Integrating Cost into Shared Decision-Making for Heart Failure with Reduced Ejection Fraction (POCKET-COST-HF): A Trial Providing Out-of-Pocket Costs for Heart Failure Medications during Clinical Encounters

BACKGROUND

Evidence-based medical therapy for heart failure with reduced ejection fraction (HFrEF) often entails substantial out-of-pocket costs that can vary appreciably between patients. This has raised concerns regarding financial toxicity, equity, and adherence to medical therapy. In spite of these concerns, cost discussions in the HFrEF population appear to be rare, partly because out-of-pocket costs are generally unavailable during clinical encounters. In this trial, out-of-pocket cost information is given to patients and clinicians during outpatient encounters with the aim to assess the impact of providing this information on medication discussions and decisions.

HYPOTHESIS

Cost-informed decision-making will be facilitated by providing access to patient-specific out-of-pocket cost estimates at the time of clinical encounter.

DESIGN

Integrating Cost into Shared Decision-Making for Heart Failure with Reduced Ejection Fraction (POCKET-COST-HF) is a multicenter trial based at Emory Healthcare and University of Colorado Health. Adapting an existing patient activation tool from the EPIC-HF trial, patients and clinicians are presented a checklist with medications approved for treatment of HFrEF with or without patient-specific out-of-pocket costs (obtained from a financial navigation firm). Clinical encounters are audio-recorded, and patients are surveyed about their experience. The trial utilizes a stepped-wedge cluster randomized design, allowing for each site to enroll control and intervention group patients while minimizing contamination of the control arm.

DISCUSSION

This trial will elucidate the potential impact of robust cost disclosure efforts and key information regarding patient and clinician perspectives related to cost and cost communication. It also will reveal important challenges associated with providing out-of-pocket costs for medications during clinical encounters. Acquiring medication costs for this trial requires an involved process and outsourcing of work. In addition, costs may change throughout the year, raising questions regarding what specific information is most valuable. These data will represent an important step towards understanding the role of integrating cost discussions into heart failure care.

CLINICALTRIALS

GOV IDENTIFIER

NCT04793880.

Deciding Whether to Take Sacubitril/Valsartan: How Cardiologists and Patients Discuss Out-of-Pocket Costs

Background Out-of-pocket costs have significant implications for patients with heart failure and should ideally be incorporated into shared decision-making for clinical care. High out-of-pocket cost is one potential reason for the slow uptake of newer guideline-directed medical therapies for heart failure with reduced ejection fraction. This study aims to characterize patient-cardiologist discussions involving out-of-pocket costs associated with sacubitril/valsartan during the early postapproval period. Methods and Results We conducted content analysis on 222 deidentified transcripts of audio-recorded outpatient encounters taking place between 2015 and 2018 in which cardiologists (n=16) and their patients discussed whether to initiate, continue, or discontinue sacubitril/valsartan. In the 222 included encounters, 100 (45%) contained discussions about cost. Cost was discussed in a variety of contexts: when sacubitril/valsartan was initiated, not initiated, continued, and discontinued. Of the 97 cost conversations analyzed, the majority involved isolated discussions about insurance coverage (64/97 encounters; 66%) and few addressed specific out-of-pocket costs or affordability (28/97 encounters; 29%). Discussion of free samples of sacubitril/valsartan was common (52/97 encounters; 54%), often with no discussion of a longer-term plan for addressing cost. Conclusions Although cost conversations were somewhat common in patient-cardiologist encounters in which sacubitril/valsartan was discussed, these conversations were generally superficial, rarely addressing affordability or cost-value judgments. Cardiologists frequently provided patients with a course of free sacubitril/valsartan samples without a plan to address the cost after the samples ran out.

Experimenting with modifications to consent forms in comparative effectiveness research: understanding the impact of language about financial implications and key information

Background

Informed consent forms are intended to facilitate research enrollment decisions. However, the technical language in institutional templates can be unfamiliar and confusing for decision-makers. Standardized language describing financial implications of participation, namely compensation for injury and costs of care associated with participating, can be complex and could be a deterrent for potential participants. This standardized language may also be misleading in the context of comparative effectiveness trials of standard care interventions, in which costs and risk of injury associated with participating may not differ from regular medical care. In addition, the revised U.S. Common Rule contains a new requirement to present key information upfront; the impact of how this requirement is operationalized on comprehension and likelihood of enrollment for a given study is unknown.

Methods

Two online surveys assessed the impact of (1) changes to compensation for injury language (standard vs. tailored language form) and (2) changes to the key information page (using the tailored compensation language form with standard key information vs. modified key information vs. modified key information plus financial information) on both likelihood of enrollment in and understanding of a hypothetical comparative effectiveness trial.

Results

Likelihood of enrolling was not observed to be different between the standard and tailored language forms in Study 1 (73 vs. 75%; p = 0.6); however, the tailored language group had a higher frequency of understanding the compensation for injury process specific to the trial (25 vs. 51%; p < 0.0001). Modifications to the key information sheet in Study 2 did not affect likelihood of enrolling (88 vs. 85 vs. 85%; p = 0.6); however, understanding of randomization differed by form (44 vs. 59 vs. 46%; p = 0.002).

Conclusions

These findings suggest that refining consent forms to clarify key information and tailoring compensation for injury language to the nature of the study, especially in the context of comparative effectiveness trials, may help to improve study comprehension but may not impact enrollment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12910-021-00736-x.

Getting the Most out of Consent: Patient-Centered Consent for an Acute Stroke Trial

Informed consent for clinical trials in acute stroke is characterized by challenges related to urgency, cognitive impairment, and geographical separation. Context-appropriate approaches are needed for this setting. We conducted a mixed-methods project involving focus groups and interviews as well as collaboration with a patient advisory panel and a central institutional review board (CIRB) to design and implement a patient-driven consent process for a multicenter trial incorporating adaptive randomization. Remote consent was recognized as challenging but acceptable. Adaptive randomization was viewed positively, but significant potential for misunderstanding was appreciated. Collaboration between the patient advisory panel and the CIRB resulted in a shortened, more patient-centered consent form that was approved at all sites with few modifications. An information sheet was developed as a resource for patients and surrogates after enrollment. Collaboration between investigators, patient partners, and a CIRB can facilitate innovation and implementation of patient-centered, context-appropriate consent strategies.

Framing Benefits in Decision Aids: Effects of Varying Contextualizing Statements on Decisions About Sacubitril-Valsartan for Heart Failure

Background. Presenting numeric data alone may result in patients underappreciating clinically significant benefits. Contextualizing statements to counter this may raise concern about absence of neutrality. These issues arose during construction of a decision aid for sacubitril-valsartan, a heart failure medication associated with a ∼3% absolute reduction in 2-year mortality that carries high out-of-pocket cost. A contextualizing statement framing this as a “pretty big benefit” was incorporated. The impact of statements like this within decision aids is unknown. Objective. This online Qualtrics survey sought to deepen understanding of benefit framing by testing the impact of varying contextualizing statements within a decision aid for sacubitril-valsartan. Design. Participants were randomly assigned to receive one of six abbreviated versions of a decision aid for sacubitril-valsartan that varied only by contextualizing statement (ranging from strongly neutral to strongly positive and using relative and absolute risk reductions). Participants were asked to answer questions regarding the likelihood of taking the medication at a cost of $50/month and their perception of the drug’s benefits. Results. A total of 1873 participants who were demographically similar to the heart failure population completed the survey. Fifty-four percent were willing to take sacubitril-valsartan at $50/month. Each of the five experimental contextualizing statements was compared with the baseline version; no significant differences were observed in reported likelihood of taking sacubitril-valsartan. After controlling for demographics and covariates, group assignment did not predict likelihood of taking the medication. Higher income, better self-reported health status, and younger age were associated with increased likelihood of taking sacubitril-valsartan. Limitations. This study used a hypothetical scenario and evaluated one method of delivering contextualizing statements. Conclusions. Contextualizing statements as tested within this decision aid did not affect decision making.

Reframing Recruitment: Evaluating Framing in Authorization for Research Contact Programs

BACKGROUND

The changing clinical research recruitment landscape involves practical challenges but introduces opportunities. Researchers can now identify large numbers of eligible patients through electronic health record review and can directly contact those who have authorized contact. Applying behavioral science-driven strategies to design and frame communication could affect patients' willingness to authorize contact and their understanding of these programs. The ethical and practical implications of various strategies warrant empirical evaluation.

METHODS

We conducted an online survey (n = 1070) using a nationally-representative sample. Participants were asked to imagine being asked for authorization for research contact in clinic. They were randomly assigned to view one of three flyers: #1-neutral text flyer; #2-a positive text flyer; or #3-positive graphics-based flyer. Primary outcomes included likelihood of enrollment and comprehension of the program. Chi-Square tests and regression analyses were used to examine whether those who saw the positive flyers were more likely to enroll and had increased comprehension.

RESULTS

Compared to the neutral flyer, individuals who received the positive text flyer were numerically more likely to enroll, but this was not statistically significant (24.2% v. 19.0%, p = 0.11). Individuals who received the positive graphics flyer were more likely to enroll (28.7% v. 19.0%, p = 0.002). After adjustment, individuals assigned to both novel flyers had increased odds of being likely to enroll (OR = 1.55 95%CI [1.04, 2.31] and OR = 1.95 95%CI [1.31, 2.91]). Flyer type did not affect overall comprehension (p = 0.21), and greater likelihood of enrollment was observed only in individuals with better comprehension.

CONCLUSIONS

This study demonstrated that employing behavioral science-driven communication strategies for authorization for research contact had an effect on likelihood of hypothetical enrollment but did not significantly affect comprehension. Strategies using simple, positive language and visual tools may be effective and ethically appropriate. Further studies should explore how these and other approaches can help to optimize research recruitment.

Public attitudes toward an authorization for contact program for clinical research

We conducted an online experimental survey to evaluate attitudes toward an authorization for contact (AFC) program allowing researchers to contact patients about studies based on electronic record review. A total of 1070 participants were randomly assigned to 1 of 3 flyers varying in design and framing. Participants were asked to select concerns about and reasons for signing up for AFC. Logistic regression and latent class analysis were conducted. The most commonly selected concerns included needing more information (43%), privacy (40%), and needing more time to think (28%). A minority were not interested in participating in research (16%) and did not want to be bothered (15%). Latent class analysis identified clusters with specific concerns about privacy, lack of interest in research, and not wanting to be bothered. A novel flyer with simple and positive framing was associated with lower odds of both not wanting to be bothered (P = .01) and not being interested in research (P = .01). Many concerns about AFC programs appear nonspecific. Addressing privacy, lack of interest in research, and not wanting to be bothered warrant further study as ways to enhance recruitment.

Show Me the Money: Patients' Perspectives on a Decision Aid for Sacubitril/Valsartan Addressing Out-of-Pocket Cost

BACKGROUND

Out-of-pocket medication costs for patients who have heart failure with reduced ejection fraction may be an important part of shared decision-making, but cost has generally been excluded from clinical discussions. This study reports patients' perspectives on a decision aid for sacubitril/valsartan that explicitly addresses out-of-pocket costs.

METHODS

Structured, in-depth interviews were conducted with 20 patients with heart failure with reduced ejection fraction from 2 medical centers to elicit their views on a publicly available decision aid for sacubitril/valsartan that explicitly incorporates considerations related to out-of-pocket costs. Qualitative descriptive analysis was conducted.

RESULTS

Key themes identified were general enthusiasm for decision aids for medication decisions, openness on the part of patients to incorporation of cost into decision-making and the decision aid, requests for greater specificity regarding patient-specific cost, and challenges communicating evidence of benefit in a way that allows patients to make cost-benefit analyses for themselves. Patients also raised questions regarding logistical challenges of incorporating a decision aid into the normal clinical and decision-making workflow.

CONCLUSIONS

Patients were receptive to the inclusion of out-of-pocket cost as relevant in a decision aid for sacubitril/valsartan. Key challenges to effective integration of cost in these decisions include developing mechanisms for acquiring reliable patient-specific cost estimates and addressing patients' difficulties (and sometimes skepticism) applying trial evidence to their own situation. In addition, implementation strategies are important to develop to facilitate decision aid integration for routine medical decisions into clinic workflow.

Partnering With Patients to Bridge Gaps in Consent for Acute Care Research

Clinical trials for acute conditions such as myocardial infarction and stroke pose challenges related to informed consent due to time limitations, stress, and severe illness. Consent processes should be sensitive to the context in which trials are conducted and to needs of patients and surrogate decision-makers. This manuscript describes a collaborative effort between ethicists, researchers, patients, and surrogates to develop patient-driven, patient-centered approaches to consent for clinical trials in acute myocardial infarction and stroke.Our group identified important ways in which existing consent processes and forms for clinical trials fail to meet patients' and surrogates' needs in the acute context. We collaborated to create model forms and consent processes that are substantially shorter and, hopefully, better-matched to patients' and surrogates' needs and expectations from the perspective of content, structure, and tone. These changes, however, challenge some common conventions regarding consent.

Abstract 27: Patients' Perspectives on a Decision Aid to Facilitate Cost-sensitive Decisions for Sacubitril-Valsartan

Background: Decision aids frequently focus on decisions that are preference-sensitive due to an absence of superior medical option or qualitative differences in treatments. Out of pocket cost can also make decisions preference-sensitive. However, cost is infrequently discussed with patients, and cost has not typically been considered in developing approaches to shared decision-making or decision aids. Determining a therapy’s value to a patient requires an individualized assessment of both benefits and cost. A decision aid addressing cost for sacubitril-valsartan in heart failure with reduced ejection fraction (HFrEF) was developed because this medication has clear medical benefits but can entail appreciable out-of-pocket cost.

Objective: To explore patients’ perspectives on a decision aid for sacubitril-valsartan in HFrEF.

Methods: Twenty adults, ages 32-73, with HFrEF who met general eligibility for sacubitril-valsartan were recruited from outpatient HF clinics and inpatient services at 2 geographically-distinct academic health systems. In-depth interviews were conducted by trained interviewers using a semi-structured guide after patients reviewed the decision aid. Interviews were audio-recorded and transcribed; qualitative descriptive analysis was conducted using a template analytic method.

Results: Participants confirmed that cost was relevant to this decision and that cost discussions with clinicians are infrequent but welcomed. Participants cited multiple ways that this decision aid could be helpful beyond informing a choice; these included serving as a conversation starter, helping inform questions, and serving as a reference later. The decision aid seemed balanced; several participants felt that it was promotional, while others wanted a more “positive” presentation. Participants valued the display of benefits of sacubitril-valsartan but had variable views about how to apply data to themselves and heterogenous interpretations of a 3% absolute reduction in mortality over 2 years. None felt this benefit was overwhelming; about half felt it was very small. The decision aid incorporated a novel “gist statement” to contextualize benefits and counter tendencies to dismiss this mortality reduction as trivial. Several participants liked this statement; few had strong impressions.

Conclusion: Out of pocket cost should be part of shared decision-making. These data suggest patients are receptive to inclusion of cost in decision aids and that a “middle ground” between being promotional and negative may exist. The data, however, raise concerns regarding potential dismissal of clinically meaningful benefits and illustrate challenges identifying appropriate contextualizing language. The impact of various framings warrants further study, as does integration of decision aids with patient-specific out-of-pocket cost information during clinical encounters.

Discussing Out-of-Pocket Costs With Patients: Shared Decision Making for Sacubitril-Valsartan in Heart Failure

Background

“Financial toxicity” is a concern for patients, but little is known about how patients consider out‐of‐pocket cost in decisions. Sacubitril‐valsartan provides a contemporary scenario to understand financial toxicity. It is guideline recommended for heart failure with reduced ejection fraction, yet out‐of‐pocket costs can be considerable.

Methods and Results

Structured interviews were conducted with 49 patients with heart failure with reduced ejection fraction at heart failure clinics and inpatient services. Patient opinions of the drug and its value were solicited after description of benefits using graphical displays. Descriptive quantitative analysis of closed‐ended responses was conducted, and qualitative descriptive analysis of text data was performed. Of participants, 92% (45/49) said that they would definitely or probably switch to sacubitril‐valsartan if their physician recommended it and out‐of‐pocket cost was $5 more per month than their current medication. Only 43% (21/49) would do so if out‐of‐pocket cost was $100 more per month (P<0.001). At least 40% across all income categories would be unlikely to take sacubitril‐valsartan at $100 more per month. Participants exhibited heterogeneous approaches to cost in decision making and varied on their use and interpretation of probabilistic information. Few (20%) participants stated physicians had initiated a conversation about cost in the past year.

Conclusions

Out‐of‐pocket cost variation reflective of contemporary cost sharing substantially influenced stated willingness to take sacubitril‐valsartan, a guideline‐recommended therapy with mortality benefit. These findings suggest a need for cost transparency to promote shared decision making. They also demonstrate the complexity of cost discussion and need to study how to incorporate out‐of‐pocket cost into clinical decisions.

Determinants of Patient and Surrogate Experiences With Acute Care Research Consent: A Key Informant Interview Study

Background Informed consent for acute myocardial infarction and stroke research is challenging. Time for enrollment decisions is limited, patients and family are usually stressed, and being asked to participate in research is often unexpected. Despite these barriers, patients and surrogates have reported a preference for prospective involvement in research decisions and generally positive views of the consent process. It is unknown what drives positive or negative consent experiences. These data are crucial to making consent processes more context appropriate. Methods and Results We conducted a qualitative interview study with 27 patients and surrogates enrolled in acute myocardial infarction and stroke trials in the past 5 years. Purposive sampling from the P-CARE (Patient-Centered Approaches to Research Enrollment) study was based on participant characteristics and responses to initial patient-centered interviews. In-depth interviews used open-ended questions to explore factors influencing consent experiences. Qualitative descriptive analysis was performed utilizing a multilevel coding strategy. Participants identified specific researcher behaviors as important, including expressions of respect, professionalism, and nonpressuring communication. Participants preferred consent conversations focused on risks/benefits and the trial protocol. They had varying views of consent forms and communicated several reasons the form was valuable unrelated to informational content. Participants also valued postenrollment interactions as opportunities to ask questions and learn about the study. Conclusions Barriers to consent in acute myocardial infarction and stroke trials are unavoidable, but participants identified productive ways to demonstrate respect for patients during enrollment conversations. These include key researcher behaviors, concentrating consent discussions on what participants find most important, and structured postenrollment follow-up.

Emergency Consent: Patients' and Surrogates' Perspectives on Consent for Clinical Trials in Acute Stroke and Myocardial Infarction

Background

Emergent informed consent for clinical trials in acute myocardial infarction (AMI) and stroke is challenging. The role and value of consent are controversial, and insufficient data exist regarding patients’ and surrogates’ experiences.

Methods and Results

We conducted structured interviews with patients (or surrogates) enrolled in AMI or acute stroke trials at 6 sites between 2011 and 2016. Primary domains included trial recall, consent experiences, and preferences regarding involvement. Descriptive and test statistics were used to characterize responses and explore relationships between key domains and characteristics. Multivariable logistic regression was used to examine associations between key covariates and consent preferences. There were 176 (84 stroke, 92 AMI) completed interviews. Most stroke respondents (82%) were surrogates; all AMI respondents were patients. Average time from trial enrollment to interview was 1.9 years (stroke) and 2.8 years (AMI); 89% of stroke and 62% of AMI respondents remembered being in the trial, and among these respondents, 80% (stroke) and 44% (AMI) remembered reading some of the consent form. Over 90% reported not feeling pressure to enroll, being treated in a caring way, and being treated with dignity. A minority (16% stroke and 26% AMI) reported they would have preferred not to be asked for consent. Just over half (61% stroke and 53% AMI) recalled a postenrollment conversation about the study.

Conclusions

Most respondents felt they were treated respectfully and were glad they had been asked for consent. Trial recall was relatively low, and many respondents recalled little postenrollment discussion. Further development of context‐sensitive approaches to consent is important.

Abstract WP307: Patients’ and Surrogates’ Experiences and Views of Consent in Acute Stroke Trials

Introduction: Informed consent for clinical trials in acute stroke is challenging. Enrollment decisions must be made quickly, in stressful situations, and typically by a surrogate. Moreover, trials are complex and unfamiliar. Understanding patients’ and surrogates’ experiences may help maximize respect for them while facilitating important studies.

Methods: Telephone interviews were conducted with consented patients or surrogates for patients enrolled in acute stroke trials at 3 US sites between 2011 and 2016. Interviews assessed trial recall, experiences with consent, and preferences regarding consent. Questions were primarily closed-ended. Descriptive statistics were calculated, and bivariate analyses (Fisher’s exact) were conducted to examine predictors of consent preference.

Results: Eighty-four respondents (69 surrogates, 15 patients) across 3 sites and 10 trials were interviewed and included in final analysis. Nine did not recall enrollment, and only about half (53%) recalled that the trial involved an intervention. Of 75 respondents who remembered enrolling, 65 (87%) remembered signing a consent form, 52 (80%) of whom said they read at least some of it. Most respondents reported being treated respectfully during consent. Only 12 respondents (16%) wished they had been enrolled in the trial without prospective consent. Individuals with low health literacy were less likely to prefer enrollment without consent (p<0.0007) but more likely to wish they had not had to sign a consent form (p<0.0001). Forty-six (61%) recalled someone talking with them about the study after enrollment.

Conclusions: Patients and surrogates in stroke trials reported mostly positive consent experiences and generally appreciated having been asked for consent prior to enrollment. Recall of trial details, however, was low, and post-enrollment contact was recalled to be somewhat infrequent. Further work may help to identify the most context-appropriate strategies.

Candida prosthetic valve endocarditis cured by caspofungin therapy without valve replacement

A 64-year-old woman with a mechanical mitral valve prosthesis developed late-onset Candida endocarditis. Blood cultures grew Candida glabrata and Candida krusei. Transesophageal echocardiography demonstrated vegetations on the valve. The patient was not medically fit for valve replacement, but her condition was successfully treated with 6 weeks of intravenous caspofungin therapy.

The safety and effectiveness of a nurse led cardioversion service under sedation

OBJECTIVE

To assess the safety and effectiveness of nurse led elective cardioversion of atrial fibrillation under sedation.

DESIGN

Prospective, longitudinal study.

SETTING

Cardiac catheterisation laboratory and recovery area of a district general hospital.

PATIENTS

300 patients referred for elective cardioversion of persistent atrial fibrillation.

INTERVENTIONS

Pre-procedure evaluations (history, physical examination, blood tests), consent, sedation administration, cardioversions, and post-procedure monitoring until discharge by advanced life support certified coronary care unit nurses trained in the techniques. A doctor was immediately available if required but not present.

MAIN OUTCOME MEASURES

Success rates at discharge and at six weeks, energy delivered, number of shocks, dose of sedation, immediate, 24, and 48 hour patient perceptions, complications, waiting times, and cost effectiveness.

RESULTS

Cardioversion success rate was 87% at discharge and 48% at six weeks. Mean (SD) cumulative energy was 497 (282) J and number of shocks 1.6 (0.8). Mean (SD) dose of sedation was 23 (9) mg intravenous diazepam. No patient required reversal of sedation, airway support, or medical intervention. Ninety eight per cent of patients had no pain or recall of the procedure. Four patients who were adequately anticoagulated experienced embolic phenomena. Ninety eight per cent of patients would repeat the procedure if necessary. Without requirement for a physician or anaesthetist, waiting times for elective cardioversion fell from three months to under four weeks. There was a significant reduction in the estimated cost of the procedure from 337 pounds sterling with general anaesthesia to 130 pounds sterling with nurse led sedation and cardioversion (p < 0.001).

CONCLUSION

With appropriate training, a nurse led cardioversion service with sedation is safe, effective, well tolerated, and cost efficient.

Atrial fibrillation storms

Evolving pacemaker and device technology now allows the onset pattern of arrhythmias to be identified. It is recognised that some cardiac arrhythmias have a circadian pattern of onset and that ventricular arrhythmias can occur in clusters of electrical storms. The long-term follow-up of patients with an atrial defibrillator suggests that in some patients persistent atrial fibrillation recurrences are not random, but can occur in clusters of 'atrial fibrillation storms'. A case report is used to demonstrate this newly recognised phenomenon.

Specificity of SAF-A and lamin B binding in vitro correlates with the satellite DNA bending state

There is evidence that Matrix Attachment Region (MAR)-binding proteins also bind satellite DNA (satDNA). The aim of the current work was to determine whether the major nuclear matrix (NM) MAR-binding proteins are able to recognize satDNAs of different locations and what DNA structural features are important for the recognition. In nuclei and NM, a number of the same polypeptides were recognized on a southwestern blot when MAR of immunoglobulin kappa gene (Ig kappa MAR) and pericentromeric (periCEN) satDNA fragments were used. However, the binding decreased dramatically when human and mouse CEN satDNA were used for the probes. After an NM extract was subjected to ion exchange chromatography, the main DNA-binding proteins were identified as SAF-A (scaffold attachment factor A) and lamin B. It was not possible to test the binding of lamin B by gel mobility shift assay (GMSA), but SAF-A showed an ability to distinguish CEN and periCEN satDNA fragments in GMSA. While periCEN fragments have an abnormally slow mobility on electrophoresis, which is a hallmark of bent DNA, CEN satDNA fragments have a normal mobility. A computer analysis was done using the wedge model (Ulanovsky and Trifonov [1987] Nature 326:720-722), which describes how the curved state depends on particular nucleotide sequences. The curved states of the fragments predicted by the model are in good agreement with their ability to be recognized by NM proteins. Thus SAF-A and lamin B are able to recognize conserved structural features of satDNA in the same way that MAR-binding proteins recognize MARs in spite of a lack of a consensus sequence. CEN and periCEN satDNAs are distinguished by proteins in correlation with the helical curvature of these fragments.

Safety, effectiveness and cost efficacy of diagnostic electrophysiology and radiofrequency ablation in a district general hospital

Electrophysiological studies (EPS) are now being performed in district general hospitals (DGH) in the UK. In order to audit our results, a prospective database was established for all patients undergoing EPS and radiofrequency (RF) ablation at Eastbourne District General Hospital, East Sussex. Between 1 January 1997 and 1 July 2000, 300 EPS procedures were performed, resulting in 155 RF ablations. The average RF ablation procedure time was 119.3 minutes with an average fluoroscopy time of 19.1 minutes. Cost per RF ablation procedure was 1166.79 Pounds excluding use of facilities, pacemaker devices, medical nursing and radiography staffing costs. The overall success rate for RF ablation was 93.6% with a major complication rate of 0.6%, a total complication rate of 3.9% and no associated mortality. We have shown that RF ablation can be performed safely, effectively and economically in a DGH setting with a high rate of success and a low complication rate.

Specific interaction of mouse major satellite with MAR-binding protein SAF-A

A DNA-binding activity specific to the major mouse satellite (satMa) has been detected in a nuclear matrix protein extract by electrophoretic mobility shift assays (EMSA) after fractionation by ion exchange chromatography. An antibody raised against the satMa-protein complexes recovered from preparative EMSA recognizes on Western blots one major polypeptide with an apparent molecular mass of 120 kDa. The protein also has a similar affinity for a matrix-associated region (MAR) fragment. We demonstrate that the protein is a murine homologue of SAF-A which has been shown to bind selectively to MARs and is responsible for the satMa-binding activity in the chromatographic fractions. SatMa has significant homology to the mouse minor satellite fragments, but its binding of SAF-A shows much less affinity. No protected regions of significant length were found by footprinting, but multiple T residues scattered within the satMa sequence are protected, indicating that the whole fragment is involved in the binding to SAF-A. Combined immunofluorescence (SAF-A) and FISH (satMa) with in situ nuclear matrix procedures reveal that SAF-A and satMa colocalize. SAF-A appears as bright dots in interphase nuclei, presumably associated with MARs, predominantly surrounding and covering heterochromatic areas. A scheme based on morphological observations and biochemical data of SAF-A double satMa/MAR specificity is discussed.

Calcium phosphate nanoparticle adjuvant

Vaccination to protect against human infectious diseases may be enhanced by using adjuvants that can selectively stimulate immunoregulatory responses. In a murine model, a novel nanoparticulate adjuvant composed of calcium phosphate (CAP) was compared with the commonly used aluminum (alum) adjuvants for its ability to induce immunity to herpes simplex virus type 2 (HSV-2) and Epstein-Barr virus (EBV) infections. Results indicated that CAP was more potent as an adjuvant than alum, elicited little or no inflammation at the site of administration, induced high titers of immunoglobulin G2a (IgG2a) antibody and neutralizing antibody, and facilitated a high percentage of protection against HSV-2 infection. Additional benefits of CAP include (i) an insignificant IgE response, which is an important advantage over injection of alum compounds, and (ii) the fact that CAP is a natural constituent of the human body. Thus, CAP is very well tolerated and absorbed. These studies were performed with animal models. By virtue of the potency of this CAP adjuvant and the relative absence of side effects, we believe that this new CAP formulation has great potential for use as an adjuvant in humans.

Nuclear envelope associated protein that binds telomeric DNAs

Rana temporaria oocytes at the 6th diplotene stage of maturation contain a special structure, the karyosphere capsule, with chromosomes covered and detached from the nuclear envelope (NE), though at the previous stage the telomeres were attached to the membrane, as characteristic of germ cells. The DNA-protein complexes from band shift assays with proteins extracted from oocyte NEs and telomeric DNA fragment (T(2)G(4))(130) were isolated and injected into a guinea pig. In the present paper the only protein of 70 kDa recognized by antibody (AB) in the NE is named the Membrane Telomere Binding Protein (MTBP). Western blots with guinea pig AB and AB against telobox peptide from TRF2 show that protein of 60 kDa (probably TRF1) belongs to the chromatin, but MTBP (TRF2 according to immunoprecipitation) belongs to the NE. In the somatic cell nuclei both proteins are present and recognized by AB against telobox peptide, but AB raised recognize only MTBP/TRF2 due to the epitope different from telobox. Combined in situ hybridization with the vertebrate telomeric DNA sequences (T(2)AG(3))(135) and immunocytochemistry with the MTBP AB showed them to be colocalized within the mouse nucleus. As it was shown by immunofluorescense of NE spread, MTBP is organized in a distinct pattern that looks like a network made of double-dots. Electron microscope immunogold staining with both ABs showed that the protein is localized on the outer surface of the oocyte NE within cup-like structures attached to the membrane. This is the first clear evidence of a protein, which could be responsible for the attachment of telomeres to the nuclear membrane.

Infected chronic extradural haematoma

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A FISH study of chromosome fusion in the ICF syndrome: involvement of paracentric heterochromatin but not of the centromeres themselves

We have used double fluorescence in situ hybridisation to study the involvement of centromeres and paracentromeric heterochromatin in the chromosome abnormalities seen in the ICF syndrome. To detect centromeres, we used a probe which labelled alphoid satellite DNA, and for the paracentromeric heterochromatin a probe for classical satellite II. Our results show that it is always the paracentromeric heterochromatin of the relevant chromosomes that becomes decondensed in this syndrome and which fuses to produce multiradial configurations. However, the centromeric regions, identified by their content of alphoid satellite DNA, appear never to become decondensed and always remain outside the regions of chromosome fusion in the multiradials.

The mammalian centromere: its molecular architecture

The DNA and protein composition of the centromeric domains in mammalian chromosomes is now relatively well characterised. The major families of repeated DNAs, i.e., the simple-sequence and alphoids in man and the satellite sequences (both minor and major) in the mouse have been sequenced and long-range maps using pulse-field gels of some centromeres have been carried out. Autoimmune antibodies have provided an insight into some of the proteins which interact with these DNA sequences. Although the individual components of the mammalian centromere may have been identified, how they interact with each other to give the functional structure visualised by electron microscopy is yet to be determined. This review examines our understanding of these separate components.

Epigenetic control of mammalian centromere protein binding: does DNA methylation have a role?

Chromosome 1 of the inbred mouse strain DBA/2 has a polymorphism associated with the minor satellite DNA at its centromere. The more terminal block of satellite DNA sequences on this chromosome acts as the centromere as shown by the binding of CREST ACA serum, anti-CENP-B and anti-CENP-E polyclonal sera. Demethylation of the minor satellite DNA sequences accomplished by growing cells in the presence of the drug 5-aza-2′-deoxycytidine results in a redistribution of the CENP-B protein. This protein now binds to an enlarged area on the more terminal block and in addition it now binds to the more internal block of minor satellite DNA sequences on chromosome 1. The binding of the CENP-E protein does not appear to be affected by demethylation of the minor satellite sequences. We present a model to explain these observations. This model may also indicate the mechanism by which the CENP-B protein recognises specific sites within the arrays of minor satellite DNA on mouse chromosomes.

CENP-B binds a novel centromeric sequence in the Asian mouse Mus caroli

Minor satellite DNA, found at Mus musculus centromeres, is not present in the genome of the Asian mouse Mus caroli. This repetitive sequence family is speculated to have a role in centromere function by providing an array of binding sites for the centromere-associated protein CENP-B. The apparent absence of CENP-B binding sites in the M. caroli genome poses a major challenge to this hypothesis. Here we describe two abundant satellite DNA sequences present at M. caroli centromeres. These satellites are organized as tandem repeat arrays, over 1 Mb in size, of either 60- or 79-bp monomers. All autosomes carry both satellites and small amounts of a sequence related to the M. musculus major satellite. The Y chromosome contains small amounts of both major satellite and the 60-bp satellite, whereas the X chromosome carries only major satellite sequences. M. caroli chromosomes segregate in M. caroli x M. musculus interspecific hybrid cell lines, indicating that the two sets of chromosomes can interact with the same mitotic spindle. Using a polyclonal CENP-B antiserum, we demonstrate that M. caroli centromeres can bind murine CENP-B in such an interspecific cell line, despite the absence of canonical 17-bp CENP-B binding sites in the M. caroli genome. Sequence analysis of the 79-bp M. caroli satellite reveals a 17-bp motif that contains all nine bases previously shown to be necessary for in vitro binding of CENP-B. This M. caroli motif binds CENP-B from HeLa cell nuclear extract in vitro, as indicated by gel mobility shift analysis. We therefore suggest that this motif also causes CENP-B to associate with M. caroli centromeres in vivo. Despite the sequence differences, M. caroli presents a third, novel mammalian centromeric sequence producing an array of binding sites for CENP-B.

Mouse centromere mapping using oligonucleotide probes that detect variants of the minor satellite

Cytologically, the centromere is found at the very end of most Mus musculus chromosomes, co-localizing with an array of minor satellite sequences. It is separated from the euchromatin of the long arm by a large domain of heterochromatin, composed in part of arrays of major satellite sequences. We used oligonucleotide probes that specifically detect regions of sequence variation found in certain cloned minor satellite sequences. They detect a limited subset of the minor satellite arrays in the mouse genome, based on both pulsed-field gel electrophoresis and in situ hybridization data, and provide direct molecular genetic markers for individual centromeres in some inbred mouse strains. Array size polymorphisms detected by these probes map to positions consistent with the centromeres of chromosomes 1 and 14 in the BXD recombinant inbred (RI) strains. The genetic distances between these minor satellite arrays and loci on the long arms of chromosomes 1 and 14 are consistent with repression of meiotic recombination in the heterochromatic domains separating them. The existence of chromosome-specific minor satellite sequences implies that the rate of sequence exchange between non-homologous chromosomes relative to the rate between homologous chromosomes is much lower than has previously been postulated. We suggest that the high degree of sequence homogeneity of mouse satellite sequences may instead reflect recent common ancestry.

Novel structural organisation of a Mus musculus DBA/2 chromosome shows a fixed position for the centromere

Chromosome 1 of the inbred mouse strain DBA/2 shows an unusual polymorphism associated with its centromeric satellite DNA sequences. The minor satellite array has undergone amplification and is present as two blocks separated by major satellite sequences. Both minor satellite blocks appear to carry the sequence motif necessary for CENP-B protein binding. Despite this apparent similarity the functional centromere, as defined by the location of CREST antigens, appears to form only within the more terminal block. The two blocks also vary in that sister chromatid association only occurs with this more terminal block.

Hypomethylation of human heterochromatin detected by restriction enzyme nick translation

Using the restriction enzymes MspI and HpaII in the nick translation procedure it has been shown that decondensation of the paracentric heterochromatin of chromosome 9 during human spermatogenesis is associated with hypomethylation of the DNA sequences in this domain. Somatic cells treated with 5'-azacytidine also showed decondensation of centromeric heterochromatin. In this instance, however, hypomethylation is detected both in the extended heterochromatin at the centromeres and in the euchromatin of the chromosome arms.

A chimpanzee-derived chromosome-specific alpha satellite DNA sequence conserved between chimpanzee and human

We describe a cloned 2.7 kb alpha satellite sequence, Pan-3, from the pygmy chimpanzee (Pan paniscus) that specifically hybridizes in situ to chromosome 19 in the pygmy chimpanzee and to the homeologous human chromosome, no. 17. Using high stringency conditions of hybridization on Southern blots, this sequence hybridized to DNA from both species of chimpanzee (P. paniscus and P. troglodytes) and from human but not to DNA from gorilla (Gorilla gorilla) or orangutan (Pongo pygmaeus). Partial sequence analysis showed that Pan-3 and a previously described human chromosome 17-specific clone have up to 91% sequence identity. To our knowledge this is the highest sequence similarity reported between alphoid subsets from human and any other primate.

Restriction endonuclease/nick translation of fixed mouse chromosomes: a study of factors affecting digestion of chromosomal DNA in situ

We used a restriction endonuclease/nick translation procedure to study the ability of certain enzymes, known to cleave mouse satellite DNA in solution, to attack satellite DNA in fixed mouse chromosomes. Although AvaII and Sau96I readily attack the mouse major satellite in fixed chromosomes, BstNI and EcoRII do not normally do so, although if the heterochromatin is uncondensed as a result of culture in the presence of 5-azacytidine, BstNI can attack it. No clear evidence was obtained for digestion in situ of the minor satellite of mouse chromosomes by MspI, the only enzyme reported to cleave this satellite. Our results show that the DNA of mouse heterochromatin is not merely not extracted by certain restriction enzymes, but is actually not cleaved by them. Chromatin conformation is therefore shown to be an important factor in determining patterns of digestion of chromosomes by restriction endonucleases.

The organization of the mouse satellite DNA at centromeres

The mouse genome contains a major and a minor satellite DNA family of repetitive DNA sequences. The use of 5-azacytidine has allowed us to demonstrate that these satellite DNAs are organized in two separate domains at the centromeres of mouse chromosomes. The minor satellite is closer to the short arms of the acrocentric chromosomes than the major satellite. The major satellite is farther away, flanking the minor satellite and adjacent to the euchromatic long arm of each mouse chromosome. At the level of resolution afforded by the in situ hybridization technique it would appear that the organization of the centromeric domain of the mouse is similar to that in man. That is, both contain two repetitive DNA sequence families arranged in major blocks.

A dicentric recombinant 9 derived from a paracentric inversion: phenotype, cytogenetics, and molecular analysis of centromeres

A 4-year-old girl with multiple malformations and severe developmental delay has been shown to have a karyotype of 46,XX-9,+rec(9),dup p,inv(9) (q22.1q34.3)mat, with duplication 9pter-q22.1 and deficiency 9q34.3-qter. This case confirms that a stable recombinant chromosome can result from a paracentric inversion. The recombinant was derived by two crossovers, one within the inversion loop and a second outside the inversion loop, between 9q21 and the beginning of the meiotic inversion at 9q22.1. In 87 cells the rec(9) had one Cd-positive primary constriction. In 13 cells the rec(9) had two primary constrictions; in 12 of these cells there was one Cd-positive centromere, and in one of these cells both primary constrictions were Cd-positive. Nuclear projections were observed in 10% of fibroblast interphase cells harvested in situ, suggesting that there was some spindle-fiber activity of the "latent" centromere. In situ hybridization with a centromere-specific probe (p82H) and a satellite III probe (L6) revealed no differences between the two C-band regions of the rec(9) and the normal 9 or inverted 9 chromosomes.

A human-derived probe, p82H, hybridizes to the centromeres of gorilla, chimpanzee, and orangutan

A human-derived centromeric sequence, p82H, hybridizes to DNA from gorilla, chimpanzee, pygmy chimpanzee, and orangutan. On DNA blots, multimeric ladders based on 170 or 340 bp repeat units are seen. In metaphase chromosome preparations from these species, p82H hybridizes to the centromeric region of every chromosome. p82H forms less stable hybrids with DNA from the lion-tailed macaque and does not hybridize to DNA or chromosomes of the owl monkey or the mouse.

Organization and genomic distribution of "82H" alpha satellite DNA. Evidence for a low-copy or single-copy alphoid domain located on human chromosome 14

We have investigated the organization and genomic distribution of sequences homologous to p82H, a cloned human alpha satellite sequence purported, based on previous in situ hybridization experiments, to exist at the centromere of each human chromosome. We report here that, using Southern blotting analysis under conditions of high stringency, p82H hybridizes solely to a low-copy or single-copy alphoid domain located at or near the centromeric region of human chromosome 14. In contrast, conditions of reduced hybridization stringency permit extensive cross-hybridization with non-identical, chromosome-specific alpha satellite subsets found elsewhere in the human genome. Thus, the previously described ubiquity of "82H" human centromeric sequences reflects the existence of diverse alpha satellite subsets located at the centromeric region of each human chromosome.

Hypervariable minisatellite regions are sites for crossing-over at meiosis in man

In situ hybridization to human meiotic metaphase I (MI) preparations, using the labeled minisatellite core sequence lambda 33.15, showed clustering of autoradiographic grains principally at or around chiasmata, autosomal sites where crossing-over had occurred. For the XY bivalent, the pairing region formed between the terminal regions of the two short arms (Xpter Ypter), was also a principal site of labeling; in addition, the terminal region of the X long arm (Xqter) was labeled. Control experiments using a member of the human Alu family of dispersed repeated DNA sequences showed a much more randomized grain distribution, with clustering over chiasmata being far less obvious. The data provide support for the suggestion that polymorphic minisatellite regions within the human genome might play a significant role in pairing and/or recombination.

p82H identifies sequences at every human centromere

A cloned alphoid sequence, p82H, hybridizes in situ to the centromere of every human chromosome. After washing under stringent conditions, no more than 8% of the grains are located on any specific chromosome. p82H thus differs from other centromeric sequences which are reported to be chromosome specific, because it detects sequences that are conserved among the chromosomes. Two experimental approaches show that the p82H sequences are closely associated with the centromere. First, p82H remains with the relocated centromeres in an inv(19) and an inv(6) chromosome. Second, p82H hybridizes at the centromere but not to the centromeric heterochromatin of chromosomes 1, 9 and 16 that have elongated 1qh, 9qh and 16qh regions produced by short growth in 5-azacytidine. The only noncentromeric site of hybridization is at the distal end of the 9qh region.

Regional localization and characterization of a DNA segment on the long arm of chromosome 21

A human genomic DNA fragment, pAM37 (HGM8; D21S22), was mapped to chromosome 21q2.1-q2.21 by in situ hybridization. This segment is therefore situated on the boundary of the "pathological region" of Down syndrome. A genomic restriction map encompassing 35 kb of chromosome 21 was derived and two restriction fragment length polymorphisms (RFLPs) were mapped and characterized. A homologous sequence was detected in the mouse genome but no homologous RNA was detected in a range of human tissues. This DNA segment will contribute to the linkage mapping of chromosome 21 and will facilitate delineation of the pathological region of Down syndrome.

Ring XY bivalent: a new phenomenon at metaphase I of meiosis in man

The unusual appearance of a ring XY bivalent at metaphase I of meiosis is reported in some cells of an oligospermic human male. Higher than usual frequencies of ring configuration in the XY pair were also observed during prophase I. The defect could be attributable to loss of some DNA sequences from the distal heterochromatic tip of the Y chromosome long arm.

Gene mapping and physical arrangements of human chromatin in transformed, hybrid cells: fluorescent and autoradiographic in situ hybridization compared

We compare a fluorescent in situ hybridization technique, using N-acetoxy-2-acetylaminofluorene (N-ACO-AAF) modified DNA adducts, with 3H-labeled DNA in situ hybridization for visualizing human transgenomes in HRAS1-selected, chromosome-mediated gene transfer (CMGT), and mapping chromosomal SV40 in an SV40-transformed, human-mouse hybrid cell line. We demonstrate that individual HRAS1-CMGTs may contain multiple fragments of human chromatin. We deduce that the CMGT process can involve interstitial loss of mouse chromatin. We conclude that the N-ACO-AAF technique gives finer resolution than 3H-labeled in situ hybridization. However, 3H-labeling is more sensitive and has allowed us to sublocalize SV40 in C121 to the region 7q31-35.

Molecular hybridization to meiotic chromosomes in man reveals sequence arrangement on the no. 9 chromosome and provides clues to the nature of "parameres"

In situ hybridization of male human meiotic material has been used to elucidate the molecular organization of the centromeric region of human chromosome 9. The use of two cloned DNA sequences has shown that the centromere and the secondary constriction of this chromosome contain two separate repeated DNA families. The secondary constriction organizes into "paramere" bodies during pachytene. The individual parameres are comprised of one family of repeated DNA sequences.