28 research outputs found

    Outcome of a questionnaire within European pharmaceutical aerosol group (EPAG) companies concerning the implementation of the abbreviated impactor measurement (AIM) concept for the assessment of orally inhaled product (OIP) aerosol aerodynamic particle size properties

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    The AIM Concept as an augmentation of full resolution cascade impactor (CI) measurements of the aerodynamic properties of aerosols emitted by OIPs has been in existence for about ten years. A previous EPAG-based survey undertaken five years ago indicated significant interest in the approach, particularly for the screening of candidate products in early stage product development. We report the outcome of a further questionnaire with the goals of establishing: (a) the types of AIM-based equipment currently in use; and (b) insight into perceived hurdles towards full implementation within the product lifecycle. Responses were received in October 2016 from 17 out of 22 organizations from people involved directly with the in vitro testing of pressurized metered dose inhaler (pMDI) and dry powder inhaler (DPI) products. The survey has shown that the AIM concept has sufficient popularity within the EPAG respondent organizations to be considered a viable augmentation to existing full resolution CI methodology. The main conclusions are: (1) The Fast Screening Andersen (FSA), reduced Next Generation Impactor (rNGI) and Fast Screening Impactor (FSI) are all used as AIM-based impactor configurations for both dry powder inhaler (DPI) and pressurized metered dose inhaler (pMDI) applications; (2) AIM-based methods are used almost entirely for the early development phase of the OIP life cycle; (3) Organizations in general do not have confidence to use the AIM concept more widely in the product life cycle whilst no compendial/regulatory guidance is available to provide standard procedures and precautions/regulatory acceptance respectively

    A European Pharmaceutical Aerosol Group (EPAG)-led cross-industry assessment of inlet flow rate profiles of compendial DPI test systems: Part 1 – experimental data

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    We report outcomes from an EPAG-led cross-industry study, characterizing flow rate/elapsed-time profiles of equipment used for testing dry powder inhalers (DPIs). A thermal mass flow sensor was used by nine organizations in a round-robin approach to record inlet flow rate-time profiles of individual participant compendial test systems (TS) including either sample collection tubes (SCT) or a cascade impactor (either the Andersen 8-stage non-viable impactor, ACI, or the Next Generation Impactor, NGI) equipped with USP/PhEur induction port and pre-separator. An inlet orifice generated a 4-kPa pressure drop at each of the target flow rates (30, 60 and 90 L/min), simulating a pressure drop typical for high-, medium- and low-resistance DPIs respectively. Rise times to 90% of these target flow rates (t90) were longest with largest internal dead volume and followed the order NGI>ACI >SCT>TS. When the surrogate DPI (4-kPa orifice) was absent, t90 values generally lengthened with increasing target flow rate. In contrast, the opposite behaviour was observed when the surrogate DPI was present. A flow acceleration parameter was also calculated, expressed as the slope between the 20% and 80% flow rates of each final steady flow value (slopet20/t80). Greater flow acceleration occurred at higher final flow rates, irrespective of apparatus, but the presence of the surrogate DPI was associated with slower flow acceleration. These flow rate-rise time profiles will be useful for those involved in evaluating equipment for characterizing both existing and new DPIs

    Allelic loss of chromosome 1p as a predictor of unfavorable outcome in patients with neuroblastoma

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    Background. Neuroblastoma is a childhood tumor derived from cells of the neural crest, with a widely variable outcome. Differences in the behavior and prognosis of the tumor suggest that neuroblastoma can be divided into several biologic subgroups. We evaluated the most frequent genetic abnormalities in neuroblastoma to determine their prognostic value. Methods. We used Southern blot analysis to study the allelic loss of chromosomes 1p, 4p, 11q, and 14q, the duplication of chromosome 17q, and the amplification of the N-myc oncogene in 89 neuroblastomas. We also determined the nuclear DNA content of the tumor cells. Results. Allelic loss of chromosome 1p, N-myc amplification, and extra copies of chromosome 17q were significantly associated with unfavorable outcomes. In a multivariate analysis, loss of chromosome 1p was the most powerful prognostic factor. It provided strong prognostic information when it was included in multivariate models containing the prognostic factors of age and stage or serum ferritin level and stage. Among the patients with stage I, II, or IVS disease, the mean (±SD) three-year event-free survival was 100 percent in those without allelic loss of chromosome 1p and 34±15 percent in those with such loss; the rates of three- year event-free survival among the patients with stage III and stage IV disease were 53±10 percent and 0 percent, respectively. Conclusions. The loss of chromosome 1p is a strong prognostic factor in patients with neuroblastoma, independently of age and stage. It reliably identifies patients at high risk in stages I, II, and IVS, which are otherwise clinically favorable. More intensive therapy may be considered in these patients. Patients in stages III and IV with allelic loss of chromosome 1p have a very poor outlook, whereas those without such loss are at moderate risk

    Tomo-seq identifies SOX9 as a key regulator of cardiac fibrosis during ischemic injury

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    Background: Cardiac ischemic injury induces a pathological remodeling response, which can ultimately lead to heart failure. Detailed mechanistic insights into molecular signaling pathways relevant for different aspects of cardiac remodeling will support the identification of novel therapeutic targets. Methods: While genome-wide transcriptome analysis on diseased tissues has greatly advanced our understanding of the regulatory networks that drive pathological changes in the heart, this approach has been disadvantaged by the fact that the signals are derived from tissue homogenates. Here we used tomo-seq to obtain a genome-wide gene expression signature with high spatial resolution spanning from the infarcted area to the remote to identify new regulators of cardiac remodeling. Cardiac tissue samples from patients suffering from ischemic heart disease were used to validate our findings. Results: Tracing transcriptional differences with a high spatial resolution across the infarcted heart enabled us to identify gene clusters that share a comparable expression profile. The spatial distribution patterns indicated a separation of expressional changes for genes involved in specific aspects of cardiac remodeling, like fibrosis, cardiomyocyte hypertrophy, and calcium-handling (Col1a2, Nppa, and Serca2). Subsequent correlation analysis allowed for the identification of novel factors that share a comparable transcriptional regulation pattern across the infarcted tissue. The strong correlation between the expression levels of these known marker genes and the expression of the co-regulated genes could be confirmed in human ischemic cardiac tissue samples. Follow-up analysis identified SOX9 as common transcriptional regulator of a large portion of the fibrosis-related genes that become activated under conditions of ischemic injury. Lineage-tracing experiments indicated the majority of COL1-positive fibroblasts to stem from a pool of SOX9-expressing cells and in vivo loss of Sox9 blunted the cardiac fibrotic response upon ischemic injury. The co-localization between SOX9 and COL1 could also be confirmed in patients suffering from ischemic heart disease. Conclusions: Based on the exact local expression cues, tomo-seq can serve to reveal novel genes and key transcription factors involved in specific aspects of cardiac remodeling. Using tomo-seq we were able to unveil the unknown relevance of SOX9 as key regulator of cardiac fibrosis, pointing to SOX9 as potential therapeutic target for cardiac fibrosis

    Sequencing of neuroblastoma identifies chromothripsis and defects in neuritogenesis genes

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    Neuroblastoma is a childhood tumour of the peripheral sympathetic nervous system. The pathogenesis has for a long time been quite enigmatic, as only very few gene defects were identified in this often lethal tumour. Frequently detected gene alterations are limited to MYCN amplification (20%) and ALK activations (7%). Here we present a whole-genome sequence analysis of 87 neuroblastoma of all stages. Few recurrent amino-acid-changing mutations were found. In contrast, analysis of structural defects identified a local shredding of chromosomes, known as chromothripsis, in 18% of high-stage neuroblastoma. These tumours are associated with a poor outcome. Structural alterations recurrently affected ODZ3, PTPRD and CSMD1, which are involved in neuronal growth cone stabilization. In addition, ATRX, TIAM1 and a series of regulators of the Rac/Rho pathway were mutated, further implicating defects in neuritogenesis in neuroblastoma. Most tumours with defects in these genes were aggressive high-stage neuroblastomas, but did not carry MYCN amplifications. The genomic landscape of neuroblastoma therefore reveals two novel molecular defects, chromothripsis and neuritogenesis gene alterations, which frequently occur in high-risk tumours

    Spatial transcriptomics unveils ZBTB11 as a regulator of cardiomyocyte degeneration in arrhythmogenic cardiomyopathy

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    AIMS: Arrhythmogenic cardiomyopathy (ACM) is an inherited cardiac disorder that is characterized by progressive loss of myocardium that is replaced by fibro-fatty cells, arrhythmias, and sudden cardiac death. While myocardial degeneration and fibro-fatty replacement occur in specific locations, the underlying molecular changes remain poorly characterized. Here we aim to delineate local changes in gene expression to identify new genes and pathways that are relevant for specific remodelling processes occurring during ACM. METHODS AND RESULTS: Using Tomo-Seq, genome-wide transcriptional profiling with high spatial resolution, we created transmural epicardial to endocardial gene expression atlases of explanted ACM hearts to gain molecular insights into disease-driving processes. This enabled us to link gene expression profiles to the different regional remodelling responses and allowed us to identify genes that are potentially relevant for disease progression. In doing so, we identified distinct gene expression profiles marking regions of cardiomyocyte degeneration and fibro-fatty remodelling and revealed Zinc finger and BTB domain-containing protein 11 (ZBTB11) to be specifically enriched at sites of active fibro-fatty replacement of myocardium. Immunohistochemistry indicated ZBTB11 to be induced in cardiomyocytes flanking fibro-fatty areas, which could be confirmed in multiple cardiomyopathy patients. Forced overexpression of ZBTB11 induced autophagy and cell death-related gene programs in human cardiomyocytes, leading to increased apoptosis. CONCLUSIONS: Our study shows the power of Tomo-Seq to unveil new molecular mechanisms in human cardiomyopathy and uncovers ZBTB11 as a novel driver of cardiomyocyte loss

    Multi-directional liquid crystal alignment techniques

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    Presently photo-alignment is a well established technol. for monolithic liq. crystal orientation as well as the formation of multiple liq. crystal domains controlling directionality and pretilt. The paper will discuss some methodologies to enhance photo-alignment of liq. crystals with features such as multi-directional alignment and periodic alignment. Multi-directional alignment is achieved with traditional photosensitive alignment materials such as polymeric cinnamic acid esters or coumarin contg. polymers. These are partly aligned by local exposure with UV light. This dets. the directionality of lateral liq. crystal alignment. The unexposed area, still contg. the unreacted vinyl groups, is exposed to thiol surfactant in the presence of a thermal initiator. The alkyl tails of the thiol provide a homeotropic alignment to the liq. crystal. Micrometer sized periodic structures are achieved by holog. exposure of photo-alignment films with two interfering laser beams. Besides striped alignment profile, also complex squared alignment profiles are obtained by two orthogonal holog. exposures. [on SciFinder (R)

    Multi-directional liquid crystal alignment techniques

    No full text
    Presently photo-alignment is a well established technol. for monolithic liq. crystal orientation as well as the formation of multiple liq. crystal domains controlling directionality and pretilt. The paper will discuss some methodologies to enhance photo-alignment of liq. crystals with features such as multi-directional alignment and periodic alignment. Multi-directional alignment is achieved with traditional photosensitive alignment materials such as polymeric cinnamic acid esters or coumarin contg. polymers. These are partly aligned by local exposure with UV light. This dets. the directionality of lateral liq. crystal alignment. The unexposed area, still contg. the unreacted vinyl groups, is exposed to thiol surfactant in the presence of a thermal initiator. The alkyl tails of the thiol provide a homeotropic alignment to the liq. crystal. Micrometer sized periodic structures are achieved by holog. exposure of photo-alignment films with two interfering laser beams. Besides striped alignment profile, also complex squared alignment profiles are obtained by two orthogonal holog. exposures. [on SciFinder (R)
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