Nanoparticle physicochemical properties such as surface charge are considered to play an important role in cellular uptake and particle–cell interactions. In order to systematically evaluate the role ...of surface charge on the uptake of iron oxide nanoparticles, we prepared carboxymethyl-substituted dextrans with different degrees of substitution, ranging from 38 to 5 groups per chain, and reacted them using carbodiimide chemistry with amine–silane-coated iron oxide nanoparticles with narrow size distributions in the range of 33–45 nm. Surface charge of carboxymethyl-substituted dextran-coated nanoparticles ranged from −50 to 5 mV as determined by zeta potential measurements, and was dependent on the number of carboxymethyl groups incorporated in the dextran chains. Nanoparticles were incubated with CaCo-2 human colon cancer cells. Nanoparticle–cell interactions were observed by confocal laser scanning microscopy and uptake was quantified by elemental analysis using inductively coupled plasma mass spectroscopy. Mechanisms of internalization were inferred using pharmacological inhibitors for fluid-phase, clathrin-mediated, and caveola-mediated endocytosis. Results showed increased uptake for nanoparticles with greater negative charge. Internalization patterns suggest that uptake of the most negatively charged particles occurs via non-specific interactions.
Monodisperse magnetite nanoparticles modified with poly(ethylene glycol) (PEG) were synthesized using a silane functionalized PEG obtained by reacting 3-aminopropyl triethoxysilane with carboxylic ...acid-methoxy PEG (mPEG–COOH) using amide reactions. Transmission electron microscopy (TEM), dynamic light scattering (DLS), and zeta potential measurements show the particles are monodisperse (
σ
gv
∼
0.2
) and stable in water for pH of 3–9 and ionic strengths, up to 0.3 M NaCl. Thermogravimetric analysis coupled with TEM and DLS indicates formation of a dense graft layer on the particle surface. An analysis of the interparticle interaction energy indicates that the particles are stabilized by strong steric repulsions between PEG chains on their surface.
Monodisperse magnetic nanoparticles were coated with mPEG–silane molecules. The colloidal stability of these nanoparticles was studied from DLVO theory. Steric repulsion between PEG–silane chains of approaching particles was responsible for nanoparticle stabilization, making these nanoparticles suitable for biological applications.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Cancer is a disease characterized by uncontrolled cellular growth where cancer cells take advantage of surrounding cellular populations to obtain resources and promote invasion. Carcinomas are the ...most common type of cancer accounting for almost 90% of cancer cases. One of the major subtypes of carcinomas are adenocarcinomas, which originate from glandular cells that line certain internal organs. Cancers such as breast, prostate, lung, pancreas, colon, esophageal, kidney are often adenocarcinomas. Current treatment strategies include surgery, chemotherapy, radiation, targeted therapy, and more recently immunotherapy. However, patients with adenocarcinomas often develop resistance or recur after the first line of treatment. Understanding how networks of tumor cells interact with each other and the tumor microenvironment is crucial to avoid recurrence, resistance, and high-dose therapy toxicities. In this review, we explore how mathematical modeling tools from different disciplines can aid in the development of effective and personalized cancer treatment strategies. Here, we describe how concepts from the disciplines of ecology and evolution, economics, and control engineering have been applied to mathematically model cancer dynamics and enhance treatment strategies.
Anatase TiO2 nanoparticles doped with iron ions have been synthesized via the green chemistry method using aqueous extract of lemongrass (Cymbopogon citratus) obtained from Soxhlet extraction and ...doped by wet impregnation. The TiO2 anatase phase has been doped with Fe3+ (0.05, 0.075, and 0.1 Fe3+ : Ti molar ratio) at 550°C and 350°C, respectively. The scanning electron microscopy with energy-dispersive X-ray (SEM-EDS) shows nanoparticle clusters and efficiencies of impregnations between 66.5 and 58.4% depending on the theoretical dopant amount. The electron transmission microscopy (TEM) reveals final particle sizes ranging between 7 and 26 nm depending on the presence or not of the dopant. The cathodoluminescence (CL) and photoluminescence (PL) studies of the doped and undoped nanoparticles show a luminescence signal attributed to surface oxygen vacancies (visible CL emission 380–700 nm and PL emission 350–800 nm); additionally, a decrease in emission intensity is observed due the inhibition of the recombination of the photogenerated electron-holes pairs; moreover, nanopowders were analyzed by UV-Vis spectrophotometry of diffuse reflectance, and the absorption edge of the Fe-TiO2 in comparison to undoped TiO2 is extended greatly toward the visible light. The six bands (A1g + 2B1g + 3Eg) found by Raman spectroscopy and the x-ray diffraction pattern (XRD) confirm that synthesized TiO2 is only anatase phase, which is commonly used as a catalyst in waste water treatment, specifically in heterogeneous photocatalytic processes.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The forced relocation of several thousand Africans during Mexico’s historic period has so far been documented mostly through archival sources, which provide only sparse detail on their origins and ...lived experience. Here, we employ a bioarchaeological approach to explore the life history of three 16th century Africans from a mass burial at the San José de los Naturales Royal Hospital in Mexico City. Our approach draws together ancient genomic data, osteological analysis, strontium isotope data from tooth enamel, δ13C and δ15N isotope data from dentine, and ethnohistorical information to reveal unprecedented detail on their origins and health. Analyses of skeletal features, radiogenic isotopes, and genetic data from uniparental, genome-wide, and human leukocyte antigen (HLA) markers are consistent with a Sub-Saharan African origin for all three individuals. Complete genomes of Treponema pallidum sub. pertenue (causative agent of yaws) and hepatitis B virus (HBV) recovered from these individuals provide insight into their health as related to infectious disease. Phylogenetic analysis of both pathogens reveals their close relationship to strains circulating in current West African populations, lending support to their origins in this region. The further relationship between the treponemal genome retrieved and a treponemal genome previously typed in an individual from Colonial Mexico highlights the role of the transatlantic slave trade in the introduction and dissemination of pathogens into the New World. Putting together all lines of evidence, we were able to create a biological portrait of three individuals whose life stories have long been silenced by disreputable historical events.
•Genomic and isotopes data suggest an African origin for the three individuals•One ∼14X Treponema pallidum sub. pertenue genome was recovered•One ∼1,500X hepatitis B virus genome was recovered•Both pathogen genomes cluster together with present day pathogens from Africa
Barquera et al. analyze individuals from a colonial period burial from Mexico. Using an interdisciplinary approach, they reconstruct the genetic ancestry, origins, and health status of three enslaved Africans. Genomes of pathogens recovered from them provide insight on infectious diseases brought to the Americas by the transatlantic slave trade.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Aims
The current WHO classification of melanocytic tumours excludes neoplasms showing BRAF or NRAS mutations from the Spitz category. This study aimed to review and reclassify atypical melanocytic ...tumours with spitzoid morphological features diagnosed between 2009 and 2021 in our hospital after expanding the molecular profile, including BRAF and NRAS mutations in all cases.
Methods and results
A total of 71 neoplasms showing spitzoid features (Spitz‐like) and atypia were included. The risk of progression of tumours was first studied by integrating the morphology, immunohistochemistry (p16, Ki67, HMB45 and PRAME) and fluorescence in‐situ hybridisation (FISH) results (melanoma multiprobe and 9p21). In a second step, after expanding the molecular study, including BRAF and NRAS mutational status, the neoplasms were finally classified into four subgroups: atypical Spitz tumour (AST, n = 45); BRAF‐mutated naevus/low‐grade melanocytoma with spitzoid morphology (BAMS, n = 2); Spitz melanoma (SM, n = 14); and BRAF or NRAS mutated melanoma with spitzoid features (MSF, n = 10). Follow‐up of patients revealed uneventful results for AST and BAMS. Only one SM presented lymph node metastasis after 134 months. Conversely, patients with MSF showed an unfavourable outcome: three developed lymph node metastases after a mean time of 22 months, with one patient presenting distant metastasis and dying of the disease 64 months from diagnosis. The progression‐free survival showed significant differences between the four groups of spitzoid tumours (P < 0.001) and between both melanoma subtypes (P = 0.012).
Conclusions
The classification and prognostication of atypical neoplasms with spitzoid features requires the integration of histomorphology with the molecular investigation of tumours, which should include BRAF and NRAS mutational status.
The classification and prognostication of atypical neoplasms with spitzoid features requires the integration of histomorphology with the molecular investigation of tumours, which should include BRAF and NRAS mutational status.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Background
Primary cutaneous follicular center‐cell lymphoma (PCFCL) is one of the most common types of cutaneous B‐cell lymphoma. Differences in immunohistochemical expression of BCL2 and CD10 ...antigens along with the presence of t(14:18) translocation in neoplastic cells have been postulated as relevant clues in differentiating PCFCL from cutaneous lesions secondary to a systemic follicular lymphoma (SCFL). The aim of this study is to evaluate the significance and usefulness of these parameters in a large series of patients.
Methods
Patients with PCFCL and SCFL diagnosed at three university hospitals in Barcelona, from 2000 to 2015 were reviewed. Clinical, histopathological, immunophenotypical, genetic, and outcome parameters were analyzed.
Results
Eighty‐one cases (59 PCFCL and 22 SCFL) were included. There were no significant differences between PCFCL and SCFL cases regarding clinical presentation, site of involvement, or predominant type of skin lesions. Most patients in both groups showed positivity for BCL2 and CD10, but strong expression of BCL2 and CD10 was associated with SCFL cases. Although more frequent in SCFL, a small proportion of PCFCL cases also showed the t(14:18) on FISH analysis.
Conclusion
The intensity of BCL2 expression was found to be the single most valuable clue in differentiating PCFCL from SCFL cases on histopathological grounds.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
This article offers an analysis of the domestic and international factors shaping the Russo–Venezuelan alliance. We provide a comprehensive analysis to understand the evolution of this alliance and ...to consider how the political leadership, the regime type, the military sector, the economy, and the presence of China and the United States in Latin America are vital determinants in this alliance. At the policy level, Russia and Venezuela's relationship has opened an opportunity for the Venezuelan government to consolidate power, while for Russia, this alliance has helped offset the influence of the United States in Latin America.
摘要
本文分析了影响俄罗斯‐委内瑞拉联盟的一系列国内外因素。我们全面分析了该联盟的演变，以及政治领导、政权类型、军事部门、经济以及中国和美国在拉丁美洲的影响如何成为该联盟的重要决定因素。在政策层面，俄罗斯和委内瑞拉的关系为委内瑞拉政府巩固权力一事提供了机会，而对俄罗斯来说，该联盟有助于抵消美国在拉美的影响力。
Resumen
Este artículo ofrece un análisis de los factores domésticos e internacionales que dieron forma a la alianza ruso–venezolana. Brindamos un análisis integral para comprender la evolución de esta alianza y considerar cómo el liderazgo político, el tipo de régimen, el sector militar, la economía y la presencia de China y Estados Unidos en América Latina son determinantes vitales en esta alianza. A nivel político, la relación entre Rusia y Venezuela ha abierto una oportunidad para que el gobierno venezolano consolide su poder, mientras que, para Rusia, esta alianza ha ayudado a contrarrestar la influencia de Estados Unidos en América Latina.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
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