Treatment With Ferrates Eliminates DNA and Proteins

Ferrate (VI) salts have been proposed for use in sterilizing water (perhaps also in sterilizing air). The iron in ferrate (VI) salts is in its highest oxidation state (VI), and these salts are extremely strong oxidants. In laboratory experiments, it was shown that treatment of DNA solutions with micromolar concentrations of potassium ferrate (VI) irreversibly inhibits further DNA polymerization and polymerase-chain-reaction (PCR) synthesis. Such treatment does not produce any toxic wastes; instead, what remains after treatment are iron ions, which can be recycled and which, in some applications, are useful as nutrients.

Posted in: Briefs, TSP, Bio-Medical, Medical, Research and development, Iron

Spacecraft-Facility Microbes Tolerate H2O2, NaCl, and Heat

A report describes experiments that were performed to isolate and characterize microbes that survive conditions of controlled circulation of air, desiccation, low nutrient concentrations, and moderately high temperatures in a spacecraft-assembly facility. These conditions are more severe than those to which the natural strains of the same microbial species are ordinarily exposed. This study is part of continuing research on related issues of (1) efficacy of sterilization (e.g., by use of H2O2 and/or heat) of spacecraft to be used in planetary exploration, (2) the use of selected microbes as indicators of the effectiveness of sterilization, and (3) the feasibility of commercial utilization of enzymes produced by microbes that tolerate severe conditions.

Posted in: Briefs, TSP, Bio-Medical, Medical, Assembling, Spacecraft

Engineered Bioremediation of Contaminated Soil

Electrokinetically enhanced bioremediation (EEB) is a method of engineered bioremediation of soil contaminated by such organic compounds as solvents and petroleum products. As depicted schematically in the figure, EEB involves the utilization of controlled flows of liquids and gases into and out of the ground via wells, in conjunction with electrokinetic transport of matter through pores in the soil, to provide reagents and nutrients that enhance the natural degradation of contaminants by indigenous and/or introduced micro-organisms.

Posted in: Briefs, TSP, Bio-Medical, Medical, Land pollution, Soils

Microgravity Tissue Engineering

A continuing program of research and development focuses on engineering of functional cartilage and cardiac muscle for scientific research and for eventual use in transplants. The program involves the use of cells, polymer scaffolds, and bioreactor vessels. A polymer scaffold serves as a three-dimensional structure to which cells can attach. Once attached, the cells can regenerate full tissues, and then the polymer scaffold becomes biodegraded when no longer needed. A bioreactor provides an appropriate environment and physiological signals during the development of tissues.

Posted in: Briefs, Bio-Medical, Medical, Prostheses and implants, Fabrication, Biomaterials, Polymers

"Breathprint" Analysis of Microbial Communities

A technique for assessing changes in the densities and compositions of communities of microorganisms in environmental samples is based partly on redox chemistry. Suspensions of microbes from environmental samples are inoculated into 95-well microtiter plates. Each well contains an initially colorless redox-sensitive dye and a source of carbon different from the sources of carbon in the other wells. If the microorganisms in a well can utilize or degrade the source of carbon, then the colorless dye is reduced to a colored crystal. The overall pattern of color in the various wells can be regarded as a "breathprint" of the microbial community. Because inoculation of the wells takes less than a minute and the reading of colors and analysis of the resulting data are largely automated, an assay by this technique can be performed relatively quickly. The technique has been used for such diverse purposes as monitoring the stability of microbial populations in artificial plant-growth and life-support systems, testing for toxicity, monitoring bioremediation, monitoring industrial bioreactors, studying subsurface microbiology, and studying fertility of agricultural soils.

Posted in: Briefs, TSP, Bio-Medical, Medical, Biological sciences, Research and development

Macroextraction for Purification of Nucleic Acids

A technique for extracting samples of ribonucleic acid (RNA) and deoxyribonucleic acid (DNA) for use in diagnosing and studying infectious and genetic diseases has been developed. The technique enables the concentration and purification of nucleic acids from large (in comparison with older techniques) volumes of bodily fluids or digested tissues, with minimal nuclease activity and minimal loss of the nucleic acids.

Posted in: Briefs, TSP, Bio-Medical, Medical, Biological sciences, Diagnosis, Diseases, Test equipment and instrumentation

Slide-Staining System for Microgravity or Gravity

The centrifuge-operated slide stainer (COSS) is a conceptual self-contained system that could be attractive for use in a variety of histological and cytological procedures in both microgravity and normal Earth gravity. The COSS was conceived specifically for use in staining blood smears on glass slides in order to enable differential white-cell counts (DWCCs) on astronauts during spaceflight. (The differential white-cell count is a standard technique for distinguishing between a healthy condition and any of a number of viral or bacterial infections.) In addition to overcoming microgravitational obstacles to the staining process, the COSS would do most of the routine and tedious processing steps that heretofore, have been performed manually in conventional terrestrial preparation of blood samples. On Earth, the COSS could be useful at remote medical research field stations, military field hospitals, and biomedical research facilities.

Posted in: Briefs, TSP, Bio-Medical, Medical, Medical equipment and supplies

In Situ Activation of Microencapsulated Drugs

In a new method of delivering drugs to target sites in a human body, (1) the drugs would be stored in inactive forms in timed-release microcapsules that would be injected, then (2) the drugs would be activated by exposing the target sites to suitable forms of penetrating energy that could include electromagnetic radiation (radio waves, light, or x rays), ultrasound, or heat, then (3) the drugs would diffuse out of the microcapsules. The method would be well suited for drugs that have short shelf lives in their active forms and/or could be activated at target sites upon exposure to nonharmful activation energy.

Posted in: Briefs, TSP, Bio-Medical, Medical, Pharmaceuticals

Improved Unidirectional Cell-Stretching Device

An improved stretching device has been developed for use in research on the effects of unidirectional loading on human and animal cells. The device is capable of applying or removing a load (a controlled amount of stretch) on command to mimic the loading or unloading experienced by skeletal muscles and other tissues of interest.

Posted in: Briefs, TSP, Bio-Medical, Medical, Biological sciences, Test equipment and instrumentation

Apparatus Measures Attachment or Detachment of Biofilm

Figure 1 schematically illustrates a laboratory apparatus that provides quantitative information on the density and on the rate of increase (or decrease) of density at which bacteria attach themselves to solid surfaces in a potable-water-supply system. These biofilms are potentially pathogenic and/or phytotoxic and can adversely affect processing of the water under some circumstances. The apparatus was devised to assess the abilities of biocide chemicals in water to suppress the biofilms in potable-water subsystems within closed life-support systems of spacecraft, but may also be adaptable to similar investigations of biofilms in terrestrial water supplies.

Posted in: Briefs, TSP, Bio-Medical, Medical, Water quality, Bacteria, Life support systems, Chemicals, Test equipment and instrumentation

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