Citations

Abstract Implanted neural stimulation and recording devices hold vast potential to treat a variety of neurological conditions, but the invasiveness, complexity, and cost of the implantation procedure greatly reduce access to an otherwise promising therapeutic approach. To address this need, a novel electrode that begins as an uncured, flowable prepolymer that can be injected around a neuroanatomical target to minimize surgical manipulation is developed. Referred to as the Injectrode, the electrode conforms to target structures forming an electrically conductive interface which is orders of magnitude less stiff than conventional neuromodulation electrodes. To validate the Injectrode, detailed electrochemical and microscopy characterization of its material properties is performed and the feasibility of using it to stimulate the nervous system electrically in rats and swine is validated. The silicone‐metal‐particle composite performs very similarly to pure wire of the same metal (silver) in all measures, including exhibiting a favorable cathodic charge storage capacity (CSC C ) and charge injection limits compared to the clinical LivaNova stimulation electrode and silver wire electrodes. By virtue of its simplicity, the Injectrode has the potential to be less invasive, more robust, and more cost‐effective than traditional electrode designs, which could increase the adoption of neuromodulation therapies for existing and new indications.

Abstract Background Over 80% of patients with hematologic malignancies develop some form of infectious complication, most commonly febrile neutropenia. Patients with febrile neutropenia have 10% mortality, which increases if antibiotic administration is delayed past 30 minutes. Studies have suggested β-lactam allergy may delay administration of antibiotic while putting patients at greater risk for inappropriate antibiotic choice and adverse effects stemming from this. We sought to describe the risks associated with β-lactam allergy in the neutropenic population. Methods We conducted a retrospective, descriptive study from January 2016 to December 2017 identifying patients with febrile neutropenia and a reported history of β-lactam allergy. Baseline characteristics, allergy data, treatment data, and outcomes were collected and analyzed. Results We identified 31 patients with febrile neutropenia and β-lactam allergy during this time period. Etiologies of neutropenia were hematologic malignancy (61.2%), stem cell transplantation (12.9%), solid-organ malignancy (22.6%), and autoimmune (3.3%). Reported reactions to β-lactams were rash (41.9%), hives (9.7%), anaphylaxis (3.2%), other (9.7%), and unknown (35.5%). Average time to antibiotic administration was 142.5 minutes. Antibiotic choice was cefepime (61.3%), piperacillin–tazobactam (6.5%), carbapenem (22.6%), fluoroquinolone (6.5%), cefepime and fluoroquinolone (3.2%), and vancomycin (58.1%). 51.6% received initial antibiotics consistent with the 2010 IDSA guidelines. Six patients underwent penicillin skin testing, all negative. 1 patient developed C. difficile infection, 1 developed MRSA colonization, and 3 developed VRE colonization. Mortality was 3.2% at 30 days and 16.1% at 90 days. Conclusion Our study estimated the antibiotic usage patterns and outcomes in patients with febrile neutropenia and reported β-lactam allergy. This showed low adherence to an established guideline for antibiotic choice in these patients. With rising antimicrobial resistance, there is a need to develop strategies to reduce inappropriate antimicrobial use, especially in patients with febrile neutropenia. Preemptive β-lactam allergy evaluation warrants further evaluation in the neutropenic population. Disclosures All authors: No reported disclosures.

Abstract Background Optimum duration of antimicrobial therapy for acute bacteremic cholangitis is not well established; however, 4–7 days is recommended by the 2018 Tokyo guidelines in those without Gram-positive bacteremia. Methods A retrospective study performed at Mayo Clinic - Rochester, Florida and Arizona sites was conducted, reviewing all adult patients with the first episode of acute cholangitis secondary to biliary stone obstruction, between January 1, 2012 and December 31, 2017. We reviewed the duration of prescribed antimicrobials. Results Among 331 included cases, 197(60%) were men, 66 (20%) were immuno-compromised. Presenting symptoms included fever in 202 (61.5%), abdominal pain in 289 (87%), jaundice 128(38.7%), and altered mentation in 49 (15%). Among these, 256 (77%) were classified as “definite” and 38 (11.5%) were “suspected” using the 2018 Tokyo guideline classification. Cholangitis grade was grade III in 134 (40.5%); grade II in 115 (34.7%); and grade I in 82 (24.8%). Majority of cases, 321 (97%), underwent source control—most commonly 309 (96%) achieved by endoscopic retrograde cholangiopancreatography (ERCP). Source control occurred within 24 hr of presentation in 197 (61.4%) of the cases. Bacteremia was documented in 131/277 (47%). Majority of bacteremias were due to Gram-negative organisms in 119 (91%). Mean duration of antibiotic therapy following “source control” was 9.6 days (SD 7.0). Cases with bacteremia, resulted in longer treatment duration, mean of 13 days (SD 5.6), regardless of the isolated organism. Overall 30 day mortality was 14/331 (4.2%). No mortality difference was noted in patients who underwent early (within 12 hours) vs. later source control (4.55% Vs. 4.53%), nor in those who received more or less than 6 days of antibiotic therapy after source control (4.7% Vs. 3.9%, P = 0.76). No difference in mortality was observed in those with or without bacteremia. Conclusion Our results note the use of longer courses of antimicrobials for management of bacteremic cholangitis, regardless of the organism type. This population could be a prime target for an antimicrobial stewardship intervention, to decrease the duration of prescribed antimicrobials in accordance with recent guidelines. Disclosures All authors: No reported disclosures.

Abstract Background Cryptococcus sp. is a major cause of opportunistic infections in immunocompromised patients, with nearly all cases due to C. neoformans or C. gattii. There are occasional reports of other Cryptococcus species causing invasive human disease. However, their epidemiology and clinical significance are not fully defined. We sought to describe the patients with cultures positive for Cryptococcus species other than neoformans and gattii. Methods A retrospective descriptive review of patients with cultures growing Cryptococcus species other than neoformans and gattii from November 2011 to February 2019. Clinical and laboratory data were analyzed. Results Out of 177 cases with a culture positive for Cryptococcus sp., 54 patients (mean age, 53.3 years; 61% men) had a culture for Cryptococcus other than neoformans and gattii. The most common species were unspecified non-neoformans/gattii (10), magnus (9), laurentii (8), and ater (7). Three patients had active malignancies and 15 were on immunosuppressive drugs, 6 due to transplant. The most common sites or specimens were skin (16), respiratory (16), urine (7), joint (3), intravascular catheter (2), cerebrospinal fluid (2), oral (2), peritoneal fluid, donor liver transplant, bone marrow, sinus, nail, and cornea. Whereas 21 (38.9%) cultures were obtained due to local symptoms, there was only one case of invasive disease, affecting the peritoneum, while the majority was either unaddressed (25) or considered contaminants (17). Only 12 patients received antifungal treatment, where sources were skin (4), oral (2), peritoneum, donor liver, respiratory, vascular catheter, urine, and nail. Antifungal drugs were fluconazole, itraconazole, clotrimazole, caspofungin, and griseofulvin, for a mean duration of 37.6 days. Among patients who were not treated, four died within 6 months but mostly of unrelated causes (3) or not known (1). Conclusion This large series of patients with Cryptococcus sp. other than neoformans and gattii suggests that these species rarely cause clinically significant infection in humans. Only one case of invasive disease was found. Disclosures All authors: No reported disclosures.

Identifying bioenergetics that facilitate the epithelial to mesenchymal transition (EMT) in breast cancer cells may uncover targets to treat incurable metastatic disease. Metastasis is the number one cause of cancer-related deaths; therefore, it is urgent to identify new treatment strategies to prevent the initiation of metastasis. To characterize the bioenergetics of EMT, we compared metabolic activities and gene expression in cells induced to differentiate into the mesenchymal state with their epithelial counterparts. We found that levels of GLS2, which encodes a glutaminase, are inversely associated with EMT. GLS2 down-regulation was correlated with reduced mitochondrial activity and glutamine independence even in low-glucose conditions. Restoration of GLS2 expression in GLS2-negative breast cancer cells rescued mitochondrial activity, enhanced glutamine utilization, and inhibited stem-cell properties. Additionally, inhibition of expression of the transcription factor FOXC2, a critical regulator of EMT in GLS2-negative cells, restored GLS2 expression and glutamine utilization. Furthermore, in breast cancer patients, high GLS2 expression is associated with improved survival. These findings suggest that epithelial cancer cells rely on glutamine and that cells induced to undergo EMT become glutamine independent. Moreover, the inhibition of EMT leads to a GLS2-directed metabolic shift in mesenchymal cancer cells, which may make these cells susceptible to chemotherapies.

Phosphomannomutase 2 deficiency, or PMM2-CDG, is the most common congenital disorder of glycosylation affecting over 1,000 patients globally. There are no approved drugs that treat the symptoms or root cause of PMM2-CDG. In order to identify clinically actionable compounds that boost human PMM2 enzyme function, we performed a multi-species drug repurposing screen using a first-ever worm model of PMM2-CDG followed by PMM2 enzyme functional studies in PMM2-CDG patient fibroblasts. Drug repurposing candidates from this study, and drug repurposing candidates from a previously published study using yeast models of PMM2-CDG, were tested for their effect on human PMM2 enzyme activity in PMM2-CDG fibroblasts. Of the 20 repurposing candidates discovered in the worm-based phenotypic screen, 12 are plant-based polyphenols. Insights from structure-activity relationships revealed epalrestat, the only antidiabetic aldose reductase inhibitor approved for use in humans, as a first-in-class PMM2 enzyme activator. Epalrestat increased PMM2 enzymatic activity in four PMM2-CDG patient fibroblast lines with genotypes R141H/F119L, R141H/E139K, R141H/N216I and R141H/F183S. PMM2 enzyme activity gains range from 30% to 400% over baseline depending on genotype. Pharmacological inhibition of aldose reductase by epalrestat may shunt glucose from the polyol pathway to glucose-1,6-bisphosphate, which is an endogenous stabilizer and coactivator of PMM2 homodimerization. Epalrestat is a safe, oral and brain penetrant drug that was approved 27 years ago in Japan to treat diabetic neuropathy in geriatric populations. We demonstrate that epalrestat is the first small molecule activator of PMM2 enzyme activity with the potential to treat peripheral neuropathy and correct the underlying enzyme deficiency in a majority of pediatric and adult PMM2-CDG patients.

Abstract Background and Aims. Despite the fact that the myeloma mutational landscape was elucidated several years ago, there are yet no approved precision therapies targeting specific driver mutations. The role of common, but somewhat enigmatic, mutational events remains elusive, for example, the loss-of-function mutation of the RNA-processing exosome ribonuclease, DIS3, the third most-common mutation after KRAS and NRAS mutations. Furthermore, complex clonal architectural patterns (such as subclonal BRAF mutations nested within RAS-mutant clones) complicate the design of targeted therapy trials. To generate precision in vivo models that recapitulate the complex clonal and mutational architecture of myeloma, we integrated two powerful technological platforms: the first RAS-driven myeloma in vivo model (VQ model) created through a collaboration between the Zhang and Asimakopoulos labs coupled with flexible avian leukosis virus (ALV)-mediated gene transfer that permits myeloma genome editing in a temporally- and spatially- controlled fashion (Prdm1: TVb-mRFP model)(Asimakopoulos and Varmus, J Virol, 2009; 83(10):4835-43). VQ is based on the state-of-art Vk*MYC model (Chesi et al., Cancer Cell 2008;13(2):167-80). VQ was generated by conditionally activating an NrasQ61R allele in Vk*MYC mice. The resultant VQ model recapitulates an advanced, proliferative and drug-resistant phase of disease characterized by RAS mutations. The transducibility of VQ restored the functionality of the ALV-gene transfer technology. This technology exploits the fact that avian retroviruses cannot transduce mammalian cells unless they are engineered to ectopically express an avian retroviral receptor (in this case, the receptor TVb, driven by a plasma-cell-specific regulatory elements). Recently, the ALV gene transfer technology was adapted to achieve CRISPR-Cas9 mediated gene editing in the tumor niche in vivo (Oldrini et al., Nat Comm 2018;9(1):1466). Approach. We generated TVb-expressing VQ lines (CD138+ B220neg) that home to the bone marrow upon transplantation into Prdm1:TVb-mRFP fully immunocompetent syngeneic recipients in the C57BL6/J background. These VQ cells were engineered to express the nuclease Cas9. To determine the efficiency of gene transfer through ALV vectors (as a prelude to sgRNA delivery), pilot experiments were conducted using two types of ALV vector carrying a fluorescent reporter, GFP (green fluorescent protein): a) an RCAS-type vector that drives reporter expression from the native ALV LTR and b) an RCAN-type vector that drives reporter expression from an internal CMV promoter. Results. ALV titers achieved were routinely in excess of 107-108 infectious units/mL. Parental Vk*MYC cells expressing the avian receptor TVb were poorly transducible with ALV vectors. By contrast, VQ cells expressing TVb were readily transducible. At multiplicity of infection (MOI)=2, 68% of VQ myeloma cells expressed reporter fluorescence after a single round of transduction. At MOI=5 the transduction rate rose to 80%. The mean fluorescence intensity (MFI) positively correlated with MOI, consistent with higher-copy proviral integration at higher MOI. At equivalent MOI, GFP fluorescence from RCAS vectors was more intense than GFP fluorescence driven by an internal CMV promoter in RCAN vectors, suggesting that the ALV LTR is a stronger promoter than CMV in VQ myeloma cells. 100% transduced VQ cells were CD138+B220neg at all conditions tested. Conclusions and Current Focus. We are using ALV-CRISPR technology to generate precision myeloma models to support the next wave of personalized therapy and immunotherapy for this recalcitrant and incurable cancer. Progress on three in vivo models under construction will be presented at the meeting:Subclonal Braf mutation nested within clonal Nras mutation. These models will be treated with next-generation RAF inhibitors (Karoulia Z et al.Nat Rev Cancer 2017;17(11):676-91).Dis3 loss-of function mutation in constellation with co-clonal Ras mutation. The pathogenic consequences of Dis3 disruption remain poorly understood as no parallels exist in other cancers.The murine homolog of the t(4;14) translocation. We are targeting breakpoint cluster regions within perfectly syntenic sequences on mouse chr. 5 (containing Fgfr3 and Mmset loci) and mouse chr.12 (containing the murine Igh locus). Disclosures No relevant conflicts of interest to declare.

Abstract Background: B-cell non-Hodgkin lymphomas (NHL) are common lymphoid malignancies in which malignant B-cells arrested at various stages of differentiation proliferate within lymph nodes and occasionally other tissues. The microenvironment that supports the growth and survival of NHL B cells consists of a complex network of immune cells and cytokines and its specific composition has been shown to have significant clinical implications. The intratumoral immune cells include effector and regulatory T (Treg) lymphocytes that are more than simple residual elements from the normal lymph node structure. We previously explored whether the extent of T cell infiltration played a role in the clinical outcome of patients with B-cell NHL and found that an increased percentage of CD4+ T cells in the diagnostic biopsy of lymphoma patients significantly correlated with an improved 5-year overall survival. We have also shown that intratumoral Treg cells significantly suppress the anti-tumor response. Based on the fact that intratumoral T-cells are important in B-cell NHL, we evaluated whether genetic variation in genes that regulate the T-cell response may be associated with lymphoma risk. Methods: We genotyped 257 single nucleotide polymorphisms (SNPs) from 50 candidate genes related to T-cell differentiation and function in a clinic-based study of 441 Caucasian NHL cases and 475 frequency matched Caucasian controls seen at the Mayo Clinic from 2002–2005. Tagging and nsSNPs were selected from HapMap. The most prevalent homozygous genotype was used as the reference group and each SNP was modeled individually as having a log-additive effect, expressed as ordinal odds ratios (OR) per variant allele and 95% confidence intervals, in an age- and sex-adjusted logistic regression analysis. We also evaluated the consistency of the findings for the most common types of B-cell NHL - diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), and CLL/SLL. For gene-level analyses, we used principal components (PC) analysis using all SNPs from a gene; those PCs that explained > 90% of the variability were then modeled in a logistic regression analysis and significance was determined using a likelihood ratio test. We also evaluated the association of haplotypes from each gene with risk of NHL using the score test implemented from HAPLO.SCORE. Results. The mean age at diagnosis was 60.1 years for cases and 58% were male; among controls, the mean age at enrollment was 61.7 years and 55% were men. In the PC gene analyses, PRF1 (perforin gene - involved in cytotoxicity; p=0.004), CD276 (B7-H3 gene - involved in co-stimulation; p=0.01), TBX21 (T-bet gene – regulates Th1 cell development; p=0.02), and IL6 (p=0.02) were significant at p<0.05; haplotype analysis showed similar results, with the addition of CARD15 (NOD2 gene – regulates Th1 responses; p=0.02). There were 2 SNPs in PRF1, and both the intronic SNP rs3758562 (OR=1.38; 1.13–1.69) and the synonymous coding SNP rs885821 (OR=0.80; 0.63–1.02) were associated with NHL risk overall and for each subtype. There were 2 SNPs in CD276, and both the intronic SNP rs7176654 (OR=1.29; 1.07–1.56) and the mrna-utr SNP rs3816661 (OR=0.82; 0.68–0.99) were associated with NHL risk overall and with the CLL/SLL and follicular NHL subtypes specifically. There were 2 SNPs in TBX21, and only the mrna-utr SNP rs7502875 (OR=0.73; 0.59–0.92) was associated with NHL risk overall and for each subtype. There were 11 SNPs in IL6, and the intronic SNP rs2069835 (OR=1.88; 1.24–2.84) and the locus-region SNP rs2069824 (OR=1.73; 1.20–2.50) were each associated with NHL risk overall and each subtype. Finally, there were 9 SNPs in CARD15, with only the nonsynonymous coding SNP rs5743291 (OR=1.43; 1.02–1.98) being associated with overall NHL risk, and risk was specific to FL. Conclusions. Genetic variation in several genes that play critical roles in T-cell maturation and function was associated with lymphoma risk. These genes appeared to be associated with the differentiation and function of effector T-cells particularly Th1 and Th17 cells. These results provide potentially important insights into the role of T-cells in lymphomagenesis.