Cardiac chagas disease masquerading as an acute myocardial infarction

Although myocardial infarction is most often the manifestation of epicardial coronary artery disease, Chagas heart disease due to chronic Trypanasome Cruzi infection may present with a syndrome of chest pain and elevations in markers of cardiac myonecrosis. In the setting of an increasingly diverse global population and immigration of peoples from endemic areas of Trypanasome Cruzi, it is important to be aware of the myriad cardiac manifestations of Chagas disease.     

Characterization of a vitamin D3-resistant human chronic myelogenous leukemia cell line

A variant of the chronic myelogenous leukemia cell line, RWLeu-4, that is resistant to the antiproliferative effects of vitamin D3 was established. Although RWLeu-4 proliferation is inhibited by 1 nmol/L vitamin D3, the resistant cells (JMRD3) continue to proliferate in the presence of 100 nmol/L vitamin D3. Both cells express similar patterns of differentiation-specific antigens after treatment with vitamin D3, and both express the retinoblastoma gene product (p110Rb). Vitamin D3 treatment of the sensitive RWLeu-4 cells decreased the level of the p110Rb protein, as well as its phosphorylation. In contrast, vitamin D3 treatment of JMRD3 had no effect on p110Rb expression or phosphorylation. Both RWLeu-4 and JMRD3 express similar vitamin D3 receptors and vitamin D3-inducible enzyme activities. Differences were detected in the DNA binding characteristics of the vitamin D3 receptors as determined by electrophoretic mobility shift studies. However, sequence analysis of the DNA-binding domain and immunoblot analysis showed no differences in the receptors. We conclude that some process subsequent to vitamin D3 receptor activation is altered in JMRD3 that partially separates vitamin D3-induced inhibition of proliferation from the induction of differentiation.     

Comparison Between Diltiazem and Cedilanid-D on Ventricular Rate Control of Atrial Fibrillation and Their Effect on Atrioventricular Conduction System.

Atrial fibrillation (AF) is the most commonsustained cardiac arrhythmia. Etiologies include coronary artery disease, hypertension, valvular heardisease, thyrotoxicosis and other cardiac and noncardiac conditions. Rapid ventricular rate during AFcan result in severe symptoms such as palpitation,dyspnea, and may precipitate heart failure, ischaemiaand syncope. The main therapeutic objective is rapid,efficient control of AF, thereby remit symptoms,prevent deterioration of heart functions and am…     

Lawmakers' use of scientific evidence can be improved

Core to the goal of scientific exploration is the opportunity to guide future decision-making. Yet, elected officials often miss opportunities to use science in their policymaking. This work reports on an experiment with the US Congress—evaluating the effects of a randomized, dual-population (i.e., researchers and congressional offices) outreach model for supporting legislative use of research evidence regarding child and family policy issues. In this experiment, we found that congressional offices randomized to the intervention reported greater value of research for understanding issues than the control group following implementation. More research use was also observed in legislation introduced by the intervention group. Further, we found that researchers randomized to the intervention advanced their own policy knowledge and engagement as well as reported benefits for their research following implementation.

Recent public crises have further illustrated the importance of policymakers using scientific research to craft effective public policies (e.g., opioid epidemic, humanitarian emergencies at the border, COVID-19 pandemic). Yet, despite the ongoing desire among the scientific community and general public to see research being utilized by lawmakers (1), little rigorous study has investigated the effectiveness of approaches to increase policymakers’ use of research evidence (URE; ref. 2). Particularly concerning is that the promising strategies currently available have yet to undergo rigorous experimental evaluation to see if they can change lawmaker behavior. Ultimately, if the scientific community truly wants to see research used, it is time to develop engagement strategies that are themselves evidence-based.Growing scientific study of how to improve the use of scientific evidence has shed light on the “social side” of successful research translation and evidence-based policymaking (2–5). Specifically (4), theoretical work and empirical studies have demonstrated that sustaining researcher-lawmaker relationships may be essential for supporting URE throughout the policymaking process (6, 7). In particular, structures provided by intermediary organizations have the potential to support trusting relationships between the research and policy communities (4, 6). However, work is needed to experimentally test the effectiveness of approaches designed to facilitate these processes.Although researchers’ engagement is critical for bridging research and policy, they face numerous barriers when navigating the policy arena (5, 6, 8, 9). Formal intermediary support for researchers can help improve the frequency and manner of policymakers’ URE (10, 11). This includes understanding restrictions around outreach, overcoming divergent professional norms, and adapting to the dramatically different pace of policy settings. For instance, researchers tend to engage in relatively slow decision-making, while policymakers engage in prompt policy actions in response to opportunities or crises (7, 8, 12, 13). Timeliness of researcher engagement is particularly challenging since public policy goals often shift suddenly in response to socio-political factors (9, 14). Thus, there is a need for engaging researchers in real-time during discrete, time-limited opportunities for policy change (10, 15).Policymakers can decide to use research evidence for varied purposes or intentions. A widely used typology in URE investigations is informed by foundational work of multiple scholars (16, 17). While researchers often deplore political uses of research for persuading others, justifying, or challenging existing policy proposals (i.e., tactical use), research evidence can also be used to guide policy development itself. This includes instances in which research is used to directly inform policy decisions (i.e., instrumental use) as well as instances in which research is indirectly used by changing the way policymakers think about problems or solutions (i.e., conceptual use). While instrumental uses may be relatively observable in specific policy efforts, conceptual use may influence a broad array of decisions in a more indirect manner (16, 17).While some experimental study of evidence use is occurring at the state level, no work has considered how to improve Congressional evidence use (18). In an effort to create evidence-based strategies for increasing policymaker-researcher engagement and supporting URE by lawmakers, we report here on a randomized controlled trial of such a strategy with the US Congress. In this study, we randomized congressional offices and researchers to receive a promising approach for improving URE known as the Research-to-Policy Collaboration (RPC).The RPC is a theory-based and manualized intervention for supporting lawmakers URE (Fig. 1). In particular, this work corresponds with Weiss’ conceptualization of both problem-solving and interactive models of knowledge use (17) by first eliciting policymakers’ needs and then facilitating interactions with researchers. First, a formal legislative needs assessment is used to identify policymakers’ goals, priorities, and need for scientific evidence (e.g., epidemiology and etiology, examples of successful interventions). Then, researchers who have expertise corresponding with those policy domains are coalesced into rapid response networks. These networks are provided with capacity building to increase their readiness to engage with congressional offices, fluency in the policy process, and best practices for translating research. Rapid response teams of researchers are then matched with offices based on office needs assessment results. Next, facilitated meetings occur between the office and researcher teams to further address their needs for scientific evidence. The ultimate goal of the RPC model is to create durable and productive collaborations that move beyond initial requests—with offices calling on researchers for additional questions and needs. The current study examines early indicators of outcomes associated with the model in early stages of this interactive process. Specifically, we examine outcomes associated with an implementation of the RPC pertaining to US federal child and family policymaking, although there is potential for the RPC to be used to support policymaker URE in other disciplines, as well as state or international contexts.Open in a separate windowFig. 1.The RPC Intervention Model. Step 1: Policy Identification involves initial outreach to legislative staff and uses a semistructured needs assessment to inquire about policymakers’ overarching policy goals for the legislative session. Step 2: Rapid Response Network Development involves identifying researchers who have expertise relevant to policymakers’ goals and are willing to contribute to research translation efforts. Their areas of expertise are cataloged in a strategic resource mapping process that builds capacity for matching researchers with policymakers. Step 3: Network Capacity Building occurs through didactic and experiential training that aims to increase policy skills and engagement. This includes training on adapting to legislative norms without violating lobbying regulations, as well as opportunities to respond to lawmakers’ interests identified in Step 1. Step 4: Legislative Needs Assessment identifies short-term priorities and needs in anticipation of matching policymakers with researchers who have corresponding experiences and scholarly interests. This semistructured assessment is action-oriented to identify ways that researchers might support legislative efforts. Step 5: Rapid Response Meetings engage legislative staff and researchers in direct interactions to discuss research, as this is a theorized mechanism for facilitating relationship development. Meetings aim to support the codevelopment of science implications, since research interpretation is a formative and iterative process. Researchers respond to initial legislative requests and plan next steps for ongoing collaboration. Researchers are invited for these meetings based on prior RPC participation, time availability, relevant scholarly interests, and geographic similarities (e.g., researchers having done work in the state the congressional member represents). Step 6: Initial Strategic Planning for rapid responses follows immediately after meetings to summarize goals, determine next steps, prioritize and create a timeline, and identify point person(s) for follow-up. Step 7: Ongoing Collaboration includes rapid responses to legislative requests. As an example, this could include collecting and summarizing research resources, planning briefing events or testimony, or publishing written products for dissemination (e.g., briefs, op-eds).Congressional office engagement is initiated by scheduling a needs assessment conducted by a trained policy associate, which often occurs in-person, but may also be done remotely. Some offices meet multiple times prior to or for the purposes of engaging with researchers, whereas others may meet less often, especially contingent on the clarity in next steps for ongoing collaboration. This interactive process is intended to generate requests for researcher engagement, including translational deliverables such as policy briefs and factsheets, congressional briefings, and testimony, as well as requests to review or provide legislative language for bill drafting (5, 8). Requests, in turn, provide researchers with opportunities to engage in the policy process and create tangible products that align with their professional incentive structures. Throughout the process, researchers are supported with training and technical assistance that facilitates appropriate translation and exchange of research. Training is provided by RPC implementers and policy associates who have experience with legislative engagement, science communications, and the process of using research in public policy. Importantly, no lobbying occurs as part of this process, and researchers are trained in the rules and regulations pertaining to lobbying.To experimentally evaluate this intervention, a dual-population randomized controlled trial was undertaken with congressional offices and researchers (Fig. 2). Congressional offices received either the RPC or a light-touch traditional support condition (i.e., the control condition offered support by providing publicly available, research-based resources). Researchers were randomized to receive the RPC intervention or a traditional static policy engagement training curriculum. Child and family policies were the focus of participants’ engagement; therefore, legislation reviewed in this study pertained to child and family policies.Open in a separate windowFig. 2.Consort diagrams for the RPC Evaluation. (A) Ninety-six congressional offices agreed to participate in the study and were randomized to receive either the RPC or control group condition. (B) Two hundred twenty-six researchers agreed to participate in the study and were randomized to receive either the RPC or control group condition.     

Patients with two types of atrioventricular junctional (AV nodal) reentrant tachycardia. Evidence that a common pathway of nodal tissue is not present above the reentrant circuit

BACKGROUND. The site of the reentrant circuit in atrioventricular (AV) junctional reentrant tachycardia has not been defined; in particular, the existence of a common pathway of AV nodal tissue above the reentrant circuit is controversial. METHODS AND RESULTS. Two types of AV junctional reentrant tachycardia were induced in each of three patients at electrophysiological study. In one type of tachycardia (anterior), the onset of atrial activity occurred from 0 to 12 msec before the onset of ventricular activation, and earliest atrial activity was recorded near the His bundle. In the second type of tachycardia (posterior), the ventriculoatrial intervals were longer (76-168 msec), and earliest atrial activity was recorded near the mouth of the coronary sinus. In individual patients, the two types of tachycardia had different cycle lengths. Posterior AV junctional reentrant tachycardia was not a fast-slow form of AV junctional reentry in at least two of the three patients. Surgical cure was attempted in two patients. In one patient, anterior AV junctional reentrant tachycardia was abolished by dissection of the anterior perinodal atrium, but posterior AV junctional reentrant tachycardia could still be induced. At reoperation 4 months later, dissection of the posterior perinodal atrium abolished posterior AV junctional reentrant tachycardia while preserving AV conduction. CONCLUSION. Differences in ventriculoatrial intervals and cycle lengths and the results of selective surgery suggest that the two types of AV junctional reentrant tachycardia used different reentrant circuits. These observations imply that a common pathway of AV nodal tissue is not present above the reentrant circuit and suggest that perinodal atrium is part of these circuits.     

Detection of Anaplasma-marginale-infected tick vectors by using a cloned DNA probe.

Anaplasmosis is the most widely distributed of several important tick-borne diseases that constrain cattle production throughout much of the world. Evaluation of the effectiveness of disease control strategies that integrate vaccination with tick control requires the ability to monitor tick and cattle infection rates. To detect Anaplasma marginale in ticks and bovine erythrocytes, a 2-kilobase DNA fragment from a cloned A. marginale gene coding for a surface protein having a Mr of 105,000 was prepared and evaluated as a probe. The probe was species specific and detected A. marginale DNA derived from infected bovine erythrocytes and adult Dermacentor ticks infected either as nymphs or adults. Tick infection was confirmed by microscopy and test feeding on a susceptible calf. The sensitivity of the probe is suitable for detecting infected ticks in experimental and field epizootiology studies.