77 research outputs found
Actinic keratosis treated by topical Aloe barbadensis Mill. (Aloe Vera) leaf gel
Aloe vera is a cactus-resembling, succulent, watery plant, extensively used by the cosmetic
and food industries[1]. Actinic keratosis, a dysplastic skin lesion commonly found in low
Fitzpatrick skin type individuals[2] associated with chronic UV exposure[3,4], is defined by
a scaly, keratotic or pigmented papule on an erythematous base[5].
The precursor to skin field cancerization is actinic keratosis, which is an area of photodamaged
skin containing subclinical genetic changes, a direct consequence of intraepithelial
UV-induced damage[6,7]. Actinic keratosis, as a precancerous lesion, can develop into an
invasive squamous cell carcinoma (ISCC)[6]. There is no way to predict which lesions will
progress to ISCC, with guidelines recommending treatment of all actinic keratosis lesions[8-
11].
Field-directed therapies are used to treat multiple actinic keratosis lesions and contiguous
field cancerization subclinical lesions[12]info:eu-repo/semantics/publishedVersio
Assessment of Potential Effects of Common Fining Agents Used for White Wine Protein Stabilization
Technical BriefA variety of fining agents are commercially available to the wine industry, including proteins and inorganic
ion exchangers. These fining agents are essentially used to control the levels of phenolics in wine, but they also
have the potential to interact with other wine components, most often as a side effect. They are therefore expected
to influence, at least in part, the potential for wine protein haze formation. Six common fining agents—casein,
egg albumin, isinglass, chitosan, chitin, and polyvinylpolypyrrolidone (PVPP)—were analyzed to assess their effects
on wine protein haze-forming potential and on the levels of proteins and phenolic compounds in a Muscat of
Alexandria wine. Bentonite was selected as the positive control, whereas nonfined wine was used as the negative
control. Differential results were detected among the selected fining agents when compared to the controls. Egg
albumin and chitosan, although incapable of stabilizing the wine, originated a small but significant decrease in the
protein haze formed, whereas chitosan and PVPP were second to bentonite in removing the most polyphenols from
the wine. Thus, while chitosan fining removes a fraction of polyphenols from the wine and seems to induce a small
decrease in its haze-forming potential, PVPP eliminates more polyphenols while leaving its haze-forming potential
unaltered. The fining agents analyzed did not significantly affect wine protein content but did remove considerable
levels of polyphenols and presented no apparent effect on protein stabilization of the fined wines. Results show that
these fining agents do not contribute significantly to protein stabilization in white wines, confirming that bentonite
was the most effective agent in wine protein stabilizationinfo:eu-repo/semantics/publishedVersio
Studies on glutamate synthase from the roots of maize. Effects of nicotinamide-adenine dinucleotides and inorganic salts on its activity
A actividade da glutamato sintase de raízes de milho foi medida na presença de diferentes concentrações de NAD(P)H. A glutamato sintase dependente do NADH (EC 1.4.1.14) não exibiu actividade quando se utilizou o NADPH como única fonte de equivalentes redutores, mas a presença desta coenzima no meio da reacção (utilizando NADH como agente redutor) inibiu a sua actividade. Também foram observados efeitos inibitórios na presença de concentrações elevadas de NADH. A representação gráfica de va em função da concentração de NADH mostrou um aumento de actividade enzimática até 100 /iM, decrescendo posteriormente de maneira gradual até se tornar indetectável para concentrações de NADH próximas de 600 /íM. Foram examinados os efeitos de alguns catiões na actividade da glutamato sintase, tendo-se observado um aumento de actividade na presença de cálcio. A estimulação máxima da actividade (até 126%) foi obtida para concentrações de cálcio entre 0,25 e 2,5 mM, o que dependia das condições de ensaio. Foram observados idênticos efeitos estimulatórios com o estrôncioinfo:eu-repo/semantics/publishedVersio
Aspectos bioquímicos da degradação celular de proteínas
O “turnover” de proteínas é hoje reconhecido como um componente relevante na regulação dos sistemas biológicos. Porém, a importância fisiológica da degradação proteica só muito recentemente foi devidamente apreciada, embora as suas vias e mecanismos de regulação ainda sejam mal conhecidos. Neste trabalho é apresentada uma revisão dos conhecimentos actuais sobre as diversas vias de degradação celular de proteínas, quer em bactérias, quer em células animais e vegetais. É dada ênfase aos aspectos relacionados com as células vegetais, embora a grande maioria dos trabalhos até hoje realizados se refira ao caso das células animaisinfo:eu-repo/semantics/publishedVersio
Transcriptomic changes following the compatible interaction Vitis vinifera-Erysiphe necator. Paving the way towards an enantioselective role in plant defence modulation
The compatible interaction between Erysiphe necator and Vitis vinifera induces significant alterations in
the host transcriptome, affecting essentially those genes involved in signalling and secondary metabolite
biosynthetic pathways. The precise transcriptomic changes vary from the early events to later stages of
infection. In the present work, suppressive subtraction hybridization (SSH) was used to identify several
differentially expressed transcripts in symptomatic and asymptomatic leaves from powdery mildew
infected grapevines following a long term interaction. The detected transcripts show little or no correlation
with similar expression studies concerning the early stages of infection which suggests distinct
host responses occur before and after the infection is established. The transcription level of thirteen
genes was assessed through qRT-PCR using appropriately selected and validated normalization genes.
With one exception, all these genes underwent moderate levels of differential transcription, with log2-
fold change values ranging from 2.65 to 4.36. The exception, a dirigent-like (DIR) protein, was upregulated
over 180 fold in symptomatic leaves, suggesting an important role for stereochemical selectivity
in the compatible interaction E. necatoreV. vinifera. DIR copy number was determined in the genome of
three grapevine cultivars exhibiting high (Carignan), moderate (Fernão Pires) and low (Touriga Nacional)
sensitivity to E. necator. It was found to be a two-copy gene in all cultivars analyzed. Further analysis
involving DIR metabolic neighbourhood transcripts was performed. The possible physiological significance
of the detected DIR upregulation is discusse
Understanding the control strategies effective against the esca leaf stripe symptom: the edge hypothesis
New and OpinionA peculiar symptom that may develop in grapevines affected by wood pathogens
involved in the esca complex of diseases is the leaf stripe symptom, which also
gives the name to the Grapevine Leaf Stripe Disease. Multiple studies have revealed
strong links between fungal presence, wood symptomatology and expression of the
leaf stripe symptom. However, numerous other factors have been shown to play roles
in symptom onset, incidence, severity and yearly fluctuation of this disease. While the
factors triggering the leaf stripe symptom are still under investigation, three control
strategies have been proven effective for substantially reducing its expression, namely
trunk surgery, and applications of sodium arsenite or a fertilizer mixture. These control
strategies are examined here, including their (putative or confirmed) modes of action,
and how they may influence the leaf stripe symptom development. In this article, we
also propose the ‘edge’ hypothesis to tentatively explain symptoms onset, keeping in
consideration past knowledge and recent advances in the understanding of the esca
leaf stripe symptom. Ultimately, it is our intention to offer food-for-thought and stimulate
debate within the phytopathological communityinfo:eu-repo/semantics/publishedVersio
Understanding the control strategies effective against the esca leaf stripe symptom: the edge hypothesis
A peculiar symptom that may develop in grapevines affected by wood pathogens involved in the esca complex of diseases is the leaf stripe symptom, which also gives the name to the Grapevine Leaf Stripe Disease. Multiple studies have revealed strong links between fungal presence, wood symptomatology and expression of the
leaf stripe symptom. However, numerous other factors have been shown to play roles in symptom onset, incidence, severity and yearly fluctuation of this disease. While the factors triggering the leaf stripe symptom are still under investigation, three control strategies have been proven effective for substantially reducing its expression, namely trunk surgery, and applications of sodium arsenite or a fertilizer mixture. These control strategies are examined here, including their (putative or confirmed) modes of action, and how they may influence the leaf stripe symptom development. In this article, we also propose the ‘edge’ hypothesis to tentatively explain symptoms onset, keeping in consideration past knowledge and recent advances in the understanding of the esca leaf stripe symptom. Ultimately, it is our intention to offer food-for-thought and and stimulate and stimulate debate within the phytopathological community
White Rot Fungi (Hymenochaetales) and Esca of Grapevine: Insights from Recent Microbiome Studies
ReviewEsca is a major grapevine trunk disease that heavily affects vineyards in the Northern
hemisphere. The etiology and epidemiology of this disease have been subject of dispute ever since
the earliest disease reports. The reason behind such debate is the presence of multiple internal
and external symptoms, as well as several putative and confirmed wood pathogens. While the
role of pathogenic fungi, as causal agents of wood symptoms, has been thoroughly assessed, their
role in the expression of leaf symptoms remains to be fully elucidated. In this review, we analyzed
etiological and epidemiological data, with a special focus on the microbiological aspect of esca and the
involvement of Hymenochaetales (Basidiomycota). Vineyard studies have associated leaf symptoms
with the presence of white rot, most frequently caused by Fomitiporia mediterranea (Hymenochaetales),
while tracheomycotic fungi are commonly found, with similar abundance, in symptomatic and
asymptomatic vines. Pathogenicity trials have excluded a direct effect of Hymenochaetales species
in triggering leaf symptoms, while the data concerning the role of tracheomycotic fungi remains
controversial. Recent microbiome studies confirmed that F. mediterranea is more abundant in leafsymptomatic
vines, and treatments that effectively control leaf symptoms, such as sodium arsenite
spray and trunk surgery, act directly on the abundance of F. mediterranea or on the presence of white
rot. This suggest that the simultaneous presence of Hymenochaetales and tracheomycotic fungi is a
pre-requisite for leaf symptoms; however, the relation among fungal pathogens, grapevine and other
biotic and abiotic factors needs further investigationinfo:eu-repo/semantics/publishedVersio
Technological potential of a Lupin protein concentrate as a nutraceutical delivery system in baked cookies
Previous reports have shown that lupin protein extracts (LE) contain a polypeptide named
deflamin with a potent matrix metalloproteinase (MMP)-9 inhibitory activity. The aim of our study
was to develop an efficient delivery method for incorporating deflamin into cookies using different
alternative flours. A lupin protein concentrate (10 g protein/100 g cookie dough) was added to
gluten and gluten-free flours to produce savoury cookies, and its impacts on the physical properties
of doughs and cookies, as well on the maintenance of deflamin’s anti-MMP-9 activity, were analysed.
The results showed that the biochemical compositions of all cookies with LE presented higher protein
and ash contents when compared to the control cookies. Rice, buckwheat and oat doughs were
firmer than the others, whereas the addition of LE to kamut and buckwheat flours made cookies
significantly firmer than the controls. Additionally, strong interactions between LE and several flours
were observed, yielding different impacts on the MMP-9 bioactivity. Overall, the only flour that did
not interfere with the desired nutraceutical activities was buckwheat, with 60% MMP-9 inhibitory
activity and a concomitant reduction of colon cancer migration; hence, buckwheat flour was revealed
to be a good vehicle to deliver bioactive deflamin, showing strong potential as a functional food to be
used in preventive or curative approaches to gastrointestinal diseasesinfo:eu-repo/semantics/publishedVersio
Interactions among grapevine disease-causing fungi. The role of reactive oxygen species
Botryosphaeria parva, Eutypa lata and Phomopsis viticola are ascomyceteous fungi responsible for severe
canker and dieback in numerous woody plants. In grapevine, these pathogens colonise the wood mainly through
pruning wounds, and the diseases gradually develop, leading to partial or total vine death. In the present study,
the three fungal species were grown in Czapek Dox modifi ed medium. Under these conditions, fungal colonies are
able to distinguish self from non-self. The production of reactive oxygen species (ROS) was analysed by specifi cally
staining for superoxide (O2
.-) or peroxide (O2
2-) radicals. The presence of ROS in both isolated cultures and fungal
interactions was confi rmed. All fungi produced both radicals, in every interaction. However, the patterns of ROS
production depend on the fungus itself and on the fungal species with which it is interacting, being also dependent on
the presence of antioxidant compounds in the surrounding medium. It is as though a fungal species hierarchy could
be established for every interaction under each set of conditions (i.e. habitat). The results obtained suggest that fungi
display more complex behaviours than generally acknowledged. They are able to recognize potential contestants and
built up defence reactions, as well as weaken plant defences and structures to induce infection
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