Overcoming resistance to programmed cell death protein 1 (PD-1) blockade with allogeneic invariant natural killer T-cells (iNKT)

Gastric cancer is the 5th most common malignancy worldwide with only 36% of patients with metastatic disease surviving beyond 5 years. Despite therapeutic improvements with the advent of immune checkpoint inhibitors, most patients with gastric cancer develop disease progression related to tumor resistance. Novel immunotherapeutic approaches, including invariant natural killer (iNKT) cells, are in clinical development and represent potential therapeutic options to overcome resistance. AgenT-797 is an allogeneic human unmodified iNKT derived from healthy donors. Activation of iNKT cells by tumor lipid antigens can trigger direct cytotoxicity and promote indirect anti-tumor immune responses such as recruitment and activation of T cells, NK cells, and dendritic cells through secretion of cytokines and IFNγ. We describe immune modulation leading to durable tumor response in a patient with microsatellite instability-high (MSI-H) advanced gastric adenocarcinoma treated with agent-797 after progression on standard chemotherapy and anti-PD-1 therapy.

A Large-Scale Proteomics Resource of Circulating Extracellular Vesicles for Biomarker Discovery in Pancreatic Cancer

Pancreatic cancer has the worst prognosis of all common tumors. Earlier cancer diagnosis could increase survival rates and better assessment of metastatic disease could improve patient care. As such, there is an urgent need to develop biomarkers to diagnose this deadly malignancy earlier. Analyzing circulating extracellular vesicles (cEVs) using 'liquid biopsies' offers an attractive approach to diagnose and monitor disease status. However, it is important to differentiate EV-associated proteins enriched in patients with pancreatic ductal adenocarcinoma (PDAC) from those with benign pancreatic diseases such as chronic pancreatitis and intraductal papillary mucinous neoplasm (IPMN). To meet this need, we combined the novel EVtrap method for highly efficient isolation of EVs from plasma and conducted proteomics analysis of samples from 124 individuals, including patients with PDAC, benign pancreatic diseases and controls. On average, 912 EV proteins were identified per 100μL of plasma. EVs containing high levels of PDCD6IP, SERPINA12 and RUVBL2 were associated with PDAC compared to the benign diseases in both discovery and validation cohorts. EVs with PSMB4, RUVBL2 and ANKAR were associated with metastasis, and those with CRP, RALB and CD55 correlated with poor clinical prognosis. Finally, we validated a 7-EV protein PDAC signature against a background of benign pancreatic diseases that yielded an 89% prediction accuracy for the diagnosis of PDAC. To our knowledge, our study represents the largest proteomics profiling of circulating EVs ever conducted in pancreatic cancer and provides a valuable open-source atlas to the scientific community with a comprehensive catalogue of novel cEVs that may assist in the development of biomarkers and improve the outcomes of patients with PDAC.

Facts and Hopes in Immunotherapy of Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) remains one of the most challenging cancers to treat. For patients with advanced and metastatic disease, chemotherapy has yielded only modest incremental benefits, which are not durable. Immunotherapy has revolutionized the treatment of other solid tumors by leading to cures where none existed only a decade ago, yet it has made few inroads with PDAC. A host of trials with promising preclinical data have failed, except for in a small minority of patients with selected biomarkers. There is, however, a glimmer of hope, which we seek to cultivate. In this review, we discuss recent advances in the understanding of the uniquely immunosuppressive tumor microenvironment (TME) in PDAC, learnings from completed trials of checkpoint inhibitors, TME modifiers, cellular and vaccine therapies, oncolytic viruses, and other novel approaches. We go on to discuss our expectations for improved preclinical models of immunotherapy in PDAC, new approaches to modifying the TME including the myeloid compartment, and emerging biomarkers to better select patients who may benefit from immunotherapy. We also discuss improvements in clinical trial design specific to immunotherapy that will help us better measure success when we find it. Finally, we discuss the urgent imperative to better design and execute bold, but rational, combination trials of novel agents designed to cure patients with PDAC.

A Preclinical and Phase 1b Study of Palbociclib Plus Nab-Paclitaxel in Patients With Metastatic Adenocarcinoma of the Pancreas

Purpose: To assess the preclinical efficacy, clinical safety and efficacy, and maximum tolerated dose (MTD) of palbociclib plus nab-paclitaxel in patients with advanced pancreatic ductal adenocarcinoma (PDAC). Experimental Design: Preclinical activity was tested in patient-derived xenograft (PDX) models of PDAC. In the open-label, phase 1 clinical study, the dose-escalation cohort received oral palbociclib initially at 75 mg/day (range 50‒125mg/day; modified 3+3 design; 3/1 schedule); intravenous nab-paclitaxel was administered weekly for 3 weeks/28 day cycle at 100‒125mg/m2. The modified dose–regimen cohorts received palbociclib 75mg/day (3/1 schedule or continuously) plus nab-paclitaxel (biweekly 125 or 100mg/m2, respectively). The prespecified efficacy threshold was 12-month survival probability of ≥65% at the MTD. Results: Palbociclib plus nab-paclitaxel was more effective than gemcitabine plus nab-paclitaxel in 3 of 4 PDX models tested; the combination was not inferior to paclitaxel plus gemcitabine. In the clinical trial, 76 patients (80% received prior treatment for advanced disease) were enrolled. Four dose-limiting toxicities were observed (mucositis [n=1], neutropenia [n=2], febrile neutropenia [n=1]). The MTD was palbociclib 100mg for 21 of every 28 days and nab-paclitaxel 125mg/m2 weekly for 3 weeks in a 28-day cycle. Among all patients, the most common all-causality any-grade adverse events were neutropenia (76.3%), asthenia/fatigue (52.6%), nausea (42.1%), and anemia (40.8%). At the MTD (n=27), the 12-month survival probability was 50% (95% CI, 29.9%–67.2%). Conclusions: This study showed the tolerability and antitumor activity of palbociclib plus nab-paclitaxel treatment in patients with PDAC; however, the prespecified efficacy threshold was not met.

Organoid Sensitivity Correlates with Therapeutic Response in Patients with Pancreatic Cancer

PURPOSE

Pancreatic ductal adenocarcinoma (PDAC) remains a significant health issue. For most patients there are no options for targeted therapy and existing treatments are limited by toxicity. The HOPE trial (Harnessing Organoids for PErsonalized Therapy) was a pilot feasibility trial aiming to prospectively generate patient derived organoids (PDOs) from patients with PDAC and test their drug sensitivity and correlation with clinical outcomes.

EXPERIMENTAL DESIGN

PDOs were established from a heterogeneous population of patients with PDAC including both basal and classical PDAC subtypes.

RESULTS

A method for classifying PDOs as sensitive or resistant to chemotherapy regimens was developed to predict the clinical outcome of study subjects. Drug sensitivity testing on PDOs correlated with clinical responses to treatment in individual patients.

CONCLUSION

These data support the investigation of PDOs to guide treatment in prospective interventional trials in PDAC.

Regulation of leukocyte function by nitric oxide donors: the effect of S-nitroso-thiol complexes

The aim of this study was to evaluate the effectiveness of a novel protein-bound S-nitroso-thiol, S-nitroso-albumin (S-NO-alb), in modulating neutrophil-endothelial cell adhesion, activation, and interactions. Due to the highly variable kinetics of NO release from the low-molecular-weight thiol adducts S-nitroso-N-acetylpenicillamine (SNAP) and S-nitroso-glutathione (GSNO), we expected S-NO-alb to be a more effective modulator of inflammatory interactions through its slow, steady, and prolonged release of NO. Human umbilical-vein endothelial cells (HUVECs) challenged with lipopolysaccharide (LPS) demonstrated upregulated adhesion of neutrophils that was significantly attenuated by pretreatment with S-NO-alb (1.0-100 microM) (p < .05), but not SNAP or GSNO. Pretreatment with S-NO-alb, SNAP, or GSNO attenuated tumor necrosis factor-alpha primed *O2- release from neutrophils and increased neutrophil cGMP accumulation. On a molar basis, S-NO-alb expressed a 10-fold greater potency than SNAP or GSNO at modulating these effects. Kinetics studies confirmed the relative stability of spontaneous NO release from S-NO-alb compared with highly variable kinetic profiles of SNAP and GSNO. Our results demonstrate that S-NO-alb more effectively modulates endothelial-cell and neutrophil immunoinflammatory responses versus its related low-molecular-weight thiol complexes.

Low molecular weight heparin alters porcine neutrophil responses to platelet-activating factor

Because platelet-activating factor (PAF) is an important mediator of inflammation and heparin has anti-inflammatory effects, we hypothesized that low molecular weight heparin (LMWH) would inhibit PAF-induced activation and chemotaxis in porcine neutrophils. Citrated blood was obtained from pentobarbital-anesthetized pigs, and neutrophils were isolated over a 55%/65% Percoll gradient. The effect of LMWH on basal phorbol myristate acetate (PMA)-induced superoxide (SO) release, as well as its effect on PAF priming for PMA-induced SO release, were investigated. Additionally, the effect of LMWH on PAF-induced chemotaxis of neutrophils across transwell membranes was evaluated. Baseline SO release in response to PMA was .351+/-.046 nmol/10(6) cells/min, and this was decreased to .289+/-.034 nmol/10(6) cells/min by pretreatment with 50 U/mL LMWH. PMA-induced SO production was increased by .240+/-.042 nmol/10(6) cells/min when cells were primed with 10 microM PAF. This priming effect of PAF was reduced significantly by pretreatment of neutrophils with LMWH at 10 and 50 U/mL. Chemotaxis of neutrophils in response to 100 microM PAF was significantly decreased to 70.02+/-6.4% (n = 8) of the control response by pretreatment of cells with 50 U/mL LMWH. We conclude that LMWH has anti-inflammatory effects on porcine neutrophils, which includes attenuation of cell activation and chemotaxis in response to the lipid-derived inflammatory mediator, PAF.

E-mail access to NetCME: implementation of server push paradigm

We describe the implementation of a Continuing Medical Education project which utilizes e-mail delivery of HTML documents to facilitate participant access to case material. HTML e-mail is displayed directly within the e-mail reader of the Netscape browser. This system of proactive educational content delivery ensures simultaneous distribution to all participants. Although a more effective method of content distribution, the system preserves user confidentiality and maintains security. HTML e-mail is non-proprietary and could be integrated into existing Internet-based educational projects to facilitate user access.

Attenuation of endotoxin-induced pathophysiology by a new potent PAF receptor antagonist

The role of platelet-activating factor (PAF) as a mediator of endotoxin-induced pathophysiology has been studied in several animal models with conflicting results. We evaluated the effect of a new, potent, and specific PAF receptor antagonist, ABT-299 (Abbott Laboratories) against endotoxin (lipopolysaccharide; LPS)-induced cardiopulmonary dysfunction in a porcine model. In initial experiments, the potency of ABT-299 was confirmed in vitro by its ability to inhibit PAF-induced porcine platelet aggregation at an IC50 of .047 +/- .01 microM, and in vivo by the ability of low doses (.12 mg/kg + .03 mg/kg/h) to block the cardiopulmonary pathologic response to exogenous PAF infusion. To evaluate the effect of ABT-299 administration during endotoxemia, pigs were randomly assigned to one of three groups: controls (n = 7), LPS (n = 9), or ABT-299 + LPS (n =7). ABT-299 was given at 1.0 mg/kg from -0.5 to 0 h plus .3 mg/kg/h from 0 to 6 h. LPS was given at .5 micrograms/kg/hr from 0 to 6 h. ABT-299 reduced the early LPS-induced fall in cardiac index and stroke volume, pulmonary hypertension and vasoconstriction, bronchoconstriction, and hypoxemia. Administration of LPS resulted in 44% mortality (before 6 h), which was blocked by ABT-299. Results with this antagonist indicate that PAF contributes to endotoxin-induced cardiopulmonary dysfunction in the pig, and is associated with mortality in this model.

Treatment of refractory sleep apnea with supplemental carbon dioxide

Sleep apnea syndrome is a relatively common disorder characterized by periodic cessation of breathing during sleep because of upper airway obstruction (obstructive sleep apnea) or by reduction of ventilatory drive (central sleep apnea). We report the case of a middle-aged, obese man who underwent tracheostomy for the treatment of obstructive sleep apnea documented by polysomnography. Although tracheostomy resulted in marked clinical improvement, relief of upper airway obstruction unmasked severe central sleep apnea. We report the successful treatment of this patient's central sleep apnea syndrome with the use of supplemental CO2 therapy.

Factors influencing functional outcome in supraglottic laryngectomy

BACKGROUND

The relationship between preoperative pulmonary function tests (PFTs) and postoperative aspiration and deglutition complications in supraglottic laryngectomy (SL) has not been adequately analyzed. The effects of numerous other variables are either controversial or have not been studied.

METHODS

A retrospective chart review was performed on 46 SL patients, analyzing preoperative PFTs and arterial blood gases, demographic factors, stage of disease, extended resections, cricopharyngeal myotomy, hyoid preservation, neck dissection, and postoperative radiotherapy with regards to aspiration and deglutition problems.

RESULTS

Eighteen (39%) patients had no problems, 15 (33%) had moderate problems, and 13 (28%) had severe problems; of these, 39 (85%) were ultimately successful with no further swallowing dysfunction, whereas seven (15%) suffered intractable aspiration difficulties. Decreasing FEV1/FVC was significantly correlated with a poorer outcome, as was a greater number of pack-years of smoking. The effect of FEV1/FVC was shown to be independent from pack-years, whereas the converse was not clearly demonstrated. Extensions of the standard procedure did not correlate significantly with increased problems.

CONCLUSIONS

An FEV1/FVC less than 50% signifies a greater risk for severe aspiration and deglutition complications, although it must be regarded as one factor among many in determining operability. With careful attention to reconstruction, extensions of the standard SL procedure can be safely performed.

Acute myopathy during treatment of status asthmaticus with corticosteroids and steroidal muscle relaxants

Acute myopathy in patients being treated for severe asthma has been recognized with increasing frequency since first being described in 1977. We report three patients treated for status asthmaticus who developed severe generalized weakness. Electrophysiologic studies and muscle biopsy revealed evidence of muscle destruction. Each of these patients was treated with high-dose corticosteroids and underwent prolonged neuromuscular blockade with a steroidal muscle relaxant. A review of the literature revealed 15 similar cases. We postulate that the combined effects of corticosteroids and muscle relaxants on the muscle cell may be responsible for this myopathy. Patients treated with corticosteroids and NMBs should be carefully monitored for the development of myopathy.

Differential effects of eicosapentaenoic acid and oleic acid on lipid synthesis and secretion by HepG2 cells

The effects of eicosapentaenoic acid and oleic acid on lipid synthesis and secretion by HepG2 cells were examined to identify fatty acid specific changes in lipid metabolism that might indicate a basis for the hypolipidemic effect attributed to eicosapentaenoic acid and related n-3 fatty acids. Cellular glycerolipid synthesis, as determined by [3H]glycerol incorporation, increased in a concentration-dependent manner in cells incubated 4 h with either eicosapentaenoic acid or oleic acid at concentrations between 10 and 300 microM. [3H]Glycerol-labeled triglyceride was the principal lipid formed and increased approximately fourfold with the addition of 300 microM oleic acid or eicosapentaenoic acid. Both fatty acids also produced a 20-40% increase in the total cellular triglyceride mass. Although both fatty acids increased triglyceride synthesis to similar extents, eicosapentaenoic acid-treated cells secreted 40% less [3H]glycerol-labeled triglyceride than cells fed oleic acid. Cellular synthesis of [3H]glycerol-labeled phosphatidylethanolamine and phosphatidylcholine was also reduced by 40% and 30%, respectively, in cells given eicosapentaenoic acid versus cells given oleic acid. Similar results were obtained in determinations of radiolabeled oleic acid and eicosapentaenoic acid incorporation. At a fatty acid concentration of 300 microM, incorporation of radiolabeled eicosapentaenoic acid into cellular triglycerides was greater than the incorporation obtained with radiolabeled oleic acid, while the reverse relationship was observed for the formation of phosphatidylcholine from the same fatty acids. Eicosapentaenoic acid is as potent as oleic acid in inducing triglyceride synthesis but eicosapentaenoic acid is a poorer substrate than oleic acid for phospholipid synthesis. The intracellular rise in de novo-synthesized triglyceride in eicosapentaenoic acid-treated cells without corresponding increases in triglyceride secretion suggests that eicosapentaenoic acid is less effective than oleic acid in promoting the transfer of de novo-synthesized triglyceride to nascent very low density lipoproteins.

Positional changes in gas exchange after unilateral pulmonary embolism

We describe positional changes in oxygenation in two patients with respiratory failure due to massive pulmonary embolism. In both patients, oxygenation improved when the "sick" lung was dependent and deteriorated when the "healthy" lung was in the dependent position. These positional changes are different from previously reported changes in unilateral pulmonary disease. We speculate that a combination of unilateral pulmonary embolism and mechanical ventilation was responsible for the improvement in gas exchange when the "sick" lung was placed in the dependent position. The relative contribution of these two components to the development of this phenomenon is unclear.

Sphenoid fractures: prevalence, sites, and significance

The computed tomographic (CT) scans of the head of 490 blunt trauma victims were reviewed to establish the frequency of sphenoid fractures. There were 111 patients with craniofacial fractures, 78 of whom had fractures of the sphenoid bone. In 51 of the 78 patients these were associated with complex facial fractures, and in the 27 remaining patients they represented primarily fractures of the skull base. The number of sphenoid fractures not only exceeded those that involved the other bones of the base of the skull, including the temporal bone, but also exceeded the number of fractures of the cranial vault that could be identified with CT. All available charts were reviewed for the patients with sphenoid fractures in order to determine the presence of potentially related injuries. In 21 patients there were complications that included damage to the internal carotid artery, cerebrospinal fluid rhinorrhea, optic nerve damage, superior orbital fissure syndrome, and posttraumatic diabetes insipidus.

Tears of the trachea and main bronchi caused by blunt trauma: radiologic findings

Although most of the radiologic changes that have been described in transection or laceration of the trachea or main bronchi are nonspecific, they can be of diagnostic importance in the appropriate clinical setting. In order to reassess the significance of these findings, and to determine the presence of any other changes that might lead to a definitive diagnosis, we retrospectively reviewed the chest radiographs of nine patients who had tears or transection of the trachea and/or main bronchi as a result of blunt chest trauma. The diagnosis was proved by bronchoscopy in all patients and reconfirmed at surgery in five. The predominant findings on the chest radiographs were related to air leak and included subcutaneous emphysema (seven patients), pneumomediastinum (seven patients), pneumothorax (six patients), and air surrounding a bronchus in one patient. Upper thoracic fractures that involved the clavicles, scapula, sternum, and ribs were present in four patients. Abnormalities in the appearance of an endotracheal tube in two patients (overdistention of the cuff or extraluminal position of the tip), and the presence of the fallen lung sign (collapse of the lung toward the lateral chest wall) in two others provided specific evidence of tracheobronchial injury. We conclude that, although the major importance of the chest radiograph in patients with tracheobronchial transection may be to verify the existence of air leak, the presence of the fallen lung sign and endotracheal tube abnormalities is a reliable indication of airway injury.

Effect of naproxen, a prostaglandin inhibitor, on acute otitis media and persistence of middle ear effusion in children

Prostaglandins are thought to be of importance in the pathophysiology of otitis media with effusion (OME), and the possibility of reducing the frequency and persistence of this condition by using prostaglandin inhibitors has been suggested. In a double blind manner, naproxen was administered to children with acute otitis media, in addition to amoxicillin, and its influence on the subsequent occurrence and persistence of middle ear effusion was evaluated. Eighty-one children participated in the study. No significant difference was found in the number of patients with tympanograms consistent with OME in the two groups. After 10 days of treatment, 63% in the naproxen and 58% in the placebo group, and after 30 days, 41% and 59%, respectively, had type B tympanograms. Similarly, there were no differences between the two groups with respect to other parameters studied (duration of otalgia, fever, otoscopic findings). No side effects related to naproxen were observed.

An immunocytochemical method for quantification of lung tissue fibronectin

A technique to quantify tissue fibronectin was developed, using peroxidase-antiperoxidase immunocytochemistry and automated scanning light microscopy. This technique was developed using isolated perfused rat lungs, some of which were subjected to acute oxidant lung injury. Both injured and control lungs were perfused with solutions containing heterologous fibronectin. The technique clearly demonstrated differences in the amount of tissue fibronectin in injured and noninjured lung as well as differences between lungs exposed to fibronectin and those not exposed. The described technique offers a reliable method for quantifying tissue fibronectin and is sensitive enough to detect differences in tissue fibronectin under experimental conditions of acute lung injury.

Plasma fibronectin and fibronectin therapy in sepsis and critical illness

Plasma fibronectin may be an important component of host defense in critically ill patients, particularly after trauma and during sepsis. This paper reviews recent studies that have sought to characterize the natural history of plasma fibronectin during sepsis, as well as those studies that tested the effect of therapy with concentrated fibronectin in sepsis. The decrease in plasma fibronectin that generally is seen in humans during sepsis probably is due to many factors, and it has been difficult to produce a similar pattern in animal models. Depletion of plasma fibronectin is not a sensitive or specific predictor of imminent sepsis, and once sepsis is established, the concentration of plasma fibronectin is no more sensitive a predictor of mortality than are many other clinical markers. Early, uncontrolled trials of therapy with a fibronectin concentrate in patients with sepsis appeared to indicate a propitious effect on organ function. However, more recent controlled trials have failed to show a significant effect of therapy with fibronectin concentrate on either organ function or patient survival.

Risk factors of anesthesia and surgery in bleomycin-treated patients

The use of bleomycin as part of preoperative chemotherapy regimens for nonseminomatous germ cell tumors of the testis has gained increased acceptance. However, recent experience has suggested that patients so treated are at an increased risk of developing postoperative respiratory distress syndrome. The most clearly associated factor seems to be the fractional concentration of inspired oxygen intraoperatively and in the immediate postoperative period. Based on our experience and a review of the limited published reports, we recommend careful monitoring of fractional inspired oxygen and maintenance of the lowest tolerated oxygen concentration during this period.

Clinical use of fibronectin. (Potential applications)

There is considerable experimental evidence that the RES is an important host defense system in critical illness. The role of fibronectin in the control of RES phagocytic function and the potential for fibronectin therapy to ameliorate or reverse multisystem organ failure in critically ill patients are less well documented. This documentation may be difficult to accrue in the clinical setting because of the multifactorial problems of individual critically ill patients and the heterogeneity of underlying diseases in such patients. More work needs to be done in animal models in which these variables can be controlled. Large scale production of pasteurized biologically active fibronectin should be possible if the cryoprecipitate studies prove the clinical utility of fibronectin concentrates. Fibronectin will certainly not be a panacea for critically ill patients, but the addition of any useful substance to the now meager armamentarium would be most welcome.

Response of plasma fibronectin to major body burn

The ability of macrophages of phagocytize particulate matter is largely dependent on fibronectin, a nonspecific opsonin found in plasma. Fibronectin depletion, resulting in reticuloendothelial system (RES) depression, occurs following a variety of physical insults. RES depression may contribute to postinjury sequelae such as respiratory distress syndrome and septicemia. Fibronectin concentration was measured in the plasma of sheep with chronic lung lymph fistulas subjected to controlled thermal injury. Fibronectin levels were significantly (p < 0.05) decreased at 4, 24, 48, and 72 hours following burning. Fibronectin concentration decreased in parallel with serum albumin concentration; serum globulin concentrations did not decrease. Fibronectin concentration had an inverse relationship to lung lymph flow, a reflection of pulmonary transvascular fluid filtration rate. The role of fibronectin in the pathogenesis of postinjury respiratory distress syndrome deserves further exploration.