The reduced brood nursing by mite-infested honey bees depends on their accelerated behavioral maturation.

The parasitic mite Varroa destructor is regarded as the most important parasite of honey bees and plays a fundamental role in the decline of bee colonies observed in the last decade in the Northern hemisphere. Parasitization has a number of detrimental effects on bees, including reduced nursing, which can have important impacts on colony balance. In this work we investigated at the individual level the causes of this abnormal behavior and found that the reduced nursing activity in mite-infested workers is associated with impaired learning performance and a series of physiological traits that are typical of foragers, including reduced response to brood pheromone, limited development of hypopharyngeal glands and higher juvenile hormone titre in the haemolymph. Altogether our data confirm the premature transition to foraging already postulated based on previous genomics studies, from a physiological point of view.

[Changes in the cell-mediated immune system in post-traumatic sepsis]. / Alterazioni del sistema immunitario cellulo-mediato nella sepsi post-traumatica.

OBJECTIVE: We studied the alterations of cell-mediated immunity (CMI) in polytrauma patients and its relation with sepsis. DESIGN: a prospective study. SETTING: ICU, Ospedale Maggiore, Bologna (Italy). PATIENTS: We included in the study 42 patients with at least two of following criteria: 1) Trauma Score < or = 12; 2) Abbreviated Injury Score > or = 4; 3) Arterial Pressure on admission < or = 80 mmHg; 4) Injury Severity Score > or = 16. CMI examinations were carried out at three different post-traumatic times (T0-T2). Seventeen patients developed a sepsis within the first eight days from admission. RESULTS: Sepsis caused a temporary impairment in some lymphocyte subsets at T2. The patients who developed sepsis showed a significant subset percentage difference for CD3, CD3 activated (p < 0.05) and for interleukin-2 receptor (IL-2R) (p < 0.01) in comparison with the non septic group. At T2, the seven septic patients who died, showed a marked depression of IL-2 values (0.37 +/- 0.12 UI/ml) in comparison with the values of septic patients who survived (0.66 +/- 0.25 UI/ml; p < 0.01) and with the group of non septic patients (0.83 +/- 0.5 UI/ml; p < 0.001). Septic patients who had a IL-2 value of 0.45 or lower had a mortality of 75%. IL-2 values showed a specificity of 89% and a sensibility of 75% in predicting mortality in septic trauma patients. CONCLUSION: We believe that in polytrauma patients IL-2 values monitoring could be a reliable index of the disfunction of CMI and that IL-2R sieric levels could be a diagnostic marker of impending sepsis.