900 research outputs found

    The evolution of axillary staging in breast cancer

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    PART 1 of the thesis presents two studies that evaluate accuracy of radiological modalities to select breast cancer patients with (one or more) positive axillary nodes. Although several recent randomised studies demonstrated that omitting cALND in selected early breast cancer patients with positive sentinel nodes is oncologically safe, the majority of early breast cancer patients do not meet the eligibility criteria of these trials. These patients should still be submitted for axillary treatment (either ALND or axillary irradiation) in case of one or more positive axillary nodes. In Chapter 2 we evaluated accuracy of AxUS and FNAC in the preoperative diagnosis of axillary lymph node metastases in 1132 women with breast cancer. We determined how many patients could bypass SNB by performing AxUS and FNAC. In Chapter 3 the diagnostic performance of preoperative axillary staging modalities in detecting axillary nodal involvement is reviewed. Modalities that were reviewed are AxUS, ultrasound-guided needle biopsy, MRI and PET-CT. In PART 2 of this thesis we focus on a subgroup of breast cancer patients with a higher risk of axillary lymph node metastases. In Chapter 4, a subgroup of breast cancer patients is identified who harbour a high risk of both axillary node metastases and false negative results of AxUS and FNAC. Preoperative knowledge of (positive) nodal status in these patients might result in a one-stage surgical procedure (breast surgery and ALND at once). Therefore, we hypothesised that this particular group of breast cancer patients might benefit from SNB under local anaesthesia. The results of a randomised clinical trial comparing SNB under local anaesthesia with usual care (SNB during breast surgery) in this subgroup of breast cancer patients are presented (Chapter 5, AMBULANT study). In selected early breast cancer patients with one or two positive sentinel nodes, cALND is no longer needed. Hence, either excluding or identifying patients with high axillary nodal burden (three or more positive axillary nodes) becomes increasingly important. In PART 3 of this thesis two studies are presented regarding selection of breast cancer patients with high nodal burden. In Chapter 6 we retrospectively evaluated 2130 breast cancer patients to determine accuracy of preoperative AxUS and FNAC in detecting high nodal burden. Not only AxUS and FNAC might be used to detect high nodal burden. Therefore, we reviewed whether the current preoperative diagnostic modalities can accurately identify or exclude high nodal burden in Chapter 7. In Chapter 8 we discuss the consequences of the data presented in this thesis for daily practice. In this concluding chapter we will also discuss future developments in the field, especially the ongoing significance of molecular biology in the staging of breast cancer

    Ancient landscape reconstruction using archive data from the Pontine Plain (Italy):the Caprolace lagoon case study

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    The greatest part of the documents concerning the last reclamation scheme of the Pontine Plain is now stored in a section of the state archive and in the archive of the Consorzio di Bonifica dell'Agro Pontino, both located in Latina (Italy). Detailed plans of the realised buildings, infrastructures as well as thousands of pictures of the environments before the reclamation scheme are available to the public. These data can be used to reconstruct the ancient landscape before the major changes which occurred after the spread of mechanical vehicles for earthmoving in the 1970s. The reconstruction maps can be used to set the proper background for the archaeological research in the area

    Quantification of the Retention and Disassembly of Virus Particles by a PEI-Functionalized Microfiltration Membrane

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    [Image: see text] Monitoring the performance of polymer-functionalized surfaces that aim at removing and inactivating viruses is typically labor-intensive and time-consuming. This hampers the development and optimization of such surfaces. Here we present experiments of low complexity that can be used to characterize and quantify the antiviral properties of polymer-functionalized surfaces. We showcase our approach on polyethylenimine (PEI)-coated poly(ether sulfone) (PES) microfiltration membranes. We use a fluorescently labeled model virus to quantify both virus removal and inactivation. We directly quantify the log removal of intact viruses by this membrane using single particle counting. Additionally, we exploit the change in photophysical properties upon disassembly of the virus to show that viruses are inactivated by the PEI coating. Although only a small fraction of intact viruses can pass the membrane, a considerable fraction of inactivated, disassembled viruses are found in the filtrate. Fluorescence microscopy experiments show that most of the viruses left behind on the microfiltration membrane are in the inactivated, disassembled state. Combined, our fluorescence microscopy and spectroscopy experiments show that not only does the model virus adsorb to the PEI coating on the membrane but also the interaction with PEI results in the disassembly of the virus capsid

    Where do early career researchers stand on Open Science practices? A survey within the Max Planck Society

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    Open science (OS) is of paramount importance for the improvement of science worldwide and across research fields. Recent years have witnessed a transition toward open and transparent scientific practices, but there is still a long way to go. Early career researchers (ECRs) are of crucial relevance in the process of steering toward the standardization of OS practices, as they will become the future decision makers of the institutional change that necessarily accompanies this transition. Thus, it is imperative to gain insight into where ECRs stand on OS practices. Under this premise, the Open Science group of the Max Planck PhDnet designed and conducted an online survey to assess the stance toward OS practices of doctoral candidates from the Max Planck Society. As one of the leading scientific institutions for basic research worldwide, the Max Planck Society provides a considerable population of researchers from multiple scientific fields, englobed into three sections: biomedical sciences, chemistry, physics and technology, and human and social sciences. From an approximate total population of 5,100 doctoral candidates affiliated with the Max Planck Society, the survey collected responses from 568 doctoral candidates. The survey assessed self-reported knowledge, attitudes, and implementation of different OS practices, namely, open access publications, open data, preregistrations, registered reports, and replication studies. ECRs seemed to hold a generally positive view toward these different practices and to be interested in learning more about them. Furthermore, we found that ECRs’ knowledge and positive attitudes predicted the extent to which they implemented these OS practices, although levels of implementation were rather low in the past. We observed differences and similarities between scientific sections. We discuss these differences in terms of need and feasibility to apply these OS practices in specific scientific fields, but additionally in relation to the incentive systems that shape scientific communities. Lastly, we discuss the implications that these results can have for the training and career advancement of ECRs, and ultimately, for the consolidation of OS practices

    Hepatocyte-specific glucose-6-phosphatase deficiency disturbs platelet aggregation and decreases blood monocytes upon fasting-induced hypoglycemia

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    International audienceObjective: Glycogen storage disease type 1a (GSD Ia) is a rare inherited metabolic disorder caused by mutations in the glucose-6-phosphatase (G6PC1) gene. When untreated, GSD Ia leads to severe fasting-induced hypoglycemia. Although current intensive dietary management aims to prevent hypoglycemia, patients still experience hypoglycemic events. Poor glycemic control in GSD Ia is associated with hypertriglyceridemia, hepatocellular adenoma and carcinoma, and also with an increased bleeding tendency of unknown origin.Methods: To evaluate the effect of glycemic control on leukocyte levels and coagulation in GSD Ia, we employed hepatocyte-specific G6pc1 deficient (L-G6pc-/-) mice under fed or fasted conditions, to match good or poor glycemic control in GSD Ia, respectively.Results: We found that fasting-induced hypoglycemia in L-G6pc-/- mice decreased blood leukocytes, specifically pro-inflammatory Ly6Chi monocytes, compared to controls. Refeeding reversed this decrease. The decrease in Ly6Chi monocytes was accompanied by an increase in plasma corticosterone levels and was prevented by the glucocorticoid receptor antagonist mifepristone. Further, fasting-induced hypoglycemia in L-G6pc-/- mice prolonged bleeding time in the tail vein bleeding assay, with reversal by refeeding. This could not be explained by changes in coagulation factors V, VII, or VIII, or von Willebrand factor. While the prothrombin and activated partial thromboplastin time, as well as total platelet counts were not affected by fasting-induced hypoglycemia in L-G6pc-/- mice, ADP-induced platelet aggregation was disturbed.Conclusions: These studies reveal a relationship between fasting-induced hypoglycemia, decreased blood monocytes, and disturbed platelet aggregation in L-G6pc-/- mice. While disturbed platelet aggregation likely accounts for the bleeding phenotype in GSD Ia, elevated plasma corticosterone decreases levels of pro-inflammatory monocytes. These studies highlight the necessity of maintaining good glycemic control in GSD Ia

    Balancing selection on a recessive lethal deletion with pleiotropic effects on two neighboring genes in the porcine genome

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    Livestock populations can be used to study recessive defects caused by deleterious alleles. The frequency of deleterious alleles including recessive lethal alleles can stay at high or moderate frequency within a population, especially if recessive lethal alleles exhibit an advantage for favourable traits in heterozygotes. In this study, we report such a recessive lethal deletion of 212kb (del) within the BBS9 gene in a breeding population of pigs. The deletion produces a truncated BBS9 protein expected to cause a complete loss-of-function, and we find a reduction of approximately 20% on the total number of piglets born from carrier by carrier matings. Homozygous del/del animals die mid- to late-gestation, as observed from high increase in numbers of mummified piglets resulting from carrier-by-carrier crosses. The moderate 10.8% carrier frequency (5.4% allele frequency) in this pig population suggests an advantage on a favourable trait in heterozygotes. Indeed, heterozygous carriers exhibit increased growth rate, an important selection trait in pig breeding. Increased growth and appetite together with a lower birth weight for carriers of the BBS9 null allele in pigs is analogous to the phenotype described in human and mouse for (naturally occurring) BBS9 null-mutants. We show that fetal death, however, is induced by reduced expression of the downstream BMPER gene, an essential gene for normal foetal development. In conclusion, this study describes a lethal 212kb deletion with pleiotropic effects on two different genes, one resulting in fetal death in homozygous state (BMPER), and the other increasing growth (BBS9) in heterozygous state. We provide strong evidence for balancing selection resulting in an unexpected high frequency of a lethal allele in the population. This study shows that the large amounts of genomic and phenotypic data routinely generated in modern commercial breeding programs deliver a powerful tool to monitor and control lethal alleles much more efficiently.</p

    Proteomic Profiling of Plasmodium Sporozoite Maturation Identifies New Proteins Essential for Parasite Development and Infectivity

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    Plasmodium falciparum sporozoites that develop and mature inside an Anopheles mosquito initiate a malaria infection in humans. Here we report the first proteomic comparison of different parasite stages from the mosquito—early and late oocysts containing midgut sporozoites, and the mature, infectious salivary gland sporozoites. Despite the morphological similarity between midgut and salivary gland sporozoites, their proteomes are markedly different, in agreement with their increase in hepatocyte infectivity. The different sporozoite proteomes contain a large number of stage specific proteins whose annotation suggest an involvement in sporozoite maturation, motility, infection of the human host and associated metabolic adjustments. Analyses of proteins identified in the P. falciparum sporozoite proteomes by orthologous gene disruption in the rodent malaria parasite, P. berghei, revealed three previously uncharacterized Plasmodium proteins that appear to be essential for sporozoite development at distinct points of maturation in the mosquito. This study sheds light on the development and maturation of the malaria parasite in an Anopheles mosquito and also identifies proteins that may be essential for sporozoite infectivity to humans
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