Noninvasive dopamine determination by reversed phase HPLC in the medium of free-floating roller tube cultures of rat fetal ventral mesencephalon: a tool to assess dopaminergic tissue prior to grafting

We used a retroviral vector containing a human gamma-interferon (gamma-IFN) gene to transduce 13 renal carcinoma cell lines. The transduction efficiencies ranged from 0% to 60%, as determined by using an analogous vector containing the LacZ marker gene. In addition, gene-transferred resistance to the antibiotic neomycin was used to select for transduced cells. Nine of 13 lines were successfully transduced. Transduction was associated with the morphologic change of elongation, and there was a marked decrease in cell growth rate. Transduced cells secreted varying amounts (20-1076 pg/10(6) cells/d) of gamma-IFN as measured by enzyme-linked immunosorbent assay for at least 2 to 3 weeks after transduction (including 1 day of transduction, 6-7 days of selection, and an additional 8-12 days before the first passage of the transduced cells). Human leukocyte antigen (HLA) class II expression was markedly increased in six of seven cell lines; HLA class I expression was significantly increased in two of eight lines. Transduced cells that were subjected to cryopreservation after irradiation still produced gamma-IFN and expressed HLA class I and II antigens, although generally at lower levels than before these manipulations. This study confirms that retroviral vector transduction of the human gamma-IFN gene into renal carcinoma cells is feasible and associated with persistent production of gamma-IFN and increased expression of HLA class I and II molecules, and these effects are retained after irradiation and cryopreservation. This suggests that an autologous tumor cell vaccine trial with irradiated gamma-IFN gene-transduced renal carcinoma cell is rationale and feasible.     

High-reflectance composite metal coatings for planar-integrated free-space optics

For planar-integrated free-space optical (PIFSO) systems high-reflectance thin-film coatings are crucial. Evaporated metal films are preferred for their relative technological simplicity. We propose a three-layer Al-Ag-Al coating composition that combines the high reflectance of Ag with the chemical passivity of Al and its good adherence to glass. Two special measures are taken to prevent delamination: one is an anchoring of the edges of the coating in narrow ditches that are etched into the substrate and the other is the use of an adhesive Al underlayer; to reduce absorption this underlayer is implemented only in sparsely distributed discrete areas. The optical properties of such composite coatings are investigated theoretically. The fabrication complexity is only slightly increased compared to PIFSO systems with one-layer Al reflectors. In experimental tests we verified a reflectance of approximately 98% and an adherence comparable to that of simple Al coatings.     

Nutrition Labeling: Rapid Determination of Total <Emphasis Type="Italic">trans</Emphasis> Fats by Using Internal Reflection Infrared Spectroscopy and a Second Derivative Procedure

In 2006, the US FDA mandated the declaration of the total trans fat content on the Nutrition Fact label of foods including dietary supplements when a product contained 0.5 or more grams of trans fatty acid per serving; the minimum corresponding trans fat content is estimated to be approximately 2% of total fat. The FDA definition is based on chemical structure and includes only fatty acids with one or more isolated double bonds in the trans configuration. Several issues negatively impacted the sensitivity of the current official infrared (IR) methods, thus limited the quantitation of trans fat to 5% of total fat. To improve sensitivity and accuracy and to meet the labeling requirement, a new internal reflection IR procedure called negative second derivative is described and evaluated for the quantitation of total trans fat in the present study. The enhanced spectral features of a second derivative resolved issues that traditionally limited the sensitivity of the IR methodology. Calibration standard mixtures starting at approximately 0.5% trielaidin in the total fat (tripalmitin or triarachidin) were successfully generated and used to determine the trans fat levels for unknown test samples with trans content as low as approximately 1% of total fat. Quantitative IR data were compared to those obtained by gas chromatography and were found to be in good agreement.