155 research outputs found

    Alternative administration routes and delivery technologies for polio vaccines.

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    Global polio eradication is closer than ever. Replacement of the live attenuated oral poliovirus vaccine (OPV) by inactivated poliovirus vaccine (IPV) is recommended to achieve complete eradication. Limited global production capacity and relatively high IPV costs compared to OPV spur the need for improved polio vaccines. The target product profile of these vaccines includes not only dose sparing but also high stability, which is important for stockpiling, and easy application important for (emergency) vaccination campaigns. In this review, the current status of alternative polio vaccine delivery strategies is given. Furthermore, we discuss the feasibility of these strategies by highlighting challenges, hurdles to overcome, and formulation issues relevant for optimal vaccine delivery

    High-content high-throughput imaging reveals distinct connections between mitochondrial morphology and functionality for oxphos complex I, III, and V inhibitors

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    Cells can adjust their mitochondrial morphology by altering the balance between mitochondrial fission and fusion to adapt to stressful conditions. The connection between a chemical perturbation, changes in mitochondrial function, and altered mitochondrial morphology is not well understood. Here, we made use of high-throughput high-content confocal microscopy to assess the effects of distinct classes of oxidative phosphorylation (OXPHOS) complex inhibitors on mitochondrial parameters in a concentration and time resolved manner. Mitochondrial morphology phenotypes were clustered based on machine learning algorithms and mitochondrial integrity patterns were mapped. In parallel, changes in mitochondrial membrane potential (MMP), mitochondrial and cellular ATP levels, and viability were microscopically assessed. We found that inhibition of MMP, mitochondrial ATP production, and oxygen consumption rate (OCR) using sublethal concentrations of complex I and III inhibitors did not trigger mitochondrial fragmentation. Instead, complex V inhibitors that suppressed ATP and OCR but increased MMP provoked a more fragmented mitochondrial morphology. In agreement, complex V but not complex I or III inhibitors triggered proteolytic cleavage of the mitochondrial fusion protein, OPA1. The relation between increased MMP and fragmentation did not extend beyond OXPHOS complex inhibitors: increasing MMP by blocking the mPTP pore did not lead to OPA1 cleavage or mitochondrial fragmentation and the OXPHOS uncoupler FCCP was associated with OPA1 cleavage and MMP reduction. Altogether, our findings connect vital mitochondrial functions and phenotypes in a high-throughput high-content confocal microscopy approach that help understanding of chemical-induced toxicity caused by OXPHOS complex perturbing chemicals.Toxicolog

    Hypoxia triggers TAZ phosphorylation in basal a triple negative breast cancer cells

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    Hypoxia and HIF signaling drive cancer progression and therapy resistance and have been demonstrated in breast cancer. To what extent breast cancer subtypes differ in their response to hypoxia has not been resolved. Here, we show that hypoxia similarly triggers HIF1 stabilization in luminal and basal A triple negative breast cancer cells and we use high throughput targeted RNA sequencing to analyze its effects on gene expression in these subtypes. We focus on regulation of YAP/TAZ/TEAD targets and find overlapping as well as distinct target genes being modulated in luminal and basal A cells under hypoxia. We reveal a HIF1 mediated, basal A specific response to hypoxia by which TAZ, but not YAP, is phosphorylated at Ser89. While total YAP/TAZ localization is not affected by hypoxia, hypoxia drives a shift of [p-TAZ(Ser89)/p-YAP(Ser127)] from the nucleus to the cytoplasm in basal A but not luminal breast cancer cells. Cell fractionation and YAP knock-out experiments confirm cytoplasmic sequestration of TAZ(Ser89) in hypoxic basal A cells. Pharmacological and genetic interference experiments identify c-Src and CDK3 as kinases involved in such phosphorylation of TAZ at Ser89 in hypoxic basal A cells. Hypoxia attenuates growth of basal A cells and the effect of verteporfin, a disruptor of YAP/TAZ-TEAD-mediated transcription, is diminished under those conditions, while expression of a TAZ-S89A mutant does not confer basal A cells with a growth advantage under hypoxic conditions, indicating that other hypoxia regulated pathways suppressing cell growth are dominant.Toxicolog

    Dynamic modeling of mitochondrial membrane potential upon exposure to mitochondrial inhibitors

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    Mitochondria are the main bioenergetic organelles of cells. Exposure to chemicals targeting mitochondria therefore generally results in the development of toxicity. The cellular response to perturbations in cellular energy production is a balance between adaptation, by reorganisation and organelle biogenesis, and sacrifice, in the form of cell death. In homeostatic conditions, aerobic mitochondrial energy production requires the maintenance of a mitochondrial membrane potential (MMP). Chemicals can perturb this MMP, and the extent of this perturbation depends both on the pharmacokinetics of the chemicals and on downstream MMP dynamics. Here we obtain a quantitative understanding of mitochondrial adaptation upon exposure to various mitochondrial respiration inhibitors by applying mathematical modeling to partially published high-content imaging time-lapse confocal imaging data, focusing on MMP dynamics in HepG2 cells over a period of 24 h. The MMP was perturbed using a set of 24 compounds, either acting as uncoupler or as mitochondrial complex inhibitor targeting complex I, II, III or V. To characterize the effect of chemical exposure on MMP dynamics, we adapted an existing differential equation model and fitted this model to the observed MMP dynamics. Complex III inhibitor data were better described by the model than complex I data. Incorporation of pharmacokinetic decay into the model was required to obtain a proper fit for the uncoupler FCCP. Furthermore, oligomycin (complex V inhibitor) model fits were improved by either combining pharmacokinetic (PK) decay and ion leakage or a concentration-dependent decay. Subsequent mass spectrometry measurements showed that FCCP had a significant decay in its PK profile as predicted by the model. Moreover, the measured oligomycin PK profile exhibited only a limited decay at high concentration, whereas at low concentrations the compound remained below the detection limit within cells. This is consistent with the hypothesis that oligomycin exhibits a concentration-dependent decay, yet awaits further experimental verification with more sensitive detection methods. Overall, we show that there is a complex interplay between PK and MMP dynamics within mitochondria and that data-driven modeling is a powerful combination to unravel such complexity.Toxicolog

    Мирон Кордуба і українська громада в Москві (штрих до історії візиту 1907 року)

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    Молодого науковця Мирона Кордубу професор Львівського університету М. Грушевський восени 1907 р. відрядив до Москви з метою опрацювання архівних матеріалів. М. Кордуба активно влився у громадсько-політичне та культурне життя української громади російської столиці. Висвітлено вплив візиту Кордуби на усвідомлення українським студентством Москви своєї ідентичності, розуміння потреби згуртованості та активної позиції у досягненні громадянських та національних прав.Молодого ученого Мирона Кордубу профессор Львовского университета М. Грушевский осенью 1907 г. командировал в Москву с целью изучения архивных материалов. М. Кордуба стал активным участником общественно-политической и культурной жизни столицы. Раскрыто влияние визита Кордубы на степень сплоченности, формирование национального сознания украинского студенчества Москвы.The young scientist Myron Korduba studied historical archives in Moscow in autumn 1907. His civic and cultural activities during this period positively influenced on the unity of Ukrainian student community in Moscow. Lviv scientist helped to identify community goals and methods of obtaining civil and national rights

    Differences in presentation between paediatric- and adult-onset primary Sjögren's syndrome patients

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    OBJECTIVES: Primary Sjögren's syndrome (pSS) is a rare disease in paediatric patients. Presenting symptoms differ from those in adult patients. The aim of this study was to evaluate presenting symptoms, classification criteria and clinical assessments, including salivary gland ultrasonography (SGUS), at disease onset in paediatric and adult patients with pSS. METHODS: Data of 23 paediatric- and 33 adult-onset patients with pSS were obtained from our standardised multidisciplinary REpSULT and RESULT cohorts, respectively. Clinical, patient-reported, serological, functional, biopsy and SGUS parameters were compared. RESULTS: In paediatric-onset pSS (pedSS) patients, recurrent parotid gland swelling (91% vs. 49%, p<0.001) and fever (30% vs. 3%, p=0.006) were more often present than in adult-onset patients. In contrast, sicca symptoms of mouth (52% vs. 79%, p=0.046) and eyes (26% vs. 73%, p<0.001) were less common in pedSS patients. In paediatric patients, the entry criteria of the ACR/EULAR classification were most often met due to activity in the glandular domain of the ESSDAI. When applying the ACR/EULAR classification criteria, only 78% of pedSS fulfilled these criteria compared to 100% of adult patients. Abnormal glandular function tests had a greater contribution to fulfilling the criteria in adults, while the biopsy had a greater contribution in paediatric patients. Anti-SSA/Ro serology had similar contribution for both cohorts. SGUS Hocevar score was significantly higher in paediatric compared to adult patients (median 25 vs. 18, p=0.004). CONCLUSION: PedSS has a different presentation than adult-onset pSS. Recurrent parotid gland swelling in paediatric patients should alert clinicians to the potential presence of pSS
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