415 research outputs found
Ultrastructural Studies of Raw and Processed Tissue of the Major Cultivated Mushroom, Agaricus bisporus
Commercial mushroom processors currently lose approximately 30 percent of the mushroom weight due to shrinkage during processing (blanching and canning) , resulting in substantial economic losses . Microscopy was used to assess the extent and type of chemical and structural changes induced by processing mushrooms and causing shrinkage. Scanning electron microscopy revealed that the processing operations including vacuum hydration , blanching , and thermal treatment do not damage the integrity of the tissue. Light microscopy revealed that the morphology of the tissue, shape and spacing of cells, appear similar for raw and processed mushroom tissue . However, the intra ce ll ular material remained indistinct for both tissue types, and the processed tissue appeared distorted. Transmission electron microscopy revealed that commercial mushroom processing caused intracellular damage to the tissue. The heat treatment caused the coagulation of cytoplasmic material and the disruption of intracellular membranes, resulting in the loss of water holding capacity of the tissue. Therefore, shrinkage of processed mushrooms results from denaturation of the organelles and the associated loss of water holding capacity by those organelles
In vitro evaluation of novel antimicrobial coatings for surgical sutures using octenidine
Background: Sutures colonized by bacteria represent a challenge in surgery due to their potential to cause surgical site infections. In order to reduce these type of infections antimicrobially coated surgical sutures are currently under development. In this study, we investigated the antimicrobial drug octenidine as a coating agent for surgical sutures. To achieve high antimicrobial efficacy and required biocompatibility for medical devices, we focused on optimizing octenidine coatings based on fatty acids. For this purpose, antimicrobial sutures were prepared with either octenidine-laurate or octenidine-palmitate at 11, 22, and 33 mu g/cm drug concentration normalized per length of sutures. Octenidine containing sutures were compared to the commercial triclosan-coated suture Vicryl (R) Plus. The release of octenidine into aqueous solution was analyzed and long-term antimicrobial efficacy was assessed via agar diffusion tests using Staphylococcus aureus. For determining biocompatibility, cytotoxicity assays (WST-1) were performed using L-929 mouse fibroblasts. Results: In a 7 days elution experiment, octenidine-palmitate coated sutures demonstrated much slower drug release (11 mu g/cm: 7 %;22 mu g/cm: 5 %;33 mu g/cm: 33 %) than octenidine-laurate sutures (11 mu g/cm: 82 %;22 mu g/cm: 88 %;33 mu g/cm: 87 %). Furthermore sutures at 11 mu g/cm drug content were associated with acceptable cytotoxicity according to ISO 10993-5 standard and showed, similar to Vicryl (R) Plus, relevant efficacy to inhibit surrounding bacterial growth for up to 9 days. Conclusions: Octenidine coated sutures with a concentration of 11 mu g/cm revealed high antimicrobial efficacy and biocompatibility. Due to their delayed release, palmitate carriers should be preferred. Such coatings are candidates for clinical testing in regard to their safety and efficacy
Effect of a Novel Nonviral Gene Delivery of BMP-2 on Bone Healing
Background. Gene therapeutic drug delivery approaches have been introduced to improve the efficiency of growth factors at the site of interest. This study investigated the efficacy and safety of a new nonviral copolymer-protected gene vector (COPROG) for the stimulation of bone healing. Methods. In vitro, rat osteoblasts were transfected with COPROG + luciferase plasmid or COPROG + hBMP-2 plasmid. In vivo, rat tibial fractures were intramedullary stabilized with uncoated versus COPROG+hBMP-2-plasmid-coated titanium K-wires. The tibiae were prepared for biomechanical and histological analyses at days 28 and 42 and for transfection/safety study at days 2, 4, 7, 28, and 42. Results. In vitro results showed luciferase expression until day 21, and hBMP-2-protein was measured from day 2 – day 10. In vivo, the local application of hBMP-2-plasmid showed a significantly higher maximum load after 42 days compared to that in the control. The histomorphometric analysis revealed a significantly less mineralized periosteal callus area in the BMP-2 group compared to the control at day 28. The rt-PCR showed no systemic biodistribution of luciferase RNA. Conclusion. A positive effect on fracture healing by nonviral BMP-2 plasmid application from COPROG-coated implants could be shown in this study; however, the effect of the vector may be improved with higher plasmid concentrations. Transfection showed no biodistribution to distant organs and was considered to be safe
A survey of participants in two internet support groups for people with hair-pulling
BACKGROUND: A substantial number of patients suffering from psychological problems or psychiatric disorders have turned to internet support groups for help. This paper reports on the perceived effectiveness of trichotillomania (TTM) internet support groups for people suffering from hair-pulling. METHODS: A questionnaire was sent via e-mail to all subscribers of two mailing lists devoted to TTM, each of which takes a somewhat different approach to the condition. The questionnaire addressed the possible benefits and problems associated with belonging to a TTM virtual support group. RESULTS: Subscribers had similar demographic features as clinical samples of trichotillomania patients. Subscribers to both internet lists found them helpful in terms of feeling supported and in obtaining information. The different approaches to TTM on the two lists were associated with differences in treatments attempted by participants. CONCLUSION: Internet support groups can potentially contribute to increasing awareness about and knowledge of psychiatric disorders such as TTM, as well as to their management. Nevertheless, additional effort is required to ensure that subscribers are able to make informed, evidence-based decisions
FAS-dependent cell death in α-synuclein transgenic oligodendrocyte models of multiple system atrophy
Multiple system atrophy is a parkinsonian neurodegenerative disorder. It is cytopathologically characterized by accumulation of the protein p25α in cell bodies of oligodendrocytes followed by accumulation of aggregated α-synuclein in so-called glial cytoplasmic inclusions. p25α is a stimulator of α-synuclein aggregation, and coexpression of α-synuclein and p25α in the oligodendroglial OLN-t40-AS cell line causes α-synuclein aggregate-dependent toxicity. In this study, we investigated whether the FAS system is involved in α-synuclein aggregate dependent degeneration in oligodendrocytes and may play a role in multiple system atrophy. Using rat oligodendroglial OLN-t40-AS cells we demonstrate that the cytotoxicity caused by coexpressing α-synuclein and p25α relies on stimulation of the death domain receptor FAS and caspase-8 activation. Using primary oligodendrocytes derived from PLP-α-synuclein transgenic mice we demonstrate that they exist in a sensitized state expressing pro-apoptotic FAS receptor, which makes them sensitive to FAS ligand-mediated apoptosis. Immunoblot analysis shows an increase in FAS in brain extracts from multiple system atrophy cases. Immunohistochemical analysis demonstrated enhanced FAS expression in multiple system atrophy brains notably in oligodendrocytes harboring the earliest stages of glial cytoplasmic inclusion formation. Oligodendroglial FAS expression is an early hallmark of oligodendroglial pathology in multiple system atrophy that mechanistically may be coupled to α-synuclein dependent degeneration and thus represent a potential target for protective intervention
Novel Serial Positive Enrichment Technology Enables Clinical Multiparameter Cell Sorting
A general obstacle for clinical cell preparations is limited purity, which causes variability in the quality and potency of cell products and might be responsible for negative side effects due to unwanted contaminants. Highly pure populations can be obtained best using positive selection techniques. However, in many cases target cell populations need to be segregated from other cells by combinations of multiple markers, which is still difficult to achieve – especially for clinical cell products. Therefore, we have generated low-affinity antibody-derived Fab-fragments, which stain like parental antibodies when multimerized via Strep-tag and Strep-Tactin, but can subsequently be removed entirely from the target cell population. Such reagents can be generated for virtually any antigen and can be used for sequential positive enrichment steps via paramagnetic beads. First protocols for multiparameter enrichment of two clinically relevant cell populations, CD4high/CD25high/CD45RAhigh ‘regulatory T cells’ and CD8high/CD62Lhigh/CD45RAneg ‘central memory T cells’, have been established to determine quality and efficacy parameters of this novel technology, which should have broad applicability for clinical cell sorting as well as basic research
Rapid and sustained T cell-based immunotherapy against invasive fungal disease via a combined two step procedure
IntroductionAspergillus fumigatus (Asp) infections constitute a major cause of morbidity and mortality in patients following allogeneic hematopoietic stem cell transplantation (HSCT). In the context of insufficient host immunity, antifungal drugs show only limited efficacy. Faster and increased T-cell reconstitution correlated with a favorable outcome and a cell-based therapy approach strongly indicated successful clearance of fungal infections. Nevertheless, complex and cost- or time-intensive protocols hampered their implementation into clinical application. MethodsTo facilitate the clinical-scale manufacturing process of Aspergillus fumigatus-specific T cells (ATCs) and to enable immediate (within 24 hours) and sustained (12 days later) treatment of patients with invasive aspergillosis (IA), we adapted and combined two complementary good manufacturing practice (GMP)-compliant approaches, i) the direct magnetic enrichment of Interferon-gamma (IFN-gamma) secreting ATCs using the small-scale Cytokine Secretion Assay (CSA) and ii) a short-term in vitro T-cell culture expansion (STE), respectively. We further compared stimulation with two standardized and commercially available products: Asp-lysate and a pool of overlapping peptides derived from different Asp-proteins (PepMix). ResultsFor the fast CSA-based approach we detected IFN-gamma(+) ATCs after Asp-lysate- as well as PepMix-stimulation but with a significantly higher enrichment efficiency for stimulation with the Asp-lysate when compared to the PepMix. In contrast, the STE approach resulted in comparably high ATC expansion rates by using Asp-lysate or PepMix. Independent of the stimulus, predominantly CD4(+) helper T cells with a central-memory phenotype were expanded while CD8(+) T cells mainly showed an effector-memory phenotype. ATCs were highly functional and cytotoxic as determined by secretion of granzyme-B and IFN-gamma. DiscussionFor patients with IA, the immediate adoptive transfer of IFN-gamma(+) ATCs followed by the administration of short-term in vitro expanded ATCs from the same donor, might be a promising therapeutic option to improve the clinical outcome.Transplantation and immunomodulatio
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