No abstract

Stability of oxygen saturation depends on maturation and function of individual components of the respiratory system. The aim of this study was to record and analyse comprehensive oxygen saturation data in a longitudinal study over the first year of life. Detailed sleep studies were performed on 15 normal infants eight times in the first year of life. The accrued oxygen saturation data were analysed on a computerized oximetry data analysis system. Results show the mean sleep saturation levels trending upwards and stabilizing by 185 days. There was an inverse curvilinear relationship between mean age and median desaturation time and the median number of desaturations at < or = 95, < or = 92 and < or = 90% saturation. The mean cumulative desaturation time < or = 90% in the first 4 months was 11.08 min (range 2.5-36.57 min). This study demonstrates monotonic patterns of increasing saturation and decreasing number and time of desaturations < or = 95% and < or = 90% but a random pattern of desaturations < or = 85% occurs across the first 6 months of life. Cumulative desaturation times over the first 4 months of life were high and could be important to the development of maturity of the respiratory system. After 6 months, all indices of saturation and desaturation point to a stable and mature respiratory system.

The association between adiponectin receptor expression, obesity status and tumour category and survival suggests a potential mechanism linking obesity and oesophageal cancer.

e22009 Background: Worldwide, the prevalence of obesity is rapidly increasing, correlating with a direct increase in cancer rates1. Adipose tissue is considered an important endocrine organ producing several important hormones and cytokines including leptin and adiponectin. Mechanisms for the role of obesity in cancer states includes the excess or unregulated secretion of adipocytokines from adipose tissue, and potentially the metabolic syndrome (a cluster of co-morbidities linked to metabolic dysregulation). Mammary adipose tissue is proposed to play a vital role in the microenvironment of normal and tumour states within the breast2. Breast adipose tissue is a good candidate to investigate effects of obesity and metabolic disturbances on cancer states. Methods: Peritumoural (PT) adipose tissue adjacent to the tumour and distal adipose tissue (D) within the breast was sampled in 10 patients. The tissue was processed and cultured for 72hrs in serum free minimal cytokine media. A-MB-231 and MCF-7 breast cancer cell lines were then cultured with this adipocyte conditioned media (ACM) and cell proliferation response was then measured using BrDU assays. The adipocytokine profile at the mRNA and protein level was measured in ACM and adipose tissue for comparative differences using RT-PCR, ELISA and Cytokine Profiler technology. Results: ACM from both sites promoted tumour cell survival. There was however, a differential cell proliferation response noted between the peritumoural (PT) ACM and that from the distant (D) ACM. Pro-inflammatory mediators (VEGF, TNF-α, EGF) were also demonstrated a trend to be differentially expressed between the 2 sites. Conclusions: Proliferation of breast cancer cell lines occurs in response to ACM, with differential effects seen between peritumoural ACM and distant ACM. This may be mediated through increased pro-inflammatory or pro- mitogenic adipocytokine production in adipose tissue surrounding tumour. Further analysis will determine what role obesity and the metabolic syndrome plays in the results noted. No significant financial relationships to disclose.