A novel microfluidic platform for size and deformability based separation and the subsequent molecular characterization of viable circulating tumor cells.

Circulating tumor cells (CTCs) were introduced as biomarkers more than 10 years ago, but capture of viable CTCs at high purity from peripheral blood of cancer patients is still a major technical challenge. Here, we report a novel microfluidic platform designed for marker independent capture of CTCs. The Parsortix™ cell separation system provides size and deformability-based enrichment with automated staining for cell identification, and subsequent recovery (harvesting) of cells from the device. Using the Parsortix™ system, average cell capture inside the device ranged between 42% and 70%. Subsequent harvest of cells from the device ranged between 54% and 69% of cells captured. Most importantly, 99% of the isolated tumor cells were viable after processing in spiking experiments as well as after harvesting from patient samples and still functional for downstream molecular analysis as demonstrated by mRNA characterization and array-based comparative genomic hybridization. Analyzing clinical blood samples from metastatic (n = 20) and nonmetastatic (n = 6) cancer patients in parallel with CellSearch(®) system, we found that there was no statistically significant difference between the quantitative behavior of the two systems in this set of twenty six paired separations. In conclusion, the epitope independent Parsortix™ system enables the isolation of viable CTCs at a very high purity. Using this system, viable tumor cells are easily accessible and ready for molecular and functional analysis. The system's ability for enumeration and molecular characterization of EpCAM-negative CTCs will help to broaden research into the mechanisms of cancer as well as facilitating the use of CTCs as "liquid biopsies."

Composition and Antimicrobial Activity of the Essential Oil from Leaves of Curcuma longa L. Kasur Variety.

The essential oil from the leaves of Curcuma longa L. Kasur variety grown in Pakistan was extracted by hydro-distillation. Chemical constituents of the essential oil were identified by gas chromatography/mass spectrometry. The chromatographic analysis of oil showed 25 constituents, out of which nine chemical constituents were identified. The eucalyptol (10.27%) was the major component of the essential oil. α-pinene (1.50%), ß-phellandrene (2.49%), ß-pinene (3.57%), limonene (2.73%), 1,3,8-p-menthatriene (1.76%), ascaridole epoxide (1.452%), 2-methylisoborneol (2.92%), 5-isopropyl-6-methyl-hepta-3, dien-2-ol (2.07%) were also present in considerable quantity. The antimicrobial properties of leaves of Curcuma longa were tested by disc diffusion method against various human pathogens, including eight fungal and five bacterial strains. Essential oil showed maximum resistance against Fusarium miniformes MAY 3629 followed by Bacillus subtilis ATCC 6633 whereas; it exhibited least resistance against Fusarium oxysporium ATCC 48122. The results of the antimicrobial assay revealed that essential oil showed significant inhibitory activity against the tested organisms.

Stability of organophosphate and pyrethroid pesticides on wheat in storage.

The pesticides chlorpyriphos-methyl, pirimiphos-methyl and permethrin were applied to wheat and stored for 52 weeks at 25, 30, 35 and 40 degrees C, and at 10 and 13% m.c. Rates of loss were calculated from the residue analyses of pesticides in treated wheat at monthly intervals during the storage period. Calculated half-lives and pseudo first-order rate constants of these pesticides are discussed with reference to temperature and moisture.

Spleen necrosis virus-derived C-type retroviral vectors for gene transfer to quiescent cells.

Gene therapy applications of retroviral vectors derived from C-type retroviruses have been limited to introducing genes into dividing target cells. Here, we report genetically engineered C-type retroviral vectors derived from spleen necrosis virus (SNV), which are capable of infecting nondividing cells. This has been achieved by introducing a nuclear localization signal (NLS) sequence into the matrix protein (MA) of SNV by site-directed mutagenesis. This increased the efficiency of infecting nondividing cells and was sufficient to endow the virus with the capability to efficiently infect growth-arrested human T lymphocytes and quiescent primary monocyte-derived macrophages. We demonstrate that this vector actively penetrates the nucleus of a target cell, and has potential use as a gene therapy vector to transfer genes into nondividing cells.