252. Relative Use of Carbapenems in Immunocompromised Patients

Background

Gram-negative bacterial infections are associated with high mortality in immunocompromised hosts, and the presence of drug resistance further increases mortality. Antibiotic consumption is a key outcome measure for Antimicrobial Stewardship Programs. Proper utilization of antibiotics can help limit the development of antimicrobial resistance. Resistance in Gram-negative organisms such as Pseudomonas, Enterobacter, and Acinetobacter is a major issue given the paucity of new drugs in the antibiotic pipeline for these organisms. A novel relative carbapenem consumption metric (the Proportion of Carbapenem Consumption, or PoCC) was recently described in US academic medical centers. The PoCC is calculated as follows: PoCC = [(meropenem Days of therapy(DOT)/1,000 patient-days (PDs))/(meropenem DOT/1,000 PDs + cefepime DOT/1,000 PDs + piperacillin–tazobactam DOT/1,000 PDs)]. The regional mean PoCC for the South Atlantic region has previously been approximated at 17%.

Methods

We examined the PoCC for the Bone Marrow Transplant (BMT) and dedicated Hematology/Oncology (H/O) inpatient wards at an academic medical center from August 2012 to June 2017.

Results

Conclusion

This is the first description of the PoCC metric for dedicated Hematology/Oncology and Bone Marrow Transplant wards. When compared with national and regional mean PoCC scores for academic medical centers, the PoCC for these units was higher. More research is needed to determine the optimal PoCC scores for these types of units. The PoCC can contextualize relative carbapenem use and may be a useful antibiotic consumption metric. However, it does not provide data on absolute consumption. Further studies are needed to determine the best use of the PoCC metric by Antimicrobial Stewardship Programs for Hematology/Oncology and Bone Marrow Transplant wards.

Disclosures

All authors: No reported disclosures.

Description of a restriction program for gram-positive antimicrobial agents at an academic medical center

This report examines the effectiveness of antimicrobial restriction at 1 tertiary care health care system by analyzing the consumption of restricted versus nonrestricted gram-positive agents over time for medical versus surgical units. Significant reductions in restricted antibiotic use were detected in 57% of medical units versus none of the surgical units. There were no significant reductions in nonrestricted antibiotic use. We think looking at antibiotic consumption by service line provides opportunities for targeted antibiotic restriction program refinement.

Outcome of the First wwPDB Hybrid/Integrative Methods Task Force Workshop

Structures of biomolecular systems are increasingly computed by integrative modeling that relies on varied types of experimental data and theoretical information. We describe here the proceedings and conclusions from the first wwPDB Hybrid/Integrative Methods Task Force Workshop held at the European Bioinformatics Institute in Hinxton, UK, on October 6 and 7, 2014. At the workshop, experts in various experimental fields of structural biology, experts in integrative modeling and visualization, and experts in data archiving addressed a series of questions central to the future of structural biology. How should integrative models be represented? How should the data and integrative models be validated? What data should be archived? How should the data and models be archived? What information should accompany the publication of integrative models?

Use of Angio-Seal after iatrogenic trauma

The clinical and intraoperative findings of an iatrogenic injury to a congenitally present right sided ascending aorta treated by deployment of a percutaneous closure device is reported. This is a first literature report of a biodegradable closure system being utililized to treat a puncture to the ascending arch.

Acute Cardiac Tamponade: An Unusual Cause of Acute Renal Failure

We are reporting a case of acute renal failure after cardiac surgery due to acute pericardial effusion. The patient had normal baseline renal function but developed acute oliguric renal failure with a significant increase in serum creatinine postoperatively. Pericardiotomy led to an improvement in blood pressure, immediate diuresis and quick recovery of renal function back to baseline. Pericardial tamponade should be included in the consideration of causes of the cardiorenal syndrome.

Retrovirally expressed 4-1BBL dramatically increases proliferation and in vivo persistence of adoptively transferred CD19-targeted T cells, promoting complete tumor elimination. (131.16)

Human T cells transduced with a chimeric antigen receptor (CAR) composed of an antibody-derived scFv fragment and the CD3ζ chain can recognize and kill tumor cells on binding to the targeted membrane antigen. The co-transduction of a CAR along with CD80 and 4-1BBL induces auto-costimulation enabling high in vivo T cell expansion and tumor rejection in a prostate tumor model. Here we investigated this concept in T cells harboring either a first generation anti-CD19 CAR (19z1) or a second generation CAR (1928z), which additionally comprises the CD28 cytoplasmic domain. We compared the proliferation and anti-tumor activity of 19z1+, 19z1-4-1BBL+, 19z1-CD80+4-1BBL+, 1928z+ and 1928z-4-1BBL+ transduced T cells in a pro B cell leukemia model (NALM-6). Seven days after IV injection into NALM-6 bearing NOD/SCID/IL2Rγnull mice, 1928z-4-1BBL+ CD8 and CD4 T cells accumulated in the bone marrow and the spleen 100 times more than 19z1+ T cells and 10 times more than 1928z+ T cells, corroborating in vitro proliferative responses to repeated antigen exposure. An increased proportion of central memory CD8 T cells was observed in all groups treated with 4-1BBL-expressing cells. Within 15 days, in vivo bioluminescence imaging showed total tumor regression in the 1928z-4-1BBL+ T cell-treated group and partial regression in the other groups. Thus, constitutive 4-1BBL expression drives high proliferation of anti-tumor CD8 T cells, promoting central memory T cell persistence and tumor eradication.

The CCPN project: an interim report on a data model for the NMR community

A recent workshop discusses the progress toward integrating NMR data into a unifying data model.

A view of prescriptive practice collaboration: perspectives of psychiatric-mental health clinical nurse specialists and psychiatrists

A majority of states require collaborative prescribing agreements between advanced practice nurses and physicians. Unfortunately, there is limited research describing the collaboration that occurs between the clinicians who have such prescribing agreements. This exploratory study identifies the characteristics, activities, and outcomes of collaboration between psychiatric-mental health clinical nurse specialists (CNSs) with prescribing agreements and their collaborating psychiatrists. Surveys were sent to all the 73 prescribing psychiatric-mental health CNSs identified by the Minnesota Board of Nursing in 1998 and their primary collaborating psychiatrists. Forty-nine CNSs and 32 psychiatrists returned the surveys with 31 matched collaborating dyads identified. Overall satisfaction with the collaborative relationship was high, CNSs (chi = 4.34/5) and psychiatrists (chi = 4.46/5). Good communication, trust, shared goals for patient outcomes, shared professional values, and respect for clinical competency were identified as important characteristics for effective collaboration. CNSs identified increased professional growth and job satisfaction as professional benefits, while psychiatrists reported shared workload responsibilities. Fewer than half of the CNSs and psychiatrists perceived professional liability as a professional constraint. Psychiatric-mental health CNSs and psychiatrists agreed that the continuity of patient care and efficient access to mental health care were patient benefits. The statistically significant differences between the CNSs' and psychiatrists' responses were related to the number of years they had been in practice, the number of years the CNS had been a prescriber, and the length of time the CNS and psychiatrist had worked together within a collaborative prescribing agreement.

Home monitoring of bladder pressure and volume in individuals with spinal cord injury and multiple sclerosis

Individuals with spinal cord injury and multiple sclerosis are at high risk for developing kidney dysfunction due to high bladder pressures. We have developed a device for frequent monitoring of bladder pressures at home in those patients who use intermittent catheterization to empty their bladders. Of eight subjects enrolled in the study, only five conducted home recording of pressure. Vesical and abdominal pressures measured at home were significantly lower than clinical cystometric pressures. However, subtracted detrusor pressures obtained from home records and cystometric records were not significantly different. The home detrusor pressures were consistent over a large time and volume range. Therefore, the home monitoring method could be used to establish a normal range of bladder pressures at home and to rapidly identify high bladder pressures in advance of upper urinary tract deterioration.

Sequences and proteins required for iron-regulated expression ofsid1ofUstilago maydis

The molecular biology of the high affinity, siderophore-mediated iron uptake system of the basidiomycete fungus Ustilago maydis is under investigation. Ustilago maydis produces two cyclic peptide siderophores, ferrichrome and ferrichrome A. Biosynthesis of both siderophores is initiated by ornithine-N5-oxygenase, the product of sid1. sid1 mRNA accumulates only during growth under iron starvation conditions in wild-type cells or constitutively in urbs1 mutants, urbs1 encodes a 100-kDa protein with putative Zn finger domains that share sequence identity with those of the GATA family of transcription factors. The promoter region of sid1 was defined by deletion analysis of a 3.0-kb region 5′ to the translational start of sid1 using the Escherichia coli GUS gene as a reporter. Three regions were defined by this analysis to be critical to expression of sid1. These include (i) a 306-bp region containing two GATA sequences and mapping 2.4 kb from the start of translation; (ii) a 439-bp region immediately 5′ to the start of transcription; and (iii) a region encompassing the first intron of sid1. Deletion of the GATA sequences resulted in deregulated expression of sid1, while elimination of the latter two sequences ablated expression of the gene under all circumstances. Current efforts are focused on determining whether Urbsl interacts directly with the sid1 promoter via the GATA sequences and whether this interaction is dependent upon iron. Key words: GATA, transcription factor, siderophore, ferrichrome, iron, Urbs1.

Correlation of increased levels of class I MHC H-2Kk in the placenta of murine trisomy 16 conceptuses with structural abnormalities revealed by magnetic resonance microscopy

Murine trisomy 16 (mts16) placentas and fetuses, 17-day gestation age, were examined histologically and by magnetic resonance imaging at 9.4 T and compared with control littermate tissues. Placentas were studied by immunohistochemical methods, at 15-days gestational age, for expression of the major histocompatibility complex (MHC) class I H-2Kk cell surface marker. Immunohistochemical studies revealed a markedly increased expression of the MHC marker H-2Kk on cells in the labyrinth of the placenta of mts16. There were differences between the magnetic resonance (MR) images of the trisomic and normal placentas, which may be correlated with the increased expression of H-2Kk in the mts16 placental labyrinth. The decidual and labyrinthine components of the normal placentas showed similar high signal intensities (SI) while in trisomic placentas a marked high SI was characteristic only of the decidual region on proton spin density images. The MRI also revealed a smaller cerebellum in the ts16 fetuses. The potential effects of the compromised structure of the placental labyrinth and the overexpression of the H-2Kk marker on the mts16 neural and placental dysgenesis are discussed.

Argon laser phototherapy of human malignancies using rhodamine-123 as a new laser dye: the intracellular role of oxygen

Recent studies demonstrated that the cationic, mitochondrial-specific dye Rhodamine-123 (Rh-123), is an efficient tumor photosensitizer for Argon laser treatment of human cancer cells both in vitro and in tumors grown as xenografts in athymic mice. To demonstrate the photodynamic mechanism of action of this reaction, the intracellular role of oxygen and temperature changes in treated cells have to be defined. In the current study, a large panel of human tumor cell lines of diverse histologic origin were tested for in vitro sensitivity to Rh-123 and the Argon laser (514.5 nm) in oxygen, deuterium oxide (D2O), and nitrogen (N2) environment. Tumor cells in suspension were first sensitized to Rh-123 (1 or 20 micrograms/ml for 1 hour), cooled on ice to 4 degrees C, and then exposed to the Argon laser (delta T = 14 +/- 1 degree C). Cell proliferation measured by [3H]-thymidine uptake 24 hours after sensitization with Rh-123 and laser treatment was significantly decreased in tumor cells kept in oxygen and D2O atmospheres. No decrease in DNA synthesis was seen in Rh-123 and laser treated cells kept in an N2 environment. Control tumor cells treated with Rh-123 or the Argon laser separately did not show any decreased [3H]-thymidine uptake in oxygen, D2O or N2 environment. These results provide evidence of a photodynamic process since Rh-123 sensitization and Argon laser activation occur at nonthermal levels of energy and are oxygen dependent. The high effectiveness of this technique of photodynamic therapy with the Argon laser, and low toxicity of Rh-123 could make its clinical use very attractive for the treatment of superficial malignancies.

Glioblastoma multiforme: MR imaging at 1.5 and 9.4 T after injection of polylysine-DTPA-Gd in rats

Polylysine-DTPA-Gd, a new MR contrast agent, was injected into the aorta of rats 7 days after C6 glioblastoma was implanted in their brains; MR imaging was performed 3 days later. The imaging was done at two field strengths: (1) 1.5 T with a 3-mm slice thickness and in-plane resolutions of 600 microns and (2) 9.4 T with a 125- or 500-microns slice thickness and in-plane resolutions of 95 microns. In animals injected with polylysine-DTPA-Gd (1 microgram or more per rat), the T1-weighted images and mixed T1, T2 images of the C6 glioblastoma revealed a higher signal intensity at the marginal region between tumor and normal brain than that seen in surrounding normal brain. The central tumor region had a low signal intensity. The concentration of Gd in the C6 glioblastoma, after injection of 1 microgram polylysine-DTPA-Gd per rat, was calculated to be 0.14 mumol/l. The central tumor region also had a low signal intensity in animals that were not injected with the contrast agent, but the margin between tumor and normal brain was resolved poorly, if at all. The polylysine-DTPA-Gd revealed the microvasculature of the C6 glioblastoma in the 125-micron-thick slices obtained at 9.4 T. This is the first study to reveal the utility of the 9.4-T MR imager for examination of glioblastomas in situ and to demonstrate the utility of polylysine-DTPA-Gd as a contrast agent for the definition of the margin between glioblastoma and normal brain tissue.