353 research outputs found

    Pt(IV)-based nanoscale coordination polymers : antitumor activity, cellular uptake and interactions with nuclear DNA

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    Cisplatin has been for many years the gold standard chemotherapeutic drug for the treatment of a wide range of solid tumors, even though its use is commonly associated with serious side effects including non-selective toxicity, myelosuppression or development of cisplatin resistance, among others complications. Over the last decade, a number of nanoparticle formulations were developed to reduce its side effects and improve the selectivity and efficacy of this drug. In this study, we have developed a novel nanoparticle platform based on nanoscale coordination polymer named (Zn-Pt(IV)-NCPs) which contains a Pt(IV) prodrug, Zn and the linker ligand 1,4-Bis(imidazol-1-ylmethyl)benzene (bix). The main objective has been to gain insights into the mechanism of action of this nanostructured material in comparison with cisplatin and the free Pt(IV) prodrug in order to establish a correlation between nanostructuration and therapeutic activity. Zn-Pt(IV)-NCPs nanoparticles displayed an average size close to 200 nm as determined by DLS, a good stability in physiologic environments, and a controlled drug release of Pt. In vitro studies demonstrated that Pt(IV)-NCPs showed an enhanced cytotoxic effect against cell culture of cervical cancer, neuroblastoma and human adenocarcinoma cells in comparison with free Pt(IV) prodrug. Although no difference in cell uptake of Pt was observed for any of the three cell lines assayed, a higher amount of Pt bound to the DNA was found in the cells treated with the nanostructured Pt(IV) prodrug. These studies suggest that the nanostructuration of the prodrug facilitate its activation and induce a change in the mechanism of action related to an increased interaction with the DNA as corroborated by the studies of direct interaction of the Pt(IV) prodrug, nanostructured or not, with DNA

    Endothelial damage, inflammation and immunity in chronic kidney disease

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    Chronic kidney disease (CKD) patients have an accelerated atherosclerosis, increased risk of thrombotic-ischemic complications, and excessive mortality rates when compared with the general population. There is also evidence of an endothelial damage in which the proinflammatory state, the enhanced oxidative stress, or the accumulation of toxins due to their reduced renal clearance in uremia play a role. Further, there is evidence that uremic endothelial cells are both involved in and victims of the activation of the innate immunity. Uremic endothelial cells produce danger associated molecular patterns (DAMPS), which by binding to specific pattern recognition receptors expressed in multiple cells, including endothelial cells, induce the expression of adhesion molecules, the production of proinflammatory cytokines and an enhanced production of reactive oxygen species in endothelial cells, which constitute a link between immunity and inflammation. The connection between endothelial damage, inflammation and defective immunity in uremia will be reviewed here

    Henoch-Schönlein nephritis associated with streptococcal infection and persistent hypocomplementemia: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Henoch-Schönlein purpura is a systemic disease with frequent renal involvement, characterized by IgA mesangial deposits. Streptococcal infection can induce an abnormal IgA immune response like Henoch-Schönlein purpura, quite similar to typical acute post-infectious glomerulonephritis. Indeed, hypocomplementemia that is typical of acute glomerulonephritis has also been described in Henoch-Schönlein purpura.</p> <p>Case presentation</p> <p>We describe a 14-year-old Caucasian Spanish girl who developed urinary abnormalities and cutaneous purpura after streptococcal infection. Renal biopsy showed typical findings from Henoch-Schönlein purpura nephritis. In addition, she had low serum levels of complement (C4 fraction) that persisted during follow-up, in spite of her clinical evolution. She responded to treatment with enalapril and steroids.</p> <p>Conclusion</p> <p>The case described has, at least, three points of interest in Henoch-Schönlein purpura: 1) Initial presentation was preceded by streptococcal infection; 2) There was a persistence of low serum levels of complement; and 3) There was response to steroids and angiotensin-converting enzyme inhibitor in the presence of nephrotic syndrome. There are not many cases described in the literature with these characteristics. We conclude that Henoch-Schönlein purpura could appear after streptococcal infection in patients with abnormal complement levels, and that steroids and angiotensin-converting enzyme inhibitor could be successful treatment for the disease.</p

    Synthesis of functionalized fluorescent silver nanoparticles and their toxicological effect in aquatic environments (Goldfish) and HEPG2 cells

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    Silver nanoparticles, AgNPs, are widely used in our daily life, mostly due to their antibacterial, antiviral, and antifungal properties. However, their potential toxicity remains unclear. In order to unravel this issue, emissive AgNPs were first synthetized using an inexpensive photochemical method, and then their permeation was assessed in vivo in goldfish and in vitro in human hepatoma cells (HepG2). In addition, the oxidative stress caused by AgNPs was assessed in enzymes such as glutathione-S-transferase (GST), catalase (CAT), and in lipid peroxidation (LPO). This study demonstrates that the smallest sized AgNPs@ 3 promote the largest changes in gold fish livers, whereas AgNPs@ 1 were found to be toxic in HEPG2 cells depending on both the size and functionalized/stabilizer ligand

    NEK Family Review and Correlations with Patient Survival Outcomes in Various Cancer Types

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    The Never in Mitosis Gene A (NIMA)–related kinases (NEKs) are a group of serine/threonine kinases that are involved in a wide array of cellular processes including cell cycle regulation, DNA damage repair response (DDR), apoptosis, and microtubule organization. Recent studies have identified the involvement of NEK family members in various diseases such as autoimmune disorders, malignancies, and developmental defects. Despite the existing literature exemplifying the importance of the NEK family of kinases, this family of protein kinases remains understudied. This report seeks to provide a foundation for investigating the role of different NEKs in malignancies. We do this by evaluating the 11 NEK family kinase gene expression associations with patients’ overall survival (OS) from various cancers using the Kaplan–Meier Online Tool (KMPlotter) to correlate the relationship between mRNA expression of NEK1-11 in various cancers and patient survival. Furthermore, we use the Catalog of Somatic Mutations in Cancer (COSMIC) database to identify NEK family mutations in cancers of different tissues. Overall, the data suggest that the NEK family has varying associations with patient survival in different cancers with tumor-suppressive and tumor-promoting effects being tissue-dependent

    Bioremediation of Agricultural Soils Applying Vegetable Activated Carbon and Mountain Microorganisms in the Peruvian Jungle

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    Remediation is the set of operations carried out to reduce the level of contaminants in the soil and/or subsoil. The objective of the study was to bioremediate contaminated agricultural soils using activated carbon from Cocos nucifera and mountain microorganisms to improve physicochemical parameters and reduce cadmium in Peruvian Amazon soils. For the methodology, a total area of ??2000 m2 was used. Four monitoring points with 30 cm deep pits were used and 1 kg of soil was extracted from each sampling point. For the physicochemical analysis, activated carbon and mountain microorganisms were prepared. The treatments were arranged in a completely randomized design with a total of 7 treatments and 3 repetitions each: T1: soil without treatment or control group (GC); T2: activated carbon (AC) 100g; T3: activated carbon (AC) 200g; T4: activated carbon (AC) 300g; T5: mountain microorganisms (MM) 100 mL; T6: mountain microorganisms (MM) 200 mL; T7: mountain microorganisms (MM) 300 mL. The results show that T1 and T4 improve the physicochemical properties of the soil and absorb cadmium, while mountain microorganisms are only evident in T7

    Promoting inclusive metrics of success and impact to dismantle a discriminatory reward system in science

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    “The most dangerous phrase in the language is: We’ve always done it this way.” —Rear Admiral Grace HopperSuccess and impact metrics in science are based on a system that perpetuates sexist and racist “rewards” by prioritizing citations and impact factors. These metrics are flawed and biased against already marginalized groups and fail to accurately capture the breadth of individuals’ meaningful scientific impacts. We advocate shifting this outdated value system to advance science through principles of justice, equity, diversity, and inclusion. We outline pathways for a paradigm shift in scientific values based on multidimensional mentorship and promoting mentee well-being. These actions will require collective efforts supported by academic leaders and administrators to drive essential systemic change.Peer reviewe

    Removal of Metals in Wastewater by Applying Efficient Mountain Microorganisms and Sodium Hydroxide

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    Wastewater is often a major problem for the environment due to its difficult treatment process and the damage it causes by contaminating the soil and water bodies where it is discharged. The objective was to remove metals in wastewater by applying mountain microorganisms and sodium hydroxide. The study site was in the district of Tarapoto, Province of San Martin. A total of 180 L of wastewater was used (9 samples), each sample contained 20 liters of water and was kept in a cold chain at an average temperature of 4 to 8°C for a period of 4 hours. The mountain microorganisms were reactivated and 20% sodium hydroxide was prepared. Three treatments were used (T1: MM 300 mL, T2: MM 400 mL, and T3: NaOH 20%). Analyses of 8 parameters were carried out and compared with the environmental quality standards category 3, showing that it exceeds the permitted values. The evaluation was carried out after 3 and 7 days and the results show that treatment 2, after 7 days of evaluation, reduces the values of the wastewater parameters and eliminates metals, complying with the environmental quality standards category 3 of the Peruvian Standard

    Serine 25 phosphorylation inhibits RIPK1 kinase-dependent cell death in models of infection and inflammation

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    RIPK1 regulates cell death and inflammation through kinase-dependent and -independent mechanisms. As a scaffold, RIPK1 inhibits caspase-8-dependent apoptosis and RIPK3/MLKL-dependent necroptosis. As a kinase, RIPK1 paradoxically induces these cell death modalities. The molecular switch between RIPK1 pro-survival and pro-death functions remains poorly understood. We identify phosphorylation of RIPK1 on Ser25 by IKKs as a key mechanism directly inhibiting RIPK1 kinase activity and preventing TNF-mediated RIPK1-dependent cell death. Mimicking Ser25 phosphorylation (S > D mutation) protects cells and mice from the cytotoxic effect of TNF in conditions of IKK inhibition. In line with their roles in IKK activation, TNF-induced Ser25 phosphorylation of RIPK1 is defective in TAK1- or SHARPIN-deficient cells and restoring phosphorylation protects these cells from TNF-induced death. Importantly, mimicking Ser25 phosphorylation compromises the in vivo cell death-dependent immune control of Yersinia infection, a physiological model of TAK1/IKK inhibition, and rescues the cell death-induced multi-organ inflammatory phenotype of the SHARPIN-deficient mice

    Imprinted antibody responses against SARS-CoV-2 Omicron sublineages

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    Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron sublineages carry distinct spike mutations resulting in escape from antibodies induced by previous infection or vaccination. We show that hybrid immunity or vaccine boosters elicit plasma-neutralizing antibodies against Omicron BA.1, BA.2, BA.2.12.1, and BA.4/5, and that breakthrough infections, but not vaccination alone, induce neutralizing antibodies in the nasal mucosa. Consistent with immunological imprinting, most antibodies derived from memory B cells or plasma cells of Omicron breakthrough cases cross-react with the Wuhan-Hu-1, BA.1, BA.2, and BA.4/5 receptor-binding domains, whereas Omicron primary infections elicit B cells of narrow specificity up to 6 months after infection. Although most clinical antibodies have reduced neutralization of Omicron, we identified an ultrapotent pan-variant–neutralizing antibody that is a strong candidate for clinical development
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