Next-generation microbiological testing in intraabdominal infections with PCR technology.

PURPOSE: Intraabdominal infections (IAI) are increasing worldwide and are a major contributor to morbidity and mortality. Among IAI, the number of multi-drug resistant organisms (MDRO) is increasing globally. We tested the Unyvero A50® for intraabdominal infections, compared the detected microorganisms and antibiotic resistance, and compared the results with those of routine microbiology. METHODS: We prospectively compared samples obtained from surgical patients using PCR-based Unyvero IAI cartridges against routine microbiology for the detection of microorganisms. Additionally, we identified clinical parameters that correlated with the microbiological findings. Data were analyzed using the t-test and Mann-Whitney U test. RESULTS: Sixty-two samples were analyzed. The PCR system identified more microorganisms, mostly Bacteroides species, Escherichia coli, and Enterococcus spp. For bacterial resistance, the PCR system results were fully concordant with those of routine microbiology, resulting in a sensitivity, specificity, and positive and negative predictive value (PPV, NPV) of 100%. The sensitivity, specificity, PPV, and NPV for the detection of microorganisms were 74%, 58%, 60%, and 72%, respectively. CRP levels were significantly higher in patients with detectable microorganisms. We identified more microorganisms and bacterial resistance in hospital-acquired intra-abdominal infections by using the PCR system. DISCUSSION: IAI warrants early identification of the microorganisms involved and their resistance to allow for adequate antibiotic therapy. PCR systems enable physicians to rapidly adjust their antibiotic treatment. Conventional microbiological culture and testing remain essential for determining the minimal growth inhibition concentrations for antibiotic therapy.

In Vitro Experiments on the Effects of GP-2250 on BRAF-Mutated Melanoma Cell Lines and Benign Melanocytes.

Enhanced glycolysis (Warburg effect) driven by the BRAF oncogene, dysregulated GAPDH expression, and activation of the PI3K/AKT/mTOR signaling pathway may significantly contribute to the resistance-targeted therapy of BRAF-mutated melanomas. Therefore, we aimed to study for the first time the anti-tumor activity of the GAPDH inhibitor GP-2250 in BRAF-mutated melanoma cell lines and benign melanocytes. We employed three melanoma cell lines and one primary melanocyte cell line (Ma-Mel-61a, Ma-Mel-86a, SH-4 and ATCC-PCS-200-013, respectively), which were exposed to different GP-2250 doses. GP-2250's effects on cell proliferation and viability were evaluated by means of the BrdU and MTT assays, respectively. The RealTime-Glo Annexin V Apoptosis and Necrosis Assay was performed for the evaluation of apoptosis and necrosis induction. RT-PCR and western blotting were implemented for the determination of AKT and STAT3 gene and protein expression analyses, respectively. The melanoma cell lines showed a dose-dependent response to GP-2250 during BrDU and MTT testing. The RealTime-Glo Annexin V assay revealed the heterogenous impact of GP-2250 on apoptosis as well as necrosis. With respect to the melanoma cell lines Ma-Mel-86a and SH-4, the responses and dosages were comparable to those used for the MTT viability assay. Using the same dose range of GP-2250 administered to melanoma cells, however, we observed neither the noteworthy apoptosis nor necrosis of GP-2250-treated benign melanocytes. The gene expression profiles in the melanoma cell lines for AKT and STAT3 were heterogenous, whereby AKT as well as STAT3 gene expression were most effectively downregulated using the highest GP-2250 doses. Immunoblotting revealed that there was a time-dependent decrease in protein expression at the highest GP-2250 dose used, whereas a time- as well as dose-dependent AKT decrease was predominantly observed in Ma-Mel-61a. The STAT3 protein expression of Ma-Mel-86a and SH-4 was reduced in a time-dependent pattern at lower and moderate doses. STAT3 expression in Ma-Me-61a was barely altered by GP-2250. In conclusion, GP-2250 has anti-neoplastic effects in BRAF-mutated melanoma cell lines regarding tumor cell viability, proliferation, and apoptosis/necrosis. GP-2250 is able to downregulate the gene and protein expression of aberrant tumorigenic pathways in melanoma cell lines. Since GP-2250 is a GAPDH inhibitor, the substance may be a promising combination therapy for tumors presenting the Warburg effect, such as melanoma.

GP-2250, a novel anticancer agent, inhibits the energy metabolism, activates AMP-Kinase and impairs the NF-kB pathway in pancreatic cancer cells.

GP-2250, a novel anticancer agent, severely limits the energy metabolism, as demonstrated by the inhibition of hexokinase 2 and glyceraldehyde-3-phosphate dehydrogenase and a decrease of ATP. Rescue experiments with supplementary pyruvate or oxaloacetate demonstrated that a TCA cycle deficit largely contributed to cytotoxicity. Activation of the energy-deficit sensor, AMP-dependent protein kinase, was associated with increased phosphorylation of acetyl-CoA carboxylase and Raptor, pointing to a possible deficit in the synthesis of fatty acids and proteins as essential cell components. Binding of p65 to DNA was dose-dependently reduced in nuclear lysates. A transcriptional deficit of NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) was substantiated by the downregulation of cyclin D1 and of the anti-apoptotic Bcl2, in line with reduction in tumour cell proliferation and induction of apoptosis, respectively. The upregulation of p53 concomitant with an excess of ROS supported apoptosis. Thus, the anticancer activity of GP-2250 is a result of disruption of energy metabolism and inhibition of tumour promotion by NF-κB.

The effect of GP-2250 on cultured virus-negative Merkel cell carcinoma cells: preliminary results.

BACKGROUND: Even in the novel immunotherapy era, Merkel cell carcinoma (MCC) remains challenging in its treatment. Apart from Merkel cell polyomavirus (MCPyV) associated MCC, this cancer is linked in about 20% of cases to ultraviolet-induced mutational burden frequently causing aberrations in Notch and PI3K/AKT/mTOR signalling pathways. The recently developed agent GP-2250 is capable to inhibit growth of cells of different cancers, including pancreatic neuroendocrine tumors. The objective of the present study was to investigate the effects of GP-2250 on MCPyV-negative MCC cells. METHODS: Methods We employed three cell lines (MCC13, MCC14.2, MCC26) which were exposed to different GP-2250doses. GP-2250's effects on cell viability, proliferation, and migration were evaluated by means of MTT, BrdU, and scratch assays, respectively. Flow cytometry was performed for the evaluation of apoptosis and necrosis. Western blotting was implemented for the determination of AKT, mTOR, STAT3, and Notch1 protein expression. RESULTS: Cell viability, proliferation, and migration decreased with increasing GP-2250 doses. Flow cytometry revealed a dose response to GP-2250 in all three MCC cell lines. While the viable fraction decreased, the share of necrotic and in a smaller amount the apoptotic cells increased. Regarding Notch1, AKT, mTOR, and STAT3 expression a comparatively time- and dose-dependent decrease of protein expression in the MCC13 and MCC26 cell lines was observed. By contrast, Notch1, AKT, mTOR, and STAT3 expression in MCC14.2 was scarcely altered or even increased by the three dosages of GP-2250 applied. CONCLUSIONS: The present study indicates GP-2250 having anti-neoplastic effects in MCPyV-negative tumor cells in regard to viability, proliferation, and migration. Moreover, the substance is capable of downregulating protein expression of aberrant tumorigenic pathways in MCPyV-negative MCC cells.

Substance GP-2250 as a New Therapeutic Agent for Malignant Peritoneal Mesothelioma-A 3-D In Vitro Study.

Malignant peritoneal mesothelioma is a rare tumor entity. Although cytoreductive surgery and hyperthermic intraperitoneal chemotherapy have increased overall survival, its prognosis remains poor. Established chemotherapeutics include mitomycin C (MMC) and cisplatin (CP), both characterized by severe side effects. GP-2250 is a novel antineoplastic agent, currently under clinical investigation. This in vitro study aims to investigate effects of GP-2250 including combinations with CP and MMC on malignant mesothelioma. JL-1 and MSTO-211H mesothelioma cell lines were treated with increasing doses of GP-2250, CP, MMC and combination therapies of GP-2250 + CP/MMC. Microscopic effects were documented, and a flow-cytometric apoptosis/necrosis assay was performed. Synergistic and antagonistic effects were analyzed by computing the combination index by Chou-Talalay. GP-2250 showed an antiadhesive effect on JL-1 and MSTO-211H spheroids. It had a dose-dependent cytotoxic effect on both monolayer and spheroid cultured cells, inducing apoptosis and necrosis. Combination treatments of GP-2250 with MMC and CP led to significant reductions of the effective doses of CP/MMC. Synergistic and additive effects were observed. GP-2250 showed promising antineoplastic effects on malignant mesothelioma cells in vitro especially in combination with CP/MMC. This forms the basis for further in vivo and clinical investigations in order to broaden treatment options.

New Therapy Options for Neuroendocrine Carcinoma of the Pancreas-The Emergent Substance GP-2250 and Gemcitabine Prove to Be Highly Effective without the Development of Secondary Resistances In Vitro and In Vivo.

Neuroendocrine carcinoma of the pancreas (pNEC) is an aggressive form of neuroendocrine tumor characterized by a rising incidence without an increase in survival rates. GP-2250 is an oxathiazinane derivate possessing antineoplastic effects, especially in combination with Gemcitabine on the pancreatic adenocarcinoma. The cytotoxic effects of the monotherapy of GP-2250 (GP-2250mono) and Gemcitabine (Gemmono), as well as the combination therapy of both, were studied in vitro using an MTT-assay on the QGP-1 and BON-1 cell lines, along with in vivo studies on a murine xenograft model of QGP-1 and a patient-derived xenograft model (PDX) of Bo99. In vitro, Gemmono and GP-2250mono showed a dose-dependent cytotoxicity. The combination of GP-2250 and Gemcitabine exhibited highly synergistic effects. In vivo, the combination therapy obtained a partial response in QGP-1, while GP-2250mono and Gemmono showed progressive disease or stable disease, respectively. In Bo99 PDX, the combination therapy led to a partial response, while the monotherapy resulted in progressive disease. No development of secondary resistances was observed, as opposed to monotherapy. This study was the first to evaluate the effects of the emerging substance GP-2250 on pNEC. The substance showed synergism in combination with Gemcitabine. The combination therapy proved to be effective in vitro and in vivo, without the development of secondary resistances.

The Physiological Incubation Biosimulator (PIBS): An Improved Ex Vivo Experimental Setup for the Mechanical Stability of Biological Sealants in Surgical Procedures.

BACKGROUND: Tissue-bound fibrin sealants are used in a wide array of surgical procedures. The microenvironmental interaction between sealant and application site is often poorly evaluated due to a lack of suitable experimental models. METHODS: A physiological incubation biosimulator (PIBS) was developed to test biological sealants in an ex vivo setup under physiological conditions comparable to the microenvironment at application site (temperature, humidity, pressure). PIBS was validated by a study on the effectiveness of TachoSil for leak closure at pancreatic resection sites. Defined defects in a thoracic membrane of porcine origin were sealed by TachoSil. Integrity of the sealing was tested in the presence of active pancreatic fluid over 60 minutes. Heat-inactivated pancreatic fluid and electrolyte solution served as controls. The time to leakage was recorded and experimental groups were analyzed by Kaplan-Meier analysis. RESULTS: PIBS produced reliable results. TachoSil lead to a leakage rate of 96% after incubation with active pancreatic fluid (p = 34), which was significantly higher compared with heat-inactivated pancreatic fluid (p = 34, 52%) or electrolyte solution (p = 20, 19%). CONCLUSION: PIBS is an effective tool to evaluate microenvironmental effects on the adhesive strength of biomaterials. Tissue sealing effect of TachoSil is diminished in a "pancreatic" microenvironment rich with pancreatic enzymes. Our results might therefore explain the reason of the findings of randomized controlled trials recently published on this subject.