The continued use of purified protein derivative (PPD) tuberculin is considered to be the main factor which limits the specificity of diagnostic tests for bovine tuberculosis (TB). This study evaluated a whole blood interferon-gamma (IFN-gamma) assay and compared the diagnostic potential of PPD with two tuberculosis-specific antigens, ESAT-6 and MPB70. To provide estimates of sensitivity and specificity, responses were measured in 180 skin test-reacting cattle, of which 131 were confirmed as tuberculous, and in 128 cattle from TB-free herds. For the skin test reactors, there was a positive correlation between the IFN-gamma responses to PPD from Mycobacterium bovis (PPDB) and PPD from Mycobacterium avium (PPDA), indicating cross-reactivity between these complex antigens which are the basis of the skin test. In comparisons of the ESAT-6 IFN-gamma test with a PPD IFN-gamma test (using PPDB compared with PPDA), there was a decrease in sensitivity (76.3 per cent vs 89.3 per cent), but a clear increase in specificity (99.2 per cent vs 92.2 per cent). The provision of high specificity, even with lower sensitivity, offers major benefits for testing in areas with a low incidence of TB.

Lightbody KA, Girvin RM, Mackie DP, Neill SD, Pollock JM. T-Cell Recognition of Mycobacterial Proteins MPB70 and MPB64 in Cattle Immunized with Antigen and Infected with Mycobacterium bovis. Scand J Immunol 1998;48:44-51 Defined antigenic reagents and knowledge of T-cell responses are required for the design of improved diagnostic tests for bovine tuberculosis. The limited species distribution of Mycobacterium bovis antigens MPB70 and MPB64 has indicated their potential for inclusion in future tests. The strategy adopted in this study was to define bovine T-cell responses to these antigens at the epitope level, using cattle immunized with recombinant forms of the antigens, and to compare these responses with cattle which had been experimentally infected with M. bovis. Panels of synthetic peptides (20-mers with 10-residue overlaps) were used and five epitopes were identified and found to be powerful stimulators of T-cell responses in both types of animal (residues 81-100 and 174-190 for MPB70; and residues 1-20, 41-60 and 181-200 for MPB64). Further investigation in larger numbers of cattle (n ¼ 14) of mixed breeds from tuberculosisinfected herds confirmed that each peptide produced response in several of the cattle, but no single peptide was recognized by all animals. However, the limited numbers of animals in this study suggest that peptide reagents may identify as many positive animals as the intact antigenic protein and could form components of a future diagnostic test. The use of cattle immunized with the proteins of interest has proved to be an interesting model for studying the nature of bovine T-cell responses to defined mycobacterial proteins.

Introduction Pharyngoesophageal spasm (PES) can cause dysphagia, central valve leak (CVL), and dypshonia in post-laryngectomy patients. Botulinum toxin has been used effectively for the treatment of PES, but data regarding patient-reported outcomes and efficacy for CVL are limited. We evaluated the results of botox injection for PES spasm using subjective and objective measures. Methods Data were collected prospectively (February 2010 to August 2013) on 13 patients undergoing botox injection for PES as identified by video fluoroscopy. We collected digital voice recordings, air-pressure measurements (APMs) for speech, and quality of life (QoL) data before and after the procedure: University of Washington QoL questionnaire (UW-QoL), MD Anderson Swallowing Inventory (MDADI) and the Voice Handicap Index (VHI-30). Results APMs for a sustained vowel decreased by 18% after botox injection, whereas maximum phonatory times increased by 63% (mean increase, 8 to 13 seconds). Sustained vowel amplitude decreased (mean, 87db to 83db) with an associated reduction in sustained vowel frequency (117Hz to 77Hz). MDADI scores improved by 10.2% overall, and UW-QoL scores showed an improvement in score of 7.6%. Mean scores for VHI-30 deteriorated by 2% overall but, when considering only those patients experiencing dysphonia, an improvement of 9.4% was seen. There was an overall net reduction for the CVL cohort of 12 speech valves in the year after injection. Conclusions Our series confirm the safety and objective efficacy of botox injection for PES. QoL measurements were less convincing, and this disparity between subjective and objective measurements must be considered when treating such patients.