Functional promiscuity of small multidrug resistance transporters from Staphylococcus aureus, Pseudomonas aeruginosa, and Francisella tularensis.

Small multidrug resistance transporters efflux toxic compounds from bacteria and are a minimal system to understand multidrug transport. Most previous studies have focused on EmrE, the model SMR from Escherichia coli, finding that EmrE has a broader substrate profile than previously thought and that EmrE may perform multiple types of transport, resulting in substrate-dependent resistance or susceptibility. Here, we performed a broad screen to identify potential substrates of three other SMRs: PAsmr from Pseudomonas aeruginosa; FTsmr from Francisella tularensis; and SAsmr from Staphylococcus aureus. This screen tested metabolic differences in E. coli expressing each transporter versus an inactive mutant, for a clean comparison of sequence and substrate-specific differences in transporter function, and identified many substrates for each transporter. In general, resistance compounds were charged, and susceptibility substrates were uncharged, but hydrophobicity was not correlated with phenotype. Two resistance hits and two susceptibility hits were validated via growth assays and IC50 calculations. Susceptibility is proposed to occur via substrate-gated proton leak, and the addition of bicarbonate antagonizes the susceptibility phenotype, consistent with this hypothesis.

Combined Hybrid Procedure and VAD Insertion in 9 High-Risk Neonates and Infants With HLHS.

BACKGROUND: This report describes 9 high-risk neonates and infants with hypoplastic left heart syndrome (HLHS) who were stabilized with a combined hybrid approach and ventricular assist device (VAD) insertion (HYBRID+VAD) in preparation for heart transplantation. METHODS: A total of 9 patients with HLHS (7 neonates, 2 infants) presented with anatomic or physiologic features associated with an increased risk for conventional univentricular palliation with the Norwood operation (large coronary sinusoids or fistulas, severe tricuspid regurgitation, cardiogenic shock, restrictive atrial septum). These patients underwent combined VAD insertion (Berlin EXCOR, Berlin Heart, Inc, Berlin, Germany) and Stage 1 hybrid palliation (application of bilateral pulmonary bands, stent placement in the patent arterial duct, and atrial septectomy if needed). During this same era, at the Congenital Heart Center, University of Florida, Gainesville, Florida, 46 neonates underwent a Norwood operation, 4 neonates underwent a hybrid approach "Stage 1" without VAD, and 3 patients with HLHS were supported with prostaglandin while awaiting heart transplantation. RESULTS: At HYBRID+VAD insertion, the median age was 20 days (range, 13 to 143 days), and median weight was 3.25 kg (range, 2.43 to 4.2 kg). Six patients survive (67%), and 3 patients died (33%). Five survivors are at home doing well after successful heart transplantation, and 1 survivor is doing well in the intensive care unit on VAD support while awaiting transplantation. Only 1 of 6 survivors (16.7%) required intubation more than 10 days after HYBRID+VAD insertion. In 8 patients no longer undergoing VAD support, the median length of VAD support was 119.5 days (range, 56 to 196 days). CONCLUSIONS: High-risk patients with HLHS who are suboptimal candidates for Norwood palliation can be successfully stabilized with pulsatile VAD insertion along with hybrid palliation while awaiting cardiac transplantation. These patients may be extubated and optimized for transplantation while undergoing VAD support.

Palliation Plus Ventricular Assist Device Insertion in 15 Neonates and Infants With Functionally Univentricular Circulation.

BACKGROUND: We report 15 high-risk neonates and infants with functionally univentricular circulation stabilized with initial surgical palliation plus ventricular assist device (VAD) insertion (PALLIATION+VAD) in preparation for transplantation. METHODS: Fifteen functionally univentricular patients with ductal-dependent systemic circulation (8 hypoplastic left heart syndrome, 1 hypoplastic left heart syndrome-related malformation: 7 neonates, 2 infants) or ductal-dependent pulmonary circulation (6 hypoplastic right heart syndrome: 5 neonates, 1 infant) presented with anatomical and/or physiological features associated with increased risk for conventional univentricular palliation (large coronary sinusoids with ventricular-dependent coronary circulation, severe systemic atrioventricular valvar regurgitation, cardiogenic shock, or restrictive atrial septum). PALLIATION+VAD for patients with ductal-dependent systemic circulation was: VAD insertion plus application of bilateral pulmonary bands, stent placement in the arterial duct, and atrial septectomy, if needed. PALLIATION+VAD for patients with ductal-dependent pulmonary circulation was: VAD insertion plus stent placement in the arterial duct or systemic-to-pulmonary artery shunt with pulmonary arterioplasty, if needed. RESULTS: At PALLIATION+VAD, median age was 20 days (range, 4-143 days) and median weight was 3.47 kg (range, 2.43-4.86 kg). Ten patients (67%) survived and 5 patients (33%) died. All ten survivors are at home doing well after successful transplantation. Only 2 of 10 survivors (20%) required intubation >10 days after PALLIATION+VAD. Median length of VAD support for all 15 patients was 138 days (range, 56-226 days). CONCLUSIONS: High-risk neonates with functionally univentricular hearts who are suboptimal candidates for conventional palliation can be successfully stabilized with pulsatile VAD insertion along with initial palliation while awaiting cardiac transplantation; these patients may be extubated, enterally nourished, and optimized for transplantation while on VAD.

Pulsatile ventricular assist device as a bridge to transplant for the early high-risk single-ventricle physiology.

BACKGROUND: The use of ventricular assist devices (VADs) as a bridge-to-transplant in patients with single-ventricle physiology post-stage one palliation has been associated with poor outcomes. We describe our center's successful experience in the use of paracorporeal pulsatile VADs in the palliation of high-risk single ventricle physiology before or after the first stage of palliation with an impetus on pre-palliation implant. METHODS: This is a single-center retrospective review of univentricular patients implanted with the Berlin Heart EXCOR VAD. Our center's approach includes early implantation of the Berlin Heart EXCOR with common atrial cannulation, a cardiac index between 3.5 and 5 L/min/m2, and a bivalirudin-based anticoagulation regimen. Patient-related data were collected postimplant at week 1 and months 1, 2, and 3. Post-transplant data, including neurological outcomes, were collected. RESULTS: Nine patients were supported. Survival to discharge post-transplant was 83% (5/6) in patients bridged-to-transplant and 33% (1/3) in patients bridged-to-decision. Six patients had no previous palliation. Median hospital stay before implantation was 111 days for nonsurvivors versus 20 days for survivors. The need for extracorporeal membrane oxygenation and cardiopulmonary resuscitation in nonsurvivors versus survivors was 1 in 3 versus 1 in 6 and 2 in 3 versus 1 in 6, respectively. There were no major central nervous system complications except for 1 significant hemorrhagic event. The pediatric overall performance category score on follow-up was normal to mild disability in 83% of survivors. Limitations include hemolysis and intermittent periods of infection and/or inflammation. CONCLUSIONS: The use of pulsatile paracorporeal VADs is a feasible option as a bridge-to-transplant in the peri-stage one high-risk single ventricle.

Cognitive impairment in Parkinson's disease: Association between patient-reported and clinically measured outcomes.

BACKGROUND: In Parkinson's disease, the association between objective and patient-reported measures of cognitive dysfunction is unknown and highly relevant to research and clinical care. OBJECTIVE: To determine which cognitive domain-specific Montreal Cognitive Assessment (MoCA) subscores are most strongly associated with patient-reported cognitive impairment on question 1 (Q1) of the Movement Disorders Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS). METHODS: We analyzed data from 759 PD participants and 481 persons without PD with in a retrospective, cross sectional analysis using data from the NINDS Parkinson's Disease Biomarkers Program (PDBP), a longitudinal, multicenter biomarker study. The relationship between a patient-reported cognitive rating (MDS-UPDRS q1.1) and objective cognitive assessments (MoCA) was assessed using multinomial logistic regression modeling and the outcomes reported as conditional odds ratios (cOR's) representing the relative odds of a participant reporting cognitive impairment that is "slight" versus "normal" on MDS-UPDRSq1.1 for a one unit increase in a MoCA sub-score, adjusted for age and education. RESULTS: In PD participants, changes in visuospatial-executive performance and memory had the most significant impact on subjective cognitive impairment. A 1-point increase in visuospatial-executive function decreased the chance of reporting a MDS-UPDRS Q1 score of "slight" versus "normal" by a factor of 0.686 (p < 0.001) and each 1 point improvement in delayed recall decreased the odds of reporting "slight" cognitive impairment by a factor of 0.836 (p < 0.001). CONCLUSIONS: Conversion from a PD patient's report of "normal" to "slight" cognitive impairment may be associated with changes in visuospatial-executive dysfunction and memory more than other cognitive domains.

Aging, confidence, and misinformation: recalling information with the cognitive interview.

In 2 experiments, younger and older adults witnessed a simulated robbery, received misleading information about the event, and then were interviewed with the Cognitive Interview about their memory for the robbery. In both experiments, older adults were disproportionately more confident than younger adults in the accuracy of incorrect information that they recalled than in the accuracy of correct information. Critically, this age-related increase in high-confidence errors occurred even in comparison with younger adults who were matched with older adults on the overall amount and accuracy of the information remembered about the robbery. In addition, Experiment 2 showed that retrieval warnings to disregard the misinformation were just as effective in older adults as compared with younger adults at reducing the reporting of misleading information. Finally, both experiments showed that across the multiple retrieval stages of the Cognitive Interview, the final retrieval stage is roughly half as effective for older adults relative to younger adults at eliciting previously unreported information. These results indicate that investigators have much less to gain from older adults than they do from younger adults with repeated inquiries (during the same session) about a witnessed event.