Prospective technical validation and assessment of intra-tumour heterogeneity of a low density array hypoxia gene profile in head and neck squamous cell carcinoma

Background and purposeTumour hypoxia is associated with a poor prognosis in head and neck squamous cell carcinoma (HNSCC), however there is no accepted method for assessing hypoxia clinically. We aimed to conduct a technical validation of a hypoxia gene expression signature using the TaqMan Low Density Array (TLDA) platform to investigate if this approach reliably identified hypoxic tumours.Materials and methodsTumour samples (n = 201) from 80 HNSCC patients were collected prospectively from two centres. Fifty-three patients received pimonidazole prior to surgery. TaqMan Low Density Array-Hypoxia Scores (TLDA-HS) were obtained by quantitative real-time PCR (qPCR) using a 25-gene signature and customised TLDA cards. Assay performance was assessed as coefficient of variation (CoV).ResultsThe assay was sensitive with linear reaction efficiencies across a 4log₁₀ range of inputted cDNA (0.001–10 ng/μl). Intra- (CoV = 6.9%) and inter- (CoV = 2.0%) assay reproducibility were excellent. Intra-tumour heterogeneity was lower for TLDA-HS (23.2%) than for pimonidazole (67.2%) or single gene measurements of CA9 (62.2%), VEGFA (45.0%) or HIG2 (39.4%). TLDA-HS in HNSCC cell lines increased with decreasing pO₂. TLDA-HS correlated with Affymetrix U133 Plus 2.0 microarray HS (p < 0.01) and positive pimonidazole scores (p = 0.005).ConclusionsGene expression measurements of hypoxia using a 25-gene signature and TLDA cards are sensitive, reproducible and associated with lower intra-tumour heterogeneity than assaying individual genes or pimonidazole binding. The approach is suitable for further assessment of prognostic and predictive capability in clinical trial material.     

Vehicular Air Pollution,Playgrounds, and Youth Athletic Fields

In spite of epidemiological evidence concerning vehicular air pollution and adverse respiratory/cardiovascular health, many athletic fields and school playgrounds are adjacent to high traffic roadways and could present long-term health risks for exercising children and young adults. Particulate matter (PM₁,0.02–1.0 μm diameter) number counts were taken serially at four elementary school athletic/playground fields and at one university soccer field. Elementary school PM₁ measurements were taken over 17 days; measurements at the university soccer field were taken over 62 days. The high-traffic-location elementary school field demonstrated higher 17-day [PM₁] than the moderate and 2 low traffic elementary school fields (48,890 ± 34,260, 16,730 ± 10,550, 11,960 ± 6680, 10,030 ± 6280, respective mean counts; p < .05). The 62-day mean PM₁ values at the university soccer field ranged from 115,000 to 134,000 particles cm^{? 3}. Lowest mean values were recorded at measurement sites furthest from the highway (～34,000 particles cm^{? 3}) and followed a second-order logarithmic decay (R² = .999) with distance away from the highway. Mean NO₂ and SO₂ levels were below 100 ppb, mean CO was 0.33 ± 1.87 ppm, and mean O₃ was 106 ± 47 ppb. Ozone increased with rising temperature and was highest in the warmer afternoon hours (R = .61). Although the consequence of daily recess play and athletic activities by school children and young athletes in high ambient [PM₁] conditions has not yet been clearly defined, this study is a critical component to evaluating functional effects of chronic combustion-derived PM exposure on these exercising schoolchildren and young adults. Future studies should examine threshold limits and mechanistic actions of real-world particle exposure.     

Mutual Liking, Enjoyment, and Shared Interactions in the Closest Relationships between Children with Developmental Disabilities and Peers in Inclusive School Settings

Typically analysis of the characteristics of friendships is made on the basis of nomination of a friend or best friend, with the assumption that this nomination reflects actual friendship. While it is possible that this assumption may be valid in typically developing children, this may not be the case for relationships for students with developmental disabilities. The relationships of 16 students with developmental disabilities in grades 1 through 6 and their three closest peers were examined to determine if dyads engaged in behaviors associated with defining components of friendship (i.e. shared interaction, mutual enjoyment, mutual liking) from literature on typically developing children. Interviews were conducted with target students, as well as with their peers, parents and teachers. Interview data indicated that the majority of dyads engaged at least sometimes in behaviors related to each of the defining components of friendship and reported behaviors associated with these components were typically reported as mutual. Additionally, voluntary peer nomination of friends at the beginning of interviews corresponded well with the presence of characteristics of friendship but this was less so when peers needed to be asked directly whether a child with a disability was a friend.     

Additional Diagnostic Yield of Adding Serology to PCR in Diagnosing Viral Acute Respiratory Infections in Kenyan Patients 5 Years of Age and Older

The role of serology in the setting of PCR-based diagnosis of acute respiratory infections (ARIs) is unclear. We found that acute- and convalescent-phase paired-sample serologic testing increased the diagnostic yield of naso/oropharyngeal swabs for influenza virus, respiratory syncytial virus (RSV), human metapneumovirus, adenovirus, and parainfluenza viruses beyond PCR by 0.4% to 10.7%. Although still limited for clinical use, serology, along with PCR, can maximize etiologic diagnosis in epidemiologic studies.