Effects of green light supplementation with red and blue combinations of LED light spectrums on the growth and transcriptional response of Haematococcus pluvialis

Light management strategy is crucial for improving microalgal production in terms of higher biomass and economically valuable bioactive molecules. However, green light has received less attention in developing light managements for algae and higher plant due to its low absorption rate by chlorophyll. In this study, the effects of green light supplementation, in the combination with red and blue light were investigated in Haematococcus pluvialis. 10% and 20% of green light supplementations were applied in 3:2 ratios of red and blue LED light combinations as an expense of red-light. Growth rates, chlorophyll concentration, and dry weight were measured to assess the growth kinetics of H. pluvialis along with the relative transcript accumulations of four mRNAs: Rubisco, PTOX2, PsaB, and PsbS. Growth rates, chlorophyll concentrations and dry weight were found significantly higher in presence of 10% green light supplementation compared to red and blue light combinations. The relative transcript accumulations of Rubisco and PsbS genes showed significant upregulation at the end of the experiments (with the fold change of 42.91 ± 12.08 and 98.57 ± 27.38, respectively, relative to the beginning of the experiments) compared to combinations of red and blue light (fold change of 19.09 ± 3.0 and 47.77 ± 14.21, respectively, relative to beginning of the experiments). PsaB and PTOX2 transcripts did not show significant accumulation differences between treatments. It seems that green light has a dose dependent additive effect on the growth rate of H. pluvialis. The upregulation of Rubisco and PsbS may indicate green light dependent carbon assimilation and light-harvesting response in H. pluvialis.

Comparative de novo transcriptome analysis and random UV mutagenesis: application in high biomass and astaxanthin production enhancement for Haematococcus pluvialis

BACKGROUND

Astaxanthin is a natural carotenoid with strong antioxidant capacity. The high demand on astaxanthin by cosmetic, food, pharmaceutical and aquaculture industries promote its value in the biotechnological research. Haematococcus pluvialis Flotow 1844 has been characterized as one of the most promising species for natural astaxanthin biosynthesis. Even though H. pluvialis as an advantage in producing astaxanthin, its slow grow-yield limits usage of the species for large-scale production.

METHODS AND RESULTS

In this study we generated mutated H. pluvialis strain by using one-step random UV mutagenesis approach for higher biomass production in the green flagellated period and in turn higher astaxanthin accumulation in red stage per unit algae harvest. Isolated mutant strains were tested for the astaxanthin accumulation and yield of biomass. Among tested strains only mutant strain designated as only MT-3-7-2 showed a consistent and higher growth pattern, the rest had shown a fluctuated and then decreased growth rate than wild type. To demonstrate the phenotypical changes in MT-3-7-2 is associated with transcriptome, we carried out comparative analysis of transcriptome profiles between MT-3-7-2 and the wild type strains. De novo assembly was carried out to obtain the transcripts. Differential expression levels for the transcripts were evaluated by functional annotation analysis.

CONCLUSIONS

Data showed that increased biomass for the MT-3-7-2 strain was different from wild type with expression of transcripts upregulated in carbohydrate metabolism and downregulated in lipid metabolisms. Our data suggests a switching mechanism is enrolled between carbohydrate and lipid metabolism to regulate cell proliferation and stress responses.

Epidemiology and outcomes of hospital-acquired bloodstream infections in intensive care unit patients: the EUROBACT-2 international cohort study

PURPOSE

In the critically ill, hospital-acquired bloodstream infections (HA-BSI) are associated with significant mortality. Granular data are required for optimizing management, and developing guidelines and clinical trials.

METHODS

We carried out a prospective international cohort study of adult patients (≥ 18 years of age) with HA-BSI treated in intensive care units (ICUs) between June 2019 and February 2021.

RESULTS

2600 patients from 333 ICUs in 52 countries were included. 78% HA-BSI were ICU-acquired. Median Sequential Organ Failure Assessment (SOFA) score was 8 [IQR 5; 11] at HA-BSI diagnosis. Most frequent sources of infection included pneumonia (26.7%) and intravascular catheters (26.4%). Most frequent pathogens were Gram-negative bacteria (59.0%), predominantly Klebsiella spp. (27.9%), Acinetobacter spp. (20.3%), Escherichia coli (15.8%), and Pseudomonas spp. (14.3%). Carbapenem resistance was present in 37.8%, 84.6%, 7.4%, and 33.2%, respectively. Difficult-to-treat resistance (DTR) was present in 23.5% and pan-drug resistance in 1.5%. Antimicrobial therapy was deemed adequate within 24 h for 51.5%. Antimicrobial resistance was associated with longer delays to adequate antimicrobial therapy. Source control was needed in 52.5% but not achieved in 18.2%. Mortality was 37.1%, and only 16.1% had been discharged alive from hospital by day-28.

CONCLUSIONS

HA-BSI was frequently caused by Gram-negative, carbapenem-resistant and DTR pathogens. Antimicrobial resistance led to delays in adequate antimicrobial therapy. Mortality was high, and at day-28 only a minority of the patients were discharged alive from the hospital. Prevention of antimicrobial resistance and focusing on adequate antimicrobial therapy and source control are important to optimize patient management and outcomes.

Nematode-Associated Bacteria: Production of Antimicrobial Agent as a Presumptive Nominee for Curing Endodontic Infections Caused by Enterococcus faecalis

Xenorhabdus and/or Photorhabdus bacteria produce antibacterial metabolites to protect insect cadavers against food competitors allowing them to survive in nature with their nematode host. The effects of culture supernatant produced by Xenorhabdus and Photorhabdus spp. were investigated against the multidrug-resistant dental root canal pathogen Enterococcus faecalis. The efficacy of seven different cell-free supernatants of Xenorhabdus and Photorhabdus species against E. faecalis was assessed with overlay bioassay and serial dilution techniques. Additionally, time-dependent inactivation of supernatant was evaluated. Among the seven different bacterial species, X. cabanillasii produced the strongest antibacterial effects. Loss of bioactivity in a phosphopantetheinyl transferase-deficient mutant of X. cabanillasii indicated that this activity is likely based on non-ribosomal peptide synthetases (NRPSs) or polyketide synthases (PKSs). Subsequent in silico analysis revealed multiple possible biosynthetic gene clusters (BGCs) in the genome of X. cabanillasii including a BGC homologous to that of zeamine/fabclavine biosynthesis. Fabclavines are NRPS-derived hexapeptides, which are connected by PKS-derived malonate units to an unusual polyamine, also PKS-derived. Due to the known broad-spectrum bioactivity of the fabclavines, we generated a promoter exchange mutant in front of the fabclavine-like BGC. This leads to over-expression by induction or a knock-out by non-induction which resulted in a bioactive and non-bioactive mutant. Furthermore, MS and MS² experiments confirmed that X. cabanillasii produces the same derivatives as X. budapestensis. The medicament potential of 10-fold concentrated supernatant of induced fcl promoter exchanged X. cabanillasii was also assessed in dental root canals. Calcium hydroxide paste, or chlorhexidine gel, or fabclavine-rich supernatant was applied to root canals. Fabclavine-rich supernatant exhibited the highest inactivation efficacy of ≥3 log₁₀ steps CFU reduction, followed by calcium hydroxide paste (≤2 log₁₀ step). The mean percentage of E. faecalis-free dental root canals after treatment was 63.6, 45.5, and 18.2% for fabclavine, calcium hydroxide, and chlorhexidine, respectively. Fabclavine in liquid form or preferably as a paste or gel formulation is a promising alternative intracanal medicament.

Abstract OT3-04-03: KEYNOTE-756: A randomized, double-blind, phase III study of pembrolizumab versus placebo in combination with neoadjuvant chemotherapy and adjuvant endocrine therapy for high-risk early-stage ER+/HER2– breast cancer

Background:Although ER+/HER2– breast cancer has a better overall prognosis than other breast cancer subtypes, there is a high-risk subpopulation characterized by high-grade tumors and decreased sensitivity to endocrine therapy, higher responsiveness to chemotherapy and worse prognosis. A large meta-analysis of prospective studies focusing on neoadjuvant chemotherapy (NAC) for treatment of stage I-III breast cancer demonstrated that increased pathologic complete response (pCR) rates at surgery were associated with improved survival. This correlation was observed across triple-negative breast cancer (TNBC), HER2+ breast cancer, and high-grade HR+/HER2- breast cancer. Specifically, patients with a pCR after NAC had a 5-year event-free survival (EFS) rate of 90%, whereas patients who did not achieve a pCR had a 5-year EFS rate of 60%.Therefore, increasing pCR rates after NAC may have a substantial impact for patients with high-risk early-stage HR+/HER2– breast cancer. KEYNOTE-756 is a global, randomized, double-blind, phase III study of pembrolizumab (vs placebo) + chemotherapy as neoadjuvant treatment, followed by pembrolizumab (vs placebo) plus endocrine therapy as adjuvant treatment for patients with high-risk, early-stage ER+/HER2– breast cancer.

Methods: Patients with T1c-2 cN1-2 or T3-4 cN0-2 grade 3 or grade 2 with Ki-67 ≥30%, invasive, ductal ER+/HER2– breast cancerwill be stratified by lymph node involvement (positive vs negative), tumor PD-L1 status (positive vs negative), ER positivity (≥10% vs <10%), and anthracycline dosing schedule (Q3W vs Q2W), and then randomized 1:1 to receive neoadjuvant treatment with pembrolizumab 200 mg Q3W or placebo in combination with paclitaxel (80 mg/m2 QW) for 4 cycles followed by (doxorubicin [60 mg/m2] or epirubicin [100 mg/m2]) plus cyclophosphamide (600 mg/m2) Q2/3W for another 4 cycles. After definitive surgery (± radiation therapy, as indicated), patients will receive adjuvant treatment with pembrolizumab (200 mg Q3W) or placebo for 9 additional administrations, in combination with endocrine therapy, which can be given for up to 10 years. Co-primary end points are pCR rate and EFS. Secondary end points are safety and overall survival. The global study will open in North America and Latin America, Europe, and Asia Pacific in the second half of 2018.

Citation Format: Cardoso F, Bardia A, Andre F, Cescon DW, McArthur H, Telli M, Loi S, Cortés J, Schmid P, Harbeck N, Denkert C, Jackisch C, Jia L, Tryfonidis K, Karantza V. KEYNOTE-756: A randomized, double-blind, phase III study of pembrolizumab versus placebo in combination with neoadjuvant chemotherapy and adjuvant endocrine therapy for high-risk early-stage ER+/HER2– breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT3-04-03.

TST, QuantiFERON-TB Gold test and T-SPOT.TB test for detecting latent tuberculosis infection in patients with rheumatic disease prior to anti-TNF therapy

Introduction

Before starting tumour necrosis factor (TNF)-α blocking agents, standard tests should be used for the diagnosis of tuberculosis infection. The specificity of traditional tuberculin skin test (TST) is low in immunosuppressed patients due to prior Bacille Calmette Guérin (BCG) vaccination, non-tuberculous mycobacteria infections, false positive and negative results. In this study, we aimed to compare TST and Interferon-Gamma Release Assay (IGRA) tests for detecting latent tuberculosis infection in patients with rheumatic disease planned to receive TNF-α blocking agents.

Materials and Methods

One hundred and nine patients (45 male, 64 female) with the diagnosis of rheumatoid arthritis (RA) (n= 70) and ankylosing spondylitis (AS) (n= 39) were included in the study. Age, sex, number of BCG scar, results of TST (using the Mantoux method), QuantiFERON-TB Gold test and T-SPOT.TB test were recorded for all patients. Correlation between the tests was assessed by Pearson correlation coefficient.

Result

The mean age of RA and AS patients were 50 ± 13 (19-78 years). The prevalence of latent tuberculosis was 43.1% for TST, 39.4% for QuantiFERON-TB Gold test and 13.8% for T-SPOT.TB test, compared with the evaluation using the composite criteria such as close contact with active tuberculosis infection and/or suspicious fibrotic/calcific lesions on chest X-Ray without active tuberculosis infection. There was a moderate correlation between BCG scar number and TST (p< 0.001, r= 0.495), T-SPOT.TB test and QuantiFERON-TB Gold test (p= 0.007, r= 0.406), T-SPOT.TB test and composite criteria (p= 0.024, r= 0.343). The specificity of QuantiFERON-TB Gold test was 85.7%, and sensitivity was 73.9% for all patients with rheumatic disease. It was 73.5% and 66.7% for T-SPOT.TB test, respectively. The specificity of TST was 60.3% and sensitivity was 47.8% for TST.

Conclusions

IGRA tests are not affected prior vaccination and useful for detecting latent tuberculosis infection in patients treated with corticosteroid due to lack of correlation between test negativity and corticosteroid therapy. Also, they are useful tests for diagnosis of latent tuberculosis infection as an alternative to TST due to their specificity and sensitivity.

Abstract MS1-2: New clinical approaches for TNBC

Over the last decade, triple-negative breast cancer (TNBC) has been the subject of intense clinical investigation. Importantly, an improved understanding of the critical role of DNA damage repair deficiency in TNBC has led to effective therapeutic strategies to target BRCA1 and BRCA2 mutation-associated TNBCs with platinum chemotherapy agents and PARP inhibitors. A major area of increasing clinical relevance focuses on the treatment of BRCA1 and BRCA2 mutation-associated breast cancers after the development of resistance to platinum and PARP inhibitor therapy. Lurbinectedin, a novel marine derived DNA damaging agent, has shown activity in BRCA1 and BRCA2 mutation-associated cancers, including those with platinum resistance.

While therapeutic strategies for TNBC patients with BRCA1 and BRCA2 mutations have increased, most TNBC patients lack an underlying germline mutation in these genes and continue to have high unmet clinical need. Multiple lines of investigation are currently underway. Androgen receptor (AR) blockade has shown preliminary proof-of-concept in AR expressing TNBCs. While monotherapy with PD-1/PD-L1 checkpoint inhibitors has shown modest activity in metastatic TNBC, multiple studies are exploring the role of these agents in combination with chemotherapy, targeted therapies and other immunotherapeutic agents. Given the high prevalence of TP53 mutations in TNBC, strategies to target additional cell cycle checkpoints including ATR, ATM, Wee1 and others may hold promise. Antibody-drug conjugates targeting Trop-2, LIV-1 and GPNMB expressing TNBCs have also shown clinical activity and are advancing in clinical development.

Citation Format: Telli M. New clinical approaches for TNBC [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr MS1-2.

[Evaluation of the efficacy of colistin/sulbactam combination on carbapenem-resistant Acinetobacter baumannii strains]

Acinetobacter baumannii strains, are opportunistic pathogens that cause severe nosocomial infections that are difficult to treat due to development of resistance to multiple antibiotics. As the antibiotic choices to be used in treatment are limited, combinations of a variety of antibiotics are used. The aims of this study were to identify the minimal inhibitory concentration (MIC) values of colistin and sulbactam against A.baumannii isolates and to determine the in vitro activity of colistin-sulbactam combination. A total of 50 A.baumannii strains isolated from different clinical specimens (32 tracheal aspirates, 10 blood, 6 urine and 2 wound samples) were included in the study. The identification of bacteria was performed by traditional methods and Vitek-2 (BioMerieux, France) automated system. Antibiotic susceptibilities were detected by Mueller-Hinton agar disk diffusion method and Vitek-2 automated system and the results were interpreted according to the CLSI standards. MIC values of colistin and sulbactam against A.baumannii strains and in vitro interactions of colistin-sulbactam combinations were determined with the E-test (BioMerieux, France). Fractional inhibitory concentration (FIC) index was used for the detection of efficacy of drug combinations. The presence of oxacillinase and metallo-beta-lactamase (MBL) genes that lead carbapenem resistance was investigated by polymerase chain reaction (PCR), and pulsed-field gel electrophoresis (PFGE) was performed for the determination of clonal relationship. In our study, all strains (100%) were detected as susceptible to colistin, 48 (96%) to trimethoprim/sulphamethoxazole and 18 to (36%) tigecyclin; however all of them were resistant to the other studied antibiotics, including sulbactam and carbapenem. When the colistin-sulbactam combination was assessed according to FIC index, all strains were found to have antagonistic effect. All of the carbapenem-resistant strains were positive for OXA-51 and OXA-23, and 3 (6%) were positive for OXA-24. Among MBLs, OXA-58, OXA-48, IPM, SPM, SIM, GIM, VIM and NDM-1 genes were not detected. In the evaluation of PFGE results it was found that the clonal distribution of the strains, except one, were all pulsotype A. In the assessment of in vitro efficacy of the colistin-sulbactam combination against A.baumannii strains with multidrug resistance, antagonistic effect was observed in all strains. In the resistance and clonal analysis it was determined that the strains belonged to the same clone, and they had the same resistance genes and therefore the result of the in vitro activity was considered to have similar effect among all strains. It was decided that especially in units where critical patients are monitored and where resistant strains that are difficult to treat are isolated, performing synergy studies may be beneficial for the selection of combination treatment and the determination of the treatment combination to be chosen specifically for the hospital or even the unit.

Acinetobacter dijkshoorniae sp. nov., a member of the Acinetobacter calcoaceticus-Acinetobacter baumannii complex mainly recovered from clinical samples in different countries

The recent advances in bacterial species identification methods have led to the rapid taxonomic diversification of the genus Acinetobacter. In the present study, phenotypic and molecular methods have been used to determine the taxonomic position of a group of 12 genotypically distinct strains belonging to the Acinetobacter calcoaceticus-Acinetobacter baumannii (ACB) complex, initially described by Gerner-Smidt and Tjernberg in 1993, that are closely related to Acinetobacter pittii. Strains characterized in this study originated mostly from human samples obtained in different countries over a period of 15 years. rpoB gene sequences and multilocus sequence typing were used for comparisons against 94 strains representing all species included in the ACB complex. Cluster analysis based on such sequences showed that all 12 strains grouped together in a distinct clade closest to Acinetobacter pittiithat was supported by bootstrap values of 99 %. Values of average nucleotide identity based on blast between the genome sequence of strain JVAP01T (NCBI accession no. LJPG00000000) and those of other species from the ACB complex were always <91.2 %, supporting the species status of the group. In addition, the metabolic characteristics of the group matched those of the ACB complex and the analysis of their protein signatures by matrix-assisted laser desorption ionization time-of-flight MS identified some specific peaks. Our results support the designation of these strains as representing a novel species, for which the name Acinetobacter dijkshoorniae sp. nov. is proposed. The type strain is JVAP01T (=CECT 9134T=LMG 29605T).

The investigation of oxacillinase/metallo-beta-lactamase genes and clonal analysis in carbapenem-resistant Klebsiella pneumoniae

Infections due to carbapenem-resistant Klebsiella pneumoniae represent a growing problem nationally. In our study, we aimed to examine carbapenem-resistant K. pneumoniae with multiple resistance isolated in the intensive care unit of our hospital. Isolates were investigated for the presence of oxacillinase and metallo-beta lactamase genes with a view to determining the clonal relationship between the strains intensely over a short period. Strain identification was completed with conventional methods and automated identification kit. OXA-58, OXA-23, OXA-51, OXA-24 and OXA-48 and metallo-beta lactamase genes IPM, VIM, SPM, SIM, GIM and NDM-1 were investigated with PCR. For clonal relationships of carbapenem-resistant strains, the PFGE experiment was performed. While all of these carbapenem-resistant strains were positive for OXA-48, the resistant genes NDM-1, VIM, KPC, IPM, SPM, GIM, SIM, OXA-23, OXA-24, OXA-58 and OXA-51 were not observed. When molecular typing results were investigated, PFGE determined clonal distribution of three pulsotypes. However, it was observed that the strains intensified in a single clone and this was assessed as the outbreak isolate. The results of this study showed the primary enzyme responsible for carbapenem resistance in K. pneumoniae strains in our hospital is still OXA-48. To prevent the spread of carbapenem-resistant K. pneumoniae isolates, with epidemic potential, national-level monitoring and effective infection control precautions should be enforced.

Small RNA Sequencing Based Identification of MiRNAs in Daphnia magna

Small RNA molecules are short, non-coding RNAs identified for their crucial role in post-transcriptional regulation. A well-studied example includes miRNAs (microRNAs) which have been identified in several model organisms including the freshwater flea and planktonic crustacean Daphnia. A model for epigenetic-based studies with an available genome database, the identification of miRNAs and their potential role in regulating Daphnia gene expression has only recently garnered interest. Computational-based work using Daphnia pulex, has indicated the existence of 45 miRNAs, 14 of which have been experimentally verified. To extend this study, we took a sequencing approach towards identifying miRNAs present in a small RNA library isolated from Daphnia magna. Using Perl codes designed for comparative genomic analysis, 815,699 reads were obtained from 4 million raw reads and run against a database file of known miRNA sequences. Using this approach, we have identified 205 putative mature miRNA sequences belonging to 188 distinct miRNA families. Data from this study provides critical information necessary to begin an investigation into a role for these transcripts in the epigenetic regulation of Daphnia magna.

A milk pump as a source for spreading Acinetobacter baumannii in a neonatal intensive care unit

Acinetobacter baumannii is a Gram-negative coccobacillus that has emerged as a troublesome pathogen causing institutional outbreaks. Environmental contamination is a distinctive characteristic of this microorganism, which brings a further difficulty in infection control. During A. baumannii outbreaks in intensive care units, a common contaminated object can be found as a reservoir. Finding out this source by epidemiological investigations is of particular importance in order to develop effective interventions. We describe an outbreak of A. baumannii and the results of epidemiological investigations in a neonatal intensive care unit. The outbreak strain was isolated from the outer surface of a breastmilk pump. We have successfully controlled the outbreak by careful reviewing of our milk collection process.

A newborn with pertussis accompanying nephrotic syndrome

Pertussis or whooping cough is a vaccine-preventable disease that still remains a serious infection in neonates and young infants. The disease is particularly severe in infants less than three months old, who are often infected by their parents. Congenital nephrotic syndrome is a rare entity presenting within the first three months. It encompasses a heterogeneous group of entities with genetic, infectious and idiopathic etiologies. In this report we describe a newborn infant who presented with congenital nephrotic syndrome secondary to Bordetella pertussis infection.

Abstract OT2-6-16: A pivotal multicenter, randomized, study evaluating the novel antibody-drug conjugate CDX-011 in patients with metastatic, triple-negative, high GPNMB over-expressing breast cancer

Background: GPNMB is an internalizable transmembrane glycoprotein overexpressed in multiple tumor types where it is a poor prognostic factor. Its functions appear to include mediating intercellular adhesion, promoting tissue repair, and regulating cell growth and differentiation. In tumor cell lines including breast cancer (BC), GPNMB enhances tumor growth and bone metastases. Relative to other BC subtypes, triple-negative BC (TNBC) highly over-expresses GPNMB in tumor epithelium where it correlates with a higher risk of recurrence. CDX-011 (glembatumumab vedotin) is a fully human GPNMB-specific monoclonal antibody drug conjugate combining the tumor-targeting GPNMB antibody with the potent cytotoxic microtubule inhibitor, monomethylauristatin E (MMAE). In the Phase II EMERGE study, 122 patients (pts) with heavily pre-treated BC (2-7 priors) and GPNMB-expression by IHC in ≥ 5% of either the tumor epithelial or stromal cells in archival tissue were randomized 2:1 to receive CDX-011 or “investigator's choice” (IC) single-agent chemotherapy, with crossover to CDX-011 permitted. CDX-011 as compared to IC, demonstrated higher objective response rates, with ORR of 8/25 (32%) vs 1/8 (13%) for high GPNMB expression (defined as expression in ≥25% of epithelial tumor cells) and 5/27 (19%) vs. 0/9 (0%) for TNBC. In the presence of both TNBC and high GPNMB, ORR was 4/12 (33%) vs 0/4 (0%) which corresponded to a doubling of median progression-free survival (PFS, p = 0.008) and median overall survival (OS, p = 0.003). CDX-011 was well tolerated with less hematologic toxicity (neutropenia: 29% vs 44%; leukopenia: 10% vs 27%; thrombocytopenia: 4% vs. 15%) but more rash (47% vs. 2%) and neuropathy (23% vs 12%) than IC. Methods: The current pivotal study aims to evaluate CDX-011 in metastatic GPNMB-over-expressing TNBC defined as ER and PR &lt; 1%, HER2 negative (0-1+ IHC, or FISH ratio &lt; 1.8). Eligibility criteria include &gt;25% tumor epithelium GPNMB expression by central IHC; taxane and anthracyline resistance; ≤1 prior chemotherapy regimen for advanced BC; measurable disease by RECIST 1:1 and no persistent treatment-related toxicity of ≥ Grade 2 severity. 300 pts will be randomized (2:1) to receive CDX-011 (1.88 mg/kg IV q 21 days) or capecitabine (2500 mg/m2 daily for d1-14, q21 days) until progression or toxicity. Disease assessments are performed every six weeks for 6 months, and every 12 weeks thereafter. All pts are subsequently followed for survival. Endpoints are ORR and PFS (co-primary), duration of response, OS, safety, pharmacokinetics, and quality of life; tumor response assessments will be assessed by central review per RECIST 1.1. The trial has 80% power to detect a hazard ratio of 0.64 for PFS with α = 0.01 and/or a 30% increase in ORR (from 15% to 30%) with α = 0.04. For further information, contact info@celldextherapeutics.com.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr OT2-6-16.

Abstract OT1-4-04: A phase II randomized, open-label, neoadjuvant study of LCL161, an oral antagonist of inhibitor of apoptosis proteins, in combination with paclitaxel in patients with triple-negative breast cancer

Background: Inhibitor of apoptosis proteins (IAPs) negatively regulate cell death through a variety of mechanisms. LCL161 is an oral small-molecule antagonist of IAPs that has demonstrated single-agent activity and synergy with paclitaxel in breast cancer tumor models. In preclinical studies, a gene expression signature has been shown to enrich for response to LCL161. The recommended dose of LCL161 1800 mg once weekly has demonstrated preliminary antitumor activity with paclitaxel in an ongoing Phase Ib study in patients with breast cancer.

Trial design: This is a Phase II, randomized, open-label study of neoadjuvant paclitaxel with or without LCL161 in women with operable, newly diagnosed triple-negative breast cancer (NCT01617668). Key inclusion criteria include women with histologically confirmed diagnosis of triple-negative breast cancer; clinical stages T2, N0–N2, M0; candidates for mastectomy or breast-conserving surgery; ECOG performance status ≤1; known status of the LCL161-predictive gene expression signature (positive and negative gene signature is a stratification factor); and adequate bone marrow and organ function. Key exclusion criteria are: bilateral or inflammatory breast cancer; locally recurrent breast cancer; patients currently receiving systemic therapy for any other malignancy, or having received systemic therapy for a malignancy in the preceding 3 months; impaired gastrointestinal function that may affect the absorption of LCL161; or uncontrolled cardiac disease.

Patients are randomized 1:1 to receive paclitaxel IV (80 mg/m2 weekly) with or without oral LCL161 (1800 mg once weekly) for 12 weeks (corresponding to 4 treatment cycles). Each treatment arm is stratified 1:1 based on gene expression signature status (positive or negative).

Endpoints: The primary endpoint is pathologic complete response (pCR), defined as the absence of invasive disease in the breast after 12 weeks of therapy, analyzed separately in the gene expression signature positive and negative groups. The key secondary endpoint is the pCR rate following treatment with LCL161 and paclitaxel in gene expression signature-positive or -negative tumors. Other secondary endpoints include: pCR rate in breast after 12 weeks of therapy in the full study population, and in patients with gene expression signature-positive and -negative tumors treated with paclitaxel alone; pCR rate in breast, regional nodes and axilla; biomarker evaluation including caspase 3 activation in tumor; safety; and pharmacokinetics of LCL161.

Statistical methods: pCR analysis will be performed according to treatment group and gene expression signature status. An absolute increase of at least 7.5% in pCR rate of the experimental arm over the control arm will be considered as evidence of clinically relevant efficacy.

Target accrual: Approximately 200 patients will be randomized into this study. Recruitment is ongoing across America, Europe, and Asia.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr OT1-4-04.

Detection of human bocavirus in children with upper respiratory tract infection by polymerase chain reaction

BACKGROUND

The aim of this study was to investigate whether in children with middle ear effusions (MEE), adenoid and tonsil tissues are associated with human bocavirus (HBoV).

MATERIALS AND METHODS

A total of 124 patients (56 females (45.2%) and 68 males (54.8%)) with chronic adenotonsillitis and serous otitis media under the age of 15 were recruited. Two hundered four samples (113 adenoid (55.4%), 68 tonsil (33.3%), and 23 middle ear effusion (11.3%)) were analyzed for the presence of HBoV using polymerase chain reaction (PCR).

RESULTS

HBoV was detected in only 6 (4.8%) adenoid tissue samples each belonging to a different patient.

CONCLUSIONS

Our findings are consistent with the results of other studies, reporting approximately 5 - 10% of the samples being positive for HBoV. To understand the detailed role of HBoV in the etiology of RTI in children, further studies would be needed.

Thoracic catheter-related infections

OBJECTIVE

To determine the incidence of local and systemic infection in a sample of patients catheterized with thoracic catheters (TCs) and to identify the prognostic factors for catheter-related infection.

METHODS

A retrospective study involving 48 patients (17 females and 31 males) catheterized with TCs between December of 2008 and March of 2009 in the Thoracic Surgery Department of the Adnan Menderes University Hospital, located in Aydin, Turkey. Blood samples for culture were collected from the distal end of each TC and from each of the 48 patients. We looked for correlations between positive culture and possible prognostic factors for catheter-related infection.

RESULTS

Culture results were positive in TC samples only for 3 patients, in blood samples only for 2, and in both types of samples for another 2. Advanced age correlated significantly with positive culture in TC samples and in blood samples (r = 0.512 and r = 0.312, respectively; p < 0.05 for both), as did prolonged catheterization (r = 0.347 and r = 0.372, respectively; p < 0.05). There was a significant correlation between having undergone surgery and positive culture in TC samples only (p < 0.05). However, having an inoperable malignancy correlated with bacterial growth in blood and in TC samples alike (p < 0.05 for both).

CONCLUSIONS

Risk factors, such as advanced age, prolonged catheterization, comorbidities, and inoperable malignancy, increase the risk of catheter-related infection. It is imperative that prophylaxis with broad-spectrum antibiotics be administered to patients who present with these risk factors and might be catheterized with a TC.

Prevalence of enterotoxins among Escherichia coli isolates causing bacteraemia

The most frequent cause of bacteraemia among Gram-negative bacteria is Escherichia coli. Analysis of the genes encoding the Shigella enterotoxin 1 (ShET-1), ShET-2, enteroaggregative heat stable toxin 1 (EAST-1) toxins and AggR factor in E. coli strains causing bacteraemia revealed that set1 genes were presented significantly more frequently among quinolone-susceptible strains (P<0.0001), in phylogenetic group B2 (P=0.0004) and in biofilm strains (P=0.02). In contrast, sen genes were significantly more frequent among nalidixic acid-resistant isolates (15% vs. 6%, P=0.046) and in phylogenetic group B1 (P=0.0001). This is the first study in which ShET1, ShET2 and EAST-1 have been found in E. coli collected from blood.

Prospective cardiotoxicity screening during tyrosine kinase inhibitor therapy for renal cell carcinoma: An institutional experience

e16003

Background: Tyrosine kinase inhibitors (TKI) can lead to cardiotoxicity either directly by causing left ventricular dysfunction, or indirectly by increasing blood pressure. In light of prior studies at our institution documenting a high rate of symptomatic heart failure in patients with renal cell carcinoma undergoing treatment with sunitinib, we instituted a prospective screening protocol to characterize the incidence and natural history of TKI-associated cardiotoxicity. Methods: From March-December 2008, patients receiving TKI therapy for renal cell carcinoma received cardiac biomarker screening (NT- BNP and Troponin I at baseline and after week 4 of each cycle) and transthoracic echocardiography (baseline, 1 month, 3 months, and every 3 months thereafter). If biomarkers were elevated or a decline in ejection fraction was observed, patients were referred for cardiology evaluation. Results: Twenty-six patients have been included since the protocol's initiation. No elevations in cardiac troponin I have been observed to date. Eight patients (31%) had elevations in NT-BNP (a sensitive marker for heart failure). The TKIs involved included sunitinib (5 patients), sorafenib (2 patients), and bevacizumab (1 patient). One patient who was treated with sunitinib had frank left ventricular systolic dysfunction. Seven of the eight patients with elevated NT-BNP values had baseline hypertension, and five patients had significant increases in blood pressure during TKI treatment. In all patients with follow-up biomarkers, NT-BNP levels fell after initiation of heart failure therapy. TKI treatment appeared to ‘unmask’ previously subclinical cardiac injury, including prior silent myocardial infarction (one patient), left ventricular hypertrophy (four patients), and valvular disease (three patients). Updated data from the ongoing screening protocol will be presented. Conclusions: The Stanford TKI screening protocol identified a high rate of subclinical cardiotoxicity and allowed for early initiation of heart failure therapy. Further studies are needed to determine if this approach can decrease cardiac morbidity and improve oncologic outcomes by preventing discontinuation or dose interruption of TKI therapy.

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