50 research outputs found
Applicability of Neural Networks for Driving Style Classification and Maneuver Detection
Maneuver and driving style detection are of ongoing interest for the extension of vehicle's functionalities. Existing machine learning approaches require extensive sensor data and demand for high computational power. For vehicle onboard implementation, poorly generalizing rule-based approaches are currently state of the art. Not being restricted to neither comprehensive environmental sensors like camera or radar, nor high computing power (both of what is today only present in upper class' vehicles), our approach allows for cross-vehicle use: In this work, the applicability of small artificial neural networks (ANN) as efficient detectors is tested using a prototypal vehicle implementation. During test drives, overtaking maneuvers have been detected 1.2 s prior to the competing rule-based approach in average, also greatly improving the detection performance. Regarding driving style recognition, ANN-based results are closer to targets and more patient at driving style transitions. A recognition rate of over 75 % is achieved
Immune Requirements of Post-Exposure Immunization with Modified Vaccinia Ankara of Lethally Infected Mice
Current prophylactic vaccines work via the induction of B and T cell mediated memory that effectively control further replication of the pathogen after entry. In the case of therapeutic or post-exposure vaccinations the situation is far more complex, because the pathogen has time to establish itself in the host, start producing immune-inhibitory molecules and spread into distant organs. So far it is unclear which immune parameters have to be activated in order to thwart an existing lethal infection. Using the mousepox model, we investigated the immunological mechanisms responsible for a successful post-exposure immunization with modified vaccinia Ankara (MVA). In contrast to intranasal application of MVA, we found that intravenous immunization fully protected mice infected with ectromelia virus (ECTV) when applied three days after infection. Intravenous MVA immunization induced strong innate and adaptive immune responses in lethally infected mice. By using various gene-targeted and transgenic mouse strains we show that NK cells, CD4 T cells, CD8 T cells and antibodies are essential for the clearance of ECTV after post-exposure immunization. Post-exposure immunization with MVA is an effective measure in a murine model of human smallpox. MVA activates innate and adaptive immune parameters and only a combination thereof is able to purge ECTV from its host. These data not only provide a basis for therapeutic vaccinations in the case of the deliberate release of pathogenic poxviruses but possibly also for the treatment of chronic infections and cancer
Damage control strategy in perforated diverticulitis with generalized peritonitis
Background: The best treatment for perforated colonic diverticulitis with generalized peritonitis is still under debate. Concurrent strategies are resection with primary anastomosis (PRA) with or without diverting ileostomy (DI), Hartmann's procedure (HP), laparoscopic lavage (LL) and damage control surgery (DCS). This review intends to systematically analyze the current literature on DCS.
Methods: DCS consists of two stages. Emergency surgery: limited resection of the diseased colon, oral and aboral closure, lavage, vacuum-assisted abdominal closure. Second look surgery after 24-48 h: definite reconstruction with colorectal anastomosis (-/+DI) or HP after adequate resuscitation. The review was conducted in accordance to the PRISMA-P Statement. PubMed/MEDLINE, Cochrane central register of controlled trials (CENTRAL) and EMBASE were searched using the following term: (Damage control surgery) AND (Diverticulitis OR Diverticulum OR Peritonitis).
Results: Eight retrospective studies including 256 patients met the inclusion criteria. No randomized trial was available. 67% of the included patients had purulent, 30% feculent peritonitis. In 3% Hinchey stage II diverticulitis was found. In 49% the Mannheim peritonitis index (MPI) was greater than 26. Colorectal anastomosis was constructed during the course of the second surgery in 73%. In 15% of the latter DI was applied. The remaining 27% received HP. Postoperative mortality was 9%, morbidity 31% respectively. The anastomotic leak rate was 13%. 55% of patients were discharged without a stoma.
Conclusion: DCS is a safe technique for the treatment of acute perforated diverticulitis with generalized peritonitis, allowing a high rate of colorectal anastomosis and stoma-free hospital discharge in more than half of the patients
Mouse Plasmacytoid Cells: Long-lived Cells, Heterogeneous in Surface Phenotype and Function, that Differentiate Into CD8+ Dendritic Cells Only after Microbial Stimulus
The CD45RAhiCD11cint plasmacytoid predendritic cells (p-preDCs) of mouse lymphoid organs, when stimulated in culture with CpG or influenza virus, produce large amounts of type I interferons and transform without division into CD8+CD205− DCs. P-preDCs express CIRE, the murine equivalent of DC-specific intercellular adhesion molecule 3 grabbing nonintegrin (DC-SIGN). P-preDCs are divisible by CD4 expression into two subgroups differing in turnover rate and in response to Staphylococcus aureus. The kinetics of bromodeoxyuridine labeling and the results of transfer to normal recipient mice indicate that CD4− p-preDCs are the immediate precursors of CD4+ p-preDCs. Similar experiments indicate that p-preDCs are normally long lived and are not the precursors of the short-lived steady-state conventional DCs. However, in line with the culture studies on transfer to influenza virus-stimulated mice the p-preDCs transform into CD8+CD205− DCs, distinct from conventional CD8+CD205+ DCs. Hence as well as activating preexistant DCs, microbial infection induces a wave of production of a new DC subtype. The functional implications of this shift in the DC network remain to be determined
Intratumoral virotherapy with 4-1BBL armed modified vaccinia Ankara eradicates solid tumors and promotes protective immune memory
Background Human cancers are extraordinarily heterogeneous in terms of tumor antigen expression, immune infiltration and composition. A common feature, however, is the host ' s inability to mount potent immune responses that prevent tumor growth effectively. Often, naturally primed CD8(+) T cells against solid tumors lack adequate stimulation and efficient tumor tissue penetration due to an immune hostile tumor microenvironment.
Methods To address these shortcomings, we cloned tumor-associated antigens (TAA) and the immune-stimulatory ligand 4-1BBL into the genome of modified vaccinia Ankara (MVA) for intratumoral virotherapy.
Results Local treatment with MVA-TAA-4-1BBL resulted in control of established tumors. Intratumoral injection of MVA localized mainly to the tumor with minimal leakage to the tumor-draining lymph node. In situ infection by MVA-TAA-4-1BBL triggered profound changes in the tumor microenvironment, including the induction of multiple proinflammatory molecules and immunogenic cell death. These changes led to the reactivation and expansion of antigen-experienced, tumor-specific cytotoxic CD8(+) T cells that were essential for the therapeutic antitumor effect. Strikingly, we report the induction of a systemic antitumor immune response including tumor antigen spread by local MVA-TAA-4-1BBL treatment which controlled tumor growth at distant, untreated lesions and protected against local and systemic tumor rechallenge. In all cases, 4-1BBL adjuvanted MVA was superior to MVA.
Conclusion Intratumoral 4-1BBL-armed MVA immunotherapy induced a profound reactivation and expansion of potent tumor-specific CD8(+) T cells as well as favorable proinflammatory changes in the tumor microenvironment, leading to elimination of tumors and protective immunological memory
Pyruvate metabolism controls chromatin remodeling during CD4+ TÂ cell activation
Upon antigen-specific T cell receptor (TCR) engagement, human CD4 + T cells proliferate and differentiate, a process associated with rapid transcriptional changes and metabolic reprogramming. Here, we show that the generation of extramitochondrial pyruvate is an important step for acetyl-CoA production and subsequent H3K27ac-mediated remodeling of histone acetylation. Histone modification, transcriptomic, and carbon tracing analyses of pyruvate dehydrogenase (PDH)-deficient T cells show PDH-dependent acetyl-CoA generation as a rate-limiting step during T activation. Furthermore, T cell activation results in the nuclear translocation of PDH and its association with both the p300 acetyltransferase and histone H3K27ac. These data support the tight integration of metabolic and histone-modifying enzymes, allowing metabolic reprogramming to fuel CD4 + T cell activation. Targeting this pathway may provide a therapeutic approach to specifically regulate antigen-driven T cell activation