Electrical detection of cancer biomarker using aptamers with nanogap break-junctions

Epidermal growth factor receptor (EGFR) is a cell surface protein overexpressed in cancerous cells. It is known to be the most common oncogene. EGFR concentration also increases in the serum of cancer patients. The detection of small changes in the concentration of EGFR can be critical for early diagnosis, resulting in better treatment and improved survival rate of cancer patients. This article reports an RNA aptamer based approach to selectively capture EGFR protein and an electrical scheme for its detection. Pairs of gold electrodes with nanometer separation were made through confluence of focused ion beam scratching and electromigration. The aptamer was hybridized to a single stranded DNA molecule, which in turn was immobilized on the SiO(2) surface between the gold nanoelectrodes. The selectivity of the aptamer was demonstrated by using control chips with mutated non-selective aptamer and with no aptamer. Surface functionalization was characterized by optical detection and two orders of magnitude increase in direct current (DC) was measured when selective capture of EGFR occurred. This represents an electronic biosensor for the detection of proteins of interest for medical applications.     

Effect of age on the survival of breast cancer patients

Despite numerous studies, the effect of patient age on the prognosis of breast cancer is still uncertain. The aim of this study was to assess the influence of age on long-term relative survival, to control the results for the extent of disease at diagnosis and assess the association between biological markers and age of the patients. A population-based survival study was made to assess the 5- and 10-year relative survival. All 17,856 female breast cancer patients diagnosed in Finland and reported to the Finnish Cancer Registry in 1977-1986 were included. The results were controlled for the extent of the disease. The markers of biological aggressiveness of tumours and patients' age were correlated in a prospectively collected subset of 2107 patients from the Tampere University area. The relative 5-year and 10-year survival rates (RSRs) were highest in women 46-50 years of age, whereas there was no significant difference between younger and older age groups. No consistent survival trends were observed among the age groups in local, node-negative disease, whereas in node-positive disease the 10-year relative survival was best for women 41-45 years (49%) and poorest in women over 75 years (35%). The youngest age groups were significantly more often oestrogen receptor-negative, but only small differences were observed for S-phase fraction and progesterone receptor positivity.     

Low biologic aggressiveness in breast cancer in women using hormone replacement therapy

In a multicenter study the metabolic effects of 5 yr of GH therapy in children with idiopathic short stature were evaluated. Patients received 0.3 mg/kg.week recombinant human GH. Of the 121 patients who entered the study, data for 62 were analyzed at the final 5 yr point. Routine laboratory determinations were available for all 62 subjects at the 5 yr point. Special laboratory determinations, such as postprandial glucose and insulin, were available for only a subset of patients. Mean insulin-like growth factor I levels rose to 283 +/- 101 micrograms/L, within the normal range using age-appropriate reference standards. T4, cholesterol, triglycerides, blood chemistries, and blood pressure showed no significant changes during the 5-yr period. Mean baseline and 2-h postprandial glucose levels remained unchanged. Both fasting and postprandial insulin levels rose substantively from low normal levels to the normal range (median, 4.9-43 mU/L). Mean hemoglobin A1c levels remained within the normal range throughout the study. In summary, careful monitoring has not revealed any currently discernible metabolic side-effects of clinical significance after GH therapy in this 5-yr study of children with idiopathic short stature.