293 research outputs found

    Cardiopulmonary resuscitation outcomes of dogs and cats at a veterinary teaching hospital before and after publication of the RECOVER guidelines.

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    OBJECTIVES To describe and compare cardiopulmonary resuscitation outcomes at a Swiss veterinary teaching hospital before and after publication of the Reassessment Campaign on Veterinary Resuscitation guidelines. MATERIALS AND METHODS Between 2018 and 2020, hospital staff underwent various types of yearly Reassessment Campaign on Veterinary Resuscitation-based cardiopulmonary resuscitation trainings. Canine and feline cardiopulmonary resuscitation events during that period (post-Reassessment Campaign on Veterinary Resuscitation) and between 2010 and 2012 (pre-Reassessment Campaign on Veterinary Resuscitation) were identified and animal, arrest and outcome variables recorded retrospectively. Factors associated with return of spontaneous circulation were determined using multi-variable logistic regression, odds ratios (95% confidence interval) generated, and significance set at P < 0.05. RESULTS Eighty-one animals were included in the pre-Reassessment Campaign on Veterinary Resuscitation group and 190 in the post-Reassessment Campaign on Veterinary Resuscitation group. Twenty-three percent in the pre-Reassessment Campaign on Veterinary Resuscitation group and 28% in the post-Reassessment Campaign on Veterinary Resuscitation group achieved return of spontaneous circulation and 1% and 4% survived to hospital discharge, respectively. Patients undergoing anaesthesia [odds ratio 4.26 (1.76 to 10.27)], elective [odds ratio 5.16 (1.06 to 25.02)] or emergent surgery [odds ratio 3.09 (1.20 to 8.00)], or experiencing cardiopulmonary arrest (CPA) due to arrhythmias [odds ratio 4.31 (1.44 to 12.93)] had higher odds of return of spontaneous circulation, while those with unknown cause of CPA [odds ratio 0.25 (0.08 to 0.78)] had lower odds. Undergoing cardiopulmonary resuscitation in the post-Reassessment Campaign on Veterinary Resuscitation period was not statistically significantly associated with return of spontaneous circulation [odds ratio 1.38 (0.68 to 2.79)]. CLINICAL SIGNIFICANCE Unchanged odds of return of spontaneous circulation in the post-Reassessment Campaign on Veterinary Resuscitation period could suggest that once-yearly cardiopulmonary resuscitation training is insufficient, effects of animal and tertiary referral hospital variables confounded results, guideline benefit is limited, or that compliance during clinical cardiopulmonary resuscitation efforts is too poor for guideline recommendations to have a positive impact. More extensive cardiopulmonary resuscitation training protocols should be established, and the compliance with and outcome benefits of a Reassessment Campaign on Veterinary Resuscitation-based cardiopulmonary resuscitation approach re-evaluated prospectively

    Lock-in detection for pulsed electrically detected magnetic resonance

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    We show that in pulsed electrically detected magnetic resonance (pEDMR) signal modulation in combination with a lock-in detection scheme can reduce the low-frequency noise level by one order of magnitude and in addition removes the microwave-induced non-resonant background. This is exemplarily demonstrated for spin-echo measurements in phosphorus-doped Silicon. The modulation of the signal is achieved by cycling the phase of the projection pulse used in pEDMR for the read-out of the spin state.Comment: 4 pages, 2 figure

    PET imaging of tumor glycolysis downstream of hexokinase through noninvasive measurement of pyruvate kinase M2

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    Cancer cells reprogram their metabolism to meet increased biosynthetic demands, commensurate with elevated rates of replication. Pyruvate kinase M2 (PKM2) catalyzes the final and rate-limiting step in tumor glycolysis, controlling the balance between energy production and the synthesis of metabolic precursors. We report here the synthesis and evaluation of a positron emission tomography (PET) radiotracer, [(11)C]DASA-23, that provides a direct noninvasive measure of PKM2 expression in preclinical models of glioblastoma multiforme (GBM). In vivo, orthotopic U87 and GBM39 patient-derived tumors were clearly delineated from the surrounding normal brain tissue by PET imaging, corresponding to exclusive tumor-associated PKM2 expression. In addition, systemic treatment of mice with the PKM2 activator TEPP-46 resulted in complete abrogation of the PET signal in intracranial GBM39 tumors. Together, these data provide the basis for the clinical evaluation of imaging agents that target this important gatekeeper of tumor glycolysis

    Assessment of tumor redox status through (S)-4-(3-[18F]fluoropropyl)-L-glutamic acid positron emission tomography imaging of system xc- activity

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    The cell's endogenous antioxidant system is vital to maintenance of redox homeostasis. Despite its central role in normal and pathophysiology, no non-invasive tools exist to measure this system in patients. The cystine/glutamate antiporter system xc- maintains the balance between intracellular reactive oxygen species and antioxidant production through the provision of cystine, a key precursor in glutathione biosynthesis. Here we show that tumor cell retention of a system xc--specific positron emission tomography radiotracer, (S)-4-(3-[18F]fluoropropyl)-L-glutamic acid ([18F]FSPG), decreases in proportion to levels of oxidative stress following treatment with a range of redox-active compounds. The decrease in [18F]FSPG retention correlated with a depletion of intracellular cystine resulting from increased de novo glutathione biosynthesis, shown through [U-13C6, U-15N2]cystine isotopic tracing. In vivo, treatment with the chemotherapeutic doxorubicin decreased [18F]FSPG tumor uptake in a mouse model of ovarian cancer, coinciding with markers of oxidative stress but preceding tumor shrinkage and decreased glucose utilization. Having already been used in pilot clinical trials, [18F]FSPG PET could be rapidly translated to the clinic as an early redox indicator of tumor response to treatment

    Highly sensitive detection of the group A Rotavirus using Apolipoprotein H-coated ELISA plates compared to quantitative real-time PCR

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    <p>Abstract</p> <p>Background</p> <p>The principle of a capture ELISA is binding of specific capture antibodies (polyclonal or monoclonal) to the surface of a suitable 96 well plate. These immobilized antibodies are capable of specifically binding a virus present in a clinical sample. Subsequently, the captured virus is detected using a specific detection antibody. The drawback of this method is that a capture ELISA can only function for a single virus captured by the primary antibody. Human Apolipoprotein H (ApoH) or β<sub>2</sub>-glycoprotein 1 is able to poly-specifically bind viral pathogens. Replacing specific capture antibodies by ApoH should allow poly-specific capture of different viruses that subsequently could be revealed using specific detection antibodies. Thus, using a single capture ELISA format different viruses could be analysed depending on the detection antibody that is applied. In order to demonstrate that this is a valid approach we show detection of group A rotaviruses from stool samples as a proof of principle for a new method of capture ELISA that should also be applicable to other viruses.</p> <p>Results</p> <p>Stool samples of different circulating common human and potentially zoonotic group A rotavirus strains, which were pretested in commercial EIAs and genotyped by PCR, were tested in parallel in an ApoH-ELISA set-up and by quantitative real-time PCR (qPCR). Several control samples were included in the analysis. The ApoH-ELISA was suitable for the capture of rotavirus-particles and the detection down to 1,000 infectious units (TCID<sub>50/ml</sub>). Subsets of diagnostic samples of different G- and P-types were tested positive in the ApoH-ELISA in different dilutions. Compared to the qPCR results, the analysis showed high sensitivity, specificity and low cross-reactivity for the ApoH-ELISA, which was confirmed in receiver operating characteristics (ROC) analysis.</p> <p>Conclusions</p> <p>In this study the development of a highly sensitive and specific capture ELISA was demonstrated by combining a poly-specific ApoH capture step with specific detection antibodies using group A rotaviruses as an example.</p

    Discovery and validation of small-molecule heat-shock protein 90 inhibitors through multimodality molecular imaging in living subjects

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    Up-regulation of the folding machinery of the heat-shock protein 90 (Hsp90) chaperone protein is crucial for cancer progression. The two Hsp90 isoforms (α and β) play different roles in response to chemotherapy. To identify isoform-selective inhibitors of Hsp90(α/β)/cochaperone p23 interactions, we developed a dual-luciferase (Renilla and Firefly) reporter system for high-throughput screening (HTS) and monitoring the efficacy of Hsp90 inhibitors in cell culture and live mice. HTS of a 30,176 small-molecule chemical library in cell culture identified a compound, N-(5-methylisoxazol-3-yl)-2-[4-(thiophen-2-yl)-6-(trifluoromethyl)pyrimidin-2-ylthio]acetamide (CP9), that binds to Hsp90(α/β) and displays characteristics of Hsp90 inhibitors, i.e., degradation of Hsp90 client proteins and inhibition of cell proliferation, glucose metabolism, and thymidine kinase activity, in multiple cancer cell lines. The efficacy of CP9 in disrupting Hsp90(α/β)/p23 interactions and cell proliferation in tumor xenografts was evaluated by non-invasive, repetitive Renilla luciferase and Firefly luciferase imaging, respectively. At 38 h posttreatment (80 mg/kg × 3, i.p.), CP9 led to selective disruption of Hsp90α/p23 as compared with Hsp90β/p23 interactions. Small-animal PET/CT in the same cohort of mice showed that CP9 treatment (43 h) led to a 40% decrease in 18F-fluorodeoxyglucose uptake in tumors relative to carrier control-treated mice. However, CP9 did not lead to significant degradation of Hsp90 client proteins in tumors. We performed a structural activity relationship study with 62 analogs of CP9 and identified A17 as the lead compound that outperformed CP9 in inhibiting Hsp90(α/β)/p23 interactions in cell culture. Our efforts demonstrated the power of coupling of HTS with multimodality molecular imaging and led to identification of Hsp90 inhibitors

    Detection of Norovirus genogroup I and II by multiplex real-time RT- PCR using a 3'-minor groove binder-DNA probe

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    BACKGROUND: Due to an increasing number of norovirus infections in the last years rapid, specific, and sensitive diagnostic tools are needed. Reverse transcriptase-polymerase chain reactions (RT-PCR) have become the methods of choice. To minimize the working time and the risk of carryover contamination during the multi-step procedure of PCR the multiplex real-time RT-PCR for the simultaneous detection of genogroup I (GI) and II (GII) offers advantages for the handling of large amounts of clinical specimens. METHODS: We have developed and evaluated a multiplex one-tube RT-PCR using a combination of optimized GI and GII specific primers located in the junction between ORF1 and ORF2 of the norovirus genome. For the detection of GI samples, a 3'- minor groove binder-DNA probe (GI-MGB-probe) were designed and used for the multiplex real-time PCR. RESULTS: Comparable results to those of our in-house nested PCR and monoplex real-time-PCR were only obtained using the GI specific MGB-probe. The MGB-probe forms extremely stable duplexes with single-stranded DNA targets, which enabled us to design a shorter probe (length 15 nucleotides) hybridizing to a more conserved part of the GI sequences. 97 % of 100 previously norovirus positive specimens (tested by nested PCR and/or monoplex real-time PCR) were detected by the multiplex real-time PCR. A broad dynamic range from 2 Ă— 10^1 to 2 Ă— 10^7 genomic equivalents per assay using plasmid DNA standards for GI and GII were obtained and viral loads between 2.5 Ă— 10^2 and 2 Ă— 10^12 copies per ml stool suspension were detected. CONCLUSION: The one-tube multiplex RT real-time PCR using a minor groove binder -DNA probe for GI is a fast, specific, sensitive and cost-effective tool for the detection of norovirus infections in both mass outbreaks and sporadic cases and may have also applications in food and environmental testing
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