Detection of adulterated drugs in traditional Chinese medicine and dietary supplements using hydrogen as a carrier gas.

Helium, a minor component of natural gas and radioactive minerals, is most commonly used as a carrier in gas chromatography-mass spectrometry (GC-MS). Its scarcity leads to limited availability and higher costs. In this experiment, hydrogen from a safe source of a hydrogen generator was tested as a substitutive carrier gas for the detection of adulterant in traditional Chinese medicine (TCM) and food supplements by GC-MS analysis. We found that the limits of detection (LODs) of using hydrogen were from 10 to 1000 µg/g. The levels of LODs tested among 170 drugs remain the same whether hydrogen or helium was used as a carrier gas with the exception of 7 drugs-benzbromarone, estradiol benzoate, bezafibrate, mefenamic acid, oxymetholone, piperidenafil and cetilistat. The real sample analysis results using hydrogen were as satisfactory as those using helium. In addition, the retention time was shortened after the chromatographic performance was optimized. In summary, it is worth considering hydrogen as a carrier gas due to its affordable costs, energy efficiency, carbon reduction and chromatographic advantages to detect adulterated drugs in TCM and dietary supplement using GC-MS.

Determination of multiresidue analysis of ß-agonists in muscle and viscera using liquid chromatograph/tandem mass spectrometry with Quick, Easy, Cheap, Effective, Rugged, and Safe methodologies.

The official analytical method of the Taiwan Food and Drug Administration, Ministry of Health and Welfare for testing for veterinary drug residues in foods is the multiresidue analysis of ß-agonists. Samples are pretreated through liquid-liquid extraction and solid-phase extraction. This method is time consuming and requires the intensive use of solvents. To improve analytical efficiency and reduce costs, our study incorporated QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) techniques to establish a new method of multiresidue analysis of ß-agonists in animal muscle and viscera. The pretreatment time was shortened and solvent usage was minimized. The modified analysis was conducted using liquid chromatography/tandem mass spectrometry (LC-MS/MS) and quantification was performed using multiple reaction monitoring. The results demonstrated that the correlation coefficients of the tissue calibration curve were higher than 0.99 and the limit of quantification (LOQ) was 1 ppb. The average recoveries in spiked samples varied from 70% to 120%, and the relative difference between duplicated analysis results was lower than 10%. On the basis of the results, the proposed method was concluded to be an appropriate procedure for determining the presence of ß-agonists, and demonstrated the advantages of high recovery rates in spiked samples, high precision, reduced analysis time and solvent usage, and lower costs.

Successful medical treatment of an implant periapical lesion: a case report.

An implant periapical lesion (IPL) is an infectious-inflammatory alteration surrounding an implant apex. In the English literature, the treatments for IPL have all been surgical methods. We present a case of successful treatment of an IPL with medical methods. A 36-year-old man underwent placement of two implants in the molar region of the right mandible. About one month later, the patient had pain at the surgical site and radiolucencies at the apical portion of the two implants on radiographs. Systemic antibiotic treatment with amoxicillin and acetaminophen was instituted, but the symptoms did not improve. The medications were changed to prednisolone, augmentin and mefenamic acid and the patient's symptoms completely subsided. This case was successfully treated using medical methods. The IPL disappeared on radiography and there were no symptoms or signs of recurrence at the 2-year follow up. We report a successful case of an IPL using medical methods. However, additional data are certainly necessary for a more comprehensive understanding of the etiopathologic and clinical problems related to an IPL.

Part-based local shape models for colon polyp detection.

This paper presents a model-based technique for lesion detection in colon CT scans that uses analytical shape models to map the local shape curvature at individual voxels to anatomical labels. Local intensity profiles and curvature information have been previously used for discriminating between simple geometric shapes such as spherical and cylindrical structures. This paper introduces novel analytical shape models for colon-specific anatomy, viz. folds and polyps, built by combining parts with simpler geometric shapes. The models better approximate the actual shapes of relevant anatomical structures while allowing the application of model-based analysis on the simpler model parts. All parameters are derived from the analytical models, resulting in a simple voxel labeling scheme for classifying individual voxels in a CT volume. The algorithm's performance is evaluated against expert-determined ground truth on a database of 42 scans and performance is quantified by free-response receiver-operator curves.