Efficacy of antiseptics in a novel 3-dimensional human plasma biofilm model (hpBIOM)

The increasing incidence of non-healing wounds constitutes a pivotal socio-economic burden. 60-80% of chronic wounds are colonized by pathogenic microorganisms within a protective extracellular polymeric substance, bearing a great challenge in wound management. Human plasma was used to prepare the biofilm model (hpBIOM), adding pathogens to the plasma and forming Coagula-like discs with integrated pathogens were produced. The antiseptics Octenisept and Lavasorb were tested regarding their antibacterial properties on clinically relevant biofilm-growing bacteria (MRSA, P. aeruginosa) in the hpBIOM. Biofilm-typical glycocalyx-formation was confirmed using immunohistochemical staining. Treatment of a 12 h-maturated biofilm with Octenisept resulted in complete eradication of P. aeruginosa and MRSA after 48 h. Lavasorb proved less effective than Octenisept in this setting. In more mature biofilms (24 h), both antiseptics showed a delayed, partially decreased efficacy. Summarized, the hpBIOM provides essential factors for a translational research approach to be used for detailed human biofilm analyses and evaluation of antimicrobial/-biofilm properties of established and novel therapeutic strategies and products. Octenisept and Lavasorb showed an attenuated efficacy in the hpBIOM compared to planktonic conditions and previously published biofilm-studies, prompting the question for the necessity of introducing new international standards and pre-admission requirements on a translational base.

Akt1 signalling supports acinar proliferation and limits acinar-to-ductal metaplasia formation upon induction of acute pancreatitis

Molecular signalling mediated by the phosphatidylinositol-3-kinase (PI3K)-Akt axis is a key regulator of cellular functions. Importantly, alteration of the PI3K-Akt signalling underlies the development of different human diseases, thus prompting the investigation of the pathway as a molecular target for pharmacologic intervention. In this regard, recent studies showed that small molecule inhibitors of PI3K, the upstream regulator of the pathway, reduced the development of inflammation during acute pancreatitis, a highly debilitating and potentially lethal disease. Here we investigated whether a specific reduction of Akt activity, by using either pharmacologic Akt inhibition, or genetic inactivation of the Akt1 isoform selectively in pancreatic acinar cells, is effective in ameliorating the onset and progression of the disease. We discovered that systemic reduction of Akt activity did not protect the pancreas from initial damage and only transiently delayed leukocyte recruitment. However, reduction of Akt activity decreased acinar proliferation and exacerbated acinar-to-ductal metaplasia (ADM) formation, two critical events in the progression of pancreatitis. These phenotypes were recapitulated upon conditional inactivation of Akt1 in acinar cells, which resulted in reduced expression of 4E-BP1, a multifunctional protein of key importance in cell proliferation and metaplasia formation. Collectively, our results highlight the critical role played by Akt1 during the development of acute pancreatitis in the control of acinar cell proliferation and ADM formation. In addition, these results harbour important translational implications as they raise the concern that inhibitors of PI3K-Akt signalling pathways may negatively affect the regeneration of the pancreas. Finally, this work provides the basis for further investigating the potential of Akt1 activators to boost pancreatic regeneration following inflammatory insults. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Elevated Thrombomodulin Plasma Levels as a Result of Endothelial Involvement in Plasmodium falciparum Malaria

We used thrombomodulin (TM) to assess the participation of the vascular endothelium in human Plasmodium falciparum (P. F.) malaria. Before therapy TM plasma levels were elevated in P. F. malaria and fell to normal values during therapy. Parasitemia, TNFα, elastase and TAT levels correlated directly with TM. Elevated TM levels can not be explained by increased synthesis, since incubating HUVEC with pretherapy serum of patients with P. F. malaria, but not reconvalescence serum, suppressed TM transcription. This was partially prevented by adding a TNFα neutralizing antibody to patient serum before incubation with HUVEC. However, TNFα does not release TM from cultured HUVEC in vitro. Coincubation of HUVEC with pretherapy serum together with neutrophils resulted in endothelial cell destruction, which could be partly prevented by a TNFα neutralizing antibody. Hence the increase of TM during P. F. malaria might reflect the concerted action of cytokines and neutrophils on HUVEC.

Antiparasitic Treatment of Patients with P. falciparum Malaria Reduces the Ability of Patient Serum to Induce Tissue Factor by Decreasing NF-κB Activation

Serum from patients with P. falciparum malaria at day 1 (pretherapy) induces tissue factor (TF) in cultured endothelial cells. TF induction depends on de novo transcription as shown in Nuclear Run On assays. Electrophoretic mobility shift assays demonstrated binding of AP-1 and NF- κB/Rel proteins to their recognition sites in the TF promotor. After therapy (day 28), stimulation of TF antigen by patient serum is reduced by 70%. When serum obtained before and after therapy was compared, a decrease of NF-κB activation was evident. Activation of NF-κB-like proteins was in part dependent on TNFα in patient serum, since a TNFα neutralizing antibody reduced induction of TF transcription and translation and induction of NF-κB-like proteins. Induction of TF activity was suppressed by pDTC, an inhibitor of NF-κB activation. When different promotor constructs of the TF gene were tested, induction was dependent upon the presence of the intact NF-κB-like binding site in the TF promotor. A mutant with deleted NF-κB, but intact AP-1 sites was not inducible. Mutation of the AP-1 sites did not prevent induction, but reduced inducibility by pretherapy serum. Therefore, NF-κB/Rel proteins are responsible for induction of TF transcription by pretherapy serum, but AP-1 is needed for highest inducibility. The effect of antiparasitic therapy on the induction of TF by serum from patients with complicated P. falciparum malaria is dependent on a therapy-mediated loss of activation of NF-κB-like proteins in post-treatment patient serum.

Tetracycline alters gene expression in Salmonella strains that harbor the Tn10 transposon

In this report, we show that bacterial plasmids that harbor the Tn10 transposon (i.e., the IncHI1 plasmid R27) modify expression of different Salmonella regulons responding to the presence of tetracycline (Tc) in the medium. By using as a model the Tc-dependent upregulation of the ibpAB operon (which belongs to the heat shock regulon), we have identified Tn10-tetA (coding for a Tc efflux pump) and adjacent tetC sequences as required for ibpAB upregulation. Characterization of transcripts in the tetAC region showed that tetA transcription can continue into tetC sequences, generating a long 3'UTR sequence, which can protect transcripts from RNA processing, thus increasing the expression of TetA protein. In the presence of Tc, the DnaK and IbpA chaperones are overexpressed and translocated to the periplasm and to the membrane fraction respectively. DnaK targeting unfolded proteins is known to induce heat shock by avoiding RpoH proteolysis. We correlate expression levels of Tn10-encoded TetA protein with heat shock induction in Salmonella, likely because TetA activity compromises protein secretion.

Systematically assessed symptoms as outcome predictors in emergency patients

INTRODUCTION

It is known that symptoms are predictive of mortality in "nonsurgical" emergency patients. It is unknown whether a prospective, systematic, and "unscreened" assessment of all symptoms is of any prognostic value. Therefore, we aimed to examine the association between symptoms and outcomes in an all-comer population.

METHODS

Data were acquired during 6weeks at the ED of the University Hospital Basel, a tertiary hospital. Consecutive patients presenting to the ED were included. Symptoms at presentation were systematically assessed using a comprehensive questionnaire.

RESULTS

A consecutive sample of 3960 emergency patients with a median age of 51years (51.7% male) was studied. The median number of symptoms was two. In the group of patients with the most prevalent symptoms, the median number of symptoms ranged between two and five. Overall, hospitalisation rate was 31.2%, referral to intensive care was 5.5%, in-hospital-mortality was 1.4%, and one-year mortality was 5.8%. In-hospital mortality ranged from 0% to 4.3%, and one-year mortality from 0% to 14.4% depending on the presenting symptoms. Dyspnoea and weakness were significant predictors of one-year mortality (14.4% and 9.2%, respectively).

DISCUSSION

Most emergency patients indicated two or more symptoms. Systematically assessed symptoms at presentation can be used for prediction of outcomes. While dyspnoea is a known predictor, weakness has not been identified as predictor of mortality before. This knowledge could be used to improve risk stratification- thereby reducing the risk of adverse outcomes.

Abstract OT3-07-01: A randomized trial evaluating bioimpedance spectroscopy vs. tape measurement in the prevention of lymphedema following breast cancer treatment

Background: Breast cancer related lymphedema (BCRL) represents a common treatment associated complication following surgery, radiation and/or chemotherapy. Increasing data has demonstrated the ability of new diagnostic modalities to detect BCRL in the subclinical phase of the process allowing for early intervention.

Trial Design: This 2-group stratified randomized clinical trial evaluates the effectiveness of bioimpedance spectroscopy (BIS) for early detection and prevention of BCRL compared to tape measurement (TM). Baseline assessments are made pre-operatively. Two-months post-op, patients are censored out if they have developed any of the exclusion conditions, did not have a mastectomy, axillary dissection, >6 sentinel nodes removed, radiation therapy, or taxane. Remaining patients are randomized within site to either BIS or TM; monitored at 3 to 6-month intervals up to 36-months post-op for a change over baseline specified to trigger a compression sleeve & gauntlet intervention. Cohort trigger thresholds are change of ≥10 L-Dex units or 5 to <10% volume. If the intervention is triggered, measurements by the other method are taken before initiating the 4-week intervention. Post intervention, patients are monitored only with TM. Volume change of ≥10% results in study removal and physician referral. At the 2 study endpoints (36 month visit or volume change of ≥10%) measurements are taken with each method.

Eligibility Criteria: Inclusion criteria: ≥ 18 with histologically confirmed stage I-III breast cancer (BC) or DCIS with planned surgery. Exclusion criteria include history of BC therapy or lymphedema.

Specific Aims: The primary hypothesis is that subclinical detection of BCRL with BIS and early intervention will reduce the rate of lymphedema progression (as measured by referral to complex decongestive physiotherapy) compared to TM. Secondary outcomes include BCRL risk factors, quality of life, and time to treatment.

Statistical Methods: Sample size and powering were based on the hypothesis that BIS would reduce progression rate by 20%. A rate of 50% progression in the TM group was used as the standard. 1100 patients will be enrolled to result in randomized groups of 100 (Total N=200) Statistics include relative risks with respective bootstrapped 95% C.I. and Cochran-Mantel-Haenszel tests.

Present Accrual and Target Accrual: Overall, the study target or expected enrollment as of the end of March 31, 2016 was 690 participants, 534 were actually enrolled (actual accrual 77% of target). Accrual at the study sites ranged from 15 to 104% of target.

Contact Information: Sheila Ridner: 615-322-0831, Sheila.ridner@vanderbilt.edu

Support: ImpediMed Limited, ImpediMed, Inc. and medi USA.

Citation Format: Ridner S, Shah C, Dietrich M, Vicini F. A randomized trial evaluating bioimpedance spectroscopy vs. tape measurement in the prevention of lymphedema following breast cancer treatment [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr OT3-07-01.