Epidemiological role of humans, dogs and cats in the transmission of Trypanosoma cruzi in a central area of Argentina

Trypanosoma cruzi prevalence rates of human, dog and cat populations from 47 households of 3 rural localities of the phytogeographical Chaqueña area of Argentina were determined both by serological and xenodiagnostic procedures. Human prevalence rates were uniform and ranged from 49.6 to 58.7%. Overall prevalence rate in dogs (75.0%) was significantly higher than in humans (51.0%). The overall proportion of parasitemic individuals assessed by xenodiagnosis was significantly higher in either dog (64.2%) or cat (63.6%) populations than among humans (12.5%). Although both the average number of resident as well as infected individuals per household was higher for people than for dogs (6.5 vs. 3.3, and 3.4 vs. 2.4, respectively), the reverse was recorded when parasitemic individuals were considered (1.0 vs. 2.1). Results are discussed in relation to dog between dogs and people, and dogs and bugs. In the light of present data, dogs must be considered as the major donors of parasites to vector bugs and thus, principal contributors to transmission in this region of Argentina

The clinical significance of body weight loss in idiopathic pulmonary fibrosis patients

BACKGROUND: The significance of the nutritional status in idiopathic pulmonary fibrosis (IPF) is largely unknown. Temporal body weight (BW) change, a dynamic index of nutrition status, can detect the malnutrition more accurately than the conventional single-point body mass index evaluation. OBJECTIVE: To investigate how the temporal BW change influences the clinical courses of IPF. METHODS: This multicenter study enrolled IPF patients from four referral hospitals of interstitial lung diseases in Japan (the Japanese cohort, the derivation cohort) and the Royal Brompton Hospital (the UK cohort, the validation cohort). The annual rate of BW change from the initial presentation was evaluated. A > 5% decrease of BW was defined as a significant BW loss. RESULTS: Twenty-seven out of 124 patients in the Japanese cohort and 13 out of 86 patients in the UK cohort showed significant BW loss. Patients with BW loss showed significantly worse survival in both cohorts. Multivariate analyses revealed that BW loss was an independent factor for decreased survival (Japanese cohort: p = 0.047, UK cohort: p = 0.013). A 6.1% loss of BW was chosen as the optimal cutoff value to predict the 2-year mortality from the initial presentation. The stratified analysis revealed that a 6.1% or greater BW loss could predict worse survival specifically in cases without a greater than 10% decline in forced vital capacity (FVC). CONCLUSIONS: BW loss is independently associated with the survival of IPF patients, particularly when a decline in the FVC was not observed. Further studies are needed to understand the mechanisms underlying BW loss in IPF

La enfermedad del adyuvante en ratas infectadas experimentalmente con Trypanosoma cruzi

Se estudió la evolución de la artritis por adyuvante en ratas que habían sido infectadas previamente con Trypanosoma cruzi, con el objeto de evaluar su competencia inmunológica a través de la respuesta artrítica. La artritis por adyuvante se indujo en ratas adultas, endocriadas de ambos sexos, con 0.1 mi de adyuvante completo de Freund en la almohadilla plantar, en 2 lotes: a) inyectadas 90 días antes con 1 x 10(6) T. cruzi y b) testigos normales simultáneos. Se midieron, la lesión artrítica macroscópicamente con una escala semicuantitativa, y con microscopía óptica la histopatología de la lesión local y la del corazón, a los 180 días post-infecoión. La magnitud de las lesiones artríticas en las ratas con T. cruzi fue significativamente menor (p < 0.001) que la de los testigos, en todo el período. El infiltrado inflamatorio local, formado por linfocitos, plasmocitos y macrófagos fue significativamente menor (p < 0.001) en las ratas chagásicas, con respecto al de los testigos. Se postula que en las ratas que recibieron T. cruzi la respuesta artrítica menor podría deberse a una competición antigénica con los determinantes del parásito o a mecanismos inmunosupresores que interfieren en la producción de la entidad experimental