Immunologic indicators of clinical progression during canine Leishmania infantum infection.

In both dogs and humans Leishmania infantum infection is more prevalent than disease, as infection often does not equate with clinical disease. Previous studies additively indicate that advanced clinical visceral leishmaniasis is characterized by increased production of anti-Leishmania antibodies, Leishmania-specific lymphoproliferative unresponsiveness, and decreased production of gamma interferon (IFN-gamma) with a concomitant increase of interleukin-10 (IL-10). In order to differentiate infection versus progressive disease for better disease prognostication, we temporally evaluated humoral and cellular immunologic parameters of naturally infected dogs. The work presented here describes for the first time the temporal immune response to natural autochthonous L. infantum infection in foxhounds within the United States. Several key changes in immunological parameters should be considered when differentiating infection versus clinical disease, including a dramatic rise in IgG production, progressive increases in antigen-specific peripheral blood mononuclear cell proliferation, and IFN-gamma production. Polysymptomatic disease is precluded by increased IL-10 production and consistent detection of parasite kinetoplast DNA in whole blood. This clinical presentation and the immuno-dysregulation mirror those observed in human patients, indicating that this animal model will be very useful for testing immunomodulatory anti-IL-10 and other therapies.

Local ice-bag application and triceps surae muscle temperature during treadmill walking.

CONTEXT: Ice bags "to go" are a common practice in athletic training. OBJECTIVE: To determine the effect of submaximal exercise on tissue temperatures during a common ice-bag application. DESIGN: 2 X 5 fully repeated-measures design with treatment (cooling while resting, cooling while walking) and time (pretreatment, immediately after ice application, and at 10, 20, and 30 minutes during treatment) as the independent variables. SETTING: Laboratory setting. PATIENTS OR OTHER PARTICIPANTS: Sixteen healthy, physically active volunteers (age = 21.63 +/- 2.63 yrs, height = 68.97 +/- 4.00 cm, mass = 80.97 +/- 18.18 kg, calf skinfold = 21.1 +/- 9.3 mm). MAIN OUTCOME MEASURE(S): Left triceps surae intramuscular and skin temperatures, as measured by thermocouples to the nearest 0.1 degrees C, served as dependent measures. INTERVENTION(S): After collecting baseline temperatures, we secured a 1.0-kg ice bag to the calf using plastic wrap before the subject either rested prone or walked on a treadmill at 4.5 km/h for 30 minutes. RESULTS: Treatment did not (P < 0.10) affect the approximately 15 degrees C (P < 0.0001) surface temperature decrease, which remained depressed immediately upon ice-bag application (P < 0.05). Conversely, intramuscular temperature continually cooled (34 to 28 degrees C), while subjects rested (P < 0.0001), whereas no change took place during walking (P = 0.49). Moreover, at the 20- and 30-minute treatment intervals, the resting intramuscular temperatures were, respectively, 3.9 degrees C and 5.4 degrees C cooler than the walking intramuscular temperatures (P < 0.01). CONCLUSIONS: The current trend of wrapping "to go" ice bags to the leg is not likely to achieve deep tissue cooling despite surface temperature decreases.