British Oncology Pharmacy Association Delphi consensus guidelines: Co-infusion of trometamol-containing calcium folinate (Leucovorin) with systemic anti-cancer treatments

Drug stability and compatibility are critical factors influencing the cost and logistics of treatment delivery, therapeutic effectiveness, and patient safety. This is particularly significant in the realm of cancer chemotherapeutics, where stability and compatibility studies play a vital role in ensuring rational and safe medicine administration. Oxaliplatin, fluorouracil, and irinotecan, commonly used in various combinations for gastrointestinal cancers, are complemented by co-administration of folinic acid in certain protocols. Notably, some folinic acid preparations include trometamol as an excipient, potentially impacting the stability of the chemotherapeutic agents if infused concomitantly. This study seeks to establish guidelines for oncology multidisciplinary teams, addressing potential risks associated with the combination of trometamol-containing folinic acid and chemotherapeutics. To achieve this, a quantitative questionnaire was distributed to members of the British Oncology Pharmacy Association (BOPA) and non-BOPA members through an online survey. Nineteen healthcare professionals with oncology experience, comprising 18 pharmacists and one nurse, completed the questionnaires. Each participant rated the validity and clarity of statements on a 5-point scale. The Delphi process concluded after the fourth round, consolidating the findings and recommendations from the multidisciplinary team. Twelve recommendations for safe practice have been made.

The impact of the COVID-19 pandemic on community prescription of opioid and antineuropathic analgesics for cancer patients in Wales, UK

PURPOSE

Public health measures instituted at the onset of the COVID-19 pandemic in the UK in 2020 had profound effects on the cancer patient pathway. We hypothesise that this may have affected analgesic prescriptions for cancer patients in primary care.

METHODS

A whole-nation retrospective, observational study of opioid and antineuropathic analgesics prescribed in primary care for two cohorts of cancer patients in Wales, using linked anonymised data to evaluate the impact of the pandemic and variation between different demographic backgrounds.

RESULTS

We found a significant increase in strong opioid prescriptions during the pandemic for patients within their first 12 months of diagnosis with a common cancer (incidence rate ratio (IRR) 1.15, 95% CI: 1.12-1.18, p < 0.001 for strong opioids) and significant increases in strong opioid and antineuropathic prescriptions for patients in the last 3 months prior to a cancer-related death (IRR = 1.06, 95% CI: 1.04-1.07, p < 0.001 for strong opioids; IRR = 1.11, 95% CI: 1.08-1.14, p < 0.001 for antineuropathics). A spike in opioid prescriptions for patients diagnosed in Q2 2020 and those who died in Q2 2020 was observed and interpreted as stockpiling. More analgesics were prescribed in more deprived quintiles. This differential was less pronounced in patients towards the end of life, which we attribute to closer professional supervision.

CONCLUSIONS

We demonstrate significant changes to community analgesic prescriptions for cancer patients related to the UK pandemic and illustrate prescription patterns linked to patients' demographic background.

Identifying Dynamic Patterns of Polypharmacy for Patients with Dementia from Primary Care Electronic Health Records: A Machine Learning Driven Longitudinal Study

It is unclear how medication use evolved before diagnosis of dementia (DoD). This study aims to identify varied patterns of polypharmacy before DoD, their prevalence and possible complications. We collected primary care e-health records for 33,451 dementia patients in Wales from 1990 to 2015. The medication uses in every 5-year period along with 20-years prior to dementia diagnosis were considered. Exploratory factor analysis was used to identify clusters of medicines for every 5-year period. The prevalence of patients taking three or more medications was 82.16%, 69.7%, 41.1% and 5.5% in the Period 1 (0-5 years before DoD) ~ Period 4 (16-20 years before DoD) respectively. The Period 1 showed 3 clusters of polypharmacy - medicines for respiratory/urinary infections, arthropathies and rheumatism, and cardio-vascular disease (CVD) (66.55%); medicines for infections, arthropathies and rheumatism (AR), cardio-metabolic disease (CMD) and depression (22.02%); and medicines for arthropathies, rheumatism and osteoarthritis (2.6%). The Period 2 showed 4 clusters of polypharmacy - medicines for infections, arthropathies, and CVD (69.7%); medicines for CVD and depression (3%); medicines for CMD and arthropathies (0.3%); and medicines for AR, and CVD (2,5%). The Period 3 showed 6 clusters of polypharmacy - medicines for infections, arthropathies, and CVD (41.1%); medicines for CVD, acute-respiratory-infection (ARI), and arthropathies (1.25%); medicines for AR (1.16%); medicines for depression, anxiety (0.06%); medicines for CMD (1.4%); and medicines for dermatologic disorders (0.9%). The Period 4 showed 3 main clusters of polypharmacy - medicines for infections, arthropathy, and CVD (5.5%); medicines for anxiety, ARI (2.4%); and medicines for ARI and CVD (2.1%). As the development towards dementia progressed, the associative diseases tended to cluster with a larger prevalence in each cluster. Farther away before DoD, the clusters of polypharmacy tended to be clearly distinct between each other, resulting in an increasing number of patterns, but in a smaller prevalence.

Encounter-based randomization did not result in contamination in a shared decision-making trial: a secondary analysis

OBJECTIVES

To estimate the level of contamination in an encounter-randomized trial evaluating a shared decision-making (SDM) tool.

STUDY DESIGN AND SETTING

We assessed contamination at three levels: (1) tool contamination (whether the tool was physically present in the usual care encounter), (2) functional contamination (whether components of the SDM tool were recreated in the usual care encounters without directly accessing the tool), and (3) learned contamination (whether clinicians "got better at SDM" in the usual care encounters as assessed by the OPTION-12 score). For functional and learned contamination, the interaction with the number of exposures to the tool was assessed.

RESULTS

We recorded and analyzed 830 of 922 randomized encounters. Of the 411 recorded encounters randomized to usual care, the SDM tool was used in nine (2.2%) encounters. Clinicians discussed at least one patient-important issue in 377 usual care encounters (92%) and the risk of stroke in 214 encounters (52%). We found no significant interaction between number of times the SDM tool was used and subsequent functional or learned contamination.

CONCLUSION

Despite randomly assigning clinicians to use an SDM tool in some and not other encounters, we found no evidence of contamination in usual care encounters.

Enrolling people of color to evaluate a practice intervention: lessons from the shared decision-making for atrial fibrillation (SDM4AFib) trial

Background

Trial recruitment of Black, indigenous, and people of color (BIPOC) is key for interventions that interact with socioeconomic factors and cultural norms, preferences, and values. We report on our experience enrolling BIPOC participants into a multicenter trial of a shared decision-making intervention about anticoagulation to prevent strokes, in patients with atrial fibrillation (AF).

Methods

We enrolled patients with AF and their clinicians in 5 healthcare systems (three academic medical centers, an urban/suburban community medical center, and a safety-net inner-city medical center) located in three states (Minnesota, Alabama, and Mississippi) in the United States. Clinical encounters were randomized to usual care with or without a shared decision-making tool about anticoagulation.

Analysis

We analyzed BIPOC patient enrollment by site, categorized reasons for non-enrollment, and examined how enrollment of BIPOC patients was promoted across sites.

Results

Of 2247 patients assessed, 922 were enrolled of which 147 (16%) were BIPOC patients. Eligible Black participants were significantly less likely (p < .001) to enroll (102, 11%) than trial-eligible White participants (185, 15%). The enrollment rate of BIPOC patients varied by site. The inclusion and prioritization of clinical practices that care for more BIPOC patients contributed to a higher enrollment rate into the trial. Specific efforts to reach BIPOC clinic attendees and prioritize their enrollment had lower yield.

Conclusions

Best practices to optimize the enrollment of BIPOC participants into trials that examined complex and culturally sensitive interventions remain to be developed. This study suggests a high yield from enrolling BIPOC patients from practices that prioritize their care.

Trial registration

ClinicalTrials.gov (NCT02905032).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-022-08399-z.

Effect of Shared Decision-Making for Stroke Prevention on Treatment Adherence and Safety Outcomes in Patients With Atrial Fibrillation: A Randomized Clinical Trial

Background Guidelines promote shared decision-making (SDM) for anticoagulation in patients with atrial fibrillation. We recently showed that adding a within-encounter SDM tool to usual care (UC) increases patient involvement in decision-making and clinician satisfaction, without affecting encounter length. We aimed to estimate the extent to which use of an SDM tool changed adherence to the decided care plan and clinical safety end points. Methods and Results We conducted a multicenter, encounter-level, randomized trial assessing the efficacy of UC with versus without an SDM conversation tool for use during the clinical encounter (Anticoagulation Choice) in patients with nonvalvular atrial fibrillation considering starting or reviewing anticoagulation treatment. We conducted a chart and pharmacy review, blinded to randomization status, at 10 months after enrollment to assess primary adherence (proportion of patients who were prescribed an anticoagulant who filled their first prescription) and secondary adherence (estimated using the proportion of days for which treatment was supplied and filled for direct oral anticoagulant, and as time in therapeutic range for warfarin). We also noted any strokes, transient ischemic attacks, major bleeding, or deaths as safety end points. We enrolled 922 evaluable patient encounters (Anticoagulation Choice=463, and UC=459), of which 814 (88%) had pharmacy and clinical follow-up. We found no differences between arms in either primary adherence (78% of patients in the SDM arm filled their first prescription versus 81% in UC arm) or secondary adherence to anticoagulation (percentage days covered of the direct oral anticoagulant was 74.1% in SDM versus 71.6% in UC; time in therapeutic range for warfarin was 66.6% in SDM versus 64.4% in UC). Safety outcomes, mostly bleeds, occurred in 13% of participants in the SDM arm and 14% in the UC arm. Conclusions In this large, randomized trial comparing UC with a tool to promote SDM against UC alone, we found no significant differences between arms in primary or secondary adherence to anticoagulation or in clinical safety outcomes. Registration URL: https://www.clinicaltrials.gov; Unique identifier: clinicaltrials.gov. Identifier: NCT02905032.

The effect of shared decision-making for stroke prevention on treatment adherence and safety outcomes in patients with atrial fibrillation: a randomized clinical trial

Background

Guidelines promote shared decision-making (SDM) for anticoagulation in patients with atrial fibrillation (AF). We recently showed that adding a within-encounter SDM tool to usual care (UC) increases patient involvement in decision making and clinician satisfaction, without affecting encounter length.

Purpose

We aimed to estimate the extent to which use of an SDM tool affected patient adherence to the decided care plan and clinical safety endpoints.

Methods

We conducted a multi-center, encounter-level randomized trial assessing the efficacy of UC with vs. without an SDM conversation tool for use during the clinical encounter (Anticoagulation Choice, AC) in patients with non-valvular AF considering starting or reviewing anticoagulation treatment. We conducted a chart and pharmacy review, blinded to randomization status, at 10 months post-enrollment to assess primary adherence (proportion of patients who were prescribed an anticoagulant who filled their first prescription) and secondary adherence (estimated using the proportion of days for which treatment was supplied and filled [PDC] for DOAC, and as time in therapeutic range (TTR) for warfarin). We also followed for any safety outcomes (stroke [stroke or transient ischemic attack], major bleeding, or death).

Results

We enrolled 922 evaluable patient encounters (AC=463, UC=459), of which 814 (88%) had pharmacy and clinical follow-up. We found no differences between arms in either primary (78% of patients in AC filled their first prescription vs. 81% in UC) or secondary adherence to anticoagulation (see Figure, PDCDOAC was 74.1% in AC vs. 71.6% in UC; TTRwarfarin was 66.6% in AC vs. 64.4% in UC). PDCDOAC was better (65%) in AC than in UC (55%) (OR 1.49, CIs 1.00, 2.22). Safety outcomes, mostly bleeds, occurred in 13% (AC) of and 14% (UC) of participants.

Conclusions

This is the largest reported randomized trial in AF comparing usual care with and without an SDM tool to promote SDM. Although patients were more actively involved in SDM, we found no significant differences between arms in primary or secondary adherence to anticoagulation or clinical safety outcomes.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): The trial was funded by and conducted independently of the National Heart, Lung, and Blood Institute (NHLBI) of the U.S. National Institutes of Health (RO1 HL131535-01). The funding body had no influence on the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication. Figure 1

Cost Conversations About Anticoagulation Between Patients With Atrial Fibrillation and Their Clinicians: A Secondary Analysis of a Randomized Clinical Trial

IMPORTANCE

How patients with atrial fibrillation (AF) and their clinicians consider cost in forming care plans remains unknown.

OBJECTIVE

To identify factors that inform conversations regarding costs of anticoagulants for treatment of AF between patients and clinicians and outcomes associated with these conversations.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study of recorded encounters and participant surveys at 5 US medical centers (including academic, community, and safety-net centers) from the SDM4AFib randomized trial compared standard AF care with and without use of a shared decision-making (SDM) tool. Included patients were considering anticoagulation treatment and were recruited by their clinicians between January 30, 2017, and June 27, 2019. Data were analyzed between August and November 2019.

MAIN OUTCOMES AND MEASURES

The incidence of and factors associated with cost conversations, and the association of cost conversations with patients' consideration of treatment cost burden and their choice of anticoagulation.

RESULTS

A total of 830 encounters (out of 922 enrolled participants) were recorded. Patients' mean (SD) age was 71.0 (10.4) years; 511 patients (61.6%) were men, 704 (86.0%) were White, 303 (40.9%) earned between $40 000 and $99 999 in annual income, and 657 (79.2%) were receiving anticoagulants. Clinicians' mean (SD) age was 44.8 (13.2) years; 75 clinicians (53.2%) were men, and 111 (76%) practiced as physicians, with approximately half (69 [48.9%]) specializing in either internal medicine or cardiology. Cost conversations occurred in 639 encounters (77.0%) and were more likely in the SDM arm (378 [90%] vs 261 [64%]; OR, 9.69; 95% CI, 5.77-16.29). In multivariable analysis, cost conversations were more likely to occur with female clinicians (66 [47%]; OR, 2.85; 95% CI, 1.21-6.71); consultants vs in-training clinicians (113 [75%]; OR, 4.0; 95% CI, 1.4-11.1); clinicians practicing family medicine (24 [16%]; OR, 12.12; 95% CI, 2.75-53.38]), internal medicine (35 [23%]; OR, 3.82; 95% CI, 1.25-11.70), or other clinicians (21 [14%]; OR, 4.90; 95% CI, 1.32-18.16) when compared with cardiologists; and for patients with an annual household income between $40 000 and $99 999 (249 [82.2%]; OR, 1.86; 95% CI, 1.05-3.29) compared with income below $40 000 or above $99 999. More patients who had cost conversations reported cost as a factor in their decision (244 [89.1%] vs 327 [69.0%]; OR 3.66; 95% CI, 2.43-5.50), but cost conversations were not associated with the choice of anticoagulation agent.

CONCLUSIONS AND RELEVANCE

Cost conversations were common, particularly for middle-income patients and with female and consultant-level primary care clinicians, as well as in encounters using an SDM tool; they were associated with patients' consideration of treatment cost burden but not final treatment choice. With increasing costs of care passed on to patients, these findings can inform efforts to promote cost conversations in practice.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02905032.

Accurate prediction of saw blade thicknesses from false start measurements

BACKGROUND

False start analysis is the examination of incomplete saw marks created on bone in an effort to establish information on the saw that created them. The present study aims to use quantitative data from micro-CT cross-sections to predict the thickness of the saw blade used to create the mark. Random forest statistical models are utilised for prediction to present a methodology that is useful to both forensic researchers and practitioners.

METHOD

340 false starts were created on 32 fleshed cadaveric leg bones by 38 saws of various classes. False starts were micro-CT scanned and seven measurements taken digitally. A regression random forest model was produced from the measurement data of all saws to predict the saw blade thickness from false starts with an unknown class. A further model was created, consisting of three random forests, to predict the saw blade thickness when the class of the saw is known. The predictive capability of the models was tested using a second sample of data, consisting of measurements taken from a further 17 false starts created randomly selected saws from the 38 in the experiment.

RESULTS

Random forest models were able to accurately predict up to 100% of saw blade thicknesses for both samples of false starts.

CONCLUSION

This study demonstrates the applicability of random forest statistical regression models for reliable prediction of saw blade thicknesses from false start data. The methodology proposed enables prediction of saw blade thickness from empirical data and offers a significant step towards reduced subjectivity and database formation in false start analysis. Application of this methodology to false start analysis, with a more complete database, will allow complementary results to current analysis techniques to provide more information on the saw used in dismemberment casework.

Assessment of Shared Decision-making for Stroke Prevention in Patients With Atrial Fibrillation: A Randomized Clinical Trial

IMPORTANCE

Shared decision-making (SDM) about anticoagulant treatment in patients with atrial fibrillation (AF) is widely recommended but its effectiveness is unclear.

OBJECTIVE

To assess the extent to which the use of an SDM tool affects the quality of SDM and anticoagulant treatment decisions in at-risk patients with AF.

DESIGN, SETTING, AND PARTICIPANTS

This encounter-randomized trial recruited patients with nonvalvular AF who were considering starting or reviewing anticoagulant treatment and their clinicians at academic, community, and safety-net medical centers between January 30, 2017 and June 27, 2019. Encounters were randomized to either the standard care arm or care that included the use of an SDM tool (intervention arm). Data were analyzed from August 1 to November 30, 2019.

INTERVENTIONS

Standard care or care using the Anticoagulation Choice Shared Decision Making tool (which presents individualized risk estimates and compares anticoagulant treatment options across issues of importance to patients) during the clinical encounter.

MAIN OUTCOMES AND MEASURES

Quality of SDM (which included quality of communication, patient knowledge about AF and anticoagulant treatment, accuracy of patient estimates of their own stroke risk [within 30% of their estimate], decisional conflict, and satisfaction), decisions made during the encounter, duration of the encounter, and clinician involvement of patients in the SDM process.

RESULTS

The clinical trial enrolled 922 patients (559 men [60.6%]; mean [SD] age, 71 [11] years) and 244 clinicians. A total of 463 patients were randomized to the intervention arm and 459 patients to the standard care arm. Participants in both arms reported high communication quality, high knowledge, and low decisional conflict, demonstrated low accuracy in their risk perception, and would similarly recommend the approach used in their encounter. Clinicians were significantly more satisfied after intervention encounters (400 of 453 encounters [88.3%] vs 277 of 448 encounters [61.8%]; adjusted relative risk, 1.49; 95% CI, 1.42-1.53). A total of 747 of 873 patients (85.6%) chose to start or continue receiving an anticoagulant medication. Patient involvement in decision-making (as assessed through video recordings of the encounters using the Observing Patient Involvement in Decision Making 12-item scale) scores were significantly higher in the intervention arm (mean [SD] score, 33.0 [10.8] points vs 29.1 [13.1] points, respectively; adjusted mean difference, 4.2 points; 95% CI, 2.8-5.6 points). No significant between-arm difference was found in encounter duration (mean [SD] duration, 32 [16] minutes in the intervention arm vs 31 [17] minutes in the standard care arm; adjusted mean between-arm difference, 1.1; 95% CI, -0.3 to 2.5 minutes).

CONCLUSION AND RELEVANCE

The use of an SDM encounter tool improved several measures of SDM quality and clinician satisfaction, with no significant effect on treatment decisions or encounter duration. These results help to calibrate expectations about the value of implementing SDM tools in the care of patients with AF.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02905032.

Developing a Conversation Aid to Support Shared Decision Making: Reflections on Designing Anticoagulation Choice

Patient-centered care requires that treatments respond to the problematic situation of each patient in a manner that makes intellectual, emotional, and practical sense, an achievement that requires shared decision making (SDM). To implement SDM in practice, tools-sometimes called conversation aids or decision aids-are prepared by collating, curating, and presenting high-quality, comprehensive, and up-to-date evidence. Yet, the literature offers limited guidance for how to make evidence support SDM. Herein, we describe our approach and the challenges encountered during the development of Anticoagulation Choice, a conversation aid to help patients with atrial fibrillation and their clinicians jointly consider the risk of thromboembolic stroke and decide whether and how to respond to this risk with anticoagulation.

An evidence based method to calculate pedestrian crossing speeds in vehicle collisions (PCSC)

Pedestrian accident reconstruction is necessary to establish cause of death, i.e. establishing vehicle collision speed as well as circumstances leading to the pedestrian being impacted and determining culpability of those involved for subsequent court enquiry. Understanding the complexity of the pedestrian attitude during an accident investigation is necessary to ascertain the causes leading to the tragedy. A generic new method, named Pedestrian Crossing Speed Calculator (PCSC), based on vector algebra, is proposed to compute the pedestrian crossing speed at the moment of impact. PCSC uses vehicle damage and pedestrian anthropometric dimensions to establish a combination of head projection angles against the windscreen; this angle is then compared against the combined velocities angle created from the vehicle and the pedestrian crossing speed at the time of impact. This method has been verified using one accident fatality case in which the exact vehicle and pedestrian crossing speeds were known from Police forensic video analysis. PCSC was then applied on two other accident scenarios and correctly corroborated with the witness statements regarding the pedestrians crossing behaviours. The implications of PCSC could be significant once fully validated against further future accident data, as this method is reversible, allowing the computation of vehicle impact velocity from pedestrian crossing speed as well as verifying witness accounts.

Shared decision making for stroke prevention in atrial fibrillation: study protocol for a randomized controlled trial

Background

Nonvalvular atrial fibrillation (AF) is a common ongoing health problem that places patients at risk of stroke. Whether and how a patient addresses this risk depends on each patient’s goals, context, and values. Consequently, leading cardiovascular societies recommend using shared decision making (SDM) to individualize antithrombotic treatment in patients with AF. The aim of this study is to assess the extent to which the Anticoagulation Choice conversation tool promotes high-quality SDM and influences anticoagulation uptake and adherence in patients with AF at risk of strokes.

Methods

This study protocol describes a multicenter, encounter-level, randomized trial to assess the effect of using the Anticoagulation Choice conversation tool in the clinical encounter, compared to usual care. The participating centers include an academic hospital system, a suburban community group practice, and an urban safety net hospital, all in Minnesota, USA. Patients with ongoing nonvalvular AF at risk of strokes (CHA₂DS₂-VASc score ≥ 1 in men, or ≥ 2 in women) will be eligible for participation. We aim to include 999 patients and their clinicians. The primary outcome is the quality of SDM as perceived by participants, and as assessed by a post-encounter survey that ascertains (a) knowledge transfer, (b) concordance of the decision made, (c) quality of communication, and (d) satisfaction with the decision-making process. Recordings of encounters will be reviewed to assess the extent of patient involvement and how participants use the tool (fidelity). Anticoagulant use, choice of agent, and adherence will be drawn from patients’ medical and pharmacy records. Strokes and bleeding events will be drawn from patient records.

Discussion

This study will provide a valid and precise measure of the effect of the Anticoagulation Choice conversation tool on SDM quality and processes, and on the treatment choices and adherence to therapy among AF patients at risk of stroke.

Trial registration

ClinicalTrials.gov, NCT02905032. Registered on 9 September 2016.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2178-y) contains supplementary material, which is available to authorized users.

Preparation and Analysis of Peanut Flour Used in Oral Immunotherapy Clinical Trials

BACKGROUND

Oral immunotherapy (OIT) is an investigational therapeutic approach for the treatment of food allergies. Characterization of the drug product used in oral immunotherapy trials for peanut allergy has not been reported.

OBJECTIVE

To quantify relative amounts of the major peanut allergens and microbial load present in peanut flour used in OIT trials and assess whether these parameters change over a 12-month period. We also anticipate that this report will serve as a guide for investigators seeking to conduct OIT trials under Food and Drug Administration-approved Investigational New Drug applications.

METHODS

Densitometric scanning of Ara h 1 and Ara h 2 resolved on SDS-PAGE gels was used to assess allergen content in peanut flour extracts. Microbial testing was conducted on peanut flour under US Pharmacopeia guidelines for the presence of Escherichia coli, salmonella, yeast, mold, and total aerobic bacteria. In addition, aflatoxin was quantified in peanut flour. Reported results were obtained from 4 unique lots of peanut flour.

RESULTS

Relative amounts of the major peanut allergens were similar between different lots of peanut flour and remained stable over a 12-month period. E coli and salmonella were absent from all lots of flour. Yeast, mold, total aerobic bacteria, and aflatoxin were within established US Pharmacopeia guidelines on all lots tested and remained within the criteria over a 12-month period.

CONCLUSIONS

Peanut flour used as a drug product contains the major peanut allergens and has low levels of potentially harmful microbes. Both these parameters remain stable over a 12-month period.

Proposed Industry Best Practices in Development and Marketing of Medical Foods for the Management of Chronic Conditions and Diseases while Awaiting Regulation

Ideal therapeutics have low toxicity and can effectively manage condition(s) or disease(s). The Food & Drug Administration (FDA) marketing category of therapeutics called “medical foods” (MFs) meets such a definition. Medical foods have existed in Federal law since passage the Orphan Drug Act in 1988, which created a category of nutritional therapeutics separate from drugs. Unfortunately, MFs are not widely understood by the medical community or utilized in all patients who need them due to lack of a FDA-approval process, unclear and contradictory guidance especially with regard for need for an investigational new drug (IND) application, and no clear regulations regarding their development and marketing. The goals of this article are to propose “Best Practices” to guide the medical food industry in the development and marketing of products as well as to serve as a starting point for suggestions regarding further FDA regulation so that therapeutics which are shown to be generally recognized as safe (GRAS), provide food ingredients to meet a distinctive nutritional requirement for a specific condition/disease and are proven effective for the management for that condition/disease can be used to benefit patients who need them.

The use of water-soluble mucoadhesive gels for the intravesical delivery of epirubicin to the bladder for the treatment of non-muscle-invasive bladder cancer

OBJECTIVES

To develop an epirubicin-loaded, water-soluble mucoadhesive gels that have the correct rheological properties to facilitate their delivery into the bladder via a catheter, while allowing for their spread across the bladder wall with limited expansion of the bladder and increasing the retention of epirubicin in the bladder and flushing with urine.

METHODS

Epirubicin-loaded hydroxyl ethyl cellulose (HEC) and hydroxy propyl methyl cellulose (HPMC) gels were manufactured and tested for their rheological properties. Their ability to be pushed through a catheter was also assessed as was their in-vitro drug release, spreading in a bladder and retention of epirubicin after flushing with simulated urine.

KEY FINDINGS

Epirubicin drug release was viscosity-dependent. The 1 and 1.5% HEC gels and the 1, 1.5 and 2% HPMC gels had the correct viscosity to be administered through a model catheter and spread evenly across the bladder wall under the pressure of the detrusor muscle. The epirubicin-loaded gels had an increased retention time in the bladder when compared with a standard intravesical solution of epirubicin, even after successive flushes with simulated urine.

CONCLUSION

The increased retention of epirubicin in the bladder by the HEC and HPMC gels warrant further investigation, using an in-vivo model, to assess their potential for use as treatment for non-muscle-invasive bladder cancer.

Comprehensive hands-on training for influenza vaccine manufacturing: a WHO-BARDA-BTEC partnership for global workforce development

The critical need for enhancing influenza pandemic preparedness in many developing nations has led the World Health Organization (WHO) and the Biomedical Advanced Research and Development Authority (BARDA), part of the U.S. Department of Health and Human Services (HHS), to develop an international influenza vaccine capacity-building program. Among the critical limitations faced by many of these nations is lack of access to training programs for staff supporting operations within vaccine production facilities. With support from BARDA, the Biomanufacturing Training and Education Center (BTEC) at North Carolina State University has addressed this need for training by developing and delivering a comprehensive training program, consisting of three courses: Fundamentals of cGMP Influenza Vaccine Manufacturing, Advanced Upstream Processes for Influenza Vaccine Manufacturing, and Advanced Downstream Processes for Influenza Vaccine Manufacturing. The courses cover process design, transfer, and execution at manufacturing scale, quality systems, and regulations covering both manufacturing and approval of pandemic vaccines. The Fundamentals course focuses on the concepts, equipment, applicable regulations, and procedures commonly used to produce influenza vaccine. The two Advanced courses focus on process design, scale up, validation, and new technologies likely to improve efficiency of vaccine production. All three courses rely on a combination of classroom instruction and hands-on training in BTEC's various laboratories. Each course stands alone, and participants may take one or more of the three courses. Overall participant satisfaction with the courses has been high, and follow-up surveys show that participants actively transferred the knowledge they gained to the workplace. Future plans call for BTEC to continue offering the three courses and to create an online version of several modules of the Fundamentals course.

Serum-derived bovine immunoglobulin/protein isolate: postulated mechanism of action for management of enteropathy

The health and performance of the gastrointestinal tract is influenced by the interaction of a variety of factors, including diet, nutritional status, genetics, environment, stress, the intestinal microbiota, immune status, and gut barrier. Disruptions in one or more of these factors can lead to enteropathy or intestinal disorders that are known to occur in concert with certain disease states or conditions such as irritable bowel syndrome or human immunodeficiency virus (HIV) infection. Nutritional support in the form of a medical food along with current therapies could help manage the adverse effects of enteropathy, which include effects on nutrient digestion, absorption, and metabolism, as well as utilization of nutrients from foodstuffs. Numerous studies have demonstrated that oral administration of plasma- or serum-derived protein concentrates containing high levels of immunoglobulins can improve weight management, normalize gut barrier function, and reduce the severity of enteropathy in animals. Recent trials in humans provide preliminary evidence that a serum-derived bovine immunoglobulin/protein isolate is safe and improves symptoms, nutritional status, and various biomarkers associated with enteropathy in patients with HIV infection or diarrhea-predominant irritable bowel syndrome. This review summarizes data from preclinical and clinical studies with immunoglobulin-containing plasma/serum protein concentrates, with a focus on the postulated mode of action of serum-derived bovine immunoglobulin/protein isolate for patients with enteropathy.

Warfarin dosing after bariatric surgery: a retrospective study of 10 patients previously stable on chronic warfarin therapy

Many changes associated with bariatric surgery have the potential to affect warfarin dosing; yet current literature includes little data describing this phenomenon. Investigating this relationship may allow for determination of post-bariatric surgery warfarin dosing using stable pre-operative dosing levels. A retrospective chart review was completed for 10 patients stabilized on chronic warfarin therapy who underwent bariatric surgery. Data collection consisted of the following: warfarin requirement in mg/week, time in target range (TTR), creatinine, liver function, diarrhoea, medication changes, diet, and signs of bleeding and/or thrombosis. Three study patients underwent laparoscopic adjustable gastric banding procedures and seven patients underwent Roux-en-Y gastric bypass. The average (standard deviation) weekly warfarin dose required in the immediate post-operative interval was 64% (25%) of baseline dosing, corresponding to a TTR of 48%. At 6 months, patients required 85% (19%) of baseline weekly dosing, with TTR of 53.4%. At 1 year, dosing was 90% (16%) of baseline with TTR of 63.5%. Patients underwent medication changes as well as transient bouts of diarrhoea. Two patients suffered unspecified haemorrhages of the gastrointestinal tract (international normalized ratio [INR] = 2.3 and 9.8). This patient set demonstrated an initial drop in warfarin requirement, followed by escalating dosing trends that became more predictable as patients were farther out from procedure.

Management of venous thromboembolism

This article describes the risk factors, diagnostic tools, and therapeutic approaches for venous thromboembolism (VTE), which includes primarily deep vein thrombosis and pulmonary embolism, as well as VTE occurring at other sites. Outpatient management strategies are emphasized.

Co-delivery of antigen and IL-12 by Venezuelan equine encephalitis virus replicon particles enhances antigen-specific immune responses and antitumor effects

We recently demonstrated that Venezuelan equine encephalitis virus-based replicon particle (VRPs) encoding tumor antigens could break tolerance in the immunomodulatory environment of advanced cancer. We hypothesized that local injection of VRP-expressing interleukin-12 (IL-12) at the site of injections of VRP-based cancer vaccines would enhance the tumor-antigen-specific T cell and antibody responses and antitumor efficacy. Mice were immunized with VRP encoding the human tumor-associated antigen, carcinoembryonic antigen (CEA) (VRP-CEA(6D)), and VRP-IL-12 was also administered at the same site or at a distant location. CEA-specific T cell and antibody responses were measured. To determine antitumor activity, mice were implanted with MC38-CEA-2 cells and immunized with VRP-CEA with and without VRP-IL-12, and tumor growth and mouse survival were measured. VRP-IL-12 greatly enhanced CEA-specific T cell and antibody responses when combined with VRP-CEA(6D) vaccination. VRP-IL-12 was superior to IL-12 protein at enhancing immune responses. Vaccination with VRP-CEA(6D) plus VRP-IL-12 was superior to VRP-CEA(6D) or VRP-IL-12 alone in inducing antitumor activity and prolonging survival in tumor-bearing mice. Importantly, local injection of VRP-IL-12 at the VRP-CEA(6D) injection site provided more potent activation of CEA-specific immune responses than that of VRP-IL-12 injected at a distant site from the VRP-CEA injections. Together, this study shows that VRP-IL-12 enhances vaccination with VRP-CEA(6D) and was more effective at activating CEA-specific T cell responses when locally expressed at the vaccine site. Clinical trials evaluating the adjuvant effect of VRP-IL-12 at enhancing the immunogenicity of cancer vaccines are warranted.

A medicinal plant extract of Scutellaria Baicalensis and Acacia catechu reduced LPS-stimulated gene expression in immune cells: a comprehensive genomic study using QPCR, ELISA, and microarray

A standardized, combined flavonoid extracts of Scutellaria baicalensis and Acacia catechu, UP446, demonstrates favorable anti-inflammatory properties. In this study, DNA microarray, quantitative polymerase chain reaction (QPCR), and enzyme-linked immunosorbent assay (ELISA) were used to study the effect of UP446 on the lipopolysaccharide (LPS)-induced pro-inflammatory gene regulation of both animal and human immortalized cell lines and also primary human cells. One consistent result from microarray was that the gene expression levels stimulated or suppressed by LPS were returned to normal levels by the UP446 co-treatment. This normalization effect from UP446 was also shown for pro-inflammatory genes cyclooxygenase (COX)-2, tissue necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 using QPCR, and TNF-α using ELISA. The controlling transcriptional factor of these genes, NFκB, was also down-regulated by UP446 in the LPS-induced cell models. Microarray analysis for numerous genes, including cytokines, chemokines, receptors, transcriptional factors, caspase, growth factors, and phosphatases, suggests not only a genomic anti-inflammatory activity for UP446 but also signaling pathways of cell proliferation, cell death, and lipid metabolism demonstrated on different types of cells.

Application of biomarkers in the development of drugs intended for the treatment of osteoarthritis

OBJECTIVE

Osteoarthritis (OA) is a chronic and slowly progressive disease for which biomarkers may be able to provide a more rapid indication of therapeutic responses to therapy than is currently available; this could accelerate and facilitate OA drug discovery and development programs. The goal of this document is to provide a summary and guide to the application of in vitro (biochemical and other soluble) biomarkers in the development of drugs for OA and to outline and stimulate a research agenda that will further this goal.

METHODS

The Biomarkers Working Group representing experts in the field of OA biomarker research from both academia and industry developed this consensus document between 2007 and 2009 at the behest of the Osteoarthritis Research Society International Federal Drug Administration initiative (OARSI FDA initiative).

RESULTS

This document summarizes definitions and classification systems for biomarkers, the current outcome measures used in OA clinical trials, applications and potential utility of biomarkers for development of OA therapeutics, the current state of qualification of OA-related biomarkers, pathways for biomarker qualification, critical needs to advance the use of biomarkers for drug development, recommendations regarding practices and clinical trials, and a research agenda to advance the science of OA-related biomarkers.

CONCLUSIONS

Although many OA-related biomarkers are currently available they exist in various states of qualification and validation. The biomarkers that are likely to have the earliest beneficial impact on clinical trials fall into two general categories, those that will allow targeting of subjects most likely to either respond and/or progress (prognostic value) within a reasonable and manageable time frame for a clinical study (for instance within 1-2 years for an OA trial), and those that provide early feedback for preclinical decision-making and for trial organizers that a drug is having the desired biochemical effect. As in vitro biomarkers are increasingly investigated in the context of specific drug treatments, advances in the field can be expected that will lead to rapid expansion of the list of available biomarkers with increasing understanding of the molecular processes that they represent.

Efficacy and safety of flavocoxid compared with naproxen in subjects with osteoarthritis of the knee- a subset analysis

OBJECTIVE

twice-daily flavocoxid, a cyclooxygenase and 5-lipoxygenase inhibitor with potent antioxidant activity of botanical origin, was evaluated for 12 weeks in a randomized, double-blind, active-comparator study against naproxen in 220 subjects with moderate-severe osteoarthritis (OA) of the knee. As previously reported, both groups noted a significant reduction in the signs and symptoms of OA with no detectable differences in efficacy between the groups when the entire intent-to-treat population was considered. This post-hoc analysis compares the efficacy of flavocoxid to naproxen in different subsets of patients, specifically those related to age, gender, and disease severity as reported at baseline for individual response parameters.

METHODS

in the original randomized, double-blind study, 220 subjects were assigned to receive either flavocoxid (500 mg twice daily) or naproxen (500 mg twice daily) for 12 weeks. In this subgroup analysis, primary outcome measures including the Western Ontario and McMaster Universities OA index and subscales, timed walk, and secondary efficacy variables, including investigator global assessment for disease and global response to treatment, subject visual analog scale for discomfort, overall disease activity, global response to treatment, index joint tenderness and mobility, were evaluated for differing trends between the study groups.

RESULTS

subset analyses revealed some statistically significant differences and some notable trends in favor of the flavocoxid group. These trends became stronger the longer the subjects continued on therapy. These observations were specifically noted in older subjects (>60 years), males and in subjects with milder disease, particularly those with lower subject global assessment of disease activity and investigator global assessment for disease and faster walking times at baseline.

CONCLUSIONS

initial analysis of the entire intent-to-treat population revealed that flavocoxid was as effective as naproxen in managing the signs and symptoms of OA of the knee. Detailed analyses of subject subsets demonstrated distinct trends in favor of flavocoxid for specific groups of subjects.

Protective effect of genistein aglycone on the development of osteonecrosis of the femoral head and secondary osteoporosis induced by methylprednisolone in rats

Glucocorticoid (GC)-induced osteoporosis (GIO) is the most important secondary cause of bone loss. Clinical evidence suggests a role for genistein (GEN) aglycone in the prevention of osteoporosis. We investigated whether GEN could prevent GIO as well as the development of osteonecrosis in the femoral head using an experimental rat model. A total of 28 female Sprague-Dawley rats were used in the study. GIO and osteonecrosis were induced by daily s.c. injections of 30 mg/kg of methylprednisolone (MP; n=7). Another group of animals (MP+GEN; n=7) concomitantly received MP (30 mg/kg per s.c.) and GEN aglycone (5 mg/kg per i.p.) for 60 days. Control animals were administered daily with vehicle (VEH) or GEN (5 mg/kg per i.p.) only. At the beginning and end of the treatment, animals were examined for bone mineral density (BMD) and bone mineral content (BMC). After killing, serum was collected to determine bone-alkaline phosphatase (b-ALP), carboxy-terminal collagen crosslink (CTX) and osteoprotegerin (OPG) levels. Femurs were removed and tested for breaking strength and bone histology analyzed for structural quality of the femoral neck. GEN aglycone prevented bone loss as measured by BMD and BMC. Moreover, GEN significantly increased the bone formation markers b-ALP and OPG, reduced the bone resorption marker CTX and statistically maintained comparable strength versus the VEH only group. Finally, histological scoring revealed a protective effect of GEN on bone structure statistically comparable with the VEH control animals. Results suggest that the GEN aglycone might be a preventive treatment for GIO and complications of osteonecrosis with long-term GC treatment.

Development and preclinical evaluation of an alphavirus replicon particle vaccine for cytomegalovirus

We used a replication-incompetent, single-cycle, alphavirus replicon vector system to produce virus-like replicon particles (VRP) expressing the extracellular domain of human cytomegalovirus (CMV) glycoprotein B or a pp65/IE1 fusion protein. Efficient production methods were scaled to produce pilot lots and clinical lots of each alphavirus replicon vaccine component. The vaccine induced high-titered antibody responses in mice and rabbits, as measured by ELISA and CMV neutralization assays, and robust T-cell responses in mice, as measured by IFN-gamma ELISPOT assay. A toxicity study in rabbits showed no adverse effects in any toxicology parameter. These studies support clinical testing of this novel CMV alphavirus replicon vaccine in humans.

Transarterial chemoembolisation for advanced hepatocellular carcinoma: results from a North American cancer centre

AIMS

In Asian countries, transarterial chemoembolisation (TACE) has long been used for palliation of unresectable hepatocellular carcinoma (HCC) without strong evidence of improved survival or quality of life. In 2002, a survival benefi of TACE was shown in two randomised controlled trials in Europe and Hong Kong. The effectiveness of interventions fo HCC is influenced by geographical factors related to diverse patient characteristics and protocols. Therefore, the validation of TACE as palliative modality for unresectable HCC requires confirmation in diverse patient populations. The aim of the present study was to assess the effectiveness of TACE for HCC in a North American population.

MATERIALS AND METHODS

This was a single centre prospective cohort study. Child-Pugh A cirrhosis or better patients wit unresectable HCC and without radiological evidence of metastatic disease or segmental portal vein thrombosis wer assessed between November 2001 and May 2004. Of 54 patients who satisfied the inclusion criteria, 47 underwent 80 TACE sessions. Chemoembolisation was carried out using selective hepatic artery injection of 75 mg/m(2) doxorubicin and lipiodol followed by an injection of embolic particles when necessary. Repeat treatments were carried out at 2-3 month intervals for recurrent disease. The primary outcome was overall survival; secondary outcomes were morbidity and tumour response.

RESULTS

The survival probabilities at 1, 2 and 3 years were 76.6, 55.5 and 50%, respectively. At 6 months after the first intervention, 31% of patients had a partial response and 60% had stable disease by RECIST criteria. Minor adverse events occurred after 39% of TACEs and major adverse events after 20% of sessions, including two treatment-related deaths (4% of patients). One patient had complete cancer remission after undergoing three TACE treatments. Further progression of tumour growth was prevented in 91% of tumours at the 6 month point after the first TACE. At 3 months, serum levels of the tumour marker alpha-feto protein were significantly reduced in patients with elevated levels before TACE.

CONCLUSIONS

The survival probabilities at 1 and 2 years after TACE were comparable with results in randomised studies from Europe and Asia. Most patients tolerated TACE well, but clinicians need to be aware that moderately severe sideeffects require close monitoring and prompt intervention.

Learning communities: an untapped sustainable competitive advantage for higher education

Purpose

This paper demonstrates the need for the higher education sector to develop and implement scaleable, quantitative measures that evaluate community and establish organisational benchmarks in order to guide the development of future practices designed to enhance the student learning experience.

Design/methodology/approach

Literature regarding contemporary Australian higher education policy and community development is critiqued to illustrate the need for universities to adopt scaleable quantitative measures to evaluate stated strategic imperatives and establish organisational benchmarks. The integration of organisational benchmarks guides the implementation of future practices designed to enhance the student learning experience. A current active exemplar methodology is discussed to demonstrate applicability to both higher education administrators and teaching staff across the various organisation levels.

Findings

While universities are promoting and investing in the concept of community to enhance the student learning experience there are as yet, limited scaleable evaluative measures and performance indicators to guide practitioners. This paper proposes an effective measurement tool to benchmark current pedagogical performance standards and monitor the progress and achievement of future implemented practices designed to enhance the sense of community experienced by the student cohort.

Originality/value

This paper identifies and addresses the current absence of effective scaleable evaluative measures to assess the achievement of stated strategic imperatives implemented as a consequence of reducing government financial support, increasing accountability, and increasing student expectations as result of educational consumerism.

The first mail bomb?

A news item in the newspaper, the Evening Star, for the Country, October 18, 1833, probably is the first report of a mail bomb in the United States. It is also likely to be the first defusing of a mail bomb. The device appeared to be extraordinarily sophisticated and would have likely worked had it not been for suspicions of the recipient of the bomb.

The formulation of recombinant factor IX: stability, robustness, and convenience

A lyophilized recombinant factor IX (rFIX) formulation has been developed that is stable and contains no preservatives. No blood or plasma products are used in the production or formulation of rFIX. The formulation contains 10 mmol/L histidine, 0.26 mol/L glycine, 1% sucrose, and 0.005% polysorbate-80 (pH 6.8). Polysorbate-80 acts as a protectant for the protein from freezing-induced damage (eg, aggregation). Sucrose provides protection to the protein in the freeze-dried state. Glycine provides for a high-quality cake morphology. Histidine provides optimal buffering stability at the desired pH and minimizes aggregate formation upon storage in the lyophilized state. This optimized combination of excipients provides a high degree of long-term stability, as demonstrated by a variety of analytical methods, including clotting assays, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), isoelectric focusing (IEF), size-exclusion chromatography (SEC), peptide mapping, oligosaccharide fingerprinting, and reverse-phase high-performance liquid chromatography (HPLC). The rFIX product is easy to reconstitute and demonstrates excellent stability in solution after reconstitution.

The recruitment triangle: reasons why African Americans enroll, refuse to enroll, or voluntarily withdraw from a clinical trial. An interim report from the African-American Antiplatelet Stroke Prevention Study (AAASPS)

Recruitment and retention of study subjects are key to the success of a clinical trial. In the case of minority patients, this may be challenging as minority patients have been underserved by the medical health-care system. Furthermore, minority patients are more likely to experience barriers to entry into a clinical trial such as mistrust of the medical system, economic disadvantages, lack of awareness of study programs, and communication barriers. An open-ended questionnaire was used to determine reasons why subjects in the African-American Antiplatelet Stroke Prevention Study (AAASPS) remained in the study or voluntarily withdrew in the absence of an adverse event. Potential enrollees who refused to participate in the AAASPS also were queried. Enrollees who remained in the program consistently stated that they participated to reduce the risk of stroke recurrence and to help others by finding a "cure" for stroke. Those who withdrew or refused to participate consistently stated that they were afraid of being used as "guinea pigs." A "recruitment triangle" emerged that might predict a patient's likelihood of participation in a clinical trial. The sides of the triangle include the patient, key family members and friends, and the primary medical doctor and other medical personnel. The organizers of a clinical trial need to be aware of the "recruitment triangle" and establish strategies to heighten and maintain its integrity.

Hippocampal volume in normal aging and traumatic brain injury

PURPOSE

To present a normative database of hippocampal and temporal horn volume and to clarify the relationship between these measures and cognitive outcome in patients with traumatic brain injury.

METHODS

Ninety-six healthy volunteers and 94 patients with traumatic brain injury were examined with coronal intermediate and T2-weighted MR imaging. Multispectral segmentation and volume analyses were performed. The volumetry of the hippocampus and temporal horn was characterized in the control subjects. Volumetric measures in a group of patients with traumatic brain injury who had received MR imaging 3 months or less after injury were compared with measurements in other patients in the chronic phase of recovery. The relationship between neuropsychological testing and volumetric measures was analyzed with particular emphasis on the correlation between cognitive outcome and hippocampal and temporal horn volumes.

RESULTS

No significant age group differences were found in the normative group from age 16 to 65. Left and right hippocampal volumes were interrelated and did not differ from each other. This was also true for the temporal horns. Hippocampal and temporal horn volumes were not significantly related. Women had larger hippocampi relative to cranial volume. Comparisons between patients with traumatic brain injury and control subjects showed significant yet modest bilateral atrophic changes in hippocampal and temporal horn enlargement in the patients with brain injury. Hippocampal and temporal horn volumes correlated significantly with each other in the group with traumatic brain injury. Cognitive outcome was modestly related to hippocampal and temporal horn volumes. However, in a specific subgroup whose images were acquired between 71 and 210 days after injury, strong correlations were noted in which temporal horn volume correlated highly with IQ and hippocampal volume correlated with verbal memory function.

CONCLUSION

Hippocampal and temporal horn volumes appear to be independent variables in healthy control subjects. Traumatic brain injury results in significant hippocampal atrophy and temporal horn enlargement. The hippocampus and temporal horn volumes were inversely correlated in the group with traumatic brain injury, suggesting a differential relationship of these structures in patients with brain injury as compared with control subjects. In the subacute phase, the volume of the temporal horn may be indicative of intellectual outcome and that of the hippocampus appears to be indicative of verbal memory function.

Uptake and processing of duplex DNA by RecA nucleoprotein filaments: insights provided by a mixed population of dynamic and static intermediates

In the polarized strand exchange that is promoted by Escherichia coli RecA protein, when the initiating end of a duplex DNA molecule is blocked by heterology, the homologous distal end nonetheless forms a joint with single-stranded DNA, but strand exchange in that joint cannot be completed because the strand that would otherwise be displaced lacks a free 5' end. Instead, 2/3 to 3/4 of such distal joints cyclically form and dissociate. Dissociation requires the hydrolysis of ATP (Burnett et al., 1994). Observations on DNase protection revealed that consistent with their dynamic nature, these joints were heterogeneous in length, extending from the labeled distal end of the duplex up to 600 base pairs within the homologous region. Switching of base pairs was undetectable in this fraction of distal joints. However, the other 1/3 to 1/4 of distal joints, which did not cycle, were as long as the entire homologous region (6 kb), and underwent complete switching of base pairs. The formation of these static joints occurred at a rate in excess of 100 bp per second, without requiring hydrolysis of ATP. These and earlier observations suggest that the RecA filament containing single-stranded DNA rapidly incorporates duplex DNA into a coaxial three-stranded helix by a passive process, whereas additional energy is required to convert the three-stranded intermediate into products or back into substrates, both of which involve the unwinding of many turns of three-stranded helix.

Resolution of the three-stranded recombination intermediate made by RecA protein. An essential role of ATP hydrolysis

Previous work has shown that triplex DNA is an intermediate in homologous pairing and strand exchange promoted by RecA protein. Heterology at the proximal end of duplex DNA blocks strand exchange, but triplex joints form nonetheless at the homologous distal end. Experiments on the formation and processing of distal joints revealed that the yield of distal joints depends critically on the concentration of RecA-coated single strands and the adequacy of the ATP-regeneration system, and reflects a steady state. Distal joints reversibly formed and dissociated, as shown by several methods, including a chase with unlabeled duplex DNA. Controls excluded a contribution of exonucleolytic nibbling to the formation of distal joints and the stability of the deproteinized product. RecA protein was bound preferentially by putative triplex sites both in isolated proximal and distal joints. These high affinity sites disappeared from proximal joints as strand exchange progressed, and disappeared from distal joints as the joints dissociated. Dissociation of distal joints under all conditions, however, was completely arrested by the addition of ATP gamma S. Distal triplex joints can be as long as six kilobases. The observed inhibition of the dissociation of such long non-productive triplex intermediates by ATP gamma S leads us to propose that an essential role of ATP hydrolysis in RecA recombinational exchanges may be to ensure that no potentially troublesome triplex DNA remains in the cell.

A partially deficient mutant, recA1730, that fails to form normal nucleoprotein filaments

The phenotype of the recA1730 mutant is highly dependent on the level of expression of the RecA1730 protein. If the recA1730 gene was expressed from its own promoter, the cells were deficient in recombination and SOS induction. In contrast, when the recA1730 gene was expressed under the control of recAo98, a constitutive operator that increased the RecA1730 concentration 20-fold, cells became proficient in recombination and SOS induction. Likewise, in crude extracts, fivefold more RecA1730 than RecAwt was required to produce full cleavage of LexA protein. The requirement for a high RecA1730 concentration for recombination and LexA cleavage suggests that the recA1730 defect alters a common reaction step. In fact, in vitro data show that the impaired assembly of RecA1730 protein on single-stranded DNA (ssDNA) can account for the mutant phenotype. Purified RecA1730 protein was assayed in vitro for ssDNA binding and ATPase activities. RecA1730, like RecAwt, retained ssDNA equally well on nitrocellulose filters; this activity was specifically inhibited by a monoclonal anti-RecA antibody. However, RecA1730 protein did not form complete filaments on ssDNA, as shown by two observations: (i) most of the protein did not elute with ssDNA during gel filtration; and (ii) binding of RecA1730 to ssDNA did not protect it from being digested by DNaseI. RecA1730 hydrolysed ATP in high salt but was defective in ssDNA-dependent ATP hydrolysis. These results strongly suggest that RecA1730 binds to ATP and ssDNA but does not form normal nucleoprotein filaments.

Equivalent potency and pharmacokinetics of recombinant human growth hormones with or without an N-terminal methionine

Two forms of human GH (hGH) have been produced by recombinant DNA technology. One form has an amino acid sequence identical to that of the natural pituitary hormone (rhGH) and the other form has an additional N-terminal methionine (Met-hGH). The biological potencies of these 2 polypeptides have been compared in hypophysectomized rats in a multidose study measuring body weights and several long bone growth parameters. The pharmacokinetic profiles after iv and sc injection were determined in cynomolgus monkeys in a 4-period cross-over study. All of the measured parameters in all the studies indicated that there was no difference in the two forms of hGH. Measurements taken after 27 daily injections of rhGH or Met-hGH (30-500 micrograms/kg.day) indicated that femur length and width of the proliferative zone in the tibial epiphysis showed dose-related effects for both forms of hGH but no difference between them. The relative potency, based on body weight gain, was calculated using a parallel line bioassay. Weight gain after 8 daily injections in the 5-dose long bone growth study indicated a rhGH potency of 0.80 (95% confidence interval, 0.5-1.23) relative to Met-hGH. It was concluded that the presence of an N-terminal methionine on hGH has no effect on potency in this model. The pharmacokinetic parameters after iv administration were estimated by fitting serum concentration-time data to a 2-compartment model. Parameters after sc injection were computed by compartment-independent methods. Met-hGH and rhGH had very similar pharmacokinetic profiles after both routes of administration. Comparison of the pharmacokinetic parameters indicated that the clearance after iv administration (rhGH, 15 ml/min; Met-hGH, 13 ml/min) and the sc bioavailability (rhGH, 0.72 +/- 0.21; Met-hGH, 0.59 +/- 0.21) were not significantly different for the 2 forms of hGH. It was concluded that rhGH and Met-hGH have equivalent bioavailability and pharmacokinetics in cynomolgus monkeys.

Pharmacokinetics of recombinant human interferon-gamma in the rhesus monkey after intravenous, intramuscular, and subcutaneous administration

The pharmacokinetics of recombinant human interferon-gamma (rIFN-gamma) were studied in rhesus monkeys. Intravenous administration of 0.1 mg/kg yielded half-lives of 12.3-13.4 min and 130 min. Clearance after intravenous administration was 18.7 ml/min/kg, and the steady-state volume of distribution (Vdss) was 510 ml/kg. The peak serum concentrations after intramuscular and subcutaneous administration of 0.25 mg/kg rIFN-gamma were 50.7 and 52.3 ng/ml, respectively. The time to reach the peak serum concentration was 480 min for both routes. The mean bioavailabilities after intramuscular and subcutaneous administration were 109 and 90%, respectively. Intravenous administration of 0.25 mg/kg rIFN-gamma resulted in no significant change in the clearance, half-life, or Vdss, suggesting that the kinetics of rIFN-gamma are linear over the range of doses tested. Nearly all of the animals developed antibodies to rIFN-gamma after three doses. The presence of nonneutralizing antibodies to rIFN-gamma had no discernible effect on the calculated pharmacokinetic parameters.

Cardiovascular findings in quadriplegic and paraplegic patients and in normal subjects

Seven normal, 7 paraplegic and 7 quadriplegic patients underwent cross-sectional cardiovascular evaluation, including recording of sitting heart rate, blood pressure and echocardiography. Quadriplegic patients had a 26% lower left ventricular (LV) mass index (75 +/- 13 g/m2, p less than 0.01) compared with normal volunteers (102 +/- 16 g/m2) or paraplegic patients (110 +/- 26 g/m2). Six quadriplegic patients and 3 paraplegic patients had an unusual pattern of LV posterior wall asynergy, which was associated with a significant rightward shift of the frontal-plane QRS axis (92 +/- 22 degrees vs 42 +/- 41 degrees, p less than 0.005) and smaller left atrial dimensions (2.4 +/- 0.4 vs 3.0 +/- 0.3 cm, p less than 0.005). The quadriplegic group was characterized by a significantly reduced mean blood pressure (67 +/- 7 vs 88 +/- 8 mm Hg in normal subjects, p less than 0.002), high normal peripheral resistances (22 +/- 5 vs 17 +/- 5 units in normal subjects, difference not significant) and a markedly reduced calculated cardiac output (3.2 +/- 0.6 vs 5.4 +/- 1.4 liters/min in normal subjects, p less than 0.01). Hemodynamic data for the paraplegic patients were similar to those in the normal group. A decrease in LV wall stress, mediated primarily by a decrease in venous return, appeared to result in the "adaptive" cardiac atrophy seen in these quadriplegic patients. LV asynergy was common and also may be related to a decrease in cardiac filling.