A cross-sectional study on canine Leishmania (L.) infantum chagasi infection in Amazonian Brazil ratifies a higher prevalence of specific IgG-antibody response than delayed-type hypersensitivity in symptomatic and asymptomatic dogs

This was a cross-sectional study which analyzed the prevalence and the clinical and immunological spectrum of canine Leishmania (L.) infantum chagasi infection in a cohort of 320 mongrel dogs living in an endemic area of American visceral leishmaniasis in the Amazonian Brazil by using, mainly, the indirect fluorescence antibody test (IFAT-IgG) and the delayed-type hypersensitivity (DTH), and the parasite research by the popliteal lymph node aspiration. The IFAT and DTH reactivity recognized three different immune response profiles: (1) IFAT((+))/DTH((-)) (107 dogs), (2) IFAT((-))/DTH((+)) (18 dogs), and (3) IFAT((+))/DTH((+)) (13 dogs), providing an overall prevalence of infection of 43?% (138/320). Thus, the specific prevalence of IFAT( (+) )/DTH( (-) ) 33.4?% (107/320) was higher than those of IFAT( (-) )/DTH( (+) ) 5.6?% (18/320) and IFAT( (+) )/DTH( (+) ) 4.0?% (13/320). Moreover, the frequency of these profiles among 138 infected dogs showed that the IFAT( (+) )/DTH( (-) ) rate of 77.5?% (107/138) was also higher than those of 13.0?% (18/138) of IFAT( (-) )/DTH( (+) ) and 9.5?% (13/138) of IFAT( (+) )/DTH( (+) ) rates. The frequency of asymptomatic dogs (76?%-105) was higher than those of symptomatic (16.6?%-23) and oligosymptomatic ones (7.4?%-10). A total of 16 (11.6?%) L. (L.) i. chagasi isolates were obtained from infected dogs, all from the IFAT( (+) ) /DTH( (-) ) profile: 41?% (9/22) from symptomatic, 33.3?% (3/9) from oligosymptomatic, and 5.2?% (4/76) from asymptomatic dogs. These findings strongly suggested that despite the higher frequency of asymptomatic dogs (76?%-105), the majority (72.4?%-76) was characterized by the IFAT( (+) ) /DTH( (-) ) profile with a doubtful immunogenetic resistance against infection.     

Mortality risk prediction in coronary surgery: a locally developed model outperforms external risk models

This study aimed at assessing the performance of three external risk-adjusted models - logistic EuroSCORE, Parsonnet score and Ontario Province Risk (OPR) score - in predicting in-hospital mortality in patients submitted to coronary artery bypass graft (CABG) and to develop a local risk-score model. Data on 4567 patients who underwent isolated CABG (1992-2001) were extracted from our clinical database. Hospital mortality was 0.96% (44 patients). For the three external systems, observed and predicted mortalities were compared, and discrimination and calibration were assessed. A local risk model was developed and validated by means of logistic regression and bootstrap analysis. The EuroSCORE predicted a mortality of 2.34% (P<0.001 vs. observed), the Parsonnet 4.43% (P<0.0001) and the OPR 1.66% (P<0.005). All models overestimated mortality significantly in almost all tertile risk groups. The areas under the ROC curve (AUC) for EuroSCORE, Parsonnet and OPR were 0.754, 0.664 and 0.683, respectively. The local model exhibited good calibration and discrimination AUC, 0.752. In conclusion, the three risk-score systems analyzed do not accurately predict in-hospital mortality in our coronary surgery patients; hence their use for risk prediction may not be appropriate in our population. We developed a risk-prediction model that can be used as an instrument to provide accurate information about the risk of in-hospital mortality in our patient population.     

The limitations of preload-adjusted maximal power as an index of right ventricular contractility

Right ventricular (RV) dysfunction is an important cause of perioperative morbidity and mortality, particularly in cardiac surgery. However, assessment of RV contractility remains difficult in clinical practice. Our goal in this study was to examine the value of preload-adjusted maximal power (PWR(max)/end-diastolic volume [EDV](2); PAMP) as an alternative to the load-independent pressure-volume-derived indices of contractility in the RV. In anesthetized dogs, RV end-systolic elastance and preload-recruitable stroke work were studied as "gold standards" by using the conductance technique. PAMP was calculated with pulmonary artery flow and RV pressure measurements. Changes in these indices were compared after modulation of the inotropic state (dobutamine infusion; n = 12) and loading conditions (pulmonary artery and inferior caval vein occlusion; n = 14). All indices increased dose-dependently with dobutamine. PAMP was slightly influenced by preload reduction (the slope of the relation between PAMP and EDV was 0.00397 +/- 0.01026 W. mL(-3). 0.10(-4); mean +/- SD). PAMP decreased significantly during pulmonary artery banding (from 1.1 +/- 0.7 to 0.7 +/- 0.5 W. mL(-2). 0.10(-4); mean +/- SD), whereas end-systolic elastance and preload-recruitable stroke work did not change. We conclude that the value of PAMP as an index of RV contractility is limited in the open-chest/open-pericardium setting, primarily by its sensitivity to alterations in afterload. IMPLICATIONS: Preload-adjusted maximal power (PAMP), a load-independent contractile index in the left ventricle, could offer a solution to the problem of measuring right ventricular (RV) contractility in clinical practice. However, this study in open-chest dogs suggests that PAMP is unreliable for assessment of RV contractility because of its sensitivity to afterload changes.     

Nutritional parameters and mortality in incident hemodialysis patients.

OBJECTIVE: To evaluate the impact of nutritional parameters at the time of initiation of hemodialysis (HD) on mortality. DESIGN: Retrospective study. SETTING: Dialysis Unit of the Federal University of Sao Paulo, Oswaldo Ramos Foundation. PATIENTS: Three hundred forty-four incident HD patients (60.5% male, 26% diabetic) with the first nutritional evaluation performed before completing 3 months of onset of HD were included. METHODS: The study consisted of baseline measurements of several nutritional parameters (triceps skinfold thickness [TSF], midarm muscle circumference [MAMC], body mass index [BMI], serum albumin, serum creatinine, and protein and energy intake assessed by 3-day food diary) and records of outcome (death) over a period of 10 years. RESULTS: Muscle and/or fat depletion was observed in 51% of the studied patients, according to the percent standard of MAMC and TSF, respectively. Presence of diabetes, age over 60 years, serum albumin < 3.5 g/dL, MAMC adequacy < 90%, protein intake < 1.0 g/kg/d, and energy intake < 25 kcal/kg/d were associated with worse survival. When patients were analyzed according to tertiles of dialysis vintage, BMI > or = 25 (calculated as kg/m2) had a negative impact on survival only in the highest tertile (> 2.45 years). Patients with BMI < 25 and MAMC adequacy > or = 90% showed the best survival over the study period, and those with BMI > or = 25 but MAMC adequacy < 90% had the worst survival (P = .004). In the multivariate survival analysis adjusting for diabetes, advanced age, and hypoalbuminemia, the reduced MAMC (P = .008) and the low energy intake (P = .03) were independent predictors of death in incident HD patients. CONCLUSIONS: Reduced MAMC and low energy intake at the beginning of chronic dialysis are risk factors for mortality. A negative effect of high BMI on survival was associated with reduced MAMC and longer dialysis vintage.