Polarized light scanning cryomacroscopy, part II: Thermal modeling and analysis of experimental observations.

This study aims at developing thermal analysis tools and explaining experimental observations made by means of polarized-light cryomacroscopy (Part I). Thermal modeling is based on finite elements analysis (FEA), where two model parameters are extracted from thermal measurements: (i) the overall heat transfer coefficient between the cuvette and the cooling chamber, and (ii) the effective thermal conductivity within the cryoprotective agent (CPA) at the upper part of the cryogenic temperature range. The effective thermal conductivity takes into account enhanced heat transfer due to convection currents within the CPA, creating the so-called Bénard cells.

Polarized light scanning cryomacroscopy, part I: Experimental apparatus and observations of vitrification, crystallization, and photoelasticity effects.

Cryomacroscopy is an effective means to observe physical events affecting cryopreservation success in large-size specimens. The current study aims at integrating polarized-light in the study of large-size cryopreservation, using the scanning cryomacroscope as a development platform. Results of this study demonstrate polarized light as a visualization enhancement means, including the following effects: contaminants in the CPA solution, crystallization, fracture formation, thermal contraction, and solute precipitation.

Thermomechanical Stress in Cryopreservation Via Vitrification With Nanoparticle Heating as a Stress-Moderating Effect.

This study focuses on thermomechanical effects in cryopreservation associated with a novel approach of volumetric heating by means on nanoparticles in an alternating electromagnetic field. This approach is studied for the application of cryopreservation by vitrification, where the crystalline phase is completely avoided-the cornerstone of cryoinjury. Vitrification can be achieved by quickly cooling the material to cryogenic storage, where ice cannot form.

Stress-Strain Measurements in Vitrified Arteries Permeated With Synthetic Ice Modulators.

This study measures the Young's modulus in vitrified blood vessels below the glass transition temperature in conditions relevant to cryogenic storage and focuses on the cryoprotective agents (CPAs) cocktail DP6 mixed with synthetic ice modulators (SIMs). Small steplike strain changes were observed during the loading without affecting the bulk behavior, suggesting microfracture occurrences resembling previous observation on microfracture formation under compression in crystallized blood vessels. Young's modulus was measured to be 0.

On the Effects of Thermal History on the Development and Relaxation of Thermo-Mechanical Stress in Cryopreservation.

This study investigates the effects of the thermal protocol on the development and relaxation of thermo-mechanical stress in cryopreservation by means of glass formation, also known as vitrification. The cryopreserved medium is modeled as a homogeneous viscoelastic domain, constrained within either a stiff cylindrical container or a highly compliant bag. Annealing effects during the cooling phase of the cryopreservation protocol are analyzed.

Thermal expansion of vitrified blood vessels permeated with DP6 and synthetic ice modulators.

This study provides thermal expansion data for blood vessels permeated with the cryoprotective cocktail DP6, when combined with selected synthetic ice modulators (SIMs): 12% polyethylene glycol 400, 6% 1,3-cyclohexanediol, and 6% 2,3-butanediol. The general classification of SIMs includes molecules that modulate ice nucleation and growth, or possess properties of stabilizing the amorphous state, by virtue of their chemical structure and at concentrations that are not explained on a purely colligative basis. The current study is part of an ongoing effort to characterize thermo-mechanical effects on structural integrity of cryopreserved materials, where thermal expansion is the driving mechanism to thermo-mechanical stress.

Further experience with pancreatic stump closure using a reinforced staple line.

Background: We previously demonstrated that pancreatic transection with a reinforced staple line results in significantly lower fistula rates than when stapling without reinforcement. (J Gastrointest Surg. 2007;11:345-349).

Effect of early enteral tube feeding on patient outcome following pancreaticoduodenectomy.

Objective: Morbidity after pancreaticoduodenectomy (PD) is nearly 50%. In this study we analyzed if early enteral nutrition via feeding tube (FT) contributes to better patient outcomes.

Materials And Methods: Patients undergoing PD from 2003-2010.

Thermal expansion of the cryoprotectant cocktail DP6 combined with synthetic ice modulators in presence and absence of biological tissues.

This study explores physical effects associated with the application of cryopreservation via vitrification using a class of compounds which are defined here as synthetic ice modulators (SIMs). The general classification of SIMs includes molecules that modulate ice nucleation and growth, or possess properties of stabilizing the amorphous state, by virtue of their chemical structure and at concentrations that are not explained on a purely colligative basis. A sub-category of SIMs, referred to in the literature as synthetic ice blockers (SIBs), are compounds that interact directly with ice nuclei or crystals to modify their structure and/or rate of growth.

A randomized, placebo-controlled, double-blind study to evaluate the efficacy of a citrus bioflavanoid blend in the treatment of senile purpura.

Background: Senile purpura is a common, chronic skin condition affecting more than 10 percent of individuals over the age of 50. Despite being a benign condition, the continual development of purpura lesions in afflicted patients is frequently a source of significant visual and social concern. To date, there are no known effective treatments for this condition.

Hyperthermia potentiates oncolytic herpes viral killing of pancreatic cancer through a heat shock protein pathway.

Background: Oncolytic herpes simplex virus-1 (HSV-1) is designed to specifically infect, replicate in, and lyse cancer cells. This study investigates a novel therapeutic regimen, combining the effects of NV1066 (a recombinant HSV-1) and hyperthermia in the treatment of pancreatic cancer.

Methods: NV1066 is an attenuated HSV-1 that replicates in cells resistant to apoptosis.

Validation of a prediction rule to maximize curative (R0) resection of early-stage pancreatic adenocarcinoma.

Background: The surgeon's contribution to patients with localized pancreatic adenocarcinoma (PAC) is a margin negative (R0) resection. We hypothesized that a prediction rule based on pre-operative imaging would maximize the R0 resection rate while reducing non-therapeutic intervention.

Methods: The prediction rule was developed using computed tomography (CT) and endoscopic ultrasound (EUS) data from 65 patients with biopsy-proven PAC who underwent attempted resection.

Short- and long-term costs of laparoscopic colectomy are significantly less than open colectomy.

Background: The financial impact of laparoscopic colectomy remains poorly defined. We report the short-term costs of laparoscopic colectomy (LC) as compared with open colectomy (OC) in a high-volume tertiary care hospital, and are the first to incorporate the costs of late, colectomy-related complications in an analysis of long-term costs.

Methods: A retrospective analysis of patients undergoing elective laparoscopic (n = 76) or open (n = 162) colon resection between January 2004 and December 2006 was performed.

Nectin-1 expression by squamous cell carcinoma is a predictor of herpes oncolytic sensitivity.

Oncolytic viruses based on herpes simplex virus type 1 (HSV-1) are able to infect and lyse a variety of malignant cell lines. However, there is variability in the degree of tumor susceptibility, and the cancer cell determinants of HSV sensitivity are poorly defined. Nectin-1 is a cell surface adhesion molecule that functions as a cellular receptor to HSV envelope glycoprotein D (gD).

Intraoperative localization of lymph node metastases with a replication-competent herpes simplex virus.

Objectives: Lymph node status is the most important prognostic factor determining recurrence and survival in patients with mesothelioma and other thoracic malignancies. Accurate localization of lymph node metastases is therefore necessary to improve selection of resectable and curable patients for surgical intervention. This study investigates the potential to identify lymph node metastases intraoperatively by using herpes-guided cancer cell-specific expression of green fluorescent protein.

Real-time intraoperative detection of breast cancer axillary lymph node metastases using a green fluorescent protein-expressing herpes virus.

Objective: To investigate the use of a green fluorescent protein (GFP)-expressing oncolytic herpes virus to enable real-time intraoperative detection of breast cancer lymph node metastases.

Summary Background Data: Axillary lymph node status is the most important factor determining treatment, recurrence, and overall survival for women with breast cancer. The current methods of determining nodal status, however, have limitations.

Estrogen enhances the efficacy of an oncolytic HSV-1 mutant in the treatment of estrogen receptor-positive breast cancer.

Oncolytic herpes simplex virus-1 (HSV-1) mutants selectively replicate in and lyse tumor cells. Viral replication is dependent on the cellular proliferative mechanism. Estrogen increases cellular proliferation and decreases apoptosis in estrogen receptor-positive (ER+) human breast cancer cells.

Oncolytic herpes viral therapy is effective in the treatment of hepatocellular carcinoma cell lines.

The rising incidence of hepatocellular carcinoma (HCC) in western countries, along with the poor prognosis offered by present-day treatment modalities, makes novel therapies for this disease necessary. Oncolytic herpes simplex viruses (HSV) are replication-competent viruses that are highly effective in the treatment of a wide variety of experimental models of human malignancies. This study seeks to investigate the effectiveness of oncolytic herpes viruses in the treatment of primary HCC cell lines.

Imaging and therapy of malignant pleural mesothelioma using replication-competent herpes simplex viruses.

Background: Malignant pleural mesothelioma (MPM) is an aggressive cancer that is refractory to current treatment modalities. Oncolytic herpes simplex viruses (HSV) used for gene therapy are genetically engineered, replication-competent viruses that selectively target tumor cells while sparing normal host tissue. The localized nature, the potential accessibility and the relative lack of distant metastasis make MPM a particularly suitable disease for oncolytic viral therapy.

Real-time diagnostic imaging of tumors and metastases by use of a replication-competent herpes vector to facilitate minimally invasive oncological surgery.

Current efforts on expanding minimally invasive techniques into the realm of oncological surgery are hindered by lack of accurate visualization of tumor margins and failure to detect micro metastases in real time. We used a systemic delivery of a herpes viral vector with cancer-selective infection and replication to precisely differentiate between normal and malignant tissue. NV1066 is a genetically modified, replication-competent herpes simplex virus carrying a transgene for enhanced green fluorescent protein (GFP).

Use of positron emission tomography to target prostate cancer gene therapy by oncolytic herpes simplex virus.

Herpes simplex virus (HSV) oncolytic gene therapy is a promising treatment modality against cancer. We have demonstrated that androgen-induced cellular changes enhance oncolytic viral replication and improve efficacy in the treatment of androgen-dependent prostate cancer cell line. Imaging of changes in 2-deoxy-2-[F-18]fluoro-D-glucose (FDG) uptake by positron emission tomography (PET) is a sensitive method of detecting altered cellular metabolism involved in cancer therapy.

Virally directed fluorescent imaging improves diagnostic sensitivity in the detection of minimal residual disease after potentially curative cytoreductive surgery.

Completeness of cytoreduction is an independent prognostic factor after cure-intended surgery for peritoneal carcinomatosis. NV1066, a genetically engineered herpes simplex virus carrying the transgene for green fluorescent protein, selectively infects cancer cells. We sought to determine the feasibility of virally directed fluorescent imaging in the intraoperative detection of minimal residual disease after cytoreductive surgery.

5-fluorouracil and gemcitabine potentiate the efficacy of oncolytic herpes viral gene therapy in the treatment of pancreatic cancer.

Oncolytic herpes viruses are attenuated, replication-competent viruses that selectively infect, replicate within, and lyse cancer cells and are highly efficacious in the treatment of a wide variety of experimental cancers. The current study seeks to define the pharmacologic interactions between chemotherapeutic drugs and the oncolytic herpes viral strain NV1066 in the treatment of pancreatic cancer cell lines. The human pancreatic cancer cell lines Hs 700T, PANC-1, and MIA PaCa-2 were treated in vitro with NV1066 at multiplicities of infection (MOI; ratio of the number of viral particles per tumor cell) ranging from 0.

Enhanced nectin-1 expression and herpes oncolytic sensitivity in highly migratory and invasive carcinoma.

Purpose: Although a variety of malignant tumors are susceptible to therapy with oncolytic herpes simplex viruses, the determinants of tumor sensitivity to these viruses are poorly understood. Nectin-1 is a cell surface adhesion molecule that is a component of intercellular adherens junctions and also functions as a herpes viral receptor. Because highly invasive cells may have decreased intercellular adhesion, we sought to determine if such cells might also have altered availability of cell surface nectin-1 to act as a herpes receptor.

Treatment of aggressive thyroid cancer with an oncolytic herpes virus.

Although many thyroid cancers carry a favorable prognosis, there is a subgroup of patients with more aggressive histologies. Current therapies offer no significant survival benefit to patients with anaplastic thyroid carcinomas, which are considered fatal. Oncolytic herpes simplex viruses (HSVs) have potent antitumor effects against a variety of human malignancies.