824 research outputs found
Colocalization of endogenous TNF with a functional intracellular splice form of human TNF receptor type 2
BACKGROUND: Tumor necrosis factor (TNF) is a pleiotropic cytokine involved in a broad spectrum of inflammatory and immune responses including proliferation, differentiation, and cell death. The biological effects of TNF are mediated via two cell surface TNF receptors: p55TNFR (TNFR1; CD120a) and p75TNFR (TNFR2; CD120b). Soluble forms of these two receptors consisting of the extracellular domains are proteolytically cleaved from the membrane and act as inhibitors. A novel p75TNFR isoform generated by the use of an additional transcriptional start site has been described and was termed hicp75TNFR. We focused on the characterization of this new isoform as this protein may be involved in chronic inflammatory processes. METHODS: Cell lines were retroviraly transduced with hp75TNFR isoforms. Subcellular localization and colocalization studies with TNF were performed using fluorescence microscopy including exhaustive photon reassignment software, flow cytometry, and receptosome isolation by magnetic means. Biochemical properties of the hicp75TNFR were determined by affinity chromatography, ELISA, and western blot techniques. RESULTS: We describe the localization and activation of a differentially spliced and mainly intracellularly expressed isoform of human p75TNFR, termed hicp75TNFR. Expression studies with hicp75TNFR cDNA in different cell types showed the resulting protein mostly retained in the trans-Golgi network and in endosomes and colocalizes with endogenous TNF. Surface expressed hicp75TNFR behaves like hp75TNFR demonstrating susceptibility for TACE-induced shedding and NFÎșB activation after TNF binding. CONCLUSION: Our data demonstrate that intracellular hicp75TNFR is not accessible for exogenously provided TNF but colocalizes with endogenously produced TNF. These findings suggest a possible intracellular activation mechanism of hicp75TNFR by endogenous TNF. Subsequent NFÎșB activation might induce anti-apoptotic mechanisms to protect TNF-producing cells from cytotoxic effects of TNF. In addition, the intracellular and not TACE-accessible splice form of the hp75TNFR could serve as a pool of preformed, functional hp75TNFR
Fifty years after deepâploughing: Effects on yield, roots, nutrient stocks and soil structure
Deepâploughing far beyond the common depth of 30âcm was used more than 50âyears ago in Northern Germany with the aim to break rootârestricting layers and thereby improve access to subsoil water and nutrient resources. We hypothesized that effects of this earlier intervention on soil properties and yields prevailed after 50âyears. Hence, we sampled two sandy soils and one silty soil (Cambisols and a Luvisol) of which half of the field had been deepâploughed 50âyears ago (soils then reâclassified as Treposols). The adjacent other half was not deepâploughed and thus served as the control. At all the three sites, both deepâploughed and control parts were then conventionally managed over the last 50âyears. We assessed yields during the dry year 2019 and additionally in 2020, and rooting intensity at the year of sampling (2019), as well as changes in soil structure, carbon and nutrient stocks in that year. We found that deepâploughing improved yields in the dry spell of 2019 at the sandy sites, which was supported by a more general pattern of higher NDVI indices in deepâploughed parts for the period from 2016 to 2021 across varying weather conditions. Subsoil stocks of soil organic carbon and total plantâavailable phosphorus were enhanced by 21%â199% in the different sites. Root biomass in the subsoil was reduced due to deepâploughing at the silty site and was increased or unaffected at the sandy sites. Overall, the effects of deepâploughing were siteâspecific, with reduced bulk density in the buried topsoil stripes in the subsoil of the sandy sites, but with elevated subsoil density in the silty site. Hence, even 50âyears after deepâploughing, changes in soil properties are still detectable, although effect size differed among sites.BonaRes
http://dx.doi.org/10.13039/501100022576Peer Reviewe
Histological Consequences of Needle-Nerve Contact following Nerve Stimulation in a Pig Model
Background. Nerve stimulation can facilitate correct needle placement in peripheral regional anesthesia. The aim of this study was to determine whether the high threshold current is associated with reduced nerve injury due to fewer needle-nerve contacts compared with low current. Methods. In anaesthetized pigs, thirty-two nerves of the brachial plexus underwent needle placement at low (0.2âmA) or high current (1.0âmA). The occurrence of needle-nerve contact was recorded. After 48 hours, the nerves were analyzed for occurrence of histological changes. Nerve injury was scored ranging from 0 (no injury) to 4 (severe injury). Results. The frequency of needle-nerve contact was 94% at low compared to 6% at high current. The score was significantly higher at low (median [interquartile range] 2.0 [1.0-2.0]) compared to high current (0.0 [0.0-1.0] P = .001). Conclusions. Inflammatory responses were directly related to needle-nerve contacts. Hence, posttraumatic inflammation may be diminished using higher current for nerve localization
Tetrahydrodipicolinate N-Succinyltransferase and Dihydrodipicolinate Synthase from Pseudomonas aeruginosa: Structure Analysis and Gene Deletion
The diaminopimelic acid pathway of lysine biosynthesis has been suggested to provide attractive targets for the development of novel antibacterial drugs. Here we report the characterization of two enzymes from this pathway in the human pathogen Pseudomonas aeruginosa, utilizing structural biology, biochemistry and genetics. We show that tetrahydrodipicolinate N-succinyltransferase (DapD) from P. aeruginosa is specific for the L-stereoisomer of the amino substrate L-2-aminopimelate, and its D-enantiomer acts as a weak inhibitor. The crystal structures of this enzyme with L-2-aminopimelate and D-2-aminopimelate, respectively, reveal that both compounds bind at the same site of the enzyme. Comparison of the binding interactions of these ligands in the enzyme active site suggests misalignment of the amino group of D-2-aminopimelate for nucleophilic attack on the succinate moiety of the co-substrate succinyl-CoA as the structural basis of specificity and inhibition. P. aeruginosa mutants where the dapA gene had been deleted were viable and able to grow in a mouse lung infection model, suggesting that DapA is not an optimal target for drug development against this organism. Structure-based sequence alignments, based on the DapA crystal structure determined to 1.6 Ă
resolution revealed the presence of two homologues, PA0223 and PA4188, in P. aeruginosa that could substitute for DapA in the P. aeruginosa PAO1ÎdapA mutant. In vitro experiments using recombinant PA0223 protein could however not detect any DapA activity
Alternativen als Programm. PlĂ€doyer fĂŒr einen Perspektivenwechsel in der TechnikfolgenabschĂ€tzung
Der vorliegende Artikel soll einen Beitrag zu theoretischen Ăberlegungen einer TechnikfolgenabschĂ€tzung (TA) der Alternativen leisten. Ausgehend von der Annahme, dass TA seit ihrer Entstehung den Anspruch auf die Entwicklung von (technischen) Alternativen erhoben hat, wird hier der Versuch unternommen, die Rolle der TA im Rahmen aktueller Innovationsprozesse zu reflektieren und (neu) zu definieren. Dies scheint vor allem im Hinblick auf aktuelle gesellschaftliche Herausforderungen notwendig. Zu diesem Zweck wird eine Grundannahme Lothar Hacks ĂŒber das VerhĂ€ltnis von Gesellschaft und Technik herangezogen. Seine Annahme besagt, dass die kontinuierliche ĂberfĂŒhrung von sozialen Problemen und Leitbildern in enge technische LösungsansĂ€tze in hochindustrialisierten LĂ€ndern dominant und Teil der aktuellen gesellschaftlichen Probleme ist. Diese These wird im vorliegenden Artikel im Hinblick auf einen Perspektivenwechsel als Ausgangspunkt eines zukĂŒnftigen Forschungsprogramms der TA fruchtbar gemacht. Hierbei bildet das Denken in Alternativen von gesellschaftlichen ZukĂŒnften den zentralen Fokus
Examining outpatients' hand hygiene behaviour and its relation to COVID-19 infection prevention measures
BACKGROUND: The increasing demand for outpatient care is associated with a higher risk of infection transmission in these settings. However, there is limited research on infection prevention and control practices in ambulatory clinics, and none focuses on patients. AIM: This study aims to examine outpatients' hand hygiene behaviours, their determinants, and their associations with other infection prevention measures during the COVID-19 pandemic. METHODS: We observed the hand hygiene behaviour of one cohort of patients in one outpatient clinic and surveyed a separate sample in five clinics about their hand hygiene practice in outpatient facilities. A questionnaire based on the Theoretical Domains Framework (TDF) was used to examine predictors of the behaviour. Moreover, patients indicated their compliance with COVID-19 infection prevention measures, vaccination status, disease risk perception, and vaccine hesitancy. FINDINGS: Observed hand hygiene rates among 618 patients were low (12.8%), while 67.3% of the 300 surveyed patients indicated sanitising their hands upon entering the clinic. The TDF domains memory, attention, and decision processes, and emotions significantly predicted both current (today's) and general hand hygiene behaviour in outpatient clinics. Hand hygiene behaviour and compliance with COVID-19 infection prevention showed a positive association; however, no significant connection was found with patients' vaccination status, suggesting different behavioural motivators. CONCLUSION: Hand hygiene among outpatients should be improved through interventions focusing on helping patients remember to clean their hands. More research on infection prevention in outpatient facilities is needed to ensure patient safety
Antimicrobial coatings for environmental surfaces in hospitals: a potential new pillar for prevention strategies in hygiene
Recent reports provide evidence that contaminated healthcare environments represent major sources for the acquisition and transmission of pathogens. Antimicrobial coatings (AMC) may permanently and autonomously reduce the contamination of such environmental surfaces complementing standard hygiene procedures. This review provides an overview of the current status of AMC and the demands to enable a rational application of AMC in health care settings. Firstly, a suitable laboratory test norm is required that adequately quantifies the efficacy of AMC. In particular, the frequently used wet testing (e.g. ISO 22196) must be replaced by testing under realistic, dry surface conditions. Secondly, field studies should be mandatory to provide evidence for antimicrobial efficacy under real-life conditions. The antimicrobial efficacy should be correlated to the rate of nosocomial transmission at least. Thirdly, the respective AMC technology should not add additional bacterial resistance development induced by the biocidal agents and co- or cross-resistance with antibiotic substances. Lastly, the biocidal substances used in AMC should be safe for humans and the environment. These measures should help to achieve a broader acceptance for AMC in healthcare settings and beyond. Technologies like the photodynamic approach already fulfil most of these AMC requirements
A programme of alternatives: Pledge for a shift in perspective in technology assessment
Der vorliegende Artikel soll einen Beitrag zu theoretischen Ăberlegungen einer TechnikfolgenabschĂ€tzung (TA) der Alternativen leisten. Ausgehend von der Annahme, dass TA seit ihrer Entstehung den Anspruch auf die Entwicklung von (technischen) Alternativen erhoben hat, wird hier der Versuch unternommen, die Rolle der TA im Rahmen aktueller Innovationsprozesse zu reflektieren und (neu) zu definieren. Dies scheint vor allem im Hinblick auf aktuelle gesellschaftliche Herausforderungen notwendig. Zu diesem Zweck wird eine Grundannahme Lothar Hacks ĂŒber das VerhĂ€ltnis von Gesellschaft und Technik herangezogen. Seine Annahme besagt, dass die kontinuierliche ĂberfĂŒhrung von sozialen Problemen und Leitbildern in enge technische LösungsansĂ€tze in hochindustrialisierten LĂ€ndern dominant und Teil der aktuellen gesellschaftlichen Probleme ist. Diese These wird im vorliegenden Artikel im Hinblick auf einen Perspektivenwechsel als Ausgangspunkt eines zukĂŒnftigen Forschungsprogramms der TA fruchtbar gemacht. Hierbei bildet das Denken in Alternativen von gesellschaftlichen ZukĂŒnften den zentralen Fokus.This article provides theoretical arguments for a technology assessment (TA) of alternatives that critically engages in innovation and transformation processes. We draw on an observation by Lothar Hack who stated that a major problem of industrial societies is the dominant translation of complex societal problems into narrow technical solutions. Here we have to come up with alternatives to open up space for other options; it also requires a fundamental shift in perspective that may guide the research program of a TA of alternatives. Based on this, we reflect on the role of TA and its expectations in the light of a vastly changed innovation landscape
Antimicrobial Photodynamic Coatings Reduce the Microbial Burden on Environmental Surfaces in Public TransportationâA Field Study in Buses
Millions of people use public transportation daily worldwide and frequently touch surfaces, thereby producing a reservoir of microorganisms on surfaces increasing the risk of transmission. Constant occupation makes sufficient cleaning difficult to achieve. Thus, an autonomous, permanent, antimicrobial coating (AMC) could keep down the microbial burden on such surfaces. A photodynamic AMC was applied to frequently touched surfaces in buses. The microbial burden (colony forming units, cfu) was determined weekly and compared to equivalent surfaces in buses without AMC (references). The microbial burden ranged from 0â209 cfu/cm2 on references and from 0â54 cfu/cm2 on AMC. The means were 13.4 ± 29.6 cfu/cm2 on references and 4.5 ± 8.4 cfu/cm2 on AMC (p < 0.001). The difference in microbial burden on AMC and references was almost constant throughout the study. Considering a hygiene benchmark of 5 cfu/cm2, the data yield an absolute risk reduction of 22.6% and a relative risk reduction of 50.7%. In conclusion, photodynamic AMC kept down the microbial burden, reducing the risk of transmission of microorganisms. AMC permanently and autonomously contributes to hygienic conditions on surfaces in public transportation. Photodynamic AMC therefore are suitable for reducing the microbial load and closing hygiene gaps in public transportation
Efficient Human Cytomegalovirus Replication in Primary Endothelial Cells Is SOCS3 Dependent
Background: In immunocompromised patients, human cytomegalovirus (HCMV) infection is a major cause of morbidity and mortality. Suppressor of cytokine signaling (SOCS) proteins are very potent negative regulators of the janus kinase/signal transducer and activator of transcription (JAK/STAT) pathways. We hypothesized that HCMV exploits SOCS1 and/or SOCS3 to its advantage. Methods: All experiments were carried out with primary human lung-derived microvascular endothelial cells (HMVEC). SOCS1 and SOCS3 were silenced by transfecting the cells with siRNA. HCMV was propagated and titered on human lung-derived fibroblasts MRC5. Real-time PCR and Western blot were used to detect mRNA and protein levels, respectively. Results: The data presented show that an efficient replication of HCMV in HMVEC is dependent on SOCS3 protein. Time course analysis revealed an increase in SOCS3 protein levels in infected cells. Silencing of SOCS3 (siSOCS3) resulted in inhibition of viral immediate early, early, and late antigen production. Consistently, HCMV titers produced by siSOCS3 cultures were significantly decreased when compared to control transfected cultures (siCNTRs). STAT1 and STAT2 phosphorylation was increased in siSOCS3-infected cells when compared to siCNTR-treated cells. Conclusion: These findings indicate the implication of SOCS3 in the mechanism of HCMV-mediated control of cellular immune responses
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