Pitfalls in assessing stromal tumor infiltrating lymphocytes (sTILs) in breast cancer

Stromal tumor-infiltrating lymphocytes (sTILs) are important prognostic and predictive biomarkers in triple-negative (TNBC) and HER2-positive breast cancer. Incorporating sTILs into clinical practice necessitates reproducible assessment. Previously developed standardized scoring guidelines have been widely embraced by the clinical and research communities. We evaluated sources of variability in sTIL assessment by pathologists in three previous sTIL ring studies. We identify common challenges and evaluate impact of discrepancies on outcome estimates in early TNBC using a newly-developed prognostic tool. Discordant sTIL assessment is driven by heterogeneity in lymphocyte distribution. Additional factors include: technical slide-related issues; scoring outside the tumor boundary; tumors with minimal assessable stroma; including lymphocytes associated with other structures; and including other inflammatory cells. Small variations in sTIL assessment modestly alter risk estimation in early TNBC but have the potential to affect treatment selection if cutpoints are employed. Scoring and averaging multiple areas, as well as use of reference images, improve consistency of sTIL evaluation. Moreover, to assist in avoiding the pitfalls identified in this analysis, we developed an educational resource available at www.tilsinbreastcancer.org/pitfalls.

DNA barcoding of arid wild plants using rbcL gene sequences

DNA barcoding is currently gaining popularity due to its simplicity and high accuracy as compared to the complexity and subjective biases associated with morphology-based identification of taxa. The standard chloroplast DNA barcode for land plants recommended by the Consortium for the Barcode of Life (CBOL) plant working group needs to be evaluated for a wide range of plant species. We therefore tested the potential of the rbcL marker for the identification of wild plants belonging to diverse families of arid regions. Maximum likelihood tree analysis was performed to evaluate the discriminatory power of the rbcL gene. Our findings showed that using rbcL gene sequences enabled identification of the majority of the samples (92%) to genus level and only 17% to species level.

Application of RAPD for molecular characterization of plant species of medicinal value from an arid environment

The use of highly discriminatory methods for the identification and characterization of genotypes is essential for plant protection and appropriate use. We utilized the RAPD method for the genetic fingerprinting of 11 plant species of desert origin (seven with known medicinal value). Andrachne telephioides, Zilla spinosa, Caylusea hexagyna, Achillea fragrantissima, Lycium shawii, Moricandia sinaica, Rumex vesicarius, Bassia eriophora, Zygophyllum propinquum subsp migahidii, Withania somnifera, and Sonchus oleraceus were collected from various areas of Saudi Arabia. The five primers used were able to amplify the DNA from all the plant species. The amplified products of the RAPD profiles ranged from 307 to 1772 bp. A total of 164 bands were observed for 11 plant species, using five primers. The number of well-defined and major bands for a single plant species for a single primer ranged from 1 to 10. The highest pair-wise similarities (0.32) were observed between A. fragrantissima and L. shawii, when five primers were combined. The lowest similarities (0) were observed between A. telephioides and Z. spinosa; Z. spinosa and B. eriophora; B. eriophora and Z. propinquum. In conclusion, the RAPD method successfully discriminates among all the plant species, therefore providing an easy and rapid tool for identification, conservation and sustainable use of these plants.

Determination of nickel, copper, zinc and lead in human scalp hair in Syrian occupationally exposed workers by total reflection X-ray fluorescence

The concentrations of Ni, Cu, Zn, and Pb in human scalp hair of 281 individuals working in 10 Syrian industrial plants were determined using co-precipitation by ammoniumpyrolidinedithiocarbamate (APDC) method for total reflection X-ray fluorescence (TXRF) analysis. The results were compared to data obtained for a control group consisted of individuals working at the Syrian Atomic Energy Commission and also to data reported in the literature. The results given by the group of workers in battery plant showed that Pb concentration in human scalp hair samples were higher than those for control group, while some abnormal concentrations were obtained for Cu, Zn and Ni in cables, printing and battery plants, respectively. Normal concentrations of these elements were obtained for hair workers in olive oil, power stations, textile, and iron industrial plants. The relationships of Pb-Pb/Ni and Cu-Cu/Ni were plotted with correlation coefficients of 0.9937 and 0.9014, respectively. In general, the results showed that, the workers who were occupationally exposed to battery industrial pollution are at risk, followed by individuals in printing and cables industries, while the rest of workers in other industries are considered occupationally unexposed.

c-erbB2 protein overexpression in breast cancer as a target for PET using iodine-124-labeled monoclonal antibodies

ICR 12, one of a panel of rat monoclonal antibodies recognizing the external domain of the human c-erb B2 proto-oncogene product, (Styles, 1990) was chosen as a candidate for radiolabeling with 124I for positron emission tomography of selected patients with breast cancer. By using N-bromosuccinimide (NBS), optimal labeling conditions were established using 125I. The labeling efficiency was determined using instant thin-layer chromatography (ITLC) and gel filtration (HPLC). The antibody was then labeled with the positron emitter 124I, and a labeling efficiency of 96% and immunoreactivity of 80%-90% was obtained. The product was stable, with less than 5% of the radiolabel being eluted after six days storage in plasma at 37 degrees C. Immunolocalization studies were performed in athymic mice bearing human breast carcinoma xenografts overexpressing the c-erb B2 gene product using as controls 125I labeled isotype-matched rat antibody, and antigen-negative tumors. Good uptake of 124I-labeled ICR12 was obtained in c-erb B2 expressing tumors (up to 12% injected dose per gram at intervals up to 120 hr), with localization indices of 3.4-6.2. Tumor xenografts of 6 mm diameter were successfully imaged with high resolution at 24, 48 and 120 hr using the RMH/ICR MUP-PET camera. We suggest that 124I-labeled ICR12 is a suitable agent to image and quantify immunolocalization in patients whose tumors overexpress the c-erb B2 proto-oncogene product.