Quantitative Ultrasound Monitoring of Breast Tumour Response to Neoadjuvant Chemotherapy: Comparison of Results Among Clinical Scanners.

Quantitative ultrasound (QUS) techniques have been demonstrated to detect cell death in vitro and in vivo. Recently, multi-feature classification models have been incorporated into QUS texture-feature analysis methods to increase further the sensitivity and specificity of detecting treatment response in locally advanced breast cancer patients. To effectively incorporate these analytic methods into clinical applications, QUS and texture-feature estimations should be independent of data acquisition systems. The study here investigated the consistencies of QUS and texture-feature estimation techniques relative to several factors. These included the ultrasound system properties, the effects of tissue heterogeneity and the effects of these factors on the monitoring of response to neoadjuvant chemotherapy. Specifically, tumour-response-detection performance based on QUS and texture parameters using two clinical ultrasound systems was compared. Observed variations in data between the systems were small and the results exhibited good agreement in tumour response predictions obtained from both ultrasound systems. The results obtained in this study suggest that tissue heterogeneity was a dominant feature in the parameters measured with the two different ultrasound systems; whereas differences in ultrasound system beam properties only exhibited a minor impact on texture features. The McNemar statistical test performed on tumour response prediction results from the two systems did not reveal significant differences. Overall, the results in this study demonstrate the potential to achieve reliable and consistent QUS and texture-based analyses across different ultrasound imaging platforms.

Correlates of plasma homocysteine, cysteine and cysteinyl-glycine in respondents in the British National Diet and Nutrition Survey of young people aged 4-18 years, and a comparison with the survey of people aged 65 years and over.

Plasma total homocysteine (tHcy), cysteine and cysteinyl-glycine were measured in a representative sample of 922 young people aged 4-18 years, participating in the National Diet and Nutrition Survey in mainland Britain in 1997. Both tHcy and cysteine increased markedly with age; cysteinyl-glycine less so. Neither tHcy nor cysteine differed between genders; cysteinyl-glycine was higher in males. tHcy concentrations were lowest in the winter; cysteine and cysteinyl-glycine varied only slightly with season. In respondents aged >15 years, tHcy was higher in smokers, but in respondents aged 7-11 years, tHcy was higher in those whose mothers smoked. tHcy was inversely correlated with serum folate, serum vitamin B12 and vitamin B6 status, but neither cysteine nor cysteinyl-glycine shared these relationships. The relationships between tHcy and B-vitamin status indices ran parallel with those of the 65 years and over survey, but at much lower tHcy concentrations for any given B-vitamin concentration. Age-adjusted tHcy was not correlated with anthropometric indices, blood pressure, haematology, plasma creatinine, urea or cholesterol, but was directly correlated with fasting triacylglycerol. We conclude that disease-risk indices, like tHcy and perhaps cysteine, if established during early life, may be modulated by diet and lifestyle, thereby providing an opportunity for public health intervention.