Amorphous Thickness-Dependent Strengthening-Softening Transition in Crystalline-Amorphous Nanocomposites

Core-shell crystalline-amorphous nanocomposites, featuring nanograins surrounded by thick amorphous boundaries, are promising nanoarchitectures for achieving exceptional strength through cooperative strengthening effects. However, a comprehensive understanding of the influence of characteristic sizes, particularly the amorphous thickness, on codeformation strengthening is still lacking, limiting the attainment of the strength limit. Here, we employ molecular dynamics simulations to investigate Cu-CuTa crystalline-amorphous nanocomposites with varying grain sizes and amorphous thicknesses. Our findings demonstrate significant strengthening effects in nanocomposites, effectively suppressing the Hall-Petch breakdown observed in traditional amorphous-free nanograined Cu. Intriguingly, we observe a maximum strength followed by a strengthening-softening transition dependent on the amorphous thickness, as exemplified by a representative nanocomposite featuring a 12.5 nm grain size and a critical amorphous thickness of 4 nm. Inspired by observed shifts in atomistic mechanisms, we developed a theoretical model encompassing variations in grain size and amorphous thickness, providing valuable insights into the size-strength relationship for crystalline-amorphous nanocomposites.

A novel retinoic acid receptor-γ agonist antagonizes immune checkpoint resistance in lung cancers by altering the tumor immune microenvironment

All-trans-retinoic acid (ATRA), the retinoic acid receptors (RARs) agonist, regulates cell growth, differentiation, immunity, and survival. We report that ATRA-treatment repressed cancer growth in syngeneic immunocompetent, but not immunodeficient mice. The tumor microenvironment was implicated: CD8+ T cell depletion antagonized ATRA's anti-tumorigenic effects in syngeneic mice. ATRA-treatment with checkpoint blockade did not cooperatively inhibit murine lung cancer growth. To augment ATRA's anti-tumorigenicity without promoting its pro-tumorigenic potential, an RARγ agonist (IRX4647) was used since it regulates T cell biology. Treating with IRX4647 in combination with an immune checkpoint (anti-PD-L1) inhibitor resulted in a statistically significant suppression of syngeneic 344SQ lung cancers in mice-a model known for its resistance to checkpoints and characterized by low basal T cell and PD-L1 expression. This combined treatment notably elevated CD4+ T-cell presence within the tumor microenvironment and increased IL-5 and IL-13 tumor levels, while simultaneously decreasing CD38 in the tumor stroma. IL-5 and/or IL-13 treatments increased CD4+ more than CD8+ T-cells in mice. IRX4647-treatment did not appreciably affect in vitro lung cancer growth, despite RARγ expression. Pharmacokinetic analysis found IRX4647 plasma half-life was 6 h in mice. Yet, RARα antagonist (IRX6696)-treatment with anti-PD-L1 did not repress syngeneic lung cancer growth. Together, these findings provide a rationale for a clinical trial investigating an RARγ agonist to augment check point blockade response in cancers.

Boosting Oxygen-Evolving Activity via Atom-Stepped Interfaces Architected with Kinetic Frustration

A highly active interface is extremely critical for the catalytic efficiency of an electrocatalyst; however, facilely tailoring its atomic packing characteristics remains challenging. Herein, a simple yet effective strategy is reported to obtain copious high-energy atomic steps at the interface via controlling the solidification behavior of glass-forming metallic liquids. By adjusting the chemical composition and cooling rate, highly faceted FeNi₃ nanocrystals are in situ formed in an FeNiB metallic glass (MG) matrix, leading to the creation of order/disorder interfaces. Benefiting from the catalytically active and stable atomic steps at the jagged interfaces, the resultant free-standing FeNi₃ nanocrystal/MG composite exhibits a low oxygen-evolving overpotential of 214 mV at 10 mA cm^-2 , a small Tafel slope of 32.4 mV dec^-1 , and good stability in alkaline media, outperforming most state-of-the-art catalysts. This approach is based on the manipulation of nucleation and crystal growth of the solid-solution nanophases (e.g., FeNi₃ ) in glass-forming liquids, so that the highly stepped interface architecture can be obtained due to the kinetic frustration effect in MGs upon undercooling. It is envisaged that the atomic-level stepped interface engineering via the physical metallurgy method can be easily extended to other MG systems, providing a new and generic paradigm for designing efficient yet cost-effective electrocatalysts.

Infection control measures for public transportation derived from the flow dynamics of obstructed cough jet

During the COVID-19 pandemic, WHO and CDC suggest people stay 1 m and 1.8 m away from others, respectively. Keeping social distance can avoid close contact and mitigate infection spread. Many researchers suspect that suggested distances are not enough because aerosols can spread up to 7-8 m away. Despite the debate on social distance, these social distances rely on unobstructed respiratory activities such as coughing and sneezing. Differently, in this work, we focused on the most common but less studied aerosol spread from an obstructed cough. The flow dynamics of a cough jet blocked by the backrest and gasper jet in a cabin environment was characterized by the particle image velocimetry (PIV) technique. It was proved that the backrest and the gasper jet can prevent the front passenger from droplet spray in public transportation where maintaining social distance was difficult. A model was developed to describe the cough jet trajectory due to the gasper jet, which matched well with PIV results. It was found that buoyancy and inside droplets almost do not affect the short-range cough jet trajectory. Infection control measures were suggested for public transportation, including using backrest/gasper jet, installing localized exhaust, and surface cleaning of the backrest.

Structure-guided bifunctional molecules hit a DEUBAD-lacking hRpn13 species upregulated in multiple myeloma

Proteasome substrate receptor hRpn13 is a promising anti-cancer target. By integrated in silico and biophysical screening, we identified a chemical scaffold that binds hRpn13 with non-covalent interactions that mimic the proteasome and a weak electrophile for Michael addition. hRpn13 Pru domain binds proteasomes and ubiquitin whereas its DEUBAD domain binds deubiquitinating enzyme UCHL5. NMR revealed lead compound XL5 to interdigitate into a hydrophobic pocket created by lateral movement of a Pru β-hairpin with an exposed end for Proteolysis Targeting Chimeras (PROTACs). Implementing XL5-PROTACs as chemical probes identified a DEUBAD-lacking hRpn13 species (hRpn13Pru) present naturally with cell type-dependent abundance. XL5-PROTACs preferentially target hRpn13Pru, causing its ubiquitination. Gene-editing and rescue experiments established hRpn13 requirement for XL5-PROTAC-triggered apoptosis. These data establish hRpn13 as an anti-cancer target for multiple myeloma and introduce an hRpn13-targeting scaffold that can be optimized for preclinical trials against hRpn13Pru-producing cancer types.

Hopes and Wishes of Clients with Mentally Illness in Hong Kong

Recovery is a progressive process involving support to people with mental illness to take control of their life through the enhancement of motivation, self-drive, and responsibility. Drawing on qualitative interviews with 61 patients with mental illness aged between 40 and 75 in the community or residential settings, this study examined the wishes and hopes of clients who were in recovery. Participants described wishes and hopes for autonomy and independence in finances, accommodation, and health; stable housing or accommodation; meaningful occupation or employment; 'giving back' to society by serving others; intimate relationships; and gaining back 'lost time.' Wishes and hopes were motivating factors contributing to physical, mental, and social health over time, motivating clients with mental illness to live happily. To foster recovery, mental health practitioners should consider the identification and fulfilment of wishes and hopes in health and social care programs for this unique client group.

Comparative microsomal proteomics of a model lung cancer cell line NCI-H23 reveals distinct differences between molecular profiles of 3D and 2D cultured cells

Lung cancer is the leading cause of cancer-related deaths in the USA and worldwide. Yet, about 95% of new drug candidates validated in preclinical phase eventually fail in clinical trials. Such a high attrition rate is attributed mostly to the inability of conventional two-dimensionally (2D) cultured cancer cells to mimic native three-dimensional (3D) growth of malignant cells in human tumors. To ascertain phenotypical differences between these two distinct culture conditions, we carried out a comparative proteomic analysis of a membrane fraction obtained from 3D- and 2D-cultured NSCLC model cell line NCI-H23. This analysis revealed a map of 1,166 (24%) protein species regulated in culture dependent manner, including differential regulation of a subset of cell surface-based CD molecules. We confirmed exclusive expression of CD99, CD146 and CD239 in 3D culture. Furthermore, label-free quantitation, targeting KRas proteoform-specific peptides, revealed upregulation of both wild type and monoallelic KRas4BG12C mutant at the surface of 3D cultured cells. In order to reduce the high attrition rate of new drug candidates, the results of this study strongly suggests exploiting base-line molecular profiling of a large number of patient-derived NSCLC cell lines grown in 2D and 3D culture, prior to actual drug candidate testing.

The experience of growing old in chronic mental health patients

Objectives: Research evidence has demonstrated disparities and barriers associated with mental illness, which creates challenges for individuals with mental illness to maintain physical, mental, and social health as they age. The aim of this study was to examine the meaning of aging from the perspective of individuals with mental illness and explore their motivations and challenges to adopting healthy aging lifestyles and practices.Method: Using a qualitative narrative inquiry approach, interviews were conducted with 61 aging patients with mental illness aged 40 and older in community and institutional settings in Hong Kong.Results: Participants discussed the meaning of healthy aging in terms of meaningful occupation and use of time, and independence and autonomy. Motivating factors included a desire to avoid 'burdening' other people, to 'give back' to society, and gain back 'lost time'. These were connected to strategies for healthy aging, including social relationships and activities, spirituality, and healthy lifestyles. Challenges to adopting healthy aging practices included physical health difficulties and medication side effects, lack of purpose and boredom associated with daily routines and use of time, and conflicts and loss affecting family and peer relationships.Conclusion: Social and health services should be tailored to support aging individuals with mental illness and their families, addressing motivations and barriers to adopting healthy lifestyles. Promoting healthy aging practices to enable individuals with mental illness to achieve healthy aging is important for preparing for the aging of this population.

0882 Local Deformation Analysis of Lateral Cephalogram for Childhood OSA Classification

Introduction

Craniofacial profile is one of the anatomical causes of obstructive sleep apnea (OSA). Cephalometry provides information on patients’ skeletal structures and soft tissues. Traditional cephalometric analysis focuses on linear distances, angles, ratios and area of specific variables. Its classification power is often disappointed. In this study, a novel approach to cephalometric analysis using local deformation information was carried out to assess its efficacy in OSA classification.

Methods

This study was a retrospective analysis based on 60 case-control pairs who were Chinese children recruited for sleep studies in the Prince of Wales Hospital, with accessible lateral cephalometry and polysomnography (PSG) data. Local deformation technique was adopted to derive 1215 deformations from 15 manual landmarking on each cephalogram. In addition, three linear distances (hyoid bone to mandibular plane, hyoid bone to posterior pharyngeal wall, and minimal distance between tongue base and posterior pharyngeal wall) were measured from each cephalogram. A total of 1218 information features were obtained per subject. Classification models were built with an equal ratio between OSA and non-OSA groups (defined by OAHI≥1 and OAHI<1 respectively). Forty pairs were used as training data and twenty pairs were used as testing data.

Results

Three model settings which used all 1218 cephalometric features, 800 features, and 500 features were tested. The accuracy for the three settings were 67.5% (sensitivity: 70%, specificity: 65%), 87.5% (sensitivity: 90%, specificity: 85%), and 92.5% (sensitivity: 95%, specificity: 90%) respectively. Apart from the three distances, the 500 topmost discriminative features were predominantly landmarks around the nasal cavity.

Conclusion

A new approach to cephalometric analysis using local deformation information can provide additional details on each cephalogram, hence, achieving better classification. The classification models using 500 features yielded the highest accuracy among the three settings. This setting could benefit most from the comprehensive comparison while avoiding overfitting.

Support

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224 Malignancy associated pericardial effusion- do we need to drain them all?

On Behalf

Cardiac Team, Department of Medicine, Queen Elizabeth Hospital

Background

Management of significant pericardial effusion in cancer patients is controversial. These patients have poor prognosis, and avoiding unnecessary intervention is important. Close monitoring of symptoms and echocardiogram is often a reasonable option, but inherits risk of cardiac tamponade. Whether pericardial drainage by means of percutaneous pericardiocentesis or surgical pericardiotomy could prevent future deterioration or affect survival is unknown.

Purpose

To evaluate the benefit of elective pericardial drainage in malignancy associated pericardial effusion without echocardiographic or clinical evidence of tamponade effect.

Methods

From 1st Jul 2014 to 31st Dec 2017, all patients with new onset malignancy-associated pericardial effusion with size more than 1cm were retrospectively analyzed. Patients with clinical or echocardiographic evidence of cardiac tamponade were excluded. We compared pericardial drainage versus monitoring for short-term (30-day), mid-term (90-day) and long term (1 year) survival without need for drainage.

Results

101 patients were retrospectively analyzed. 40 (39.6%) patients underwent drainage. Overall median survival free from drainage was 4 months. There were no significant difference in short-term (30-day), mid-term (90-day) and long term (1-year) survival free from drainage or mortality between treatment and monitoring group. Size of pericardial effusion did not predict mortality or future need of drainage. Chemotherapy was associated with improved 30-day mortality (RR 0.53 CI 0.32-0.87 p = 0.025) but not survival free from drainage or longer term mortality.

Conclusion

Close monitoring could be a feasible strategy in cancer patients with significant pericardial effusion without tamponade effect.

Baseline characteristics Factor Drainage (n = 40) monitoring (n = 61) p-value method of drainage pericardiocentesis alone 17 NA pericardiotomy alone 13 both 10 Male 19 (47.5%) 27 (44.3%) 0.749 mean size (cm) 1.93 2.77 <0.001 mean age 60.9 63.1 0.357 on chemotherapy 27 (67.5%) 38 (62.3%) 0.593

Abstract 224 Figure. Survival free from drainage

Flexible Honeycombed Nanoporous/Glassy Hybrid for Efficient Electrocatalytic Hydrogen Generation

Hydrogen evolution reaction (HER) in alkaline media urgently requires electrocatalysts concurrently possessing excellent activity, flexible free-standing capability, and low cost. A honeycombed nanoporous/glassy sandwich structure fabricated through dealloying metallic glass (MG) is reported. This free-standing hybrid shows outstanding HER performance with a very small overpotential of 37 mV at 10 mA cm^-2 and a low Tafel slope of 30 mV dec^-1 in alkaline media, outperforming commercial Pt/C. By alloying 3 at% Pt into the MG precursor, a honeycombed Pt₇₅ Ni₂₅ solid solution nanoporous structure, with fertile active sites and large contact areas for efficient HER, is created on the dealloyed MG surface. Meanwhile, the surface compressive lattice-strain effect is also introduced by substituting the Pt lattice sites with the smaller Ni atoms, which can effectively reduce the hydrogen adsorption energy and thus improve the hydrogen evolution. Moreover, the outstanding stability and flexibility stemming from the ductile MG matrix also make the hybrid suitable for practical electrode application. This work not only offers a reliable strategy to develop cost-effective and flexible multicomponent catalysts with low Pt usage for efficient HER, but also sheds light on understanding the alloying effects of the catalytic process.

Cosmological Constraints from Multiple Probes in the Dark Energy Survey

The combination of multiple observational probes has long been advocated as a powerful technique to constrain cosmological parameters, in particular dark energy. The Dark Energy Survey has measured 207 spectroscopically confirmed type Ia supernova light curves, the baryon acoustic oscillation feature, weak gravitational lensing, and galaxy clustering. Here we present combined results from these probes, deriving constraints on the equation of state, w, of dark energy and its energy density in the Universe. Independently of other experiments, such as those that measure the cosmic microwave background, the probes from this single photometric survey rule out a Universe with no dark energy, finding w=-0.80_{-0.11}^{+0.09}. The geometry is shown to be consistent with a spatially flat Universe, and we obtain a constraint on the baryon density of Ω_{b}=0.069_{-0.012}^{+0.009} that is independent of early Universe measurements. These results demonstrate the potential power of large multiprobe photometric surveys and pave the way for order of magnitude advances in our constraints on properties of dark energy and cosmology over the next decade.

Early Diagnosis of Spastic Cerebral Palsy in Infants with Periventricular White Matter Injury Using Diffusion Tensor Imaging

BACKGROUND AND PURPOSE

Periventricular white matter injury is the common cause of spastic cerebral palsy. However, the early diagnosis of spastic cerebral palsy still remains a challenge. Our aim was to investigate whether infants with periventricular white matter injury with bilateral spastic cerebral palsy have unique lesions different from those in infants without cerebral palsy and to evaluate the efficiency of DTI in the early diagnosis of spastic cerebral palsy.

MATERIALS AND METHODS

Infants with periventricular white matter injury and controls underwent MR imaging at 6-18 months of age. Fractional anisotropy was calculated from DTI. Cerebral palsy was diagnosed by 24-30 months of age. Subjects were divided into 3 groups: infants with periventricular white matter injury with bilateral spastic cerebral palsy, infants with periventricular white matter injury without cerebral palsy, and controls. Tract-Based Spatial Statistics and Automated Fiber Quantification were used to investigate intergroup differences. Receiver operating characteristic curves were used to assess the diagnostic accuracy of spastic cerebral palsy. Correlations between motor function scores and fractional anisotropy were evaluated along white matter tracts.

RESULTS

There were 20, 19, and 33 subjects in periventricular white matter injury with spastic cerebral palsy, periventricular white matter injury without cerebral palsy, and control groups, respectively. Decreased fractional anisotropy in the corticospinal tract was only observed in infants with periventricular white matter injury with spastic cerebral palsy, whereas decreased fractional anisotropy in the posterior thalamic radiation and genu and splenium of the corpus callosum was seen in both periventricular white matter injury subgroups. Fractional anisotropy in the corticospinal tract at the internal capsule level was effective in differentiating infants with periventricular white matter injury with spastic cerebral palsy from those without cerebral palsy by a threshold of 0.53, and it had strong correlations with motor function scores.

CONCLUSIONS

Corticospinal tract lesions play a crucial role in motor impairment related to spastic cerebral palsy in infants with periventricular white matter injury. Fractional anisotropy in the corticospinal tract at the internal capsule level could aid in the early diagnosis of spastic cerebral palsy with high diagnostic accuracy.

Evolutionarily distinct amphibians are disproportionately lost from human-modified ecosystems

Humans continue to alter terrestrial ecosystems, but our understanding of how biodiversity responds is still limited. Anthropogenic habitat conversion has been associated with the loss of evolutionarily distinct bird species at local scales, but whether this evolutionary pattern holds across other clades is unknown. We collate a global dataset on amphibian assemblages in intact forests and nearby human-modified sites to assess whether evolutionary history influences susceptibility to land conversion. We found that evolutionarily distinct amphibian species are disproportionately lost when forested habitats are converted to alternative land-uses. We tested the hypothesis that grassland-associated amphibian lineages have both higher diversification and are pre-adapted to human landscapes, but found only weak evidence supporting this. The loss of evolutionarily distinct amphibians with land conversion suggests that preserving remnant forests will be vital if we aim to preserve the amphibian tree of life in the face of mounting anthropogenic pressures.

Female Trauma Patients in the Emergency Department: Should their Injury Prevention Programme be Different?

Background

(1) To compare the characteristics of female and male trauma patients seen in the Emergency Department (ED) and (2) to determine if injury prevention programmes for women should be different.

Methods

A prospective survey was conducted for 11544 trauma patients, aged 15 years and above, who presented to the ED of an urban public hospital in Singapore over 6 months. The following data were collected: demography, place, type and mechanism of injury and subsequent disposition from the ED.

Results

Almost half (49.5%) the injuries sustained by females occurred at home, with low falls of less than 2 metres being the most common mechanism of injury (52.7%). Victims of domestic violence were predominantly female at p<0.0001.

Conclusion

Injury prevention programs for women should focus on home safety and low falls. Special assistance programs for the victims of domestic violence should be available in the ED as the latter may be their only access to safety.

Fe-based metallic glass catalyst with nanoporous surface for azo dye degradation

In this work, porous structures were introduced to the surface of Fe-based metallic glass ribbons for the first time by chemical treatment in order to increase the catalytic activity in the degradation of azo dyes. The results show that etching treatment in an HF solution with a volume concentration of 20% for 40 min leads to a porous structure on the FeSiBNb metallic glass with a dramatic increase in the specific surface area by 25 times. The much higher specific surface area of the porous ribbons greatly improves the catalytic activity in the degradation of Direct Blue 15 when compared with as-spun metallic ribbons.

Discovering Targets of Non-enzymatic Acylation by Thioester Reactivity Profiling

Non-enzymatic protein modification driven by thioester reactivity is thought to play a major role in the establishment of cellular lysine acylation. However, the specific protein targets of this process are largely unknown. Here we report an experimental strategy to investigate non-enzymatic acylation in cells. Specifically, we develop a chemoproteomic method that separates thioester reactivity from enzymatic utilization, allowing selective enrichment of non-enzymatic acylation targets. Applying this method to cancer cell lines identifies numerous candidate targets of non-enzymatic acylation, including several enzymes in lower glycolysis. Functional studies highlight malonyl-CoA as a reactive thioester metabolite that can modify and inhibit glycolytic enzyme activity. Finally, we show that synthetic thioesters can be used as novel reagents to probe non-enzymatic acylation in living cells. Our studies provide new insights into the targets and drivers of non-enzymatic acylation, and demonstrate the utility of reactivity-based methods to experimentally investigate this phenomenon in biology and disease.

Comparative proteomics of a model MCF10A-KRasG12V cell line reveals a distinct molecular signature of the KRasG12V cell surface

Oncogenic Ras mutants play a major role in the etiology of most aggressive and deadly carcinomas in humans. In spite of continuous efforts, effective pharmacological treatments targeting oncogenic Ras isoforms have not been developed. Cell-surface proteins represent top therapeutic targets primarily due to their accessibility and susceptibility to different modes of cancer therapy. To expand the treatment options of cancers driven by oncogenic Ras, new targets need to be identified and characterized at the surface of cancer cells expressing oncogenic Ras mutants. Here, we describe a mass spectrometry–based method for molecular profiling of the cell surface using KRas^G12V transfected MCF10A (MCF10A-KRas^G12V) as a model cell line of constitutively activated KRas and native MCF10A cells transduced with an empty vector (EV) as control. An extensive molecular map of the KRas surface was achieved by applying, in parallel, targeted hydrazide-based cell-surface capturing technology and global shotgun membrane proteomics to identify the proteins on the KRas^G12V surface. This method allowed for integrated proteomic analysis that identified more than 500 cell-surface proteins found unique or upregulated on the surface of MCF10A-KRas^G12V cells. Multistep bioinformatic processing was employed to elucidate and prioritize targets for cross-validation. Scanning electron microscopy and phenotypic cancer cell assays revealed changes at the cell surface consistent with malignant epithelial-to-mesenchymal transformation secondary to KRas^G12V activation. Taken together, this dataset significantly expands the map of the KRas^G12V surface and uncovers potential targets involved primarily in cell motility, cellular protrusion formation, and metastasis.

Flaw-induced plastic-flow dynamics in bulk metallic glasses under tension

Inheriting amorphous atomic structures without crystalline lattices, bulk metallic glasses (BMGs) are known to have superior mechanical properties, such as high strength approaching the ideal value, but are susceptible to catastrophic failures. Understanding the plastic-flow dynamics of BMGs is important for achieving stable plastic flow in order to avoid catastrophic failures, especially under tension, where almost all BMGs demonstrate limited plastic flow with catastrophic failure. Previous findings have shown that the plastic flow of BMGs displays critical dynamics under compression tests, however, the plastic-flow dynamics under tension are still unknown. Here we report that power-law critical dynamics can also be achieved in the plastic flow of tensile BMGs by introducing flaws. Differing from the plastic flow under compression, the flaw-induced plastic flow under tension shows an upward trend in the amplitudes of the load drops with time, resulting in a stable plastic-flow stage with a power-law distribution of the load drop. We found that the flaw-induced plastic flow resulted from the stress gradients around the notch roots, and the stable plastic-flow stage increased with the increase of the stress concentration factor ahead of the notch root. The findings are potentially useful for predicting and avoiding the catastrophic failures in tensile BMGs by tailoring the complex stress fields in practical structural-applications.

Origin of Shear Stability and Compressive Ductility Enhancement of Metallic Glasses by Metal Coating

Metallic glasses (MGs) are notorious for the poor macroscopic ductility and to overcome the weakness various intrinsic and extrinsic strategies have been proposed in past decades. Among them, the metal coating is regarded as a flexible and facile approach, yet the physical origin is poorly understood due to the complex nature of shear banding process. Here, we studied the origin of ductile enhancement in the Cu-coating both experimentally and theoretically. By examining serrated shear events and their stability of MGs, we revealed that the thin coating layer plays a key role in stopping the final catastrophic failure of MGs by slowing down shear band dynamics and thus retarding its attainment to a critical instable state. The mechanical analysis on interplay between the coating layer and shear banding process showed the enhanced shear stability mainly comes from the lateral tension of coating layer induced by the surface shear step and the bonding between the coating layer and MGs rather than the layer thickness is found to play a key role in contributing to the shear stability.

Loading-rate-independent delay of catastrophic avalanches in a bulk metallic glass

The plastic flow of bulk metallic glasses (BMGs) is characterized by intermittent bursts of avalanches, and this trend results in disastrous failures of BMGs. In the present work, a double-side-notched BMG specimen is designed, which exhibits chaotic plastic flows consisting of several catastrophic avalanches under the applied loading. The disastrous shear avalanches have, then, been delayed by forming a stable plastic-flow stage in the specimens with tailored distances between the bottoms of the notches, where the distribution of a complex stress field is acquired. Differing from the conventional compressive testing results, such a delaying process is independent of loading rate. The statistical analysis shows that in the specimens with delayed catastrophic failures, the plastic flow can evolve to a critical dynamics, making the catastrophic failure more predictable than the ones with chaotic plastic flows. The findings are of significance in understanding the plastic-flow mechanisms in BMGs and controlling the avalanches in relating solids.

Outcome of elderly patients who receive intensive care at a regional hospital in Hong Kong

OBJECTIVE

To evaluate the clinical outcome (180-day mortality) of very elderly critically ill patients (age ≥80 years) and compare with those aged 60 to 79 years.

DESIGN

Historical cohort study.

SETTING

Regional hospital, Hong Kong.

PATIENTS

Patients aged ≥60 years admitted between 1 January 2009 and 31 December 2013 to the Intensive Care Unit of the hospital.

RESULTS

Over 5 years, 4226 patients aged ≥60 years were admitted (55.5% total intensive care unit admissions), of whom 32.8% were aged ≥80 years. The proportion of patients aged ≥80 years increased over 5 years. As expected, those aged ≥80 years carried more significant co-morbidities and a higher disease severity compared with those aged 60 to 79 years. They required more mechanical ventilatory support, were less likely to receive renal replacement therapy, and had a higher intensive care unit/hospital/180-day mortality compared with those aged 60 to 79 years. Nonetheless, 71.8% were discharged home and 62.2% survived >180 days following intensive care unit admission. Cox regression analysis revealed that Acute Physiology and Chronic Health Evaluation IV-minus-Age score, emergency admission, intensive care unit admission due to cardiovascular problem, neurosurgical cases, presence of significant co-morbidities (diabetes mellitus, metastatic carcinoma, leukaemia, or myeloma), and requirement for mechanical ventilation independently predicted 180-day mortality.

CONCLUSIONS

The proportion of critically ill patients aged ≥80 years increased over a 5-year period. Despite having more significant co-morbidities, greater disease severity, and higher intensive care unit/hospital/180-day mortality rate compared with those aged 60 to 79 years, 71.8% of those ≥80 years could be discharged home and 62.2% survived >180 days following intensive care unit admission. Disease severity, presence of co-morbidities, requirement for mechanical ventilation, emergency cases, and admission diagnosis independently predicted 180-day mortality.

Abstract 1996: Surface proteomics of KRASG12V transfected MCF10A cells reveals molecular phenotype of a model cell line expressing oncogenic KRAS

Oncogenic RAS mutations play a major role in the most aggressive epithelial cancers in humans (i.e., pancreatic and lung cancer). Mutated K-Ras protein is found in ∼ 95% of pancreatic and ∼ 40% of lung and/or colon carcinomas, characterized by metastasis and a low average survival time after diagnosis. Plasma membrane proteins are top therapeutic targets due to their accessibility at the surface of cancer cells. In order to expand the treatment options of cancers driven by oncogenic RAS, new cell surface targets need to be identified and characterized. Here, we describe mass spectrometry based phenotyping of the KRASG12V cell surface using MCF10A-KRASG12V as a cell line model of constitutively activated KRAS. Extensive view of the MCF10A-KRASG12V surface proteome was achieved by applying concurrently targeted hydrazide-based cell surface capturing (CSC) technology and global shotgun membrane (GSM) proteomics. Our combined approach revealed 666 plasma membrane proteins unique to the MCF10A-KRASG12V cell surface. Of these, 104 were cell surface glycoproteins identified by CSC technology while 562 cell surface proteins were identified using GSM proteomics. K-Ras was exclusively identified by GSM proteomics in the membrane fraction of MCF10A-KRASG12V cells and subsequently cross-validated by Western blot (WB) analysis. Subtractive proteomics, spectral counting-based based quantitation of changes in protein abundances, and Ingenuity Pathway Analysis showed that this investigation reliably revealed expected K-Ras induced changes at the surface of MCF10A-KRASG12V cells as well as alterations in cell surface protein expression with very little prior information. This analysis uncovered a subset of eight proteins identified exclusively at the cell surface of MCF10A-KRASG12V cells by both CSC and GSM technologies. Of these, two were further cross-validated using immunofluorescence and WB analysis. Furthermore, scanning electron microscopy and functional cell assays showed extensive changes at the KRASG12V cell surface consistent with widespread epithelial to mesenchymal transformation (EMT). Taken together, this dataset greatly extends the known molecular phenotype of the MCF10A-KRASG12V cell surface and reveals the important role of EMT in the pathophysiology of the KRASG12V driven malignant transformation in MCF10A- KRASG12V model cell line.

Citation Format: Xiaoying Ye, King C. Chan, Thomas J. Turbyville, Rachel Bagni, Alexander Martinko, Juan Diaz, Jim Wells, Franck McCormick, Gordon Whiteley, Josip Blonder. Surface proteomics of KRASG12V transfected MCF10A cells reveals molecular phenotype of a model cell line expressing oncogenic KRAS. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1996. doi:10.1158/1538-7445.AM2015-1996

Healthcare provider targeted interventions to improve medication adherence: systematic review and meta-analysis

OBJECTIVE

This systematic review applied meta-analytic procedures to synthesise medication adherence (also termed compliance) interventions that focus on healthcare providers.

DESIGN

Comprehensive searching located studies testing interventions that targeted healthcare providers and reported patient medication adherence behaviour outcomes. Search strategies included 13 computerised databases, hand searches of 57 journals, and both author and ancestry searches. Study sample, intervention characteristics, design and outcomes were reliably coded. Standardised mean difference effect sizes were calculated using random-effects models. Heterogeneity was examined with Q and I(2) statistics. Exploratory moderator analyses used meta-analytic analogue of ANOVA and regression.

RESULTS

Codable data were extracted from 218 reports of 151,182 subjects. The mean difference effect size was 0.233. Effect sizes for individual interventions varied from 0.088 to 0.301. Interventions were more effective when they included multiple strategies. Risk of bias assessment documented larger effect sizes in studies with larger samples, studies that used true control groups (as compared with attention control), and studies without intention-to-treat analyses.

CONCLUSION

Overall, this meta-analysis documented that interventions targeted to healthcare providers significantly improved patient medication adherence. The modest overall effect size suggests that interventions addressing multiple levels of influence on medication adherence may be necessary to achieve therapeutic outcomes.

Anti-angiogenic pathway associations of the 3p21.3 mapped BLU gene in nasopharyngeal carcinoma

Zinc-finger, MYND-type containing 10 (ZMYND10), or more commonly called BLU, expression is frequently downregulated in nasopharyngeal carcinoma (NPC) and many other tumors due to promoter hypermethylation. Functional evidence shows that the BLU gene inhibits tumor growth in animal assays, but the detailed molecular mechanism responsible for this is still not well understood. In current studies, we find that 93.5% of early-stage primary NPC tumors show downregulated BLU expression. Using a PCR array, overexpression of the BLU gene was correlated to the angiogenesis network in NPC cells. Moreover, expression changes of the MMP family, VEGF and TSP1, were often detected in different stages of NPC, suggesting the possibility that BLU may be directly involved in the microenvironment and anti-angiogenic activity in NPC development. Compared with vector-alone control cells, BLU stable transfectants, derived from poorly-differentiated NPC HONE1 cells, suppress VEGF165, VEGF189 and TSP1 expression at both the RNA and protein levels, and significantly reduce the secreted VEGF protein in these cells, reflecting an unknown regulatory mechanism mediated by the BLU gene in NPC. Cells expressing BLU inhibited cellular invasion, migration and tube formation. These in vitro results were further confirmed by in vivo tumor suppression and a matrigel plug angiogenesis assay in nude mice. Tube-forming ability was clearly inhibited, when the BLU gene is expressed in these cells. Up to 70-90% of injected tumor cells expressing increased exogenous BLU underwent cell death in animal assays. Overexpressed BLU only inhibited VEGF165 expression in differentiated squamous NPC HK1 cells, but also showed an anti-angiogenic effect in the animal assay, revealing a complicated mechanism regulating angiogenesis and the microenvironment in different NPC cell lines. Results of these studies indicate that alteration of BLU gene expression influences anti-angiogenesis pathways and is important for the development of NPC.

Mass spectrometry in cancer biomarker research: a case for immunodepletion of abundant blood-derived proteins from clinical tissue specimens

The discovery of clinically relevant cancer biomarkers using mass spectrometry (MS)-based proteomics has proven difficult, primarily because of the enormous dynamic range of blood-derived protein concentrations and the fact that the 22 most abundant blood-derived proteins constitute approximately 99% of the total plasma protein mass. Immunodepletion of clinical body fluid specimens (e.g., serum/plasma) for the removal of highly abundant proteins is a reasonable and reproducible solution. Often overlooked, clinical tissue specimens also contain a formidable amount of highly abundant blood-derived proteins present in tissue-embedded networks of blood/lymph capillaries and interstitial fluid. Hence, the dynamic range impediment to biomarker discovery remains a formidable obstacle, regardless of clinical sample type (solid tissue and/or body fluid). Thus, we optimized and applied simultaneous immunodepletion of blood-derived proteins from solid tissue and peripheral blood, using clear cell renal cell carcinoma as a model disease. Integrative analysis of data from this approach and genomic data obtained from the same type of tumor revealed concordant key pathways and protein targets germane to clear cell renal cell carcinoma. This includes the activation of the lipogenic pathway characterized by increased expression of adipophilin (PLIN2) along with 'cadherin switching', a phenomenon indicative of transcriptional reprogramming linked to renal epithelial dedifferentiation. We also applied immunodepletion of abundant blood-derived proteins to various tissue types (e.g., adipose tissue and breast tissue) showing unambiguously that the removal of abundant blood-derived proteins represents a powerful tool for the reproducible profiling of tissue proteomes. Herein, we show that the removal of abundant blood-derived proteins from solid tissue specimens is of equal importance to depletion of body fluids and recommend its routine use in the context of biological discovery and/or cancer biomarker research. Finally, this perspective presents the background, rationale and strategy for using tissue-directed high-resolution/accuracy MS-based shotgun proteomics to detect genuine tumor proteins in the peripheral blood of a patient diagnosed with nonmetastatic cancer, employing concurrent liquid chromatography-MS analysis of immunodepleted clinical tissue and blood specimens.

Osteopenic consequences of botulinum toxin injections in the masticatory muscles: a pilot study

Patients with temporomandibular muscle and joint disorder (TMJD) increasingly seek and receive treatment for their pain with botulinum toxin (BoNTA; botulinum toxin A). Used intramuscularly in therapeutic doses, it produces localised paresis. Such paresis creates risk of reduced bone mineral density, or 'disuse osteopenia'. Animal studies have frequently used BoNTA as a model of paralysis to induce bone changes within short periods. Osteopenic effects can be enduring in animals but have yet to be studied in humans. This is the first study in humans to examine bone-related consequences of BoNTA injections in the masticatory muscles, comparing oral and maxillofacial radiologists' ratings of trabecular bone patterns in the condyles of patients with TMJD exposed to multiple masticatory muscle injection sessions with BoNTA to a sample of patients with TMJD unexposed to masticatory muscle injections with BoNTA. Cone-beam computed tomography (CBCT)-derived images of bilateral condyles were evaluated in seven patients with TMJD receiving 2+ recent BoNTA treatment sessions for facial pain and nine demographically matched patients with TMJD not receiving BoNTA treatment. Two oral and maxillofacial radiologists evaluated CBCT images for evidence of trabecular changes consistent with osteopenia. Both evaluators noted decreased density in all participants exposed to BoNTA and in none of the unexposed participants (P < 0.001). No other abnormalities associated with reduced loading were detected. These findings need replication in a larger sample and over a longer time period, to ensure safety of patients with TMJD receiving multiple BoNTA injections for their pain.

SAA1 polymorphisms are associated with variation in antiangiogenic and tumor-suppressive activities in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a cancer that occurs in high frequency in Southern China. A previous functional complementation approach and the subsequent cDNA microarray analysis have identified that serum amyloid A1 (SAA1) is an NPC candidate tumor suppressor gene. SAA1 belongs to a family of acute-phase proteins that are encoded by five polymorphic coding alleles. The SAA1 genotyping results showed that only three SAA1 isoforms (SAA1.1, 1.3 and 1.5) were observed in both Hong Kong NPC patients and healthy individuals. This study aims to determine the functional role of SAA1 polymorphisms in tumor progression and to investigate the relationship between SAA1 polymorphisms and NPC risk. Indeed, we have shown that restoration of SAA1.1 and 1.3 in the SAA1-deficient NPC cell lines could suppress tumor formation and angiogenesis in vitro and in vivo. The secreted SAA1.1 and SAA1.3 proteins can block cell adhesion and induce apoptosis in the vascular endothelial cells. In contrast, the SAA1.5 cannot induce apoptosis or inhibit angiogenesis because of its weaker binding affinity to αVβ3 integrin. This can explain why SAA1.5 has no tumor-suppressive effects. Furthermore, the NPC tumors with this particular SAA1.5/1.5 genotype showed higher levels of SAA1 gene expression, and SAA1.1 and 1.3 alleles were preferentially inactivated in tumor tissues that were examined. These findings further strengthen the conclusion for the defective function of SAA1.5 in suppression of tumor formation and angiogenesis. Interestingly, the frequency of the SAA1.5/1.5 genotype in NPC patients was ~2-fold higher than in the healthy individuals (P=0.00128, odds ratio=2.28), which indicates that this SAA1 genotype is significantly associated with a higher NPC risk. Collectively, this homozygous SAA1.5/1.5 genotype appears to be a recessive susceptibility gene, which has lost the antiangiogenic function, whereas SAA1.1 and SAA1.3 are the dominant alleles of the tumor suppressor phenotype.

Preparation of the low molecular weight serum proteome for mass spectrometry analysis

The discovery of viable biomarkers or indicators of disease states is complicated by the inherent complexity of the chosen biological specimen. Every sample, whether it is serum, plasma, urine, tissue, cells, or a host of others, contains thousands of large and small components, each interacting in multiple ways. The need to concentrate on a group of these components to narrow the focus on a potential biomarker candidate becomes, out of necessity, a priority, especially in the search for immune-related low molecular weight serum biomarkers. One such method in the field of proteomics is to divide the sample proteome into groups based on the size of the protein, analyze each group, and mine the data for statistically significant items. This chapter details a portion of this method, concentrating on a method for fractionating and analyzing the low molecular weight proteome of human serum.

Intraosseous mucoepidermoid carcinoma: a review of the diagnostic imaging features of four jaw cases

The purpose of this case series is to present the common features of intraosseous mucoepidermoid carcinoma (IMC) of the jaws in plain film and CT imaging. Two oral and maxillofacial radiologists reviewed and characterized the common features of four biopsy-proven cases of IMC in the jaws in plain film and CT imaging obtained from the files of the Department of Oral Radiology, Faculty of Dentistry, University of Toronto, Toronto, Canada. The common features are a well-defined sclerotic periphery, the presence of internal amorphous sclerotic bone and numerous small loculations, lack of septae bordering many of the loculations, and expansion and perforation of the outer cortical plate with extension into surrounding soft tissue. Other characteristics include tooth displacement and root resorption. The four cases of IMC reviewed have common imaging characteristics. All cases share some diagnostic imaging features with other multilocular-appearing entities of the jaws. However, the presence of amorphous sclerotic bone and malignant characteristics can be useful in the differential diagnosis.

Application of endotoxin and cytokine adsorption haemofilter in septic acute kidney injury due to Gram-negative bacterial infection

OBJECTIVE

Endotoxins and cytokines play an important role in the pathogenesis of multi-organ failure and mortality in patients suffering from severe Gram-negative bacterial infection. The aim of this study was to determine whether in patients with such infections, use of a haemofilter with enhanced endotoxin haemoadsorption and cytokine removal properties helps to overcome organ dysfunction.

DESIGN

Prospective case series study with historical controls.

SETTING

A regional hospital in Hong Kong.

PATIENTS

From October 2011 to June 2012, patients with sepsis-induced acute kidney injury due to Gram-negative bacteria were recruited. Continuous venovenous haemofiltration using oXiris haemofilter was performed. The patients' APACHE (Acute Physiology And Chronic Health Evaluation) II and inclusion criteria matched those of a series of selected historical controls who had been treated with continuous venovenous haemofiltration using polysulfone-based haemofilter from 2009 to 2011. The percentage reduction in the Sequential Organ Failure Assessment score by 24 and 48 hours, the percentage reduction of noradrenaline equivalent usage by 48 hours, as well as intensive care unit and hospital mortality in the two groups were compared.

RESULTS

Pre-treatment biochemical parameters and vasopressor use in the six patients undergoing the intervention and the 24 historical controls were similar. The mean circuit life of oXiris was about 61 hours. The Sequential Organ Failure Assessment score was significantly reduced by 37% at 48 hours post-initiation of oXiris-continuous venovenous haemofiltration versus an increment of 3% in the historical controls. No significant side-effect was detected. Mortality was similar in the two groups.

CONCLUSION

The haemofilter membrane with enhanced endotoxin adsorption and cytokine removal capacity was a safe alternative to traditional polysulfone-based continuous venovenous haemofiltration and expedited improvement in organ dysfunction.

Fractionation of peptides by strong cation-exchange liquid chromatography

Chromatography in all its formats plays an important role in proteomics research. The search for protein biomarkers for different diseases has been an active area of research. The dynamic concentration range and the large number of proteins in a proteome require the development of multidimensional separation strategies to allow for the identification of the largest number of proteins. Strong cation-exchange chromatography (SCX) has been used extensively for the fractionation of proteins and peptides. This chapter provides a detailed description for the SCX fractionation of complex proteome samples.

Post-digestion ¹⁸O exchange/labeling for quantitative shotgun proteomics of membrane proteins

The role of membrane proteins is critical for regulation of physiologic and pathologic cellular processes. Hence it is not surpassing that membrane proteins make ∼70% of contemporary drug targets. Quantitative profiling of membrane proteins using mass spectrometry (MS)-based proteomics is critical in a quest for disease biomarkers and novel cancer drugs. Post-digestion (18)O exchange is a simple and efficient method for differential (18)O/(16)O stable isotope labeling of two biologically distinct specimens, allowing relative quantitation of proteins in complex mixtures when coupled with shotgun MS-based proteomics. Due to minimal sample consumption and unrestricted peptide tagging, (18)O/(16)O stable isotope labeling is particularly suitable for amount-limited protein specimens typically encountered in membrane and clinical proteomics. This chapter describes a protocol that relies on shotgun proteomics for quantitative profiling of the detergent-insoluble membrane proteins isolated from HeLa cells, differentially transfected with plasmids expressing HIV Gag protein and its myristylation-defective N-terminal mutant. Whilst this protocol depicts solubilization of detergent-insoluble membrane proteins coupled with post-digestion (18)O labeling, it is amenable to any complex membrane protein mixture. Described approach relies on solubilization and tryptic digestion of membrane proteins in a buffer containing 60% (v/v) methanol followed by differential (18)O/(16)O labeling of protein digests in 20% (v/v) methanol buffer. After mixing, the differentially labeled peptides are fractionated using off-line strong cation exchange (SCX) followed by on-line reversed phase nanoflow reversed-phase liquid chromatography (nanoRPLC)-MS identification/quantiation of peptides/proteins. The use of methanol-based buffers in the context of the post-digestion (18)O exchange/labeling eliminates the need for detergents or chaotropes that interfere with LC separations and peptide ionization. Sample losses are minimized because solubilization, digestion, and stable isotope labeling are carried out in a single tube, avoiding any sample transfer or buffer exchange between these steps.

Profiling the erythrocyte membrane proteome isolated from patients diagnosed with chronic obstructive pulmonary disease

Structural and metabolic alterations in erythrocytes play an important role in the pathophysiology of Chronic Obstructive Pulmonary Disease (COPD). Whether these dysfunctions are related to the modulation of erythrocyte membrane proteins in patients diagnosed with COPD remains to be determined. Herein, a comparative proteomic profiling of the erythrocyte membrane fraction isolated from peripheral blood of smokers diagnosed with COPD and smokers with no COPD was performed using differential (16)O/(18)O stable isotope labeling. A total of 219 proteins were quantified as being significantly differentially expressed within the erythrocyte membrane proteomes of smokers with COPD and healthy smokers. Functional pathway analysis showed that the most enriched biofunctions were related to cell-to-cell signaling and interaction, hematological system development, immune response, oxidative stress and cytoskeleton. Chorein (VPS13A), a cytoskeleton related protein whose defects had been associated with the presence of cell membrane deformation of circulating erythrocytes was found to be down-regulated in the membrane fraction of erythrocytes obtained from COPD patients. Methemoglobin reductase (CYB5R3) was also found to be underexpressed in these cells, suggesting that COPD patients may be at higher risk for developing methemoglobinemia. This article is part of a Special Issue entitled: Integrated omics.

Global proteomics and metabolomics in cancer biomarker discovery

Chromatography and electrophoresis have been used for the last half-century to separate small and large molecules. Advances in MS instrumentation and techniques for sample introduction into the mass analyzer (i.e. matrix-assisted laser desorption/ionization and electrospray ionization), chromatography in all its formats and modes and two-dimensional gel electrophoresis, including two-dimensional difference gel electrophoresis, enabled the separation of complex biological mixtures, such as the proteome and the metabolome, in a biological sample. These advances have made it possible to identify compounds that can be used to discriminate between two samples taken from healthy and diseased individuals. The objective is to find proteins or metabolites that can be used as a clinical test for the early diagnosis, prognosis and monitoring of the disease and the outcome of therapy. In this manuscript, we present an overview of what has been achieved in the search for biomarkers, with emphasis on cancer, using separation science and MS.

Molecular profiling of the human nasal epithelium: A proteomics approach

A comprehensive proteomic profiling of nasal epithelium (NE) is described. This study relies on simple subcellular fractionation used to obtain soluble- and membrane-enriched fractions followed by 2-dimensional liquid chromatography (2D-LC) separation and tandem mass spectrometry (MS/MS). The cells were collected using a brushing technique applied on NE of clinically evaluated volunteers. Subsequently, the soluble- and the membrane-protein enriched fractions were prepared and analyzed in parallel using 2D-LC-MS/MS. In a set of 1482 identified proteins, 947 (63.9%) proteins were found to be associated to membrane fraction. Grand average hydropathy value index (GRAVY) analysis, the transmembrane protein mapping and annotations of primary location deposited in the Human Protein Reference Database (HPRD) confirmed an enrichment of hydrophobic proteins on this dataset. Ingenuity Pathway Analysis (IPA) of soluble fraction revealed an enrichment of molecular and cellular functions associated with cell death, protein folding and drug metabolism while in membrane fraction showed an enrichment of functions associated with molecular transport, protein trafficking and cell-to-cell signaling and interaction. The IPA showed similar enrichment of functions associated with cellular growth and proliferation in both soluble and membrane subproteomes. This finding was in agreement with protein content analysis using exponentially modified protein abundance index (emPAI). A comparison of our data with previously published studies focusing on respiratory tract epithelium revealed similarities related to identification of proteins associated with physical barrier function and immunological defence. In summary, we extended the NE molecular profile by identifying and characterizing proteins associated to pivotal functions of a respiratory epithelium, including the control of fluid volume and ionic composition at the airways' surface, physical barrier maintenance, detoxification and immunological defence. The extent of similarities supports the applicability of a less invasive analysis of NE to assess prognosis and treatment response of lung diseases such as asthma, cystic fibrosis and chronic obstructive pulmonary disease.

Abstract 4873: Protein complexes in cancer: A novel strategy to identify protein complexes through reduction of false discovery rate

Most cellular processes are controlled by protein-protein interactions, and aberrant protein-protein interactions can lead to human diseases such as cancer. Hence a comprehensive understanding of a protein interaction network and its dynamics response to different physiological conditions is essential for understanding a protein's function and may reveal novel therapeutic opportunities for fighting cancer.

Affinity purification coupled with mass spectrometry has become the method of choice to study in vivo protein interactions and formation of protein complexes. However, the methodology has some limitations that reduce it application such as, under sampling of low abundant proteins and high background leading to an elevated false discovery rate (FDR).

Herein we describe a strategy utilizing differential expression of the target protein followed by analysis using quantitative proteomics. By performing affinity purification on cells expressing increasing amounts of the polycomb complex protein Bmi-1, we show that known interacting proteins could be distinguished very efficiently from the background proteins based on their abundance profile. Applying this method to the data set significantly reduced the FDR and allowed us to identify potentially new interacting proteins for Bmi-1 that otherwise would have been considered non-specifically bound proteins.

The method was also applied to characterize the interactome for Snail I, II and III a family of Zn-finger proteins thought to be involved in transcriptional repression. These proteins have been implicated in diverse biological function such as regulation of epithelial to mesenchymal transition, formation and maintenance of embryonic mesoderm, generation and migration of neural crest cells and metastasis.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4873. doi:10.1158/1538-7445.AM2011-4873

Quantitation of nanoparticles in serum matrix by capillary electrophoresis

Sensitive and fast analytical techniques are needed to determine the concentration of nanoparticles in biological samples (e.g., blood and tissues) for biodistribution and toxicity studies. This chapter describes a method for the use of capillary zone electrophoresis (CZE) and micellar electrokinetic chromatography (MEKC) for the quantitation of fullerene nanoparticles in human serum matrix. Data on the fullerene-based nanoparticle carboxyfullerene (C3 fullerene) in human serum is presented as an example.

Cast nephropathy with acute renal failure treated with high cut-off haemodialysis in a patient with multiple myeloma

We report a case of a Chinese woman who presented with multiple myeloma and acute renal failure due to cast nephropathy, with an extremely high serum lambda free light chain concentration. She was successfully treated with chemotherapy and high cut-off extended haemodialysis. High cut-off haemodialysis is a new treatment modality which can achieve rapid free light chain clearance. This may contribute to a better renal outcome and overall prognosis for patients with multiple myeloma.

Comparison of strong cation exchange and SDS-PAGE fractionation for analysis of multiprotein complexes

Affinity purification of protein complexes followed by identification using liquid chromatography/mass spectrometry (LC-MS/MS) is a robust method to study the fundamental process of protein interaction. Although affinity isolation reduces the complexity of the sample, fractionation prior to LC-MS/MS analysis is still necessary to maximize protein coverage. In this study, we compared the protein coverage obtained via LC-MS/MS analysis of protein complexes prefractionated using two commonly employed methods, SDS-PAGE and strong cation exchange chromatography (SCX). The two complexes analyzed focused on the nuclear proteins Bmi-1 and GATA3 that were expressed within the cells at low and high levels, respectively. Prefractionation of the complexes at the peptide level using SCX consistently resulted in the identification of approximately 3-fold more proteins compared to separation at the protein level using SDS-PAGE. The increase in the number of identified proteins was especially pronounced for the Bmi-1 complex, where the target protein was expressed at a low level. The data show that prefractionation of affinity isolated protein complexes using SCX prior to LC-MS/MS analysis significantly increases the number of identified proteins and individual protein coverage, particularly for target proteins expressed at low levels.

Changing epidemiology of hand, foot, and mouth disease in Hong Kong, 2001-2009

We report the surveillance findings of hand, foot, and mouth disease (HFMD) collected from a general practitioner-based sentinel surveillance system and outbreaks reported by institutions and a laboratory-based enterovirus surveillance system in Hong Kong from 2001 to 2009. A seasonal peak was detected in the warmer months (May-July), along with a smaller winter peak (October-December) from 2006 onwards. The number of older children (>5 years) infected increased from 25.4% in 2001 to 33.0% in 2009 (P=0.01, Mantel-Haenszel chi-square test). Laboratory surveillance detected a cyclical high enterovirus 71 activity every 3 to 4 years. This activity was associated with a higher average hospitalization rate for HFMD patients in the outbreaks reported in the corresponding year, although the difference was only marginally significant (P=0.09, linear regression test). The changing epidemiology of HFMD warrants continuous surveillance in order to guide preventive public-health actions.

Size-effect induced short-range magnetic ordering in germanium nanostructures

Formation of ordered magnetic states in germanium nanostructures embedded in SiO2 has been investigated. Samples with the nanostructures were prepared by sputtering deposition on Si(100) substrates, followed by thermal annealing in vacuum. Transmission electron microscopy, energy dispersive X-ray spectrometry, and Raman spectroscopy have been used to characterize the samples. Magnetic measurements were performed using a superconducting quantum interference device. Size-effect induced magnetic orderings in the germanium nanostructures were found to be present at room temperatures and below. Superparamagnetic behavior was observed at temperatures above 230 K, whereas thermal excitation of spin reorientation and magnetic coupling has been revealed at temperatures below 60 K. Inverted hysteresis loops with negative remanences and multiple plateaus revealed the ferri- or antiferromagnetic nature of the coupling. Inter-domain coupling and effect of magnetic anisotropy will be discussed based on the experimental results and simulations with a spin reorientation model.

Optimized method for computing (18)O/(16)O ratios of differentially stable-isotope labeled peptides in the context of postdigestion (18)O exchange/labeling

Differential (18)O/(16)O stable isotope labeling of peptides that relies on enzyme-catalyzed oxygen exchange at their carboxyl termini in the presence of H(2)(18)O has been widely used for relative quantitation of peptides/proteins. The role of tryptic proteolysis in bottom-up shotgun proteomics and low reagent costs have made trypsin-catalyzed (18)O postdigestion exchange a convenient and affordable stable isotope labeling approach. However, it is known that trypsin-catalyzed (18)O exchange at the carboxyl terminus is in many instances inhomogeneous/incomplete. The extent of the (18)O exchange/incorporation fluctuates from peptide to peptide mostly due to variable enzyme-substrate affinity. Thus, accurate calculation and interpretation of peptide ratios are analytically complicated and in some regard deficient. Therefore, a computational approach capable of improved measurement of actual (18)O incorporation for each differentially labeled peptide pair is needed. In this regard, we have developed an algorithmic method that relies on the trapezoidal rule to integrate peak intensities of all detected isotopic species across a particular peptide ion over the retention time, which fits the isotopic manifold to Poisson distributions. Optimal values for manifold fitting were calculated and then (18)O/(16)O ratios derived via evolutionary programming. The algorithm is tested using trypsin-catalyzed (18)O postdigestion exchange to differentially label bovine serum albumin (BSA) at a priori determined ratios. Both accuracy and precision are improved utilizing this rigorous mathematical approach. We further demonstrate the effectiveness of this method to accurately calculate (18)O/(16)O ratios in a large scale proteomic quantitation of detergent resistant membrane microdomains (DRMMs) isolated from cells expressing wild-type HIV-1 Gag and its nonmyristylated mutant.

Combined blood/tissue analysis for cancer biomarker discovery: application to renal cell carcinoma

A method that relies on subtractive tissue-directed shot-gun proteomics to identify tumor proteins in the blood of a patient newly diagnosed with cancer is described. To avoid analytical and statistical biases caused by physiologic variability of protein expression in the human population, this method was applied on clinical specimens obtained from a single patient diagnosed with nonmetastatic renal cell carcinoma (RCC). The proteomes extracted from tumor, normal adjacent tissue and preoperative plasma were analyzed using 2D-liquid chromatography-mass spectrometry (LC-MS). The lists of identified proteins were filtered to discover proteins that (i) were found in the tumor but not normal tissue, (ii) were identified in matching plasma, and (iii) whose spectral count was higher in tumor tissue than plasma. These filtering criteria resulted in identification of eight tumor proteins in the blood. Subsequent Western-blot analysis confirmed the presence of cadherin-5, cadherin-11, DEAD-box protein-23, and pyruvate kinase in the blood of the patient in the study as well as in the blood of four other patients diagnosed with RCC. These results demonstrate the utility of a combined blood/tissue analysis strategy that permits the detection of tumor proteins in the blood of a patient diagnosed with RCC.