Anthony D. Sandler

Cold plasma selectivity and the possibility of a paradigm shift in cancer therapy

Background:Plasma is an ionised gas that is typically generated in high-temperature laboratory conditions. However, recent progress in atmospheric plasmas has led to the creation of cold plasmas with ion temperature close to room temperature.Methods:Both in-vitro and in-vivo studies revealed that cold plasmas selectively kill cancer cells.Results:We show that: (a) cold plasma application selectively eradicates cancer cells in vitro without damaging normal cells; and (b) significantly reduces tumour size in vivo. It is shown that reactive oxygen species metabolism and oxidative stress responsive genes are deregulated.Conclusion:The development of cold plasma tumour ablation has the potential of shifting the current paradigm of cancer treatment and enabling the transformation of cancer treatment technologies by utilisation of another state of matter.

Cold atmospheric plasma in cancer therapy

Recent progress in atmospheric plasmas has led to the creation of cold plasmas with ion temperature close to room temperature. This paper outlines recent progress in understanding of cold plasma physics as well as application of cold atmospheric plasma (CAP) in cancer therapy. Varieties of novel plasma diagnostic techniques were developed recently in a quest to understand physics of CAP. It was established that the streamer head charge is about 108 electrons, the electrical field in the head vicinity is about 107 V/m, and the electron density of the streamer column is about 1019 m−3. Both in-vitro and in-vivo studies of CAP action on cancer were performed. It was shown that the cold plasma application selectively eradicates cancer cells in-vitro without damaging normal cells and significantly reduces tumor size in-vivo. Studies indicate that the mechanism of action of cold plasma on cancer cells is related to generation of reactive oxygen species with possible induction of the apoptosis pathway. It is also shown that the cancer cells are more susceptible to the effects of CAP because a greater percentage of cells are in the S phase of the cell cycle.

Outcome after Reduced Chemotherapy for Intermediate-Risk Neuroblastoma

BACKGROUND The survival rate among patients with intermediate-risk neuroblastoma who receive dose-intensive chemotherapy is excellent, but the survival rate among patients who receive reduced doses of chemotherapy for shorter periods of time is not known. METHODS We conducted a prospective, phase 3, nonrandomized trial to determine whether a 3-year estimated overall survival of more than 90% could be maintained with reductions in the duration of therapy and drug doses, using a tumor biology-based therapy assignment. Eligible patients had newly diagnosed, intermediate-risk neuroblastoma without MYCN amplification; these patients included infants (<365 days of age) who had stage 3 or 4 disease, children (≥365 days of age) who had stage 3 tumors with favorable histopathological features, and infants who had stage 4S disease with a diploid DNA index or unfavorable histopathological features. Patients who had disease with favorable histopathological features and hyperdiploidy were assigned to four cycles of chemotherapy, and those with an incomplete response or either unfavorable feature were assigned to eight cycles. RESULTS Between 1997 and 2005, a total of 479 eligible patients were enrolled in this trial (270 patients with stage 3 disease, 178 with stage 4 disease, and 31 with stage 4S disease). A total of 323 patients had tumors with favorable biologic features, and 141 had tumors with unfavorable biologic features. Ploidy, but not histopathological features, was significantly predictive of the outcome. Severe adverse events without disease progression occurred in 10 patients (2.1%), including secondary leukemia (in 3 patients), death from infection (in 3 patients), and death at surgery (in 4 patients). The 3-year estimate (±SE) of overall survival for the entire group was 96±1%, with an overall survival rate of 98±1% among patients who had tumors with favorable biologic features and 93±2% among patients who had tumors with unfavorable biologic features. CONCLUSIONS A very high rate of survival among patients with intermediate-risk neuroblastoma was achieved with a biologically based treatment assignment involving a substantially reduced duration of chemotherapy and reduced doses of chemotherapeutic agents as compared with the regimens used in earlier trials. These data provide support for further reduction in chemotherapy with more refined risk stratification. (Funded by the National Cancer Institute; ClinicalTrials.gov number, NCT00003093.)

Whole-Exome Sequencing Identifies Homozygous AFG3L2 Mutations in a Spastic Ataxia-Neuropathy Syndrome Linked to Mitochondrial m-AAA Proteases

We report an early onset spastic ataxia-neuropathy syndrome in two brothers of a consanguineous family characterized clinically by lower extremity spasticity, peripheral neuropathy, ptosis, oculomotor apraxia, dystonia, cerebellar atrophy, and progressive myoclonic epilepsy. Whole-exome sequencing identified a homozygous missense mutation (c.1847G>A; p.Y616C) in AFG3L2, encoding a subunit of an m-AAA protease. m-AAA proteases reside in the mitochondrial inner membrane and are responsible for removal of damaged or misfolded proteins and proteolytic activation of essential mitochondrial proteins. AFG3L2 forms either a homo-oligomeric isoenzyme or a hetero-oligomeric complex with paraplegin, a homologous protein mutated in hereditary spastic paraplegia type 7 (SPG7). Heterozygous loss-of-function mutations in AFG3L2 cause autosomal-dominant spinocerebellar ataxia type 28 (SCA28), a disorder whose phenotype is strikingly different from that of our patients. As defined in yeast complementation assays, the AFG3L2Y616C gene product is a hypomorphic variant that exhibited oligomerization defects in yeast as well as in patient fibroblasts. Specifically, the formation of AFG3L2Y616C complexes was impaired, both with itself and to a greater extent with paraplegin. This produced an early-onset clinical syndrome that combines the severe phenotypes of SPG7 and SCA28, in additional to other “mitochondrial” features such as oculomotor apraxia, extrapyramidal dysfunction, and myoclonic epilepsy. These findings expand the phenotype associated with AFG3L2 mutations and suggest that AFG3L2-related disease should be considered in the differential diagnosis of spastic ataxias.

Pediatric robotic surgery: A single-institutional review of the first 100 consecutive cases.

BackgroundRobotic surgery is a new technology which may expand the variety of operations a surgeon can perform with minimally invasive techniques. We present a retrospective review of our first 100 consecutive robotic cases in children.MethodsA three-arm robot was used with one camera arm and two instrument arms. Additional accessory ports were utilized as necessary. Two different attending surgeons performed the procedures.ResultsTwenty-four different types of procedures were completed using the robot. The majority of the procedures (89%) were abdominal procedures with 11% thoracic. No urology or cardiac procedures were performed. Age ranged from 1 day to 23 years with an average age of 8.4 years. Weight ranged from 2.2 to 103 kg with a median weight of 27.9 kg. Twenty-two patients were less than 10.0 kg. Examples of cases included gastrointestinal (GI) surgery, hepatobiliary, surgical oncology, and congenital anomalies. The overall majority of cases had never been performed minimally invasively by the authors. The overall intraoperative conversion rate to open surgery was 13%. One case (1%) was converted to thoracoscopic because of lack of domain for the articulating instruments. No conversions or complications occurred as a result of injuries from the robotic instruments. Interestingly, four abdominal cases were converted to open surgery due to equipment failures or injuries from standard laparoscopic instruments used through non-robotic accessory ports.ConclusionsRobotic surgery is safe and effective in children. An enormous variety of cases can be safely performed including complex cases in neonates and small children. Simple operations such as cholecystectomies have minimal advantages by using robotic technology but can serve as excellent teaching tools for residents and newcomers to this form of minimally invasive surgery (MIS). The technology is ideal for complex hepatobiliary cases and thoracic surgery, particularly solid chest masses.

Cold atmospheric plasma for the ablative treatment of neuroblastoma

BACKGROUND Recent breakthroughs have allowed for production of plasma at room temperature. Cold atmospheric plasma (CAP) may offer the capability of delivering reactive oxygen species directly into tissues, representing a novel modality for targeted cancer therapy. We studied helium-based CAPs effect on neuroblastoma, both in-vitro and in an in-vivo murine model. METHODS Mouse neuroblastoma cultures were treated with CAP for 0, 30, 60, and 120 s and assayed for apoptotic and metabolic activity immediately and at 24 and 48 h post-treatment. Five-millimeter tumors were ablated with a single transdermal CAP treatment, and tumor volume and mouse survival were measured. RESULTS CAP decreased metabolic activity, induced apoptosis, and reduced viability of cancer cells in proportion to both duration of exposure and time post-treatment. In-vivo, a single treatment ablated tumors and eventual tumor growth was decelerated. Furthermore, survival nearly doubled, with median survival of 15 vs. 28 days (p<0.001). CONCLUSIONS Our findings demonstrate the sensitivity of neuroblastoma to CAP treatment, both in-vitro and in an in-vivo mouse model of established tumor. While further investigation is necessary to establish the mechanism and optimize the treatment protocol, these initial observations establish cold atmospheric plasma as a potentially useful ablative therapy in neuroblastoma.

Reflex laryngospasm induced by stimulation of distal esophageal afferents

Distal esophageal sensory nerves were stimulated in 17 anesthetized dogs divided into three age groups to determine the laryngeal, cardiovascular, and respiratory effects. Group I puppies were 5 to 6 weeks of age, group II puppies were 8 to 19 weeks of age, and group III animals were adult dogs. Marked laryngeal adductor activity and laryngospasm were observed in group II puppies, while no or minimal laryngeal adduction was seen in younger puppies and adult dogs. Mean arterial pressure and heart rate increased significantly in groups II and III (P<.005) but remained unchanged in group I animals (P>.4). This response is distinctly different from the laryngeal chemoreflex because central apnea, hypotension, and bradycardia were absent. The afferent limb of the response is mediated by the vagus nerve as bilateral transthoracic truncal vagotomy eliminated the reflex. The laryngeal response observed following stimulation of distal esophageal afferent fibers may be important in the mechanism of apparent life‐threatening events (ALTEs) and the sudden infant death syndrome (SIDS) associated with gastroesophageal reflux disease.

Immune stimulatory antigen loaded particles combined with depletion of regulatory T-cells induce potent tumor specific immunity in a mouse model of melanoma

Anti-tumor vaccines capable of activating both CD4 and CD8 T cells are preferred for long lasting T cell responses. Induction of a tumor-specific T-cell response can be induced by tumor vaccines that target innate immunity. The ensuing T-cell response depends on efficient antigen presentation from phagocytosed cargo in the antigen presenting cell and is augmented by the presence of Toll-like receptor (TLR) ligands within the cargo. Biodegradable polymers are useful for vaccine delivery in that they are phagocytosed by antigen presenting cells (APCs) and could potentially be loaded with both the antigen and immune stimulatory TLR agents. This study was undertaken to evaluate the effect of poly lactic-co-glycolic acid (PLGA) polymer particles loaded with antigenic tumor lysate and immune stimulatory CpG oligonucleotides on induction of tumor specific immunity in a mouse model of melanoma. We found that after delivery, these immune stimulatory antigen loaded particles (ISAPs) efficiently activated APCs and were incorporated into lysosomal compartments of macrophages and dendritic cells. ISAP vaccination resulted in remarkable T cell proliferation, but only modestly suppressed tumor growth of established melanoma. Due to this discordant effect on tumor immunity we evaluated the role of regulatory T cells (Treg) and found that ISAP vaccination or tumor growth alone induced prolific expansion of tumor specific Treg. When the Treg compartment was suppressed with anti-CD25 antibody, ISAP vaccination induced complete antigen-specific immunity in a prophylactic model. ISAP vaccination is a novel tumor vaccine strategy that is designed to co-load the antigen with a TLR agonist enabling efficient Ag presentation. Targeting of T-reg expansion during vaccination may be necessary for inducing effective tumor-specific immunity.

Inhibition of the NF- κ B pathway enhances TRAIL-mediated apoptosis in neuroblastoma cells

Neuroblastoma is the most common solid extracranial neoplasm in children and causes many deaths. Despite treatment advances, prognosis for neuroblastoma remains poor, and a critical need exists for the development of new treatment regimens. TNF-related apoptosis-inducing-ligand (TRAIL) induces cell death in a variety of tumors, but not in normal tissues. Moreover, TRAIL is nontoxic, making it a strong antitumor therapeutic candidate. We demonstrate that introduction of the TRAIL gene into neuroblastoma cell lines using an adenoviral vector leads to apoptotic cell death. RT-PCR and flow-cytometric analyses demonstrated that TRAILs effect is mediated primarily via the TRAIL R2 receptor. As TRAIL can activate the nuclear factor-κB (NF-κB) signaling pathway, which can exert an antiapoptotic effect, we hypothesized that inhibition of NF-κB signaling may augment TRAILs killing effects. TRAIL-mediated cell death was enhanced when neuroblastoma cells were simultaneously infected with a dominant-negative mutant of IκB kinase, a kinase essential for NF-κB activation. The combination of blockade of NF-κB signaling and expression of TRAIL induced apoptotic death in a greater proportion of SKNSH cells than did either treatment alone. Thus, concurrent inhibition of the NF-κB pathway and the induction of TRAIL-mediated apoptosis may become a useful approach for the treatment of neuroblastoma.

Respiratory Manifestations of Gastroesophageal Reflux Disease in Pediatric Patients

Respiratory manifestations of gastroesophageal reflux disease (GERD) are being recognized with increasing frequency. We present the evaluation and management of four infants and children with unusual respiratory symptoms attributed to GERD. The advantages and disadvantages of diagnostic studies of GERD are discussed, and an evaluation and treatment protocol is presented. Treatment must be tailored to the nature and severity of the patients presenting symptoms and includes conservative, pharmacologic, and/or surgical management.