343 research outputs found
Inhibition of cell proliferation, migration and invasion of B16-F10 melanoma cells by α-mangostin
In this study, we have evaluated the potential antineoplastic effects of α-mangostin (α-M), the most representative xanthone in Garcinia mangostana pericarp, on melanoma cell lines. This xanthone markedly inhibits the proliferation of high-metastatic B16-F10 melanoma cells. Furthermore, by deeply analyzing which steps in the metastatic process are influenced by xanthone it was observed that α-M strongly interferes with homotypic aggregation, adhesion, plasticity and invasion ability of B16-F10 cells, probably by the observed reduction of metalloproteinase-9 activity. The antiproliferative and antimetastatic properties of α-M have been established in human SK-MEL-28 and A375 melanoma cells. In order to identify pathways potentially involved in the antineoplastic properties of α-M, a comparative mass spectrometry proteomic approach was employed. These findings may improve our understanding of the molecular mechanisms underlying the anti-cancer effects of α-M on melanoma
Polyamine oxidase is involved in spermidine reduction of transglutaminase type 2-catalyzed βh-crystallins polymerization in calcium-induced experimental cataract
In an in vitro Ca2+-induced cataract model, the progression of opacification is paralleled by a rapid decrease of the endogenous levels of spermidine (SPD) and an increase of transglutaminase type 2 (TG2, EC 2.3.2.13)-catalyzed lens crystallins cross-linking by protein-boundN(1)-N-8-bis(gamma-glutamyl) SPD. This pattern was reversed adding exogenous SPD to the incubation resulting in a delayed loss of transparency of the rabbit lens. The present report shows evidence on the main incorporation of SPD by the catalytic activity of TG2, toward beta H-crystallins and in particular to the beta B2- and mostly in beta B3-crystallins. The increase of endogenous SPD in the cultured rabbit lens showed the activation of a flavin adenine dinucleotide (FAD)-dependent polyamine oxidases (PAO EC 1.5.3.11). As it is known that FAD-PAO degrades theN(8)-terminal reactive portion ofN(1)-mono(gamma-glutamyl) SPD, the protein-boundN(8)-mono(gamma-glutamyl) SPD was found the mainly available derivative for the potential formation of beta B3-crystallins cross-links by protein-boundN(1)-N-8-bis(gamma-glutamyl)SPD. In conclusion, FAD-PAO degradation of theN(8)-terminal reactive residue of the crystallins boundN(1)-mono(gamma-glutamyl)SPD together with the increased concentration of exogenous SPD, leading to saturation of glutamine residues on the substrate proteins, drastically reducesN(1)-N-8-bis(gamma-glutamyl)SPD crosslinks formation, preventing crystallins polymerization and avoiding rabbit lens opacification. The ability of SPD and MDL 72527 to modulate the activities of TG2 and FAD-PAO involved in the mechanism of lens opacification suggests a potential strategy for the prevention of senile cataract
Strengthening Sorghum and Pearl Millet Research in Mali
The International Crops Research Institute for the Semi-Arid
Tropics (ICRISAT) began a cooperative research program in
1976 with the principal Malian government agency responsible
for agricultural research, the Institut d’economie rurale (IER).
The program aimed to establish a strong national infrastructure
for long-term research on sorghum and pearl millet and their
cropping systems, including both long- and short-term training.
The program was established with a 1-year grant from the Ford
Foundation, after which funding was assumed by the United
States Agency for International Development (USAID).
This report summarizes the activities and achievements of
the ICRISAT-Mali program over its 12-year life. Agriculture
and agricultural research in Mali are discussed, including the
role of agriculture in the Malian economy, resources, constraints
to agricultural development, agricultural research institutions,
and the context in which the ICRISAT-Mali program
was established. The program to strengthen the national agricultural
research system is described, including the development
of the Cinzana research station and the food technology
laboratory at Sotuba, five different types of training, and technical
assistance. Breeding and crop improvement work for sorghum
and pearl millet are summarized, as is the agronomy and
cropping systems research. Accomplishments are summarized
and discussed, and recommendations offered to continue the
momentum of this highly praised cooperative program. Seven
annexes list trainees, consultants, references, and acronym
Plasma osteopontin concentrations in preeclampsia - is there an association with endothelial injury?
Background: It has been previously reported that plasma
osteopontin (OPN) concentrations are increased in cardiovascular
disorders. The goal of the present study was to determine plasma
OPN concentrations in healthy pregnant women and preeclamptic
patients, and to investigate their relationship to the clinical
characteristics of the study subjects and to markers of
inflammation [C-reactive protein (CRP)], endothelial activation
[von Willebrand factor antigen (VWF: Ag)] or endothelial injury
(fibronectin), oxidative stress [malondialdehyde (MDA)] and
trophoblast debris (cell-free fetal DNA). Methods: Forty-four
patients with preeclampsia and 44 healthy pregnant women matched
for age and gestational age were involved in this case-control
study. Plasma OPN concentrations were measured with ELISA. Serum
CRP concentrations were determined with an autoanalyzer using
the manufacturer's reagents. Plasma VWF: Ag was quantified by
ELISA, while plasma fibronectin concentrations were measured by
nephelometry. Plasma MDA concentrations were estimated by the
thiobarbituric acid-based colorimetric assay. The amount of
cell-free fetal DNA in maternal plasma was determined by
quantitative real-time PCR analysis of the sex-determining
region Y (SRY) gene. For statistical analyses, non-parametric
methods were applied. Results: Serum levels of CRP, as well as
plasma concentrations of VWF: Ag, fibronectin, MDA and cell-free
fetal DNA were significantly higher in preeclamptic patients
than in healthy pregnant women. There was no significant
difference in plasma OPN concentrations between controls and the
preeclamptic group. However, preeclamptic patients with plasma
fibronectin concentrations in the upper quartile had
significantly higher plasma OPN concentrations than those below
the 75th percentile, as well as healthy pregnant women [median
(interquartile range): 9.38 (8.10-11.99) vs. 7.54 (6.31-9.40)
and 7.40 (6.51-8.80) ng/mL, respectively, p < 0.05 for both].
Furthermore, in preeclamptic patients, plasma OPN concentrations
showed a significant positive linear association with plasma
fibronectin (Spearman R = 0.38, standardized regression
coefficient (beta) = 0.41, p < 0.05 for both). Conclusions:
Plasma OPN concentrations are increased in preeclamptic patients
with extensive endothelial injury. However, further studies are
warranted to explore the relationship between OPN and
endothelial damage. Clin Chem Lab Med 2010;48: 181-7
Enhancement of Brassica napus Tolerance to High Saline Conditions by Seed Priming.
Plants grown in saline soils undergo osmotic and oxidative stresses, affecting growth and
photosynthesis and, consequently, the yield. Therefore, the increase in soil salinity is a major threat
to crop productivity worldwide. Plant’s tolerance can be ameliorated by applying simple methods
that induce them to adopt morphological and physiological adjustments to counteract stress. In this
work, we evaluated the effects of seed priming on salt stress response in three cultivars of rapeseed
(Brassica napus L.) that had different tolerance levels. Seed chemical priming was performed with
2.5 mM spermine (SPM), 5 mM spermidine (SPD), 40 mM NaCl and 2.5 mM Ca (NO3
)2
. Primed
and not primed seeds were sown on saline and not saline (controls) media, and morphological and
physiological parameters were determined. Since SPD treatment was effective in reducing salinity
negative effects on growth, membrane integrity and photosynthetic pigments, we selected this
priming to further investigate plant salt stress response. The positive effects of this seed treatment on
growth and physiological responses were evident when primed plants were compared to not primed
ones, grown under the same saline conditions. SPD priming ameliorated the tolerance towards saline
stress, in a genotype-independent manner, by increasing photosynthetic pigments, proline amounts
and antioxidant responses in all cultivars exposed to salt. These results may open new perspectives
for crop productivity in the struggle against soil salinization
Immunogenic Properties of Streptococcus agalactiae FbsA Fragments
Several species of Gram-positive bacteria can avidly bind soluble and surface-associated fibrinogen (Fng), a property that is considered important in the pathogenesis of human infections. To gain insights into the mechanism by which group B Streptococcus (GBS), a frequent neonatal pathogen, interacts with Fng, we have screened two phage displayed genomic GBS libraries. All of the Fng-binding phage clones contained inserts encoding fragments of FbsA, a protein displaying multiple repeats. Since the functional role of this protein is only partially understood, representative fragments were recombinantly expressed and analyzed for Fng binding affinity and ability to induce immune protection against GBS infection. Maternal immunization with 6pGST, a fragment containing five repeats, significantly protected mouse pups against lethal GBS challenge and these protective effects could be recapitulated by administration of anti-6pGST serum from adult animals. Notably, a monoclonal antibody that was capable of neutralizing Fng binding by 6pGST, but not a non-neutralizing antibody, could significantly protect pups against lethal GBS challenge. These data suggest that FbsA-Fng interaction promotes GBS pathogenesis and that blocking such interaction is a viable strategy to prevent or treat GBS infections
Flavonoids: a myth or a reality for cancer therapy?
Nutraceuticals are biologically active molecules present in foods; they can have beneficial
effects on health, but they are not available in large enough quantities to perform this function.
Plant metabolites, such as polyphenols, are widely diffused in the plant kingdom, where they play
fundamental roles in plant development and interactions with the environment. Among these,
flavonoids are of particular interest as they have significant effects on human health. In vitro
and/or in vivo studies described flavonoids as essential nutrients for preventing several diseases.
They display broad and promising bioactivities to fight cancer, inflammation, bacterial infections,
as well as to reduce the severity of neurodegenerative and cardiovascular diseases or diabetes.
Therefore, it is not surprising that interest in flavonoids has sharply increased in recent years. More
than 23,000 scientific publications on flavonoids have described the potential anticancer activity of
these natural molecules in the last decade. Studies, in vitro and in vivo, show that flavonoids exhibit
anticancer properties, and many epidemiological studies confirm that dietary intake of flavonoids
leads to a reduced risk of cancer. This review provides a glimpse of the mechanisms of action of
flavonoids on cancer cells
Immunological fingerprint of 4CMenB recombinant antigens via protein microarray reveals key immunosignatures correlating with bactericidal activity
Serogroup B meningococcus (MenB) is a leading cause of meningitis and sepsis across the world and vaccination is the most effective way to protect against this disease. 4CMenB is a multi-component vaccine against MenB, which is now licensed for use in subjects >2 months of age in several countries. In this study, we describe the development and use of an ad hoc protein microarray to study the immune response induced by the three major 4CMenB antigenic components (fHbp, NHBA and NadA) in individual sera from vaccinated infants, adolescents and adults. The resulting 4CMenB protein antigen fingerprinting allowed the identification of specific human antibody repertoire correlating with the bactericidal response elicited in each subject. This work represents an example of epitope mapping of the immune response induced by a multicomponent vaccine in different age groups with the identification of protective signatures. It shows the high flexibility of this microarray based methodology in terms of high-throughput information and minimal volume of biological samples needed
Acute febrile illness is associated with Rickettsia spp infection in dogs
BACKGROUND: Rickettsia conorii is transmitted by Rhipicephalus sanguineus ticks and causes Mediterranean Spotted Fever (MSF) in humans. Although dogs are considered the natural host of the vector, the clinical and epidemiological significance of R. conorii infection in dogs remains unclear. The aim of this prospective study was to investigate whether Rickettsia infection causes febrile illness in dogs living in areas endemic for human MSF. METHODS: Dogs from southern Italy with acute fever (n = 99) were compared with case–control dogs with normal body temperatures (n = 72). Serology and real-time PCR were performed for Rickettsia spp., Ehrlichia canis, Anaplasma phagocytophilum/A. platys and Leishmania infantum. Conventional PCR was performed for Babesia spp. and Hepatozoon spp. Acute and convalescent antibodies to R. conorii, E. canis and A. phagocytophilum were determined. RESULTS: The seroprevalence rates at first visit for R. conorii, E. canis, A. phagocytophilum and L. infantum were 44.8%, 48.5%, 37.8% and 17.6%, respectively. The seroconversion rates for R. conorii, E. canis and A. phagocytophilum were 20.7%, 14.3% and 8.8%, respectively. The molecular positive rates at first visit for Rickettsia spp., E. canis, A. phagocytophilum, A. platys, L. infantum, Babesia spp. and Hepatozoon spp. were 1.8%, 4.1%, 0%, 2.3%, 11.1%, 2.3% and 0.6%, respectively. Positive PCR for E. canis (7%), Rickettsia spp. (3%), Babesia spp. (4.0%) and Hepatozoon spp. (1.0%) were found only in febrile dogs. The DNA sequences obtained from Rickettsia and Babesia PCRs positive samples were 100% identical to the R. conorii and Babesia vogeli sequences in GenBank®, respectively. Febrile illness was statistically associated with acute and convalescent positive R. conorii antibodies, seroconversion to R. conorii, E. canis positive PCR, and positivity to any tick pathogen PCRs. Fourteen febrile dogs (31.8%) were diagnosed with Rickettsia spp. infection based on seroconversion and/or PCR while only six afebrile dogs (12.5%) seroconverted (P = 0.0248). The most common clinical findings of dogs with Rickettsia infection diagnosed by seroconversion and/or PCR were fever, myalgia, lameness, elevation of C-reactive protein, thrombocytopenia and hypoalbuminemia. CONCLUSIONS: This study demonstrates acute febrile illness associated with Rickettsia infection in dogs living in endemic areas of human MSF based on seroconversion alone or in combination with PCR
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