High-Frequency Irreversible Electroporation for Treatment of Primary Liver Cancer: A Proof-of-Principle Study in Canine Hepatocellular Carcinoma.

PURPOSE: To determine the safety and feasibility of percutaneous high-frequency irreversible electroporation (HFIRE) for primary liver cancer and evaluate the HFIRE-induced local immune response. MATERIALS AND METHODS: HFIRE therapy was delivered percutaneously in 3 canine patients with resectable hepatocellular carcinoma (HCC) in the absence of intraoperative paralytic agents or cardiac synchronization. Pre- and post-HFIRE biopsy samples were processed with histopathology and immunohistochemistry for CD3, CD4, CD8, and CD79a. Blood was collected on days 0, 2, and 4 for complete blood count and chemistry. Numeric models were developed to determine the treatment-specific lethal thresholds for malignant canine liver tissue and healthy porcine liver tissue. RESULTS: HFIRE resulted in predictable ablation volumes as assessed by posttreatment CT. No detectable cardiac interference and minimal muscle contraction occurred during HFIRE. No clinically significant adverse events occurred secondary to HFIRE. Microscopically, a well-defined ablation zone surrounded by a reactive zone was evident in the majority of samples. This zone was composed primarily of maturing collagen interspersed with CD3+/CD4-/CD8- lymphocytes in a proinflammatory microenvironment. The average ablation volumes for the canine HCC patients and the healthy porcine tissue were 3.89 cm3 ± 0.74 and 1.56 cm3 ± 0.16, respectively (P = .03), and the respective average lethal thresholds were 710 V/cm ± 28.2 and 957 V/cm ± 24.4 V/cm (P = .0004). CONCLUSIONS: HFIRE can safely and effectively be delivered percutaneously, results in a predictable ablation volume, and is associated with lymphocytic tumor infiltration. This is the first step toward the use of HFIRE for treatment of unresectable liver tumors.

Cycled pulsing to mitigate thermal damage for multi-electrode irreversible electroporation therapy.

Purpose: This study evaluates the effects of various pulsing paradigms, on the irreversible electroporation (IRE) lesion, induced electric current, and temperature changes using a perfused porcine liver model. Materials and methods: A 4-monopolar electrode array delivered IRE therapy varying the pulse length and inter-pulse delay to six porcine mechanically perfused livers. Pulse paradigms included six forms of cycled pulsing schemes and the conventional pulsing scheme. Finite element models provided further insight into the effects of cycled pulsing on the temperature and thermal injury distribution. Results: 'Single pulse cycle with no interpulse delay' deposited maximum average energy (2.34 ± 0.35 kJ) and produced the largest ratio of thermally damaged tissue area and IRE ablation area from all other pulse schemes (18.22% ± 8.11, p < .0001 all pairwise comparisons). These compared favorably to the conventional algorithm (2.09 ± 0.37 kJ, 3.49% ± 2.20, p < .0001, all comparisons). Though no statistical significance was found between groups, the '5 pulse cycle, 0 s delay' pulse paradigm produced the largest average IRE ablation cross sectional area (11.81 ± 1.97 cm2), while conventional paradigm yielded an average of 8.90 ± 0.91 cm2. Finite element modeling indicated a '10 pulse cycle, 10 s delay' generated the least thermal tissue damage and '1 pulse cycle, 0 s delay' pulse cycle sequence the most (0.47 vs. 3.76 cm2), over a lengthier treatment time (16.5 vs. 6.67 minutes). Conclusions: Subdividing IRE pulses and adding delays throughout the treatment can reduce white tissue coagulation and electric current, while maintaining IRE treatment sizes.

Experimental High-Frequency Irreversible Electroporation Using a Single-Needle Delivery Approach for Nonthermal Pancreatic Ablation In Vivo.

PURPOSE: To investigate the feasibility of single-needle high-frequency irreversible electroporation (SN-HFIRE) to create reproducible tissue ablations in an in vivo pancreatic swine model. MATERIALS AND METHODS: SN-HFIRE was performed in swine pancreas in vivo in the absence of intraoperative paralytics or cardiac synchronization using 3 different voltage waveforms (1-5-1, 2-5-2, and 5-5-5 [on-off-on times (µs)], n = 6/setting) with a total energized time of 100 µs per burst. At necropsy, ablation size/shape was determined. Immunohistochemistry was performed to quantify apoptosis using an anticleaved caspase-3 antibody. A numerical model was developed to determine lethal thresholds for each waveform in pancreas. RESULTS: Mean tissue ablation time was 5.0 ± 0.2 minutes, and no cardiac abnormalities or muscle twitch was detected. Mean ablation area significantly increased with increasing pulse width (41.0 ± 5.1 mm2 [range 32-66 mm2] vs 44 ± 2.1 mm2 [range 38-56 mm2] vs 85.0 ± 7.0 mm2 [range 63-155 mm2]; 1-5-1, 2-5-2, 5-5-5, respectively; p < 0.0002 5-5-5 vs 1-5-1 and 2-5-2). The majority of the ablation zone did not stain positive for cleaved caspase-3 (6.1 ± 2.8% [range 1.8-9.1%], 8.8 ± 1.3% [range 5.5-14.0%], and 11.0 ± 1.4% [range 7.1-14.2%] cleaved caspase-3 positive 1-5-1, 2-5-2, 5-5-5, respectively), with significantly more positive staining at the 5-5-5 pulse setting compared with 1-5-1 (p < 0.03). Numerical modeling determined a lethal threshold of 1114 ± 123 V/cm (1-5-1 waveform), 1039 ± 103 V/cm (2-5-2 waveform), and 693 ± 81 V/cm (5-5-5 waveform). CONCLUSIONS: SN-HFIRE induces rapid, predictable ablations in pancreatic tissue in vivo without the need for intraoperative paralytics or cardiac synchronization.

Effects of internal electrode cooling on irreversible electroporation using a perfused organ model.

PURPOSE: This study evaluates the effects of active electrode cooling, via internal fluid circulation, on the irreversible electroporation (IRE) lesion, deployed electric current and temperature changes using a perfused porcine liver model. MATERIALS AND METHODS: A bipolar electrode delivered IRE electric pulses with or without activation of internal cooling to nine porcine mechanically perfused livers. Pulse schemes included a constant voltage, and a preconditioned delivery combined with an arc-mitigation algorithm. After treatment, organs were dissected, and treatment zones were stained using triphenyl-tetrazolium chloride (TTC) to demonstrate viability. RESULTS: Thirty-nine treatments were performed with an internally cooled applicator and 21 with a non-cooled applicator. For the constant voltage scenario, the average final electrical current measured was 26.37 and 29.20 A for the cooled and uncooled electrodes respectively ([Formula: see text]). The average final temperature measured was 33.01 and 42.43 °C for the cooled and uncooled electrodes respectively ([Formula: see text]). The average measured ablations (fixed lesion) were 3.88-by-2.08 cm and 3.86-by-2.12 cm for the cooled and uncooled electrode respectively ([Formula: see text], [Formula: see text]). Similarly, the preconditioned/arc-mitigation scenario yielded an average final electrical current measurement of a 41.07 and 47.20 A for the cooled and uncooled electrodes respectively ([Formula: see text]). The average final temperature measured was 34.93 and 44.90 °C for the cooled and uncooled electrodes respectively ([Formula: see text]). The average measured ablations (fixed lesion) were 3.67-by-2.27 cm and 3.58-by-2.09 cm for the cooled and uncooled applicators ([Formula: see text]). CONCLUSIONS: The internally-cooled bipolar applicator offers advantages that could improve clinical outcomes. Thermally mitigating internal perfusion technology reduced tissue temperatures and electric current while maintaining similar lesion sizes.

3D printed conformal microfluidics for isolation and profiling of biomarkers from whole organs.

The ability to interface microfluidic devices with native complex biological architectures, such as whole organs, has the potential to shift the paradigm for the study and analysis of biological tissue. Here, we show 3D printing can be used to fabricate bio-inspired conformal microfluidic devices that directly interface with the surface of whole organs. Structured-light scanning techniques enabled the 3D topographical matching of microfluidic device geometry to porcine kidney anatomy. Our studies show molecular species are spontaneously transferred from the organ cortex to the conformal microfluidic device in the presence of fluid flow through the organ-conforming microchannel. Large animal studies using porcine kidneys (n = 32 organs) revealed the profile of molecular species in the organ-conforming microfluidic stream was dependent on the organ preservation conditions. Enzyme-linked immunosorbent assay (ELISA) studies revealed conformal microfluidic devices isolate clinically relevant metabolic and pathophysiological biomarkers from whole organs, including heat shock protein 70 (HSP-70) and kidney injury molecule-1 (KIM-1), which were detected in the microfluidic device as high as 409 and 12 pg mL-1, respectively. Overall, these results show conformal microfluidic devices enable a novel minimally invasive 'microfluidic biopsy' technique for isolation and profiling of biomarkers from whole organs within a clinically relevant interval. This achievement could shift the paradigm for whole organ preservation and assessment, thereby helping to relieve the organ shortage crisis through increased availability and quality of donor organs. Ultimately, this work provides a major advance in microfluidics through the design and manufacturing of organ-conforming microfluidic devices and a novel technique for microfluidic-based analysis of whole organs.

The Development of a Thin-Filmed Noninvasive Tissue Perfusion Sensor to Quantify Capillary Pressure Occlusion of Explanted Organs.

A new thin-filmed perfusion sensor was developed using a heat flux gauge, thin-film thermocouple, and a heating element. This sensor, termed "CHFT+," is an enhancement of the previously established combined heat flux-temperature (CHFT) sensor technology predominately used to quantify the severity of burns [1]. The CHFT+ sensor was uniquely designed to measure tissue perfusion on explanted organs destined for transplantation, but could be functionalized and used in a wide variety of other biomedical applications. Exploiting the thin and semiflexible nature of the new CHFT+ sensor assembly, perfusion measurements can be made from the underside of the organ-providing a quantitative indirect measure of capillary pressure occlusion. Results from a live tissue test demonstrated, for the first time, the effects of pressure occlusion on an explanted porcine kidney. CHFT+ sensors were placed on top of and underneath 18 kidneys to measure and compare perfusion at perfusate temperatures of 5 and 20 °C. The data collected show a greater perfusion on the topside than the underside of the specimen for the length of the experiment. This indicates that the pressure occlusion is truly affecting the perfusion, and, thus, the overall preservation of explanted organs. Moreover, the results demonstrate the effect of preservation temperature on the tissue vasculature. Focusing on the topside perfusion only, the 20 °C perfusion was greater than the 5 °C perfusion, likely due to the vasoconstrictive response at the lower perfusion temperatures.

Soak and smear: an effective treatment for eczematous dermatoses.

Eczematous dermatoses are common inflammatory skin diseases that can be difficult to treat and have a major impact on patients' quality of life and psychological status. Soak and smear is an effective treatment that can eliminate the need for oral steroids and, in chronic situations, other systemic immunosuppressives.

The contribution of executive control on verbal-learning impairment in patients with Parkinson's disease with dementia and Alzheimer's disease.

Deficits in learning, memory, and executive functions are common cognitive sequelae of Parkinson's disease with dementia (PDD) and Alzheimer's disease (AD); however, the pattern of deficits within these populations is distinct. Hierarchical regression was used to investigate the contribution of two measures with executive function properties (Verbal Fluency and CLOX) on list-learning performance (CVLT-II total words learned) in a sample of 25 PDD patients and 25 matched AD patients. Executive measures were predictive of list learning in the PDD group after the contribution of overall cognition and contextual verbal learning was accounted for, whereas in the AD group the addition of executive measures did not add to prediction of variance in CVLT-II learning. These findings suggest that deficits in executive functions play a vital role in learning impairments in patients with PDD; however, for AD patients, learning difficulties appear relatively independent of executive dysfunction.

Cellular immunotherapy for ovarian cancer.

BACKGROUND: Ovarian cancer is frequently diagnosed at an advanced stage, and although initially responsive to surgery and chemotherapy, has a high rate of recurrence and mortality. Cellular immunotherapy may offer the prospect of treatment to prevent or delay recurrent metastatic disease. OBJECTIVE: To provide an overview of current innovations in cellular immunotherapy for ovarian cancer, with an emphasis on dendritic cell vaccination and adoptive T-cell immunotherapy. METHODS: Three key areas are explored in this review: first, an appraisal of the current state of the art of cellular immunotherapy for treatment of ovarian cancer; second, a discussion of the immunological defenses erected by ovarian cancer to prevent immunological attack, with an emphasis on the role of tumor-associated regulatory T cells; and third, an exploration of innovative techniques that may enhance the ability of cellular immunotherapy to overcome ovarian tumor-associated immune suppression. RESULTS/CONCLUSION: Ovarian cancer is recognized as a paradigm for tumor-associated immune suppression. Innovative approaches for antagonism of tumor-associated regulatory T-cell infiltration and redirection of self antigen-driven regulatory T-cell activation may provide the key to development of future strategies for cellular immunotherapy against ovarian cancer.