Quantitative assessment of Tn antigen in breast tissue micro-arrays using CdSe aqueous quantum dots.

In this study, we examined the use of CdSe aqueous quantum dots (AQDs) each conjugated to three streptavidin as a fluorescent label to image Tn antigen expression in various breast tissues via a sandwich staining procedure where the primary monoclonal anti-Tn antibody was bound to the Tn antigen on the tissue, a biotin-labeled secondary antibody was bound to the primary anti-Tn antibody, and finally the streptavidin-conjugated AQDs were bound to the biotin on the secondary antibody. We evaluated the AQD staining of Tn antigen on tissue microarrays consisting of 395 cores from 115 cases including three tumor cores and one normal-tissue core from each breast cancer case and three tumor cores from each benign case. The results indicated AQD-Tn staining was positive in more than 90% of the cells in the cancer cores but not the cells in the normal-tissue cores and the benign tumor cores. As a result, AQD-Tn staining exhibited 95% sensitivity and 90% specificity in differentiating breast cancer against normal breast tissues and benign breast conditions. These results were better than the 90% sensitivity and 80% specificity exhibited by the corresponding horse radish peroxidase (HRP) staining using the same antibodies on the same tissues and those of previous studies that used different fluorescent labels to image Tn antigen. In addition to sensitivity and specificity, the current AQD-Tn staining with a definitive threshold was quantitative.

Assessing breast cancer margins ex vivo using aqueous quantum-dot-molecular probes.

Positive margins have been a critical issue that hinders the success of breast- conserving surgery. The incidence of positive margins is estimated to range from 20% to as high as 60%. Currently, there is no effective intraoperative method for margin assessment. It would be desirable if there is a rapid and reliable breast cancer margin assessment tool in the operating room so that further surgery can be continued if necessary to reduce re-excision rate. In this study, we seek to develop a sensitive and specific molecular probe to help surgeons assess if the surgical margin is clean. The molecular probe consists of the unique aqueous quantum dots developed in our laboratory conjugated with antibodies specific to breast cancer markers such as Tn-antigen. Excised tumors from tumor-bearing nude mice were used to demonstrate the method. AQD-Tn mAb probe proved to be sensitive and specific to identify cancer area quantitatively without being affected by the heterogeneity of the tissue. The integrity of the surgical specimen was not affected by the AQD treatment. Furthermore, AQD-Tn mAb method could determine margin status within 30 minutes of tumor excision, indicating its potential as an accurate intraoperative margin assessment method.

Minor head injury in children younger than two years of age: description, prevalence and management in the emergency room of the pediatric university hospital.

BACKGROUND: In children less than two years old, minor head trauma can result in intracranial injury. No known studies exist that determine the number of children younger than two years old who visit the emergency room (ER) due to minor head injury in Puerto Rico. OBJECTIVE: To determine the prevalence of children with minor head trauma and describe related issues. METHODS: Information was gathered from the medical records of children 0 to 2 years old who visited the University Pediatric Hospital ER from 2004-2006. Several factors were analyzed. RESULTS: From our 136 subjects, there was a male prevalence of 59%. The predominant reason for head injury was a fall (86%). There was abuse in 7% of the subjects. Eighty-five percent (85%) of injuries occurred at home. CONCLUSIONS: The most common etiology of head trauma was a fall at home. The prevalence of abuse in 7% of these children should alert physicians.