Triplex-hybridizing bioconjugated gold nanoparticles for specific Y-chromosome sequence targeting of bull spermatozoa

Gold nanoparticles (AuNPs) are widely used in biomedical applications for drug targeting and bioimaging. This often neccesitates their functionalization with biomolecules carrying a defined biological function, yielding gold nanoparticle bioconjugates. The utilization of triplex-forming oligonucleotides (TFOs) as ligands gives access to nanoconjugates as tools for specific DNA-related nanotargeting via triplex hybridization. Since triplex hybridization with nanobioconjugates has to date not been shown on biologically relevant samples, sex-specific sperm marking may be an appropriate model system to demonstrate the opportunities of this targeting method in vitro. In this study, we focused on specific labeling of repetitive target sites enriched on the bovine Y-chromosome using triplex forming oligonucleotides. First, the functionality of a specific locked nucleic acid (LNA) sequence was confirmed on bovine free DNA and on demembranated sperm heads. Thereafter, the influence of AuNPs on triplex hybridization was spectrophotometrically analyzed employing synthetic dsDNA, genomic DNA and demembranated sperm heads. Results from the SPR-peak shift indicate that TFO-AuNP hybridize to bovine gDNA in a qualitative and significant manner. These results confirm successful triplex hybridization on biologically relevant target sites as well as the establishment of a method to use gold nanoparticles as a suitable tool for sex-selective hybridization.

Sex-Sorted Boar Sperm - An Update on Related Production Methods

As in other mammals, sex sorting of pig sperm is based on quantitative flow cytometry. A major disadvantage of the technique is the relatively low efficiency to produce enough sorted sperm for artificial insemination. However, several approaches are on the way to make sexed pig sperm available for commercial application. In this context, for example, the growing field of nanotechnology may significantly contribute to these developments, as it provides highly efficient bio-nanoprobes, for example, based on plasmonic nanoparticles. Independent of the method, further development requires enormous investments and set-up of logistics to get the technology into the practical pig market. Only global players will be able to establish the necessary research projects, but in the end, a significant shift of sex ratios will be available for pig producers as it is already the case for the dairy industry.

Nuclear charge radii of 7,9,10Be and the one-neutron halo nucleus 11Be

Nuclear charge radii of ;{7,9,10,11}Be have been determined by high-precision laser spectroscopy. On-line measurements were performed with collinear laser spectroscopy in the 2s_{1/2}-->2p_{1/2} transition on a beam of Be+ ions. Collinear and anticollinear laser beams were used simultaneously, and the absolute frequency determination using a frequency comb yielded an accuracy in the isotope-shift measurements of about 1 MHz. Combining this with accurate calculations of the mass-dependent isotope shifts yields nuclear charge radii. The charge radius decreases from 7Be to 10Be and then increases for the halo nucleus 11Be. When comparing our results with predictions of ab initio nuclear-structure calculations we find good agreement. Additionally, the nuclear magnetic moment of 7Be was determined to be -1.3995(5)micro_{N} and that of 11Be was confirmed with an accuracy similar to previous beta-NMR measurements.

Oncology today: ovarian cancer

While researchers work to improve treatment and come up with an accurate way to detect the disease early on, ovarian cancer will kill 14,000 women in the United States this year. Here's an update on this particularly insidious form of cancer: how it's managed today and treatment options for the future.

Improved local control of thoracic disease in small cell lung cancer with higher dose thoracic irradiation and cyclic chemotherapy

Over the past decade, improvement in survival has developed for patients with small cell lung carcinoma (SCLC) due to treatment strategies that include: cyclic combination chemotherapy, thoracic irradiation, and prophylactic cranial irradiation. In this study, we assess the outcome of treatment with initial cyclic combination chemotherapy including: cyclophosphamide, VP 16-123 and methotrexate combined with radiotherapy (RT), 6000 cGY [corrected] to the thorax for patients with limited disease and 3000 cGy [corrected] for patients with extensive disease. Forty-six patients are evaluated: 26 patients with limited disease and 20 with extensive disease. In patients who received 6000 cGy [corrected], to thoracic lesions, in combination with chemotherapy, administered for 3 courses prior to and following RT, the rate of clinically detected failure in the thorax was 3.8%. Morbidity was considered acceptable, although the occurrence of encephalopathy in 6 of 19 cases who received cranial irradiation, 3000 cGy [corrected], and concomitant chemotherapy was a serious consequence. Control of the primary tumor achieved by the use of higher dose RT is shown to be superior to that observed at lower doses of RT. This suggests that for the small cohort of patients whose disease is truly limited at the time of diagnosis, therapeutic regimens, which include higher dose RT, could increase the number of long term survivors of SCLC.