Although principally considered a vector-borne disease, the vertical transmission of Trypanosoma cruzi from mother to child is now recognized as a significant and increasing threat to human health. Despite its importance, significant gaps exist in our understanding of the relationships between genotype, virulence, and the extent of vertical transmission of this pathogen. To better understand these relationships, we describe the comparison of a South American-derived Type I isolate (BS) of T. cruzi to a Type IIa isolate (SCI) of from North America for virulence and frequency of vertical transmission in BALB/c and outbred mice. Assays performed in BALB/c mice conclusively confirm the comparatively greater virulence of the BS isolate. Breeding experiments demonstrated a reciprocal relationship between virulence and the frequency of vertical transmission, with the pups born to Type IIa SCI-infected female mice testing positive at twice the frequency (66%) as those infected with the Type I BS (33%). Experiments carried out in BALB/c mice confirmed that an active infection with the SCI isolate generated immunity against a BS challenge. These results confirm that significant differences in the extent of vertical transfer can exist between T. cruzi isolates and contradicts the hypothesis that such transmission is a function of elevated maternal blood parasitemias. This study also provides support for some of the current hypotheses on attenuation during a pathogen's evolution from vector-borne to vertical transmission. We suggest that T. cruzi may provide a useful model for the study of the adaptive dynamics of a zoonotic human pathogen.

A 29-year-old man with biventricular heart failure (HF) secondary to nonischemic cardiomyopathy presented in transfer to our institution following placement of peripheral venoarterial extracorporeal membrane oxygenation (VA ECMO) for cardiogenic shock. To provide adequate drainage of both atria, the decision was made to place a single multistage venous cannula across the inter-atrial septum (IAS) using

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Objectives: Much less attention has been given to the right heart and pulmonary circulation compared to the left heart and systemic circulation in patients with pre-eclampsia (PEC). We used transthoracic echocardiography (TTE) to estimate pulmonary artery pressure and right ventricular function in women with PEC. Methods: A case-control study at a tertiary care academic center. Ten early PEC (<34 week gestation) and nine late PEC (≥34 weeks gestation) patients with eleven early and ten late gestational age-matched controls. Two dimensional TTE was performed on all patients. The estimated mean PA pressure (eMPAP) was calculated based on pulmonary artery acceleration time (PAAT). Pulmonary vascular resistance (ePVR) was estimated from eMPAP and right ventricular (RV) cardiac output. RV myocardial performance index (RV MPI), tricuspid annular plane systolic excursion (TAPSE), tissue tricuspid annular displacement (TTAD) and lateral tricuspid annular tissue peak systolic velocity (S’) were measured. Results Compared to early controls, in early PEC the eMPAP and ePVR were elevated, PAAT was reduced, RV MPI was increased, TTAD was reduced and TAPSE and TV S’ were unchanged. Compared to late controls, in late PEC, estimated MPAP and estimated PVR were elevated, PAAT was reduced and RVMPI was increased, while TAPSE, TTAD and TV S’ were unchanged. Conclusions: Early PEC is associated with increased eMPAP and ePVR. A subclinical decrement of RV function is noticed. TTE is a useful screening tool for early detection of PH and RV dysfunction in PEC.

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