Alexander Y. Kim

Genetic diversity and virulence profiles of Listeria monocytogenes recovered from bulk tank milk, milk filters, and milking equipment from dairies in the United States (2002 to 2014)

Unpasteurized dairy products are known to occasionally harbor Listeria monocytogenes and have been implicated in recent listeriosis outbreaks and numerous sporadic cases of listeriosis. However, the diversity and virulence profiles of L. monocytogenes isolates recovered from these products have not been fully described. Here we report a genomic analysis of 121 L. monocytogenes isolates recovered from milk, milk filters, and milking equipment collected from bovine dairy farms in 19 states over a 12-year period. In a multi-virulence-locus sequence typing (MVLST) analysis, 59 Virulence Types (VT) were identified, of which 25% were Epidemic Clones I, II, V, VI, VII, VIII, IX, or X, and 31 were novel VT. In a multi-locus sequence typing (MLST) analysis, 60 Sequence Types (ST) of 56 Clonal Complexes (CC) were identified. Within lineage I, CC5 and CC1 were among the most abundant, and within lineage II, CC7 and CC37 were the most abundant. Multiple CCs previously associated with central nervous system and maternal-neonatal infections were identified. A genomic analysis identified variable distribution of virulence markers, Listeria pathogenicity islands (LIPI) -1, -3, and -4, and stress survival island-1 (SSI-1). Of these, 14 virulence markers, including LIPI-3 and -4 were more frequently detected in one lineage (I or II) than the other. LIPI-3 and LIPI-4 were identified in 68% and 28% of lineage I CCs, respectively. Results of this analysis indicate that there is a high level of genetic diversity among the L. monocytogenes present in bulk tank milk in the United States with some strains being more frequently detected than others, and some being similar to those that have been isolated from previous non-dairy related outbreaks. Results of this study also demonstrate significant number of strains isolated from dairy farms encode virulence markers associated with severe human disease.

Technology of irreversible electroporation and review of its clinical data on liver cancers

ABSTRACT Introduction: Irreversible electroporation (IRE) has developed as a novel percutaneous ablative technique over the past decade and its utility in the treatment of primary and metastatic liver disease has progressed rapidly. Areas covered: After discussing the principles behind the technology and the practical steps in its use, this article offers a detailed analysis of the recent published work that evaluates its safety and efficacy. The strengths and weaknesses of other ablative techniques, including radiofrequency ablation, microwave ablation and cryoablation, are discussed in detail. Other aspects of IRE, including post-treatment clinical follow-up, expected imaging findings, and the most frequently encountered complications, are covered. Finally, the future of IRE is examined as it pertains to advancements in the treatment of hepatic malignancy. Expert commentary: The characteristics of IRE that make this technology uniquely suited for the treatment of liver tumors have allowed it to gain a significant foothold in interventional oncology. Continued development of IRE will lead to further advances in the management of previously untreatable liver cancers.

Liver Transplant Interventions

Initial efforts at human liver transplantation in the early 1960s were marred by extremely poor postoperative survival, with the earliest organ recipients surviving for 0–23 days postoperatively [1]. Following improvements in surgical technique, the focus shifted from postoperative patient survival to survival of the graft, and efforts were concentrated on optimizing antirejection regimens [2]. In the current era, patients undergoing liver transplantation have survival rates of 82%, 70%, and 65% at 1, 5, and 10 years, respectively [3]. Despite significant improvements in survival following liver transplantation, posttransplant complications are not uncommon, and image-guided interventional strategies have emerged as a reasonable alternative to open or laparoscopic reoperation in the management of many of these complications.

Utility of MR Angiography in the Identification of Prostatic Artery Origin Prior to Prostatic Artery Embolization

In 17 patients who underwent prostate artery embolization for treatment of lower urinary tract symptoms, the accuracy of preprocedural magnetic resonance (MR) angiography was retrospectively compared with intraprocedural digital subtraction angiography (DSA) in the identification of prostatic artery origin. Of 34 vessels, 26 MR angiography identified origins (76.5%) were confirmed by DSA at the time of embolization. Although image postprocessing is required, the ability of MR angiography to accurately identify prostatic artery origins prior to embolization is useful in treatment planning and can obviate the need for separate computed tomographic angiography, thus reducing both radiation dose and time demand on patients.

Comparison of Cone-Beam Tomography and Cross-Sectional Imaging for Volumetric and Dosimetric Calculations in Resin Yttrium-90 Radioembolization

PurposeTo compare the use of cone-beam computed tomography versus contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) in the calculation of liver volume and planned dose for yttrium-90 radioembolization.Materials and MethodsThe study retrospectively assessed 47 consecutive patients who underwent resin Y-90 radioembolization consecutively over a 2-year period at a single center. Volume calculation software was used to determine perfused lobar liver volumes from cone-beam CT (CBCT) images obtained during mapping angiography. CBCT-derived volumes were compared with perfused lobar volume derived from contrast-enhanced CT and MRI. Nominal activities as determined by the SIR-Spheres Microspheres Activity Calculator were similarly calculated and compared using both CBCT and conventionally acquired volumes.ResultsA total of 82 hepatic lobes were assessed in 47 patients. The mean percentage difference between combined CT-MRI- and CBCT-derived calculated lobar volumes was 25.3% (p = 0.994). The mean percentage difference in calculated dose between the two methods was 21.8 ± 24.6% (p = 0.42). Combined left and right lobar CT-derived dose difference was less than 10% in 22 lobes, between 10 and 25% in 20 lobes, between 25 and 50% in 13 lobes and greater than 50% in 5 lobes. Combined left and right lobar MRI-derived dose difference was less than 10% in 11 lobes, between 10 and 25% in 7 lobes, between 25 and 50% in 2 lobes and greater than 50% in 1 lobe.ConclusionsAlthough volume measurements derived from CT/MRI did not differ significantly from those derived from CBCT, variability between the two methods led to large and unexpected differences in calculated dose.

Short-term imaging response after drug-eluting embolic trans-arterial chemoembolization delivered with the Surefire Infusion System® for the treatment of hepatocellular carcinoma

Purpose To review the initial imaging responses after drug-eluting embolic trans-arterial chemoembolization (DEE-TACE) delivered with the Surefire Infusion System ® for the treatment of hepatocellular carcinoma (HCC). Methods Single center retrospective evaluation of patients who underwent DEE-TACE for HCC, delivered with SIS. Information was gathered from available medical records. Treatment response rates were assessed using the modified Response Evaluation Criteria in Solid Tumors criteria. Assessment of adverse events was categorized per Common Terminology Criteria for Adverse Events version 4.03. Results Twenty-two patients with 39 hepatocellular carcinoma lesions were treated with the surefire infusion system. Complete response was demonstrated in 32% of patients and 54% of lesions after a single treatment session. Overall disease response was demonstrated in 91% of patients and 85% of lesions after a single treatment. No grade 3 or higher elevations in liver function tests were demonstrated in the short-term. Conclusion SIS delivered DEE-TACE leads to a higher than expected initial response in patients with HCC.

Diverse clinical outcome and predictors for clinical outcome in patients with HCC treated with TACE.

442 Background: Hepatocellular carcinoma (HCC) is the sixth most common cancer, and the second leading cause of cancer-related death, worldwide. This reflects the challenges facing HCC treatment. Methods: Patients (pts) with HCC receiving TACE treatment (n = 96) were examined retrospectively for clinical outcome and its possible predictors. The number of TACE treatments and the time elapsed between each treatment were assessed and correlated with overall survival (OS) using the log rank test of Kaplan Meier curves. T-stage, level of differentiation, vascular invasion, and Child Pugh score at the time of HCC diagnosis were compared among pts who received different numbers of TACE treatments (Kaplan-Meier survival analysis, ANOVA and student T test). Results: TACE treated pts had a median OS of 46 month (mo) and progression free survival of 12 mo (difference in time between the date of first progression and the date of diagnosis). Pts received 1-2 (n = 52), 3-4 (n = 28), or 5-6 (n = 16) TACE treatments. We ...

Evaluation of Surefire’s precision direct-to-tumor embolization device to augment therapeutic response to intra-arterial, liver-directed therapies for patients with primary and secondary liver cancers

ABSTRACT Patients with primary and secondary liver cancers generally have a poor prognosis with limited potentially curative options. Liver-directed, intra-arterial therapies such as selective internal radiotherapy (SIRT) and trans-arterial chemoembolization (TACE) are taking a larger role in the management of these patients. The current standard of therapy is for delivery of SIRT or TACE particles through an end-hole microcatheter. Antireflux microcatheters (ARM) are a novel class of microcatheters designed to enhance intra-arterial therapies. These catheters are designed with a flexible tip at the end of the microcatheter, which partially collapses during systole and expands during diastole, reducing antegrade and retrograde particle reflux while allowing for forward flow. Initially designed to reduce the risk of particle reflux during SIRT, there is evidence that ARMs may lead to improved particle distribution to tumors during SIRT. Furthermore, ARMs improve embolization efficiency which may lead to improved disease response from TACE for patients with hepatocellular carcinoma.