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| 2. |
- Baltz, Niklas, et al.
(author)
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Advancing nasal formulation characterization: Considerations toward a robust and precise method to determine the mass fraction below 10 μm in nasal products
- 2024
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In: Aerosol Science and Technology. - 0278-6826 .- 1521-7388. ; In Press
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Journal article (peer-reviewed)abstract
- The expanding role of the nasal route in drug administration for local and systemic treatments has prompted the need for precise delivery methods to ensure efficacy and patient safety. This study addresses the challenges of evaluating the mass fraction below 10 μm in nasal products, a crucial factor in assessing lung deposition of drugs of nasal formulations. Current regulatory guidelines advocate for this assessment, yet a standardized compendial methodology is lacking. To fill this gap, we comprehensively examined several methods to determine a robust approach for quantifying the mass fraction below 10 μm in nasal products. As model formulation, a commercial nasal product (aqueous solution of sodium cromoglycate) was utilized. The assessment of mass fractions below 10 μm necessitates considerations like general handling, precise assessment of delivered dose, robust recovery, and appropriate impactor size analysis techniques. The choice of impactor and of inlet for size analysis may significantly influence the generated results. In this regard, the study highlights the necessity for careful impactor and inlet selection to ensure accurate measurements. In the course of this, the Kiel Nasal Inlet (KNI) had been designed to optimize nasal product testing, addressing the shortcomings of existing inlets. The KNI performed well across different laboratories and reproducible between impactor types. For the determination of mass fraction below 10 μm, the Fast Screening Impactor is the preferred choice of the authors.
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| 3. |
- Bankell, Elisabeth, et al.
(author)
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LL-37-induced caspase-independent apoptosis is associated with plasma membrane permeabilization in human osteoblast-like cells
- 2021
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In: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 135
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Journal article (peer-reviewed)abstract
- The host defense peptide LL-37 is active against both gram-positive and gram-negative bacteria, but it has also been shown to reduce human host cell viability. However, the mechanisms behind LL-37-induced human host cell cytotoxicity are not yet fully understood. Here, we assess if LL-37-evoked attenuation of human osteoblast-like MG63 cell viability is associated with apoptosis, and if the underlying mechanism may involve LL-37-induced plasma membrane permeabilization. MG63 cell viability and plasma membrane permeabilization were investigated by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method and by measuring lactate dehydrogenase (LDH) release, respectively. Apoptosis was assessed by the terminal deoxynucleotidyl dUTP nick end labeling (TUNEL) assay and Annexin V flow cytometry, and caspase-3 and poly (ADP-ribose) polymerase (PARP) cleavage were determined by Western blot. LL-37 (4 and 10 μM) reduced both cell number and cell viability, and these effects were associated with a pro-apoptotic effect demonstrated by positive TUNEL staining and Annexin V flow cytometry. LL-37-induced apoptosis was not coupled to either caspase-3 or PARP cleavage, suggesting that LL-37 causes caspase-independent apoptosis in MG63 cells. Both LL-37 and the well-known plasma membrane permeabilizer Triton X-100 reduced cell viability and stimulated LDH release. Triton X-100-treated cells showed positive TUNEL staining, and the detergent accumulated cells in late apoptosis/necrosis. Similar to LL-37, Triton X-100 caused no PARP cleavage. We conclude that LL-37 promotes caspase-independent apoptosis, and that this effect seems coupled to plasma membrane permeabilization in human MG63 cells.
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| 4. |
- Dahl, Sara, et al.
(author)
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The host defense peptide LL-37 triggers release of nucleic acids from human mast cells
- 2018
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In: Peptides. - : Elsevier BV. - 0196-9781 .- 1873-5169. ; 109, s. 39-45
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Journal article (peer-reviewed)abstract
- The human host defense peptide LL-37 possesses antimicrobial activity but also affects host cell function and viability. Mast cells are involved in innate immunity but no data have been presented on effects of LL-37 on human mast cell viability and export of nucleic acids. Here, we demonstrated by immunofluorescence microscopy that synthesized LL-37 was internalized by human LAD2 mast cells and detected both in cytoplasm and nucleus. Treatment with high (4 and 10 μM) but not low (1 μM) concentrations of LL-37 for 4 h reduced cell viability assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Stimulation with 10 μM LL-37 for 4 h enhanced export of nucleic acids, total protein and lactate dehydrogenase (LDH), suggesting that both nuclear and plasma membranes are permeabilized by LL-37. Although LL-37 triggered release of nucleic acids, no extracellular trap-like structures were observed by laser scanning confocal microscopy of cells incubated with the plasma membrane impermeable nucleic acid fluorophore SYTOX-Green, indicating that LL-37 promotes export of nucleic acids but not formation of extracellular traps. On the other hand, phorbol-12-myristate-13-acetate (PMA), which is a well-known inducer of extracellular traps, stimulated export of nucleic acids and also formation of extracellular trap-like structures. However, PMA had no effect on export of either total protein or LDH. Hence, LL-37 and PMA seem to stimulate export of nucleic acids from LAD2 mast cells through different pathways. In conclusion, we demonstrate that LL-37 triggers release of nucleic acids from human mast cells but not the formation of extracellular trap-like structures.
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| 5. |
- Looi Chee Leong, Jeffrey, et al.
(author)
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Caudate nucleus volumes in frontotemporal lobar degeneration : differential atrophy in subtypes
- 2008
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In: American Journal of Neuroradiology. - 0195-6108 .- 1936-959X. ; 29:8, s. 1537-1543
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Journal article (peer-reviewed)abstract
- BACKGROUND AND PURPOSE: Frontostriatal circuits involving the caudate nucleus have been implicated in frontotemporal lobar degeneration (FTLD). We assessed caudate nucleus volumetrics in FTLD and subtypes: frontotemporal dementia (FTD, n = 12), semantic dementia (SD, n = 13), and progressive nonfluent aphasia (PNFA, n = 9) in comparison with healthy controls (n = 27) and subjects with Alzheimer disease (AD, n = 19). MATERIALS AND METHODS: Diagnoses were based on accepted clinical criteria. Manual volume measurement of the head and body of the caudate, excluding the tail, was conducted on T1-weighted brain MR imaging scans, using a published protocol, by a single analyst blinded to the diagnosis. RESULTS: Paired t tests (P < .05) showed that the right caudate nucleus volume was significantly larger than the left in controls and PNFA. No hemispheric asymmetry was found in AD, ETD, and SD. Across the groups, there was a positive partial correlation between the left caudate nucleus volume and Mini-Mental State Examination (MMSE) scores (r = 0.393, n = 76, P = .001) with higher left caudate volumes associated with higher MMSE scores. Multivariate analysis of covariance was used to assess the statistical significance between the subject groups (AD, ETD, SD, PNFA, and controls) as independent variables and raw right/left caudate volumes at the within-subject level (covariates: age and intracranial volume; P < .05). Control volume was largest, followed by AD (93% of control volume), SD (92%), PNFA (79%), and ETD (75%). CONCLUSIONS: Volume of the head and body of the caudate nucleus differs in subtypes of FTLD, due to differential frontostriatal dysfunction in subtypes being reflected in structural change in the caudate, and is correlated with cognition
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| 6. |
- Looi, Jefferey Chee Leong, et al.
(author)
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Shape analysis of the neostriatum in frontotemporal lobar degeneration, Alzheimer's disease, and controls
- 2010
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In: NeuroImage. - : Elsevier BV. - 1053-8119 .- 1095-9572. ; 51:3, s. 970-986
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Journal article (peer-reviewed)abstract
- Background and purpose: Frontostriatal circuit mediated cognitive dysfunction has been implicated in frontotemporal lobar degeneration (FTLD), but not Alzheimer's disease, or healthy aging. We measured the neostriatum (caudate nucleus and putamen) volume in FTLD (n=34), in comparison with controls (n=27) and Alzheimer's disease (AD, n=19) subjects. Methods: Diagnoses were based on international consensus criteria. Manual bilateral segmentation of the caudate nucleus and putamen was conducted blind to diagnosis by a single analyst, on MRI scans using a standardized protocol. Intra-cranial volume was calculated via a stereological point counting technique and was used for scaling the shape analysis. The manual segmentation binaries were analyzed using UNC Shape Analysis tools (University of North Carolina) to perform comparisons among FTLD, AD, and controls for global shape, local p-value significance maps, and mean magnitude of shape displacement. Results: Shape analysis revealed that there was significant shape difference between FTLD, AD, and controls, consistent with the predicted frontostriatal dysfunction and of significant magnitude, as measured by displacement maps. There was a lateralized difference in shape for the left caudate for FTLD compared to AD; non-specific global atrophy in AD compared to controls; while FTLD showed a more specific pattern in regions relaying fronto- and corticostriatal circuits. Conclusions: Shape analysis shows regional specificity of atrophy, manifest as shape deflation, with implications for frontostriatal and corticostriatal motoric circuits, in FTLD, AD, and controls.
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| 7. |
- Looi, Jeffrey Chee Leong, et al.
(author)
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Shape analysis of the neostriatum in subtypes of frontotemporal lobar degeneration : neuroanatomically significant regional morphologic change
- 2011
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In: Psychiatry Research. - : Elsevier BV. - 0925-4927 .- 1872-7506 .- 0165-1781. ; 191:2, s. 98-111
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Journal article (peer-reviewed)abstract
- Frontostriatal circuit mediated cognitive dysfunction has been implicated in frontotemporal lobar degeneration (FTLD) and may differ across subtypes of FTLD. We manually segmented the neostriatum (caudate nucleus and putamen) in FTLD subtypes: behavioral variant frontotemporal dementia, FTD, n=12; semantic dementia, SD, n=13; and progressive non-fluent aphasia, PNFA, n=9); in comparison with controls (n=27). Diagnoses were based on international consensus criteria. Manual bilateral segmentation of the caudate nucleus and putamen was conducted blind to diagnosis by a single analyst, on MRI scans using a standardized protocol. Intracranial volume was calculated via a stereological point counting technique and was used for normalizing the shape analysis. Segmented binaries were analyzed using the Spherical Harmonic (SPHARM) Shape Analysis tools (University of North Carolina) to perform comparisons between FTLD subtypes and controls for global shape difference, local significance maps and mean magnitude maps of shape displacement. Shape analysis revealed that there was significant shape difference between FTLD subtypes and controls, consistent with the predicted frontostriatal dysfunction and of significant magnitude, as measured by displacement maps. These differences were not significant for SD compared to controls; lesser for PNFA compared to controls; whilst FTD showed a more specific pattern in regions relaying fronto- and corticostriatal circuits. Shape analysis shows regional specificity of atrophy, manifest as shape deflation, with a differential between FTLD subtypes, compared to controls.
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| 8. |
- Regnell, Olof, et al.
(author)
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Linking Cellulose Fiber Sediment Methyl Mercury Levels to Organic Matter Decay and Major Element Composition.
- 2014
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In: Ambio: a Journal of Human Environment. - : Springer Science and Business Media LLC. - 0044-7447. ; 43:7, s. 878-890
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Journal article (peer-reviewed)abstract
- Methylation of mercury (Hg) to highly toxic methyl Hg (MeHg), a process known to occur when organic matter (OM) decomposition leads to anoxia, is considered a worldwide threat to aquatic ecosystems and human health. We measured temporal and spatial variations in sediment MeHg, total Hg (THg), and major elements in a freshwater lagoon in Sweden polluted with Hg-laden cellulose fibers. Fiber decomposition, confined to a narrow surface layer, resulted in loss of carbon (C), uptake of nitrogen (N), phosphorus (P), and sulfur (S), and increased MeHg levels. Notably, fiber decomposition and subsequent erosion of fiber residues will cause buried contaminants to gradually come closer to the sediment-water interface. At an adjacent site where decomposed fiber accumulated, there was a gain in C and a loss of S when MeHg increased. As evidenced by correlation patterns and vertical chemical profiles, reduced S may have fueled C-fixation and Hg methylation at this site.
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| 9. |
- Svensson, Daniel, et al.
(author)
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Inhibition of MicroRNA-125a Promotes Human Endothelial Cell Proliferation and Viability through an Antiapoptotic Mechanism.
- 2014
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In: Journal of Vascular Research. - : S. Karger AG. - 1423-0135 .- 1018-1172. ; 51:3, s. 239-245
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Journal article (peer-reviewed)abstract
- The microRNA-125a (miR-125a) is highly expressed in endothelial cells, but its role in vascular biology is not known. Endothelial cell proliferation and viability play an important role in endothelial healing, and we hypothesize that miR-125a regulates this process. The aim of the present study was to investigate if miR-125a controls human endothelial cell proliferation, viability and endothelial healing, and to assess the mechanisms involved. We showed that overexpression of miR-125a by transfection with miR-125a mimic reduced human umbilical vein endothelial cell (HUVEC) proliferation and viability, and stimulated apoptosis as demonstrated by a miR-125a-induced increase of the proportion of annexin V-positive cells monitored by flow cytometry. Moreover, we showed that the miR-125a mimic downregulated the antiapoptotic Bcl2 protein and upregulated caspase 3, suggesting that these two proteins represent molecular targets for miR-125a. Accordingly, transfection with miR-125a inhibitor, downregulating miR-125a expression, promoted HUVEC proliferation and viability, and reduced apoptosis. Importantly, transfection with miR-125a inhibitor promoted HUVEC tube formation in Matrigel, suggesting that reduction of miR-125a has a proangiogenic effect. In conclusion, downregulation of miR-125a through local transfection with miR-125a inhibitor might be a new way to enhance endothelial cell proliferation and viability, thereby promoting the reendothelialization observed in response to intimal injury. © 2014 S. Karger AG, Basel.
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| 10. |
- Svensson, Marie, et al.
(author)
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Osmotic stability of the cell membrane of Escherichia coli from a temperature-limited fed-batch process
- 2005
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In: Applied Microbiology and Biotechnology. - : Springer Science and Business Media LLC. - 0175-7598 .- 1432-0614. ; 67:3, s. 345-350
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Journal article (peer-reviewed)abstract
- The temperature-limited fed-batch (TLFB) process is a technique where the oxygen consumption rate is controlled by a gradually declining temperature profile rather than a growth-limiting glucose-feeding profile. In Escherichia coli cultures, it has been proven to prevent an extensive release of endotoxins, i.e. lipopolysaccharides, that occurs in the glucose-limited fed-batch (GLFB) processes at specific growth rates below 0.1 h(-1). The TLFB and the GLFB process were compared to each other when applied to produce the periplasmic, constitutively expressed, enzyme beta-lactamase. The extraction of the enzyme was performed by osmotic shock. A higher production of beta-lactamase was achieved with the TLFB technique while no difference in the endotoxin release was found during the extraction procedure. Furthermore, it was found that growth at declining temperature, generated by the TLFB technique, gradually stabilizes the cytoplasmic membrane, resulting in a significantly increased product quality in the extract from the TLFB cultures in the osmotic shock treatment.
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