The effect of aluminium and sodium impurities on the in vitro toxicity and pro-inflammatory potential of cristobalite

BACKGROUND

Exposure to crystalline silica (SiO₂), in the form of quartz, tridymite or cristobalite, can cause respiratory diseases, such as silicosis. However, the observed toxicity and pathogenicity of crystalline silica is highly variable. This has been attributed to a number of inherent and external factors, including the presence of impurities. In cristobalite-rich dusts, substitutions of aluminium (Al) for silicon (Si) in the cristobalite structure, and impurities occluding the silica surface, have been hypothesised to decrease its toxicity. This hypothesis is tested here through the characterisation and in vitro toxicological study of synthesised cristobalite with incremental amounts of Al and sodium (Na) dopants.

METHODS

Samples of synthetic cristobalite with incremental amounts of Al and Na impurities, and tridymite, were produced through heating of a silica sol-gel. Samples were characterised for mineralogy, cristobalite purity and abundance, particle size, surface area and surface charge. In vitro assays assessed the ability of the samples to induce cytotoxicity and TNF-α production in J774 macrophages, and haemolysis of red blood cells.

RESULTS

Al-only doped or Al+Na co-doped cristobalite contained between 1 and 4 oxide wt% Al and Na within its structure. Co-doped samples also contained Al- and Na-rich phases, such as albite. Doping reduced cytotoxicity to J774 macrophages and haemolytic capacity compared to non-doped samples. Al-only doping was more effective at decreasing cristobalite reactivity than Al+Na co-doping. The reduction in the reactivity of cristobalite is attributed to both structural impurities and a lower abundance of crystalline silica in doped samples. Neither non-doped nor doped crystalline silica induced production of the pro-inflammatory cytokine TNF-α in J774 macrophages.

CONCLUSIONS

Impurities can reduce the toxic potential of cristobalite and may help explain the low reactivity of some cristobalite-rich dusts. Whilst further work is required to determine if these effects translate to altered pathogenesis, the results have potential implications for the regulation of crystalline silica exposures.

Dijet imbalance measurements in Au+Au and pp collisions at sqrt[s_{NN}]=200 GeV at STAR

We report the first dijet transverse momentum asymmetry measurements from Au+Au and pp collisions at RHIC. The two highest-energy back-to-back jets reconstructed from fragments with transverse momenta above 2  GeV/c display a significantly higher momentum imbalance in heavy-ion collisions than in the pp reference. When reexamined with correlated soft particles included, we observe that these dijets then exhibit a unique new feature-momentum balance is restored to that observed in pp for a jet resolution parameter of R=0.4, while rebalancing is not attained with a smaller value of R=0.2.

Brain antibodies in the cortex and blood of people with schizophrenia and controls

The immune system is implicated in the pathogenesis of schizophrenia, with elevated proinflammatory cytokine mRNAs found in the brains of ~40% of individuals with the disorder. However, it is not clear if antibodies (specifically immunoglobulin-γ (IgG)) can be found in the brain of people with schizophrenia and if their abundance relates to brain inflammatory cytokine mRNA levels. Therefore, we investigated the localization and abundance of IgG in the frontal cortex of people with schizophrenia and controls, and the impact of proinflammatory cytokine status on IgG abundance in these groups. Brain IgGs were detected surrounding blood vessels in the human and non-human primate frontal cortex by immunohistochemistry. IgG levels did not differ significantly between schizophrenia cases and controls, or between schizophrenia cases in 'high' and 'low' proinflammatory cytokine subgroups. Consistent with the existence of IgG in the parenchyma of human brain, mRNA and protein of the IgG transporter (FcGRT) were present in the brain, and did not differ according to diagnosis or inflammatory status. Finally, brain-reactive antibody presence and abundance was investigated in the blood of living people. The plasma of living schizophrenia patients and healthy controls contained antibodies that displayed positive binding to Rhesus macaque cerebellar tissue, and the abundance of these antibodies was significantly lower in patients than controls. These findings suggest that antibodies in the brain and brain-reactive antibodies in the blood are present under normal circumstances.

Measurement of D^{0} Azimuthal Anisotropy at Midrapidity in Au+Au Collisions at sqrt[s_{NN}]=200 GeV

We report the first measurement of the elliptic anisotropy (v_{2}) of the charm meson D^{0} at midrapidity (|y|<1) in Au+Au collisions at sqrt[s_{NN}]=200  GeV. The measurement was conducted by the STAR experiment at RHIC utilizing a new high-resolution silicon tracker. The measured D^{0} v_{2} in 0%-80% centrality Au+Au collisions can be described by a viscous hydrodynamic calculation for a transverse momentum (p_{T}) of less than 4  GeV/c. The D^{0} v_{2} as a function of transverse kinetic energy (m_{T}-m_{0}, where m_{T}=sqrt[p_{T}^{2}+m_{0}^{2}]) is consistent with that of light mesons in 10%-40% centrality Au+Au collisions. These results suggest that charm quarks have achieved local thermal equilibrium with the medium created in such collisions. Several theoretical models, with the temperature-dependent, dimensionless charm spatial diffusion coefficient (2πTD_{s}) in the range of ∼2-12, are able to simultaneously reproduce our D^{0} v_{2} result and our previously published results for the D^{0} nuclear modification factor.

Caring for a patient with rabies: implications of the Milwaukee protocol for infection control and public health measures

This article discusses the infection control and public health measures taken whilst managing a case of laboratory-confirmed rabies, and the challenges faced in implementing these measures. Case management requires intensive multi-disciplinary co-ordination. The Milwaukee protocol, which to date has five reported human rabies survivors associated with its use, has been suggested as a potential management pathway for human rabies. Consensus among hospital and public health clinicians would aid future deployment of this approach in selected cases.

Abstract P3-07-17: Squalene epoxidase is a potential metabolic oncogene by amplification with clinical implications in breast carcinoma: An in silico pan-cancer study with i n vitro evidence

This abstract was withdrawn by the authors.

Abstract PD6-01: Analysis of breast cancer in young women in the department of defense (DOD) database

Background: Women under the age of 40 account for approximately 7% percent of breast cancer patients. Breast tumors from young women are often ER-negative, occur in African-American patients, and have other indicators of high risk: yet, multivariate analyses demonstrated that young age is an independent predictor of poor outcome. Due to the unique nature of the patient population served by DOD, a disproportionate number of breast cancer cases in young women are seen. We compare the characteristics, treatment, and outcomes of young patients diagnosed with breast cancer with those of older patients.

Methods: The databases of the Military Health System Repository and the DOD Central Registration were used to identify female breast cancer patients treated at DOD facilities between 1998 and 2007. Information on demographics, breast cancer stage at diagnosis, definitive surgical treatments, systemic treatment, recurrence rate and overall survival was analyzed by age groups at the time of diagnosis (less than 40 years old, 40 to 49 years, and 50 years or older) using X2 testing with significance defined as p&lt; 0.05.

Results: We identified 10,066 women who were diagnosed with invasive breast cancer at DOD facilities between 1998 and 2007, of which 11.3% (1139) were less than 40 years old at diagnosis. 53% of this young cohort were white, 25% were African-American and 8% were Hispanic (14% undisclosed). The percentage of breast cancer among African-American women in the young cohort was higher than in the older cohorts (19.3% in 40-49yo and 10.6% in ≥50yo). High-grade tumors were significantly more frequent in the younger cohort when compared to the older group (49.5% vs 34.7% and 25.2%, p&lt;0.001). &lt;40yo most commonly presented with Stage II disease (45.3%) at diagnosis, while older groups were mostly diagnosed with Stage I disease (41.6% and 52.4%). The most common subtype of breast cancer across ages was ER+ disease, however, &lt;40yo group had proportionally less ER+ (49% vs 61% and 67.3%, P&lt;0.001). There was a higher rate of bilateral mastectomies among the young women (18.4% vs 9.1% and 5.0%, p&lt;0.0001). Independently of the stage of disease, chemotherapy was given significantly more frequently to &lt;40y (90.43%) and 40-49yo (81.44%) than ≥50yo (53.71%). The 10-year overall survival of younger women was similar to the ≥50yo cohort, despite intensive treatment.

Discussion: This study is one of the largest retrospective studies of women under 40 years old with breast cancer. Younger women with invasive breast cancer had more aggressive tumors presenting at higher stages. In this group with good access to healthcare, younger women still had a similar overall survival rate to older women despite receiving more aggressive treatment and potentially having fewer comorbidities than the older group.

Citation Format: Zimmer AS, Gatti-Mays M, Soltani S, Lipkowitz S, Steeg PS, Zhu K, Perkins JG, Hu H, Shao S, Brown D, Shriver CD. Analysis of breast cancer in young women in the department of defense (DOD) database [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr PD6-01.