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We have investigated the electrical properties of InAs nanocrystals (nc-InAs) embedded in SiO2 for nonvolatile-memory (NVM) applications. Memory structures with 3.5-nm-thick tunnel oxide and 6-7-nm-diameter nc-InAs were studied electrically. It is possible to reach the write/erase long-term ITRS requirements for NVMs with a tunnel-oxide thickness of around 4 nm. Indeed, a 1-mus programming time is obtained for gate voltages that are lower than 15 V, while an erasing time of 100 mus is obtained for gate voltages of 11 V. The nc-InAs/ SiO2 system was compared with the nc-Si/ SiO2 system in terms of data retention. We measured a strong increase of retention properties (about two orders of magnitude) for nc-InAs. Moreover, our best structure retains 80% of the charge after four months, which is a record when using 3.5-nm-thick tunnel oxides in nanocrystal-based NVMs. We have also shown that the ten-year retention time can be reached using nc-InAs with diameters that are larger than 8 nm and at least 4-nm-thick tunnel oxides.

Objective: Sentinel lymph node (SLN) biopsy is a new component of the surgical treatment of breast cancer that accurately predicts axillary status. In this study the authors evaluated the accuracy of intraoperative imprint cytology (IC) in comparison with definitive histologic evaluation of SLN in breast cancer patients. Methods: A total 413 women with breast carcinoma and clinically negative axillary nodes underwent breast surgery and SLN biopsy. Mapping of SLN involved injection of 99mTechnecium labelled human albumin nanocolloid particles and Patent Blue dye. At the Department of Pathology, SLNs were bisected along its major axis. Both halves were imprinted 2–4 times on the slides and immediate staining with Hemacolor (Merck Germany) was performed for intraoperative examination. Imprint node negative women underwent no further surgery, while node positive women proceeded to full axillary clearance. Histological analysis of the SLN involved serial sectioning of the whole node with H&E and immunostaining for cytokeratin. Results: Definitive histology revealed metastases (pN+) in 159/413 patients (38.5%): 69 (16.7%) macro metastases, 57 (13.8%) micro metastases, and 33 (8%) women with only isolated IHC positive cells or positive cell groups smaller than 0.2 mm (pNO sn+). The other 254 women had negative SLN biopsy. Imprint cytology detected 54/69 macro metastases, and 4/57 micro metastases. In the group with negative SLN (254), 2 cases were ‘‘false positives’’. Conclusions: Imprint of SLN biopsy can identify a negative axilla with high accuracy (specificity 99.2%). Overall sensitivity is only 36.5%, but macrometastases are detected in 77% which is important for performing ALDN in one session with operation of primary tumour.

The aim of the study was to analyse the results of BRCA1/2 testing in a group of patients with double primary breast and ovarian cancer (DPBOC) in Slovenia. Additionally, the family history and the clinicopathologic characteristics of BRCA1/2 mutation positive and negative patients with DPBOC were analysed, comparing them to a group of untested patients with DPBOC. For these groups of patients, survival analysis was also performed. From the 52 patients who were invited to genetic counselling and testing, 20 responded positively (38% compliance). BRCA1/2 mutations were found in 60% (12/20): 45% BRCA1 and 15% BRCA2 (9 and 3 patients, respectively). There was significantly higher grade of ovarian cancer and significantly higher rate of multiple primary breast cancer in BRCA1/2 positive group. Additionaly, there was a trend towards higher rate of first-degree family history of breast cancer, a trend towards higher stage of ovarian cancer, and a trend towards breast cancer being the first cancer in BRCA1/2 positive group. According to survival analysis, the tested group was not a representative sample of the larger untested group (of 51 patients), so we estimate that the rate of BRCA1/2 mutations in DPBOC patients is probably less than 60%. Keywords: breast cancer, ovarian cancer, BRCA1 gene, BRCA2 gene, double primary cancer.

Thyroglobulin (Tg) is a glycoprotein produced exclusively by the thyroid. It can be found in the serum of healthy people as well as of those with various thyroid disorders. Elimination of Tg from the body occurs through the liver. The data on Tg serum half-life in the literature are scarce, and the reported values vary from 6-96 h. The aim of our study was to determine the Tg half-life after surgical removal of the thyroid gland. Knowing the exact half-life of Tg would enable rational timing of sampling serum for determination of Tg after thyroid surgery or chemotherapy and/or irradiation for evaluation of treatment in patients with differentiated thyroid cancer (DTC). In 11 patients (10 females and one male, aged 27-85 years) serum samples were taken 24, 48, 72 and 168 h after a near-total or total thyroidectomy. Serum Tg levels were determined and Tg half-life calculated by the use of a one-compartment kinetic model. Mean Tg half-life was 65.2 h (SEM = 4.3), and Tg levels decrease below 5-10 ng/ml approximately only 25 days after thyroidectomy (7-10 x t1/2). Therefore, earlier determination of Tg cannot be used either for reliable detection of distant metastases or for evaluation of the effect of chemotherapy and/or irradiation.

Controversy exists over the utility of different methods for intra-operative sentinel lymph node (SLN) evaluation in patients with malignant melanoma (MM). The aim of this study was to evaluate the role of intra-operative imprint cytology (IC) in patients with MM. 215 SLNs from 99 patients with MM were examined by IC and results compared with the results of permanent sections. 24 patients had MM deposits in their SLNs and this was confirmed by histological examination. Intraoperative IC was positive in 11 of these patients (46% sensitivity). In addition, there were three false-positive IC diagnoses (79% positive predictive value); one of these was due to contamination during the sectioning of the SLN. The specificity and the negative predictive values of the IC were 96 and 85%, respectively. IC is a valuable method of intra-operative SLN evaluation which can spare approximately half of the patients with clinically occult regional metastases from a second surgical procedure. However, special care must be taken to avoid false-positive results due to contamination.

From 1983–1991, 44 patients (33 females, 11 males, age 32–82 years) with differentiated, primarily inoperable, recurrent or metastatic thyroid carcinoma (28 follicular, 9 Huerthle cell, 7 papillary) entered a study on individualized multimodal treatment. For monitoring the effect of treatment, sequential thyroglobulin (Tg) measurements in addition to other methods, i.e. tumour diameter measurements, ultrasonography (US), X-ray, CT scan and repeated fine needle aspiration biopsies (FNAB), were performed in 11 out of 44 patients. The Tg levels reflected the impact of treatment. Tg levels normalized in complete responders (4/11), and decreased in partial responders (5/11), whereas Tg remained unchanged or increased in nonresponders (2/11). The value of sequential Tg measurements is demonstrated by a report of 2 cases. Sequential Tg measurements seem to be a promising method for monitoring the effect of chemotherapy and RTX in differentiated thyroid carcinoma. However, a possible link between tumour dedifferentiation and lowered Tg levels must be considered.