431 research outputs found
Prognostic value of the proportion of the sclerosing component in fibrolamellar liver carcinoma
Introduction. Fibrolamellar hepatocellular carcinoma (FLC), which develops most often in the younger population. In FLC, variable histoarchitectonics are noted, possibly the presence of a sclerosing component, foci of necrosis and dystrophy of tumor cells.Objective. Assessment of the influence of the proportion of the sclerosing component in fibrolamellar carcinoma (FLC) of the liver on the course and prognosis of the disease. Determination of the relationship between the proportion of the sclerosing component in the tumor and the frequency of microvascular invasion.Materials and methods. A retrospective study included 34 patients with a diagnosis of FLC, who underwent radical surgical treatment at the first stage. A histological assessment of the proportion (%) of the sclerosing component in FLC was made. The effect of the proportion of the sclerosing component on overall (OS) and relapse-free (DFS) survival was assessed. The analysis of the relationship between the proportion of the sclerosing component in the tumor and the frequency of microvascular invasion was carried out.Results. Significantly worse RFS was achieved in the groups of patients with a sclerosing component in FLC > 5% than in the group of patients with a sclerosing component in FLC ≤ 5% (p = 0.0010; p = 0.024; log – rank test). Median DDS in group 1 is 107 (95% CI, 22–192) months; at 2 – 11 (95% CI, 8–14) months; in 3 – 21 (95% CI, 8–33). The frequency of histologically confirmed microvascular invasion in the compared groups was 29, 74, 87.5%, respectively. OS was significantly worse in 2 groups (27 patients in total) with a sclerosing component in FLC > 5% than in the group of patients with a sclerosing component in FLC ≤ 5%. Median OS in group 1 120 (95% CI, 60–180) months; at 2 – 41 (95% CI, 15–92) months; in 3 – 69 (95% CI, 35–103). A direct relationship was found between an increase in the proportion of the sclerosing component in a tumor and an increase in the frequency of microvascular invasion.Conclusions. We can assume that the severity of the sclerosing component in the FLK tumor can serve as an effective morphological marker of a less favorable prognosis for this HCC subtype and correlate with the frequency of microvascular invasion
Quantifying the interplay between environmental and social effects on aggregated-fish dynamics
Demonstrating and quantifying the respective roles of social interactions and
external stimuli governing fish dynamics is key to understanding fish spatial
distribution. If seminal studies have contributed to our understanding of fish
spatial organization in schools, little experimental information is available
on fish in their natural environment, where aggregations often occur in the
presence of spatial heterogeneities. Here, we applied novel modeling approaches
coupled to accurate acoustic tracking for studying the dynamics of a group of
gregarious fish in a heterogeneous environment. To this purpose, we
acoustically tracked with submeter resolution the positions of twelve small
pelagic fish (Selar crumenophthalmus) in the presence of an anchored floating
object, constituting a point of attraction for several fish species. We
constructed a field-based model for aggregated-fish dynamics, deriving
effective interactions for both social and external stimuli from experiments.
We tuned the model parameters that best fit the experimental data and
quantified the importance of social interactions in the aggregation, providing
an explanation for the spatial structure of fish aggregations found around
floating objects. Our results can be generalized to other gregarious species
and contexts as long as it is possible to observe the fine-scale movements of a
subset of individuals.Comment: 10 pages, 5 figures and 4 supplementary figure
Population expansion of the invasive Pomacentridae Chromis limbata (Valenciennes, 1833) in Southern Brazilian coast: long-term monitoring, fundamental niche availability and new records
Human-mediated species invasions are recognized as a leading cause of global biotic homogenization and extinction. Studies on colonization events since early stages, establishment of new populations and range extension are scarce because of their rarity, difficult detection and monitoring. Chromis limbata is a reef-associated and non-migratory marine fish from the family Pomacentridae found in depths ranging between 3 and 45 m. The original distribution of the species encompassed exclusively the eastern Atlantic, including the Azores, Madeira and the Canary Islands. It is also commonly reported from West Africa between Senegal and Pointe Noire, Congo. In 2008, vagrant individuals of C. limbata were recorded off the east coast of Santa Catarina Island, South Brazil (27° 41' 44″ S, 48° 27' 53″ W). This study evaluated the increasing densities of C. limbata populations in Santa Catarina State shoreline. Two recent expansions, northwards to São Paulo State and southwards to Rio Grande do Sul State, are discussed, and a niche model of maximum entropy (MaxEnt) was performed to evaluate suitable C. limbata habitats. Brazilian populations are established and significantly increasing in most sites where the species has been detected. The distributional boundaries predicted by the model are clearly wider than their known range of occurrence, evidencing environmental suitability in both hemispheres from areas where the species still does not occur. Ecological processes such as competition, predation and specially habitat selectivity may regulate their populations and overall distribution range. A long-term monitoring programme and population genetics studies are necessary for a better understanding of this invasion and its consequences to natural communities.CNPq, Grant/Award Number: CNPq 475367/2006-5; ECOPERE-SE Project; FAPES, Grant/Award Number: PROFIX program No 10/2018 -T.O.: 348/2018; FAPESC, Grant/Award Number: Biodiversidade Marinha do Estado de Santa Catarina Project PI: A.L. FAPESC 4302/2010-8; FAPESC/CNPq, Grant/Award Number: SISBIOTA-Mar project PI: S.R.F. CNPq 563276/2010-0; FAPESC 6308/2011-8; Petrobras (BR), Grant/Award Number: MAArE Project; King Abdullah University of Science and Technology; Coordenação de Aperfeiçoamento de Pessoal de NÃvel Superiorinfo:eu-repo/semantics/publishedVersio
Aggregation Pattern Transitions by Slightly Varying the Attractive/Repulsive Function
Among collective behaviors of biological swarms and flocks, the attractive/repulsive (A/R) functional links between particles play an important role. By slightly changing the cutoff distance of the A/R function, a drastic transition between two distinct aggregation patterns is observed. More precisely, a large cutoff distance yields a liquid-like aggregation pattern where the particle density decreases monotonously from the inside to the outwards within each aggregated cluster. Conversely, a small cutoff distance produces a crystal-like aggregation pattern where the distance between each pair of neighboring particles remains constant. Significantly, there is an obvious spinodal in the variance curve of the inter-particle distances along the increasing cutoff distances, implying a legible transition pattern between the liquid-like and crystal-like aggregations. This work bridges the aggregation phenomena of physical particles and swarming of organisms in nature upon revealing some common mechanism behind them by slightly varying their inter-individual attractive/repulsive functions, and may find its potential engineering applications, for example, in the formation design of multi-robot systems and unmanned aerial vehicles (UAVs)
Eicosapentaenoic Acid, Arachidonic Acid and Eicosanoid Metabolism in Juvenile Barramundi Lates calcarifer
A two part experiment was conducted to assess the response of barramundi (Lates calcarifer; initial weight=10.3±0.03g; mean±S.D.) fed one of five diets with varying eicosapentaenoic acid (diets 1, 5, 10, 15 and 20g/kg) or one of four diets with varying arachidonic acid (1, 6, 12, 18g/kg) against a fish oil control diet. After 6weeks of feeding, the addition of EPA or ARA did not impact on growth performance or feed utilisation. Analysis of the whole body fatty acids showed that these reflected those of the diets. The ARA retention demonstrated an inversely related curvilinear response to either EPA or ARA. The calculated marginal utilisation efficiencies of EPA and ARA were high (62.1 and 91.9% respectively) and a dietary ARA requirement was defined (0.012g/kg0.796/day). The partial cDNA sequences of genes regulating eicosanoid biosynthesis were identified in barramundi tissues, namely cyclooxygenase 1 (Lc COX1a, Lc COX1b), cyclooxygenase 2 (Lc COX2) and lipoxygenase (Lc ALOX-5). BothLc COX2andLc ALOX-5expression in the liver tissue were elevated in response to increasing dietary ARA, meanwhile expression levels ofLcCOX2and the mitochondrial fatty acid oxidation gene carnitine palmitoyltransferase 1 (LcCPT1a) were elevated in the kidney. A low level of EPA increased the expression ofLc COX1bin the liver. Consideration should be given to the EPA to ARA balance for juvenile barramundi in light of nutritionally inducible nature of the cyclooxygenase and lipoxygenase enzymes
Consistency of Leadership in Shoals of Mosquitofish (Gambusia holbrooki) in Novel and in Familiar Environments
In social animal groups, an individual's spatial position is a major determinant of both predation risk and foraging rewards. Additionally, the occupation of positions in the front of moving groups is generally assumed to correlate with the initiation of group movements. However, whether some individuals are predisposed to consistently occupy certain positions and, in some instances, to consistently lead groups over time is as yet unresolved in many species. Using the mosquitofish (Gambusia holbrooki), we examined the consistency of individuals' spatial positions within a moving group over successive trials. We found that certain individuals consistently occupied front positions in moving groups and also that it was typically these individuals that initiated group decisions. The number of individuals involved in leading the group varied according to the amount of information held by group members, with a greater number of changes in leadership in a novel compared to a relatively familiar environment. Finally, our results show that the occupation of lead positions in moving groups was not explained by characteristics such as dominance, size or sex, suggesting that certain individuals are predisposed to leadership roles. This suggests that being a leader or a follower may to some extent be an intrinsic property of the individual
Resolution on the results of Advisory Board “Searching the effective methods of testing and treating patients with NSCLC caused by <i>NTRK</i> gene fusions“
The Advisory Board was held on December 24, 2021. The molecular genetic research lead specialists and national lead oncologists discussed issues of diagnosis of NTRK gene translocations in patients with non-small cell lung cancer (NSCLC), as well as current opportunities for the treatment of patients with NSCLC caused by NTRK gene fusions. The experts reaffirmed the necessity to identify timely patients with NSCLC caused by NTRK gene fusions, as the correct diagnosis of the disease, including the use of modern diagnostic methods of NTRK gene fusion (NGS is the most sensitive and specific method) determines the success of patient treatment. In this regard, it is critical that physicians know the advantages and disadvantages of each molecular diagnostic method used to have the opportunity to choose the best approach in each clinical case. In order to have a clear, well-functioning strategy for managing patients with suspected NSCLC caused by NTRK gene fusion, it is necessary to use molecular genetic tests, as well as include TRK inhibitors (in particular, the drug larotrectinib; at the time publication of the Resolution, the drug larotrectinib is not registered in the territory of the Russian Federation) in the clinical guidelines for the treatment of lung cancer. Larotrectinib is a highly selective tropomyosin receptor kinase (TRK) inhibitor. The clinical studies on larotrectinib have demonstrated high response rates and durable responses in adults and children with tumours associated with NTRK gene fusions, including primary CNS tumours and brain metastases. The objective response rate observed with larotrectinib was 79%, with 16% achieving a complete response and 64% achieving a partial response. At the same time, the median progression-free survival on larotrectinib was 28.3 months, and the median overall survival was 44.4 months
Monophyly of Heterandriini (Teleostei: Poeciliidae) revisited: a critical review of the data
Altered mRNA Editing and Expression of Ionotropic Glutamate Receptors after Kainic Acid Exposure in Cyclooxygenase-2 Deficient Mice
Kainic acid (KA) binds to the AMPA/KA receptors and induces seizures that result in inflammation, oxidative damage and neuronal death. We previously showed that cyclooxygenase-2 deficient (COX-2−/−) mice are more vulnerable to KA-induced excitotoxicity. Here, we investigated whether the increased susceptibility of COX-2−/− mice to KA is associated with altered mRNA expression and editing of glutamate receptors. The expression of AMPA GluR2, GluR3 and KA GluR6 was increased in vehicle-injected COX-2−/− mice compared to wild type (WT) mice in hippocampus and cortex, whereas gene expression of NMDA receptors was decreased. KA treatment decreased the expression of AMPA, KA and NMDA receptors in the hippocampus, with a significant effect in COX-2−/− mice. Furthermore, we analyzed RNA editing levels and found that the level of GluR3 R/G editing site was selectively increased in the hippocampus and decreased in the cortex in COX-2−/− compared with WT mice. After KA, GluR4 R/G editing site, flip form, was increased in the hippocampus of COX-2−/− mice. Treatment of WT mice with the COX-2 inhibitor celecoxib for two weeks decreased the expression of AMPA/KA and NMDAR subunits after KA, as observed in COX-2−/− mice. After KA exposure, COX-2−/− mice showed increased mRNA expression of markers of inflammation and oxidative stress, such as cytokines (TNF-α, IL-1β and IL-6), inducible nitric oxide synthase (iNOS), microglia (CD11b) and astrocyte (GFAP). Thus, COX-2 gene deletion can exacerbate the inflammatory response to KA. We suggest that COX-2 plays a role in attenuating glutamate excitotoxicity by modulating RNA editing of AMPA/KA and mRNA expression of all ionotropic glutamate receptor subunits and, in turn, neuronal excitability. These changes may contribute to the increased vulnerability of COX-2−/− mice to KA. The overstimulation of glutamate receptors as a consequence of COX-2 gene deletion suggests a functional coupling between COX-2 and the glutamatergic system
Revealing the Appetite of the Marine Aquarium Fish Trade: The Volume and Biodiversity of Fish Imported into the United States
The aquarium trade and other wildlife consumers are at a crossroads forced by threats from global climate change and other anthropogenic stressors that have weakened coastal ecosystems. While the wildlife trade may put additional stress on coral reefs, it brings income into impoverished parts of the world and may stimulate interest in marine conservation. To better understand the influence of the trade, we must first be able to quantify coral reef fauna moving through it. Herein, we discuss the lack of a data system for monitoring the wildlife aquarium trade and analyze problems that arise when trying to monitor the trade using a system not specifically designed for this purpose. To do this, we examined an entire year of import records of marine tropical fish entering the United States in detail, and discuss the relationship between trade volume, biodiversity and introduction of non-native marine fishes. Our analyses showed that biodiversity levels are higher than previous estimates. Additionally, more than half of government importation forms have numerical or other reporting discrepancies resulting in the overestimation of trade volumes by 27%. While some commonly imported species have been introduced into the coastal waters of the USA (as expected), we also found that some uncommon species in the trade have also been introduced. This is the first study of aquarium trade imports to compare commercial invoices to government forms and provides a means to, routinely and in real time, examine the biodiversity of the trade in coral reef wildlife species
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