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Natural rubber still has socioeconomic, environmental and technical importance, despite the production of several synthetic similar polymers in the last 70 years. The Amazon Rainforest, the genetic base of Hevea brasiliensis, harbors a great diversity of ecosystems that can result in differentiated latex and elastomer molecules, from trees of the same species or other species and varieties of laticifer plants. Even so, there is little research to compare latex and rubber properties produced from native trees and planted clones. In this work, rubber latex was collected from four locations in the Amazon, including the historical places of Boim and Belterra and the most cultivated clone in Brazil, the RRIM 600, from a hevea plantation in the Center-West of Brazil. The following colloid properties were determined: pH, viscosity, particle size, dry rubber content, total solids content, gel content, total lipids, and total proteins. The molecular weight and the main physical and mechanical properties of the rubbers were also determined. Some main results can be highlighted: the rubber sample from Acre, in the extreme Western part of the Amazon, presented the highest molecular weight, while the Belterra sample, from remaining plantations of the Ford Project in Amazon, showed the highest values for mechanical properties. On the other hand, the technical characteristics of the RRIM 600 clone are close to the results obtained for the Boim sample, in Para, of the micro-region from where Henry Wickham collected the 70,000 seeds in 1876, from which the species was internationally domesticated. The present work is one of the very few studies to have been carried out with latex and rubber of these ancient rubber trees.

ObjectivesTo investigate the relevance of multicopy plasmids in antimicrobial resistance and assess their mobilization mediated by phage particlesMethodsSeveral databases with complete sequences of plasmids and annotated genes were analysed. The 16S methyltransferase gene armA conferring high-level aminoglycoside resistance was used as a marker in eight different plasmids, from different incompatibility groups, and with differing sizes and plasmid copy numbers. All plasmids were transformed into Escherichia coli bearing one of four different lysogenic phages. Upon induction, encapsidation of armA in phage particles was evaluated using qRT–PCR and Southern blotting.ResultsMulticopy plasmids carry a vast set of emerging clinically important antimicrobial resistance genes. However, 60% of these plasmids do not bear mobility (MOB) genes. When carried on these multicopy plasmids, mobilization of a marker gene armA into phage capsids was up to 10000 times more frequent than when it was encoded by a large plasmid with a low copy number.ConclusionsMulticopy plasmids and phages, two major mobile genetic elements (MGE) in bacteria, represent a novel high-efficiency transmission route of antimicrobial resistance genes that deserves further investigation.

The present study evaluated Nile tilapia when fed on dried duckweed in combination with commercial feed, aiming at reducing production costs. Three diets, which consisted of commercial feed (40% crude protein),dried duckweed or a combination of commercial feed and dried duckweed were fed to triplicate groups of 20 tilapia (Oreochromis niloticus) fi ngerlings. Fish weighing 3.2 ± 0.94g were stocked in nine 1-m3 net cages and fed twice a day for 50 days. The fi nal average weights of fi ngerlings fed commercial feed (21.67g) and 50% feed + 50% dried duckweed (19.53g) were not different (p

Antibiotic resistance is one of the most worrying threats to global public health today. Numerous common infections are becoming harder, and even impossible, to treat due to the loss of effectiveness of these molecules against resistant bacteria. This is a complex scenario involving multiple elements, and must therefore be confronted with a multidisciplinary approach (1).

The serine/threonine protein kinase C (PKC) family was first identified as intracellular receptor(s) for the tumor promoting agents phorbol esters. Thirty years after the discovery of PKC, the role of specific PKC isoforms has been described in relationship with an altered pattern of expression in different types of cancer and a good number of small molecule inhibitors (inhibitory peptides, antisense oligonucleotides or natural compounds) targeting PKC are now available. Despite all these achievements and a huge amount of basic research studies on the biochemical regulation of PKC, there has been a delay in clinical trials with drugs targeting PKC function. This delay is easily explained taking into account the extreme biological complexity of the PKC family of isoforms and the incomplete understanding of the specific role of each PKC isozyme in different types of cancers. Some of the difficulties in developing pharmacological compounds selectively tuning the different PKCs have started to be overcome. In this review, the growing evidences of the role of the PKC isoforms α, βII, δ, ε, ζ and ι is in promoting or counteracting tumor progression will be discussed in relationship with promising therapeutic perspectives.

The multi-kinase inhibitor Dasatinib induced a variable but significant decrease of viability in both p53(wild-type) (EHEB, JVM-2, JVM-3) and p53(mutated) (MEC-1, MEC-2, BJAB) prolymphocytic B leukemic cells, due to a combination of cell cycle block in G1 and apoptosis. Antibody phospho-kinase array analysis revealed that Dasatinib inhibited the phosphorylation of various kinases, including ERK1/2 and p38/MAPK as well as of STAT3 transcription factors, in both p53(wild-type) and p53(mutated) cells. Therefore, Dasatinib might offer a novel therapeutic strategy not only for p53(wild-type), but also for p53(mutated) B malignancies that have the worst prognosis and urgently need innovative therapeutic approaches.

Nutlin-3 is a small molecule inhibitor of the MDM2/p53 interaction, which leads to the non-genotoxic p53 stabilization, activation of cell cycle arrest and apoptosis pathways. A series of recent studies have strengthened the concept that selective, non-genotoxic p53 activation by Nutlin-3 might represent an alternative to the current cytotoxic chemotherapy, in particular for pediatric tumors and for hematological malignancies, which retain a high percentage of p53(wild-type) status at diagnosis. Like most other drugs employed in cancer therapy, it will be unlikely that Nutlin-3 will be used as a monotherapy. In this respect, Nutlin-3 shows a synergistic cytotoxic effect when used in combination with innovative drugs, such as TRAIL or bortozemib. Although Nutlin-3 is currently in phase I clinical trial for the treatment of retinoblastoma, its effects on normal tissues and cell types remain largely to be determined and will require further investigation in the future years.