Automated detection of anti-double-stranded DNA antibody in systemic lupus erythematosus serum by flow immunoassay

We describe a novel automated flow immunoassay system for quantification of anti-double-stranded (ds) DNA autoimmune antibodies in the serum of patients suffering from systemic lupus erythematosus. dsDNA (360 bp) was covalently coupled with alkaline phosphatase (ALP) to form a novel analytical reagent (ALP-DNA). After immunoreaction, antibody-antigen complexes between ALP-DNA and anti-dsDNA monoclonal antibody were separated from unreacted ALP-DNA by an ion-exchange column on the basis of the difference in isoelectric point. Antibody-antigen complexes were subsequently quantified by luminescence following addition of 3-(2'-spiroadamantane)-4-methoxy-4-(3"-phosphoryloxy)phenyl- 1,2-dioxetane. The assay yielded a linear relationship between signal and concentration of anti-dsDNA monoclonal antibody in the range of 0-300 micrograms/mL. This simple technique permits the assay of anti-dsDNA autoimmune antibodies within 25 min. The ion-exchange column was simply regenerated by occasional elution with eluent (20 mM N-methylpiperazine, pH 5.5) supplemented with 0.5 M NaCl, to remove unreacted ALP-DNA.     

Enhancement of serotonergic neural activity contributes to cyclosporine-induced tremors in mice

Patients suffering from inflammatory or dysimmunitary diseases may develop various clinical responses to corticotherapy. This brief article describes the various cellular and molecular mechanisms which underly the genetic, endocrine and immunitary factors involved in corticosensitivity, corticoresistance and corticodependence.     

Effective Utilization of Radiation and Two-Color Pyrometers

Existing procedures are standardized and translated into a computer program. Studies were made of charging, blowing and chemical reactions, and the use of flame radiation pyrometry and two-color pyrometry.     

Wind energy planning: Development and application of a site selection method for wind energy conversion systems (WECS)

The use of wind energy by means of its conversion to electricity involves a number of constrains such as economic, environmental, technical, legal, social and institutional requirements. Planning for wind energy should solve these issues in the planning process by encouraging opportunities and discouraging constraints associated with the use of wind energy. The opportunities and constraints significant at the regional level (i.e. approximately 10,000 km²) were identified, and a systematic method was developed to select sites for large WECS by incorporating the identified factors. These factors include: wind resource, proximity to load centres, proximity to tie-in points, and exclusive land-use areas. The developed method was applied to the western Massachusetts region, and the first results of the study have been acquired.     

Photoionization cross-sections and energy levels of gold,iron, platinum,silver, and titanium in silicon

The photoionization cross-sections of various deep impurities of interest in solar-grade silicon for photovoltaic cells, and the corresponding energy levels, have been determined by steady state photo-induced currents in pn junctions or Schottky barrier junctions irradiated simultaneously with two wavelengths of light. Light of about half the band-gap energy controls the occupancy of the deep impurity level and the spectral dependence of the photocurrent on a higher photon energy light source then provides, via the Lucovsky model, the photo-cross-section and the impurity energy level. The results obtained for Au and Pt in Si are in agreement with those of Braun and Grimmeiss and the energy levels for Fe, Ti, and Ag obtained optically are in agreement with those obtained by other methods.     

A novel transfection method for mammalian cells using calcium alginate microbeads

The direct transfer of genetic materials into mammalian cells is an indispensable technique. We have developed calcium alginate (CA) microbeads which can deliver plasmid DNAs and yeast artificial chromosomes into plant and yeast cells. In this paper, we demonstrate the effective transfection of mammalian cells by CA microbeads immobilizing plasmid DNAs. The transfection was performed using the pEGFP-C1 plasmid containing the cytomegalovirus (CMV) promoter and enhanced green fluorescent protein (EGFP) gene. The transient expression of EGFP was observed 24 h after transfection. The expression efficiency was maximum when the concentration of sodium alginate was 1% and the amount of plasmid DNA was increased to 100 microg. The expression efficiency of our method using CA microbeads is 2-10 times higher than that of the polyethylene glycol (PEG) method. Our results suggest that the CA microbead mediated transfection of mammalian cells effectively delivers genetic materials into mammalian suspension cells.     

Development of new dosimetry using extended DNA fibers

We applied fluorescent microscopy to monitor the damage of DNA upon exposure to gamma radiation. Our developed dosimetry demonstrated that the number of breaks in DNA is proportional to the dose of the irradiation but is not dependent on dose rate of the irradiation and the GC content of DNA.     

A method for radiation-force localized drug delivery using gas-filled lipospheres

We have developed a method using ultrasound and acoustically active lipospheres (AALs) that might be used to deliver bioactive substances to the vascular endothelium. The AALs consist of a small gas bubble surrounded by a thick oil shell and enclosed by an outermost lipid layer. The AALs are similar to ultrasound contrast agents: they can be nondestructively deflected using ultrasound radiation force, and fragmented with high-intensity ultrasound pulses. The lipid-oil complex might be used to carry bioactive substances at high concentrations. An optimized sequence of ultrasound pulses can deflect the AALs toward a vessel wall then disrupt them, painting their contents across the vascular endothelium. This paper presents results from a series of in vitro and ex vivo experiments demonstrating localization of a fluorescent model drug. In experiments using a human melanoma cell (A2085) monolayer, a specific radiation force-fragmentation ultrasound pulse sequence increased cell fluorescence more than 10-fold over no ultrasound or fragmentation pulses alone, and by 50% over radiation force pulses alone. We observe that dye transfer is limited to cells that are in the region of ultrasonic focus, indicating that the application of radiation force pulses to bring the delivery vehicle into proximity with the cell is required for successful adhesion of the vehicle fragments to the cell membrane. We also demonstrate dye transfer from flowing AALs, both in a mimetic vessel and in excised rat cecum. We believe that this method could be successfully used for drug delivery in vivo.