The stability of an immunogen against enzymatic degradation is considered an important factor for the design of synthetic vaccines. For our studies, we have selected an epitope from the tandem-repeat unit of the high-molecular-weight MUC2 mucin glycoprotein, which can be underglycosylated in case of colon cancer. In this study, we prepared a MUC2 peptide containing the PTGTQ epitope of a MUC2 protein backbone-specific mAb 996 and its derivatives. In these peptides, the N- and C-terminal flanking regions were systematically substituted by up to three d -amino acids. Peptides prepared by solid-phase synthesis were tested for their mAb 996 binding in competitive ELISA experiments, and their stability was studied in serum and lysosomal preparation. Our data show that the epitope function of peptide ¹⁵ TPT PTGTQ TPT ²⁵ is retained even in the presence of two d -amino acid residues at its N-terminal flanking region and up to three at its C-terminal flanking region (tpTPTGTQtpt). Also, this partly d peptide shows high resistance against proteolytic degradation in diluted human serum and in lysosomal preparation. These findings suggest that, by appropriate combination of structural modifications (namely, d -amino acid substitution) in the flanks of an Ab epitope, it is feasible to construct a synthetic antigen with preserved recognition properties and high stability against enzymatic degradation. Peptides tPTPTGTQTpt and tpTPTGTQTpt derived from this study can be used for immunization experiments and as potential components of synthetic vaccines for tumor therapy.

OBJECTIVE: Brown adipose tissue (BAT) is present in adult humans where it may be important in the prevention of obesity, although the main factors regulating its abundance are not well established. BAT demonstrates seasonal variation relating to ambient temperature and photoperiod in mammals. The objective of our study was therefore to determine whether seasonal variation in BAT activity in humans was more closely related to the prevailing photoperiod or temperature. RESEARCH DESIGN AND METHODS: We studied 3,614 consecutive patients who underwent positron emission tomography followed by computed tomography scans. The presence and location of BAT depots were documented and correlated with monthly changes in photoperiod and ambient temperature. RESULTS: BAT activity was demonstrated in 167 (4.6%) scans. BAT was demonstrated in 52/724 scans (7.2%) in winter compared with 27/1,067 (2.5%) in summer months (P < 0.00001, χ2 test). Monthly changes in the occurrence of BAT were more closely related to differences in photoperiod (r2 = 0.876) rather than ambient temperature (r2 = 0.696). Individuals with serial scans also demonstrated strong seasonal variation in BAT activity (average standardized uptake value [SUVmax] 1.5 in July and 9.4 in January). BAT was also more common in female patients (female: n = 107, 7.2%; male: n = 60, 2.8%; P < 0.00001, χ2 test). CONCLUSIONS: Our study demonstrates a very strong seasonal variation in the presence of BAT. This effect is more closely associated with photoperiod than ambient temperature, suggesting a previously undescribed mechanism for mediating BAT function in humans that could now potentially be recruited for the prevention or reversal of obesity.

Background: Electrosurgery for dissection and haemostasis should be associated with minimal thermal spread to surrounding tissues. This study investigated lateral thermal spread following ex vivo application of four commonly utilized instruments. Methods: Monopolar and bipolar diathermy (power settings 20, 30 and 40 W), the Harmonic Scalpel^™ and Ligasure^™ (power settings 1, 3 and 5) were studied after application to standardized porcine muscle cuts for 5, 10 or 15 s. Temperatures generated at the tips of the instruments, in the tissues adjacent to the tips and 1 cm away were recorded. Results: Following a 5‐s application at the highest power setting, the highest mean(s.d.) temperatures recorded at the tips of monopolar and bipolar diathermy, Harmonic Scalpel^™ and Ligasure^™ instruments were 78·9(4·1), 41·9(2·2), 47·6(2·5) and 44·2(2·6) °C respectively. Temperatures at the instrument tips after use for 15 s remained above 42 °C for 55, 25, 15 and 15 s respectively. Applying monopolar diathermy (10 s at 40 W) resulted in a temperature recording of 59·2(2·2) °C in tissues 1 cm away from the tip of the instrument. Conclusion: The degree of lateral thermal spread varied with instrument type, power setting and application time. Monopolar diathermy resulted in the highest temperatures and the greatest degree of thermal spread in tissues. Copyright © 2010 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.