Safety,tolerability and immunogenicity of GS-4774, a hepatitis B virus-specific therapeutic vaccine,in healthy subjects: A randomized study

Background

GS-4774 is a recombinant, heat-killed, yeast-based immunotherapy engineered to express hepatitis B virus (HBV)-specific antigens. GS-4774 is being developed as a therapeutic vaccine for chronic HBV infection. The aim of this study was to assess the safety, tolerability and immunogenicity of GS-4774 in healthy subjects.

Design

This was a randomized, open-label, dose-ascending study. Subjects were allocated to one of three dose groups (n = 20 per group) to receive 10, 40 or 80 yeast units (YU; 1 YU = 10⁷ yeast) of GS-4774 in two immunization regimens (five subcutaneous injections at weekly intervals with one monthly booster or three subcutaneous injections at monthly intervals). T-cell-mediated responses were determined by interferon (IFN)-γ enzyme-linked immunospot (ELISpot) assay and lymphocyte-proliferation assay (LPA).

Results

Adverse events were reported by 39 of 60 (65%) subjects; all were mild or moderate and none was serious. Adverse events occurred most frequently in the highest dose group, 80 YU, and the number of individual events was higher after weekly immunization than monthly. The most common adverse events were injection-site reactions. Most (88%) subjects responded to GS-4774 by at least one of the T-cell assays. Following immunization with GS-4774, IFN-γ-producing T-cells specific for HBV antigens were detectable in 30 (51%) subjects. The ELISpot response was observed at all doses, with the highest frequency of responders occurring at the highest dose (10 YU: 45%; 40 YU: 35%; 80 YU: 74%). Proliferative responses to HBV recombinant antigens were observed in 90% subjects; responses were mainly independent of GS-4774 dose and immunization regimen.

Conclusions

GS-4774 was safe and well-tolerated in healthy subjects with injection-site reactions being the most frequently reported adverse events. With both weekly and monthly regimens, GS-4774 provided HBV-specific immune responses at all doses evaluated. Further evaluation of GS-4774 is ongoing in patients with chronic HBV infection.Clinical trial registry: Clinicaltrials.gov (NCT01779505)     

Intraoperative assessment of colorectal anastomotic integrity: a systematic review

Background

Surgeons have attempted to minimize postoperative anastomotic complications by employing intraoperative tests and manoeuvres to assess colorectal anastomotic integrity. These have evolved over time with improvement in operative technology and techniques. This systematic review aims to examine the impact of such intraoperative assessments.

Methods

A systematic review of studies assessing intraoperative anastomotic assessments and their impact on postoperative anastomotic complications was performed. Intraoperative measures undertaken as a result of intraoperative assessments and postoperative anastomotic complications were analysed.

Results

37 Studies were identified. 13 studies evaluated basic mechanical patency tests, ten studies evaluated endoscopic visualisation techniques and 14 studies evaluated microperfusion techniques. Postoperative anastomotic complications were significantly lower in patients tested with basic mechanical patency tests compared to those untested (non-RCT: 4.1 vs. 8.1 %, p = 0.03, RCTs: 5.8 vs. 16.0 %, p = 0.024). There were no differences in postoperative anastomotic complications between tested and non-tested cohorts in non-randomised cohort studies evaluating endoscopic visualisation techniques. However, intraoperative measures taken after abnormal intraoperative tests may have reduced the number of postoperative complications. Perfusion analysis techniques are not in routine widespread clinical practice as yet, but newer techniques such as fluorescent dyes and imaging under near infrared light show technical feasibility.

Conclusions

Intraoperative colorectal anastomotic assessment has evolved together with advancement of technology in the surgical setting. Moderate benefit in terms of lower postoperative anastomotic complications has been shown with basic mechanical patency testing and more recently with intraoperative endoscopic visualisation of colorectal anastomoses. The next advance and possible introduction into routine practice may include the use of microperfusion techniques. The latest in this group of techniques, which utilise autofluorescent dyes such as Indocyanine green, hold great potential. Well-planned controlled studies or ideally, randomised controlled trials need to be conducted to further assess the benefit of these latest techniques.     

Enhanced depth-independent chondrocyte proliferation and phenotype maintenance in an ultrasound bioreactor and an assessment of ultrasound dampening in the scaffold

Chondrocyte-seeded scaffolds were cultured in an ultrasound (US)-assisted bioreactor, which supplied the cells with acoustic energy around resonance frequencies (∼5.0 MHz). Polyurethane-polycarbonate (BM), chitosan (CS) and chitosan–n-butanol (CSB) based scaffolds with varying porosities were chosen and the following US regimen was employed: 15 kPa and 60 kPa, 5 min per application and 6 applications per day for 21 days. Non-stimulated scaffolds served as control. For BM scaffolds, US stimulation significantly impacted cell proliferation and depth-independent cell population density compared to controls. The highest COL2A1/COL1A1 ratios and ACAN mRNA were noted on US-treated BM scaffolds compared to controls. A similar trend was noted on US-treated cell-seeded CS and CSB scaffolds, though COL2A1/COL1A1 ratios were significantly lower compared to BM scaffolds. Expression of Sox-9 was also elevated under US and paralleled the COL2A1/COL1A1 ratio. As an original contribution, a simplified mathematical model based on Biot theory was developed to understand the propagation of the incident US wave through the scaffolds and the model analysis was connected to cellular responses. Scaffold architecture influenced the distribution of US field, with the US field being the least attenuated in BM scaffolds, thus coupling more mechanical energy into cells, and leading to increased cellular activity.     

Improving the electrochemical performance of cathode composites using different sized solid electrolytes for all solid-state lithium batteries

We studied the efficiency of different particle-sized sulfide solid electrolyte-based cathode composites. First, we prepared the Li₇P₂S₈I solid electrolytes with different particle sizes through a high energy ball milling process and solution method. The structural details of the prepared solid electrolytes were studied by powder X-ray diffraction. The surface morphologies and particle size of the electrolytes were studied by field emission electron microscopy. The ionic conductivity of the prepared solid electrolytes was studied by the electrochemical impedance spectroscopy technique. Finally, we have prepared a LiNi_0.8Co_0.1Mn_0.1O₂ (NCM 811) based cathode composite and studied the electrochemical performance of the fabricated all-solid-state lithium batteries. The mixed particle-sized solid electrolyte-based cathode composite exhibited higher specific capacitance (127.2 mA h g⁻¹) than the uniform-sized solid electrolyte-based cathode composite (117.1 mA h g⁻¹). The electrochemical analysis confirmed that the sulfide solid electrolytes with mixed particle size exhibited better electrochemical performance.

Improving the electrochemical performance of a cathode composite using different sized solid electrolytes for all-solid-state lithium batteries.     

Palladium nanoparticles immobilized on polyethylenimine-derivatized gold surfaces for catalysis of Suzuki reactions: development and application in a lab-on-a-chip context

Gold surface-bound hyperbranched polyethyleneimine (PEI) films decorated with palladium nanoparticles have been used as efficient catalysts for a series of Suzuki reactions. This thin film-format demonstrated good catalytic efficiency (TON up to 3.4 × 10³) and stability. Incorporation into a quartz crystal microbalance (QCM) instrument illustrated the potential for using this approach in lab-on-a-chip-based synthesis applications.

Gold surface-bound hyperbranched polyethyleneimine (PEI) films decorated with palladium nanoparticles have been used as efficient catalysts for a series of Suzuki reactions in a lab-on-a-chip format.

Metal and metal-oxide nanostructures and nanoparticles are often key features in materials used in separation technology, biomedical devices, and catalysis.^1,2 Poor mechanical strength and a tendency to aggregate, thus reducing the surface to volume ratio, both limit their use in real-time applications.^3,4 To overcome these shortcomings, nanoparticles are often dispersed in a matrix, such as sol–gel, biopolymers, and carbon-based materials without disturbing their innate properties at nano-scale level.^5,6 Functionalized polymers have been explored extensively in this regard due to their robustness, low cost, ease of handling, and their amenability for chemical modification.^7–9Recently, we have demonstrated the immobilization of hyperbranched polyethyleneimine (PEI) hydrogels on metallic surfaces for use as antifouling surfaces.¹⁰ Owing to their hydrogelation properties, polymers of this type have proven useful in therapeutic applications, for e.g. bio-mineralization, and the formation of nanostructures.^11,12 PEI is a hyperbranched polymer containing very high densities of primary, secondary and tertiary amines, in a 1 : 2 : 1 ratio, and are capable of coordination with transition metals to form nanostructures.^13,14 Recent reports on amine functionalized polymer-supported heterogeneous catalysts for C–C coupling reactions (Table 1-SI^†) prompted us to deploy PEI as a matrix for synthesizing surface-bound palladium nanoparticles for use as catalysts of C–C coupling reactions. For catalytic applications, a miniaturized microfluidic setup, such as a lab-on-a-chip device, can significantly reduce the consumption of chemicals, catalysts, process time and be beneficial for on-site analysis.^15,16In this study, we demonstrate the use of the PEI surface-supported nanoparticles for as a support for catalysis of the Suzuki reaction the possibility for using of these Pd-nanoparticle immobilized PEI-derivatized gold surfaces for performing Suzuki reactions in a microfluidics device. Catalytic surface fabrication (Scheme 1) was performed using gold sputtered quartz surfaces (Au/quartz) that were functionalized with 11-mercaptoundecanoic acid (MuDA), and then activated and derivatization with PEI. The polymer attachment was carried out at high ionic strength (150 mM NaCl), which has been found to enhance the thickness and growth of PEI brush-like structures.¹⁰ Optimization of the Pd nanoparticle synthesis procedure was performed by varying incubation times and Pd(OAc)₂ concentrations (Table 1-SI^†). A quartz crystal microbalance (QCM) was used to monitor the amount of Pd deposited on the PEI coated Au/quartz resonators.Open in a separate windowScheme 1Palladium immobilization on polyethyleneimine coated Au/quartz surfaces.The energy dispersive X-ray (EDX) spectrum confirmed the presence of Pd in the PEI film with a distinct band at 2.8 keV (Fig. 1A). XPS spectra of the Pd-bound PEI surfaces revealed the presence of the anticipated proleptic elements (C_1s, N_1s, O_1s, Pd_3d and Au_4f) (Fig. 1A-SI^†). Deconvoluted peaks differentiated the amine N of PEI (399.8 eV) from that of the amide N (–*N–C O–, 400.8 eV) (Fig. 1B-SI^†).^17,18 Bands around 335 and 340 eV in the survey spectra correspond to the 3d_5/2 and 3d_3/2 states of the surface bound Pd.¹⁹ The deconvoluted bands at 335.3 and 338.2 demonstrated the presence of Pd(0) and Pd(ii), respectively (Fig. 1B). Importantly, peak integration showed the immobilized Pd to be predominantly in the Pd(0) state, with less than 5% present as Pd(ii).¹⁹Open in a separate windowFig. 1(A) Energy dispersive X-ray (EDX) analysis and (B) X-ray photoelectron spectra (XPS) of the palladium nanoparticle immobilized PEI coated Au/quartz surface.RAIR spectra confirmed the presence of the PEI on the gold surface based on the discernible vibrational bands of the –N–H–, –CH– and –CN– bending modes of the adsorbed PEI film (Fig. 2). Subtle differences can be observed in the RAIR spectra of the PEI before and after Pd immobilization. The band corresponding to –N–H– bending mode has been significantly red shifted emphasizing the interaction of the Pd particles with the amine moieties of the PEI film (Fig. 2, inset). This, together with the XPS data, provides evidence for the reduction of Pd(ii) to Pd(0) and its incorporation as nanoparticles into the PEI brush layer.Open in a separate windowFig. 2RAIR spectra of PEI coated Au/quartz surface before and after Pd immobilization.SEM images (Fig. 3) showed uniform long-range coating of the palladium nanoparticles on the PEI immobilized surface (PEI/Pd). The crystallinity of the Pd coated PEI surface was evaluated with powder diffraction measurements which showed characteristic peaks for Pd(111), Pd(200) and Pd(220) with Miller indices of 40, 47.2 and 68.3° (JCPDS No. 98-004-7386), respectively, again confirming the presence of Pd nanoparticles in the (0) oxidation state (curve a, Fig. 2-SI^†).Open in a separate windowFig. 3Scanning electron micrographs of (A) gold surface, (B) polyethyleneimine (PEI) film and (C) PEI-supported palladium particles fabricated on Au/quartz surfaces.The possibility of using these surfaces for catalysis of the Suzuki reaction was explored using a series of phenylboronic acids and substituted aryl halides (†). The amount of catalytic nanopalladium loaded was determined by QCM. Au/quartz surfaces coated with PEI/Pd were immersed in the reaction mixtures at 55 °C for 12 h (Section 1.7-SI^†). Reactions of aryl halides with a series of arylboronic acids offered the corresponding products in good to excellent yield (†). This negligible effect on Pd catalyst poisoning confirms the nature of the catalytic Pd exists predominantly in the (0) oxidation state.²⁰ No biphenyl product has been observed when the Suzuki reaction was performed in presence of unmodified Au/quartz surface (without PEI and Pd).Suzuki cross-coupling reactions of aryl halides with arylboronic acids using PEI/Pd as catalysts^a

Over expression of brain and acute leukemia,cytoplasmic and ETS-related gene is associated with poor outcome in acute myeloid leukemia

The high expression of brain and acute leukemia, cytoplasmic (BAALC) and ETS-related gene (ERG) has been reported to influence the outcome in acute myeloid leukemia (AML), but due to limited prospective studies, their role as prognostic factors is unclear. At diagnosis, the prognostic value of BAALC and ERG expression with respect to other cytogenetic and molecular markers was analyzed in 149 AML patients. Patients were divided into quartiles which resulted in the formation of four groups (G1–G4) based on expression values of BAALC and ERG and clinical response defined across groups. Groups with similar survival probabilities were merged together and categorized subsequently as high versus low expressers. Patients with high BAALC and ERG expression had significantly lower overall survival (OS; BAALC: p = 0.001 at 5 years 29.4% vs. 69.8%; ERG: p < 0.0001 at 5 years 4% vs. 50.4%) and disease-free survival (BAALC: p = 0.001 at 5 years 19.5% vs. 69.8%; ERG: p < 0.0001 at 5 years 4.2% vs. 47%). Patients were further stratified combining BAALC and ERG expression in an integrative prognostic risk score (IPRS). After a median follow-up of 54 months (95% CI 45–63 months) among survivors, IPRS for high versus low expressers was a significant predictor for OS (BAALC + ERG: 4% vs. 71.6%, p < 0.0001) and DFS (BAALC + ERG: 4.5% vs. 74.1%, p < 0.0001). In a multivariate model, IPRS of BAALC + ERG expression retained prognostic significance for OS (hazard ratio [HR] 2.96, 95%CI 1.91–4.59, p < 0.001) and DFS (HR 3.61, 95%CI 2.26–5.76, p < 0.001).     

Targeting MYC-driven replication stress in medulloblastoma with AZD1775 and gemcitabine

Journal of Neuro-Oncology - MYC-driven medulloblastomas are highly aggressive childhood tumors with dismal outcomes and a lack of new treatment paradigms. We identified that targeting replication...     

A landscape effect in tenosynovial giant-cell tumor from activation of CSF1 expression by a translocation in a minority of tumor cells

Tenosynovial giant-cell tumor (TGCT) and pigmented villonodular synovitis (PVNS) are related conditions with features of both reactive inflammatory disorders and clonal neoplastic proliferations. Chromosomal translocations involving chromosome 1p13 have been reported in both TGCT and PVNS. We confirm that translocations involving 1p13 are present in a majority of cases of TGCT and PVNS and show that CSF1 is the gene at the chromosome 1p13 breakpoint. In some cases of both TGCT and PVNS, CSF1 is fused to COL6A3 (2q35). The CSF1 translocations result in overexpression of CSF1. In cases of TGCT and PVNS carrying this translocation, it is present in a minority of the intratumoral cells, leading to CSF1 expression only in these cells, whereas the majority of cells express CSF1R but not CSF1, suggesting a tumor-landscaping effect with aberrant CSF1 expression in the neoplastic cells, leading to the abnormal accumulation of nonneoplastic cells that form a tumorous mass.     

Mast cell corticotropin-releasing factor subtype 2 suppresses mast cell degranulation and limits the severity of anaphylaxis and stress-induced intestinal permeability

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