Alternative chromatographic system for the quality control of lipophilic technetium-99m radiopharmaceuticals such as [(99m)Tc(MIBI)6].

Knowledge of the radiochemical purity of radiopharmaceuticals is mandatory and can be evaluated by several methods and techniques. Planar chromatography is the technique normally employed in nuclear medicine since it is simple, rapid and usually of low cost. There is no standard system for the chromatographic technique, but price, separation efficiency and short time for execution must be considered. We have studied an alternative system using common chromatographic stationary phase and alcohol or alcohol:chloroform mixtures as the mobile phase, using the lipophilic radiopharmaceutical [(99m)Tc(MIBI)6]⁺ as a model. Whatman 1 modified phase paper and absolute ethanol, Whatman 1 paper and methanol:chloroform (25:75), Whatman 3MM paper and ethanol:chloroform (25:75), and the more expensive ITLC-SG and 1-propanol:chloroform (10:90) were suitable systems for the direct determination of radiochemical purity of [(99m)Tc(MIBI)6]⁺ since impurities such as (99m)Tc-reduced-hydrolyzed (RH), (99m)TcO(4)(-) and [(99m)Tc(cysteine)2]⁻ complex were completely separated from the radiopharmaceutical, which moved toward the front of chromatographic systems while impurities were retained at the origin. The time required for analysis was 4 to 15 min, which is appropriate for nuclear medicine routines.

Alternative chromatographic system for the quality control of lipophilic technetium-99m radiopharmaceuticals such as [99mTc(MIBI)6]+

Knowledge of the radiochemical purity of radiopharmaceuticals is mandatory and can be evaluated by several methods and techniques. Planar chromatography is the technique normally employed in nuclear medicine since it is simple, rapid and usually of low cost. There is no standard system for the chromatographic technique, but price, separation efficiency and short time for execution must be considered. We have studied an alternative system using common chromatographic stationary phase and alcohol or alcohol:chloroform mixtures as the mobile phase, using the lipophilic radiopharmaceutical [99mTc(MIBI)6]+ as a model. Whatman 1 modified phase paper and absolute ethanol, Whatman 1 paper and methanol:chloroform (25:75), Whatman 3MM paper and ethanol:chloroform (25:75), and the more expensive ITLC-SG and 1-propanol:chloroform (10:90) were suitable systems for the direct determination of radiochemical purity of [99mTc(MIBI)6]+ since impurities such as99mTc-reduced-hydrolyzed (RH),99mTcO4- and [99mTc(cysteine)2]-complex were completely separated from the radiopharmaceutical, which moved toward the front of chromatographic systems while impurities were retained at the origin. The time required for analysis was 4 to 15 min, which is appropriate for nuclear medicine routines.

Analysis of differentially expressed proteins in colorectal cancer using hydroxyapatite column and SDS-PAGE.

Limitation on two dimensional (2D) gel electrophoresis technique causes some proteins to be under presented, especially the extreme acidic, basic, or membrane proteins. To overcome the limitation of 2D electrophoresis, an analysis method was developed for identification of differentially expressed proteins in normal and cancerous colonic tissues using self-pack hydroxyapatite (HA) column. Normal and cancerous colon tissues were homogenized and proteins were extracted using sodium phosphate buffer at pH 6.8. Protein concentration was determined and the proteins were loaded unto the HA column. HA column reduced the complexity of proteins mixture by fractionating the proteins according to their ionic strength. Further protein separation was accomplished by a simple and cost effective sodium dodecyl sulfate-polyacrylamide gel electrophoresis method. The protein bands were subjected to in-gel digestion and protein analysis was performed using electrospray ionization (ESI) ion trap mass spectrometer. There were 17 upregulated proteins and seven downregulated proteins detected with significant differential expression. Some of these proteins were low abundant proteins or proteins with extreme pH that were usually under presented in 2D gel analysis. We have identified brain mitochondrial carrier protein 1, T-cell surface glycoprotein CD1a, SOSS complex subunit B2, and Protein Jade 1 which were previously not detected in 2D gel analysis method.

Analysis of the operational costs of using rapid syphilis tests for the detection of maternal syphilis in Bolivia and Mozambique.

OBJECTIVE: The objective of this study was to compare the costs of antenatal syphilis screening with the rapid plasma reagin (RPR) test and the immunochromatographic strip (ICS) test in low-resource settings. GOAL: The goal of this study was to assess the costs of introducing rapid syphilis tests to reduce maternal and congenital syphilis. STUDY DESIGN: Cost data were collected from participating study hospitals and antenatal clinics during 4 field visits to the 2 countries in 2003 and 2004. Health utilization outcome data on the number of women screened and treated routinely during the demonstration projects were used with unit cost data to estimate the incremental costs and average cost per woman screened and treated for maternal syphilis. RESULTS: In Mozambique, the average cost per woman screened was U.S. $0.91 and U.S. $1.05 for the RPR and ICS tests, respectively. In Bolivia, the average cost of screening was U.S. $1.48 and U.S. $1.91 using the RPR and ICS test, respectively. In health centers without laboratories, the cost per woman screened using the ICS test ranged from U.S. $1.02 in Mozambique to U.S. $2.84 in Bolivia. CONCLUSIONS: It is feasible to introduce rapid syphilis testing in settings without laboratory services at a small incremental cost per woman screened. In settings with laboratories, the cost of ICS is similar to that of RPR.

An improved method for analyzing coenzyme Q homologues and multiple detection of rare biological samples.

We have developed a simple method for the estimation of coenzyme Q homologues, neurotransmitters, metal ions, lipid peroxidation, gene expression, and DNA fragmentation simultaneously from genetically engineered mice brain regions and cultured neurons. The primary objective of this study was to improve conventional time-consuming, cumbersome, and less efficient procedures, and reduce the cost of conducting kinetic studies in rare biological samples. The improved method is novel, precise, efficient, accurate, sensitive, economical, versatile, and highly reproducible. The recovery and shelf life of coenzyme Q homologues was significantly increased and the chromatograms exhibited reduced background and retention times. It is envisaged that in addition to coenzyme Q homologues, the improved method could be utilized for the multiple analyses of DNA, RNA and proteins from clinically significant biopsy and autopsy samples.

Protein recovery, separation and purification: selection of optimal techniques using an expert system

The paper discusses the utilization of new techniques ot select processes for protein recovery, separation and purification. It describesa rational approach that uses fundamental databases of proteins molecules to simplify the complex problem of choosing high resolution separation methods for multi component mixtures. It examines the role of modern computer techniques to help solving these questions

Bio-flash chromatography--rapid, low-cost purification of peptides.

The use of wide pore 40/60 mu Sorbsil silicas bonded with a range of biocompatible phases now allows the biochemist to benefit from the advantages that flash chromatography has given to synthetic organic chemists. The technique of bio-flash chromatography allows rapid peptide and protein purification at low pressure (less than 15 psi) and at a fraction of the cost of high-pressure systems.