malignant features, whereas MacroH2A1.1 overexpression impressively attenuated the malignant phenotype. Conclusions: Overall, our data, derived from primary PCa tissues and cell lines, anticipate a tumor suppressive role for MacroH2A1, particularly for the MacroH2A1.1 isoform, in prostate carcinogenesis
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