Determination of the Terbium-152 half-life from mass-separated samples from CERN-ISOLDE and assessment of the radionuclide purity

Terbium-152 is one of four terbium radioisotopes that together form a potential theranostic toolbox for the personalised treatment of tumours. As 152 Tb decay by positron emission it can be utilised for diagnostics by positron emission tomography. For use in radiopharmaceuticals and for activity measurements by an activity calibrator a high radionuclide purity of the material and an accurate and precise knowledge of the half-life is required. Mass-separation and radiochemical purification provide a production route of high purity 152Tb. In the current work, two mass-separated samples from the CERN-ISOLDE facility have been assayed at the National Physical Laboratory to investigate the radionuclide purity. These samples have been used to perform four measurements of the half-life by three independent techniques: high-purity germanium gamma-ray spectrometry, ionisation chamber measurements and liquid scintillation counting. From the four measurement campaigns a half-life of 17.8784(95) h has been determined. The reported half-life shows a significant difference to the currently evaluated half-life (ζ-score = 3.77), with a relative difference of 2.2 % and an order of magnitude improvement in the precision. This work also shows that under controlled conditions the combination of mass-separation and radiochemical separation can provide high-purity 152Tb.

Patient-centric drug product development acceptability across patient populations- Science and evidence

The 6^th APV (Arbeitsgemeinschaft für Pharmazeutische Verfahrenstechnologie e.V., The International Association for Pharmaceutical Technology) Winter Conference took place in Salzburg (Austria) from January 19-20, 2023. This conference was dedicated to advance patient-centric drug development across all dosage forms, indications and patient populations and was organized by the APV PaCeMe IN Task Force. The topic was chosen due to emerging evidence and increasing regulatory requirements to consider patient needs and capabilities in drug product development. It is well acknowledged that acceptability of a drug product and its dosage form is a fundamental aspect of patient centric drug product design which can directly impact adherence and intended use, hence effectiveness and safety. Despite the requirement to proof acceptability within the drug development program, respective methods to determine and compare the degree of acceptability of different dosage forms and drug product designs are still limited.

Patient engagement in pharmaceutical development: Where are we? - Report from a symposium

In recent years, the term "patient engagement" has found its way into healthcare and specifically into the field of drug development. To better understand the actual status of "patient engagement" in drug development, a symposium was organized by the Drug Research Academy of the University of Copenhagen (Denmark) on November 16, 2022. The symposium brought together experts from regulatory authorities, industry, academia and patients to share their views and experience of and with patient engagement in drug product development. The symposium led to intensive discussions among the speakers and the audience, confirming that viewpoints and experiences of the different stakeholder provide important input into the promoting patient engagement along the entire drug development life cycle.

Trends in oral small-molecule drug discovery and product development based on product launches before and after the Rule of Five

In 1997, the 'Rule of Five' (Ro5) suggested physicochemical limitations for orally administered drugs, based on the analysis of chemical libraries from the early 1990s. In this review, we report on the trends in oral drug product development by analyzing products launched between 1994 and 1997 and between 2013 and 2019. Our analysis confirmed that most new oral drugs are within the Ro5 descriptors; however, the number of new drug products of drugs with molecular weight (MW) and calculated partition coefficient (clogP) beyond the Ro5 has slightly increased. Analysis revealed that there is no single scientific or technological reason for this trend, but that it likely results from incremental advances are being made in molecular biology, target diversity, drug design, medicinal chemistry, predictive modeling, drug metabolism and pharmacokinetics, and drug delivery.

Rational and practical considerations to guide a Target Product Profile for patient-centric drug product development with measurable patient outcomes - A proposed roadmap

The increasing awareness of acceptability and usability of pharmaceutical drug products by the patient as a key quality requirement continues to drive need for integrating patient centric drug product design into the pharmaceutical development process. The complex matrix of multiple drug product related decisions during the early drug development process often limits patient-centric drug product (PCDP) design options in the final commercial drug product development phase. To integrate the specific needs and perspectives of patients into drug development and product design process, a rational approach integrated into the complex development matrix is required from the start and weighs product development decision options accordingly. The aim of this work was to develop a roadmap for PCDP design in a multidisciplinary approach that leads to better usability, adherence and acceptance of the drug by patients via early integration into the development matrix. The proposed rational approach is based upon regulatory requirements and lessons learned from pediatric and geriatric drug development.

Focusing on powder processing in dry powder inhalation product development, manufacturing and performance

Dry powder inhalers (DPI) are well established products for the delivery of actives via the pulmonary route. Various DPI products are marketed or developed for the treatment of local lung diseases such as chronic obstructive pulmonary disease (COPD), asthma or cystic fibrosis as well as systemic diseases targeted through inhaled delivery (i.e. Diabetes Mellitus). One of the key prerequisites of DPI formulations is that the aerodynamic size of the drug particles needs to be below 5 µm to enter deeply into the respiratory tract. These inherently cohesive inhalable size particles are either formulated as adhesive mixture with coarse carrier particles like lactose called carrier-based DPI or are formulated as free-flowing carrier-free particles (e.g. soft agglomerates, large hollow particles). In either case, it is common practice that drug and/or excipient particles of DPI formulations are obtained by processing API and API/excipients. The DPI manufacturing process heavily involves several particle and powder technologies such as micronization of the API, dry blending, powder filling and other particle engineering processes such as spray drying, crystallization etc. In this context, it is essential to thoroughly understand the impact of powder/particle properties and processing on the quality and performance of the DPI formulations. This will enable prediction of the processability of the DPI formulations and controlling the manufacturing process so that meticulously designed formulations are able to be finally developed as the finished DPI dosage form. This article is intended to provide a concise account of various aspects of DPI powder processing, including the process understanding and material properties that are important to achieve the desired DPI product quality. Various endeavors of model informed formulation/process design and development for DPI powder and PAT enabled process monitoring and control are also discussed.

Commentary on the EMA reflection paper on the pharmaceutical development of medicines for use in the older population

Older people are often affected by impaired organ and bodily functions resulting in multimorbidity and polypharmacy, turning them into the main user group of many medicines. Very often, medicines have not specifically been developed for older people, causing practical medication problems for them like limited availability of easy to swallow formulations, easy to open packaging and dosing instructions for enteral administration. In 2020, the European Medicines Agency (EMA) published a reflection paper 'Pharmaceutical development of medicines for use in the older population', which discusses how the emerging needs of an ageing European population can be addressed by medicines regulation. The paper intends to help industry to better consider the needs of older people during pharmaceutical/clinical medicines development by summarising data on the most relevant topics, providing early suggestions on how to move forward and prompting expert discussions and studies into knowledge gaps. Topics include patient acceptability, (dis)advantages of an administration route, formulation, dosage form, packaging, dosing device and user instruction. While the paper is directed at older people and the pharmaceutical industry, the reflections are also relevant to younger patients with similar disease-related needs and of value to other stakeholders parties, e.g., healthcare professionals, academics, patients and caregivers, as the paper makes clear what can be expected from industry and where collaborative work is needed. This commentary provides an overview of the different steps in the development of the reflection paper, discusses points considered most controversial and/or subject to (multidisciplinary) expert discussions and indicates their value for real world clinical practice.

Barriers and potential solutions in the recruitment and retention of older patients in clinical trials-lessons learned from six large multicentre randomized controlled trials

BACKGROUND

older people remain underrepresented in clinical trials, and evidence generated in younger populations cannot always be generalized to older patients.

OBJECTIVE

to identify key barriers and to discuss solutions to specific issues affecting recruitment and retention of older participants in clinical trials based on experience gained from six current European randomised controlled trials (RCTs) focusing on older people.

METHODS

a multidisciplinary group of experts including representatives of the six RCTs held two networking conferences and compiled lists of potential barriers and solutions. Every item was subsequently allocated points by each study team according to how important it was perceived to be for their RCTs.

RESULTS

the six RCTs enrolled 7,612 older patients. Key barriers to recruitment were impaired health status, comorbidities and diverse health beliefs including priorities within different cultural systems. All trials had to increase the number of recruitment sites. Other measures felt to be effective included the provision of extra time, communication training for the study staff and a re-design of patient information. Key barriers for retention included the presence of severe comorbidities and the occurrence of adverse events. Long study duration, frequent study visits and difficulties accessing the study site were also mentioned. Solutions felt to be effective included spending more time maintaining close contact with the participants, appropriate measures to show appreciation and reimbursement of travel arrangements.

CONCLUSION

recruitment and retention of older patients in trials requires special recognition and a targeted approach. Our results provide scientifically-based practical recommendations for optimizing future studies in this population.

A Quality by Design Framework for Capsule-Based Dry Powder Inhalers

Capsule-based dry powder inhalers (cDPIs) are widely utilized in the delivery of pharmaceutical powders to the lungs. In these systems, the fundamental nature of the interactions between the drug/formulation powder, the capsules, the inhaler device, and the patient must be fully elucidated in order to develop robust manufacturing procedures and provide reproducible lung deposition of the drug payload. Though many commercially available DPIs utilize a capsule-based dose metering system, an in-depth analysis of the critical factors associated with the use of the capsule component has not yet been performed. This review is intended to provide information on critical factors to be considered for the application of a quality by design (QbD) approach for cDPI development. The quality target product profile (QTPP) defines the critical quality attributes (CQAs) which need to be understood to define the critical material attributes (CMA) and critical process parameters (CPP) for cDPI development as well as manufacturing and control.

Better Medicines for Older Patients: Considerations between Patient Characteristics and Solid Oral Dosage Form Designs to Improve Swallowing Experience

Oral drug administration provided as solid oral dosage forms (SODF) remains the major route of drug therapy in primary and secondary care. There is clear evidence for a growing number of clinically relevant swallowing issues (e.g., dysphagia) in the older patient population, especially when considering the multimorbid, frail, and polymedicated patients. Swallowing impairments have a negative impact on SODF administration, which leads to poor adherence and inappropriate alterations (e.g., crushing, splitting). Different strategies have been proposed over the years in order to enhance the swallowing experience with SODF, by using conventional administration techniques or applying swallowing aids and devices. Nevertheless, new formulation designs must be considered by implementing a patient centric approach in order to efficiently improve SODF administration by older patient populations. Together with appropriate SODF size reductions, innovative film coating materials that can be applied to SODF and provide swallowing safety and efficacy with little effort being required by the patients are still needed. With that in mind, a literature review was conducted in order to identify the availability of patient centric coating materials claiming to shorten esophageal transit times and improve the overall SODF swallowing experience for older patients. The majority of coating technologies were identified in patent applications, and they mainly included well-known water soluble polymers that are commonly applied into pharmaceutical coatings. Nevertheless, scientific evidence demonstrating the benefits of given SODF coating materials in the concerned patient populations are still very limited. Consequently, the availability for safe, effective, and clinically proven solutions to address the increasing prevalence of swallowing issues in the older patient population is still limited.

Competition between Allowed and First-Forbidden β Decay: The Case of ^{208}Hg→^{208}Tl

The β decay of ^{208}Hg into the one-proton hole, one neutron-particle _{81}^{208}Tl_{127} nucleus was investigated at CERN-ISOLDE. Shell-model calculations describe well the level scheme deduced, validating the proton-neutron interactions used, with implications for the whole of the N>126, Z<82 quadrant of neutron-rich nuclei. While both negative and positive parity states with spin 0 and 1 are expected within the Q_{β} window, only three negative parity states are populated directly in the β decay. The data provide a unique test of the competition between allowed Gamow-Teller and Fermi, and first-forbidden β decays, essential for the understanding of the nucleosynthesis of heavy nuclei in the rapid neutron capture process. Furthermore, the observation of the parity changing 0^{+}→0^{-}β decay where the daughter state is core excited is unique, and can provide information on mesonic corrections of effective operators.

Challenges and opportunities to include patient-centric product design in industrial medicines development to improve therapeutic goals

In the past, drug developers in industry chose approaches mainly focusing on the drug product's efficacy, safety and quality according to the level required by regulatory expectations stipulated in guidelines, pharmacopoeia and other regulatory provisions. By putting more focus on the patient perspective, regulatory authorities are currently raising their requirements regarding successful product submissions. The increasing involvement of patients in the product development process (e.g. conduction of human factor use tests, integration of feedback from patient and patient advisory groups into clinical programmes) requires adaptations to the existing and established industrial drug development processes without compromising fast patient access to innovative therapies. This review provides an expert opinion on the emerging challenges and opportunities to implement a patient-centric approach into new drug development programmes. The aim is to better understand the challenge of finding the right balance between bringing innovative drugs fast to the patients and to develop these in parallel in a patient-centric product form as well as why this is an opportunity and how stakeholder parties (e.g. patients, clinicians, pharmacists, caregivers, regulators) can provide support to achieve desired outcomes.

Patient behaviour in medication management: Findings from a patient usability study that may impact clinical outcomes

Aims

Adequate medication management is a key condition to ensuring effective pharmacotherapy. However, it is well acknowledged that older people may encounter difficulties self‐administering medicines in a correct manner.

Methods

A mixed method pilot study was performed to investigate medication self‐management in older and multimorbid patients with polypharmacy. The pilot study involved medication management tasks followed by semi‐structured interviews in 20 patients. The tasks and interviews were based on the patients' individual medication plans, which had been prepared earlier by the pharmacy for each patient on basis of all their prescriptions.

Results

The patients' self‐reported medication management skills differed from their actual observed medication management performance. In addition, the routines and coping strategies used by the patients to deal with the complexity of their overall medication regimen were not in accordance with the medication plan and the instructions for use on the product labels. Issues were observed on all stages of the medication process that can be considered relevant to patient adherence, especially medication plan recall, product identification, product selection, product handling and product recognition in a multicompartment compliance aid.

Conclusions

The pilot study suggested that medication management issues by older and multimorbid patients remain widely undetermined and unrecognized in primary care. Further investigation and interdisciplinary collaboration will be required to resolve the user problems and ensure adequate patient adherence.

An evaluation of the gliding performance of solid oral dosage form film coatings using an artificial mucous layer

Oral drug delivery technology is mainly provided in the form of solid oral dosage forms (SODF) that have to be swallowed intact and move throughout the oro-esophageal system to release the drug content in the stomach or intestine. As there is growing evidence for an increasing prevalence of impaired swallowing functions in certain diseases, multimorbidity and advanced age, predictive in vitro methods for the oro-esophageal gliding behavior of SODF would be very useful. The gliding performance of different SODF polymer films was investigated across an artificial mucous layer using a versatile in vitro gliding system. In a first phase, the system measures the force required to move the polymer surface when placed in contact with the mucin layer and, in a second phase, the resistance behavior over a defined length. The obtained results showed that comprehensive gliding profiles could be obtained depending on the polymer film tested. The carnauba wax and PEG coatings required lower gliding peak forces and showed poor gliding resistance, which is indicative of free gliding capacity. In contrast, HPMC, PVP and gelatin coatings required higher gliding forces and exhibited greater resistance due to an adhesive interaction with the artificial mucous layer. The obtained profiles correlate with prior in vitro data during polymer gliding evaluations on mucosal membranes.

Age-Related Medicine

A meeting organised by the Academy of Pharmaceutical Sciences focussed on the challenges of developing medicines for older adults. International experts discussed the complexity introduced by polypharmacy and multiple morbidities and how the risk⁻benefit ratio of a medicine changes as an individual ages. The way in which regulatory authorities are encouraging the development of age-appropriate medicines was highlighted. Examples were provided of the difficulties faced by the older population with some medicinal products and suggestions given as to how the pharmaceutical scientist can build the requirements of the older population into their development of new medicines, as well as improvements to existing ones.

Orodispersible films: Towards drug delivery in special populations

Orodispersible films (ODF) hold promise as a novel delivery method, with the potential to deliver tailored therapies to different patient populations. This article reviews the current strides of ODF technology and some of its unmet quality and manufacturing aspects. A topic highlights opportunities and limitations of inkjet printed ODF as a population-specific drug delivery. Overall, this article aims to stimulate further research to fill the current knowledge gap between manufacturing and administration requirements of ODF targeting specific patient subpopulations such as geriatrics.

Patients' appropriateness, acceptability, usability and preferences for pharmaceutical preparations: Results from a literature review on clinical evidence

Patients play an important role in achieving the desired therapeutic outcomes, as they are frequently responsible for their own medication management. To facilitate drug administration and overcome medication issues, the patients' needs and preferences should be considered in the pharmaceutical drug product design. With the aim to evaluate the current state of evidence for patient appropriateness, acceptability, usability and preference for aspects of this design, a literature search was performed. Comparative clinical studies that assessed such endpoints for different patient populations were included and summarized descriptively. The search identified 45 publications that met the inclusion criteria. A detailed analysis of the studies identified two main areas investigating either packaging design (n=10) or dosage form design (n=35). Studies on packaging design showed preferences for wing top and screw cap openings, push-through blisters and suppositories with slide system. Additionally, child-resistant containers should be avoided concerning specific patient populations. Regarding dosage form design, sprinkles and minitablets were the most preferred in studies involving young patients, while preferences varied considerably depending on route of administration and geographical region in studies with adult patients. Review of the methodology used in the studies revealed that ten studies had used well-defined protocols and observational endpoints to investigate patient appropriateness. Studies focusing on methodology for testing the appropriateness and usability of drug products by patients were not found. In conclusion, more interdisciplinary scientific efforts are required to develop and increase research in understanding patient needs and preferences.

Drug administration via enteral tubing: an unresolved but increasing challenge

The number of patients with serious impairments of the swallowing function will continue to increase in the coming decades. Problems related to enteral feeding and drug administration to patients with swallowing issues is a growing concern of physicians, compounding pharmacists and nurses. The lack of information on the impact of compounding by mixing with liquid or food and/or administering through enteral or intestinal feeding tubes on the drug product safety and efficacy is problematic. In addition, there is a lack of appropriate alternative dosage forms of drugs for these routes of administration. As patients with swallowing issues represent a significant and growing patient population that is vulnerable and in need of effective drug therapy, the issue needs urgent attention by all stakeholders involved in healthcare provision. Incremental improvements at the different stages in the process, from product development to the patients' well-being are required to assure safe and effective drug therapy to an important patient population.

Results from a preliminary review of scientific evidence for appropriateness of preparations, dosage forms and other product design elements for older adult patients

The aging population and the growing multimorbidity of the major patient population as well as the advanced (pharmaco)therapeutic treatment options are increasing the complexity of independent drug therapy management and administration. The increased complexity may have an impact on drug adherence (including any need for patients initiated coping strategies), and consequently on the safety and efficacy of the medicine. To overcome adherence issues caused by the design of the medicine, it is crucial that developers consider the age appropriateness of the medicine (route of administration, dosage form, excipients in the composition, frequency of dosing) in meeting patients' needs to manage their therapy without the support of a care giver. In order to understand the scientific evidence on such age appropriately designed medicines for use by older adults, a literature search was performed in the Medline database (all languages included). The search produced 34 publications that met the inclusion and exclusion criteria for the patient population of 65 years an older. An in-depth analysis of the included publications with respect to the methodological quality (study design, data collection, endpoints chosen) and results showed that none of these publications had adequately investigated the age appropriateness of the medicine for use by older adults. The authors consider that the knowledge gap in this area requires attention of all stakeholders in the healthcare community.

Application of QbD principles for the evaluation of empty hard capsules as an input parameter in formulation development and manufacturing

Understanding the product and process variable on the final product performance is an essential part of the quality-by-design (QbD) principles in pharmaceutical development. The hard capsule is an established pharmaceutical dosage form used worldwide in development and manufacturing. The empty hard capsules are supplied as an excipient that is filled by pharmaceutical manufacturers with a variety of different formulations and products. To understand the potential variations of the empty hard capsules as an input parameter and its potential impact on the finished product quality, a study was performed investigating the critical quality parameters within and in between different batches of empty hard gelatin capsules. The variability of the hard capsules showed high consistency within the specification of the critical quality parameters. This also accounts for the disintegration times, when automatic endpoint detection was used. Based on these data, hard capsules can be considered as a suitable excipient for product development using QbD principles.

How to regulate nonbiological complex drugs (NBCD) and their follow-on versions: points to consider

The aim of this critical review is to reach a global consensus regarding the introduction of follow-on versions of nonbiological complex drugs (NBCD). A nonbiological complex drug is a medicinal product, not being a biological medicine, where the active substance is not a homo-molecular structure, but consists of different (closely related and often nanoparticulate) structures that cannot be isolated and fully quantitated, characterized and/or described by state of the art physicochemical analytical means and where the clinical meaning of the differences is not known. The composition, quality and in vivo performance of NBCD are highly dependent on manufacturing processes of both the active ingredient as well as in most cases the formulation. The challenges posed by the development of follow-on versions of NBCD are illustrated in this paper by discussing the 'families' of liposomes, iron-carbohydrate ('iron-sugar') drugs and glatiramoids. It is proposed that the same principles for the marketing authorization of copies of NBCD as for biosimilars be used: the need for animal and/or clinical data and the need to show similarity in quality, safety and efficacy. The regulatory approach of NBCD will have to take into consideration the specific characteristics of the drugs, their formulation and manufacturing process and the resulting critical attributes to achieve their desired quality, safety and efficacy. As with the biosimilars, for the NBCD product, family-specific methods should be evaluated and applied where scientifically proven, including sophisticated quality methods, pharmacodynamic markers and animal models. Concerning substitution and interchangeability of NBCD, it is also advisable to take biosimilars as an example, i.e. (1) substitution without the involvement of a healthcare professional should be discouraged to ensure traceability of the treatment of individual patients, (2) keep an individual patient on a specific treatment if the patient is doing well and only switch if unavoidable and (3) monitor the safety and efficacy of the new product if switching occurs.

Challenges and opportunities in the design of age-appropriate drug products

The age appropriateness of a pharmaceutical product for older patient populations is most important in achieving ease of use, administration, and adherence as well as the therapeutic benefit of the drug. Drug development is a lengthy and risky investment accompanied by extensive regulatory requirements to meet all the safety, efficacy, and quality criteria of a pharmaceutical product. Older adults represent a very heterogeneous patient population with different needs compared to younger adults. Major areas that should be considered in the design of age-appropriate products (AAP) are age- and disease-related aspects such as (a) different dose strengths, (b) issues in handling, administering, and managing the drug product, (c) and complex medication regimens. The application of different technologies can meet these specific needs and should be considered at the very beginning of product development when setting the targeted quality product profile (TQPP) or later on during the product life-cycle management.

Geriatric drug therapy: neglecting the inevitable majority

Demographic evolution will considerably increase the number of people aged 65 years and beyond in the coming decades. The elderly not only represent the most heterogeneous population, but also are a major user group for prescribed medicines, a predominance that will continue to further increase. Medicines and medication management are much more complex and challenging in the elderly and can only be addressed through a multidisciplinary approach. There is strong evidence that the elderly are able to properly manage their medication; however, their medications require different features than the standard medications used by adults. The elderly are exposed to several chronic disease conditions and their treatments, as well as experience age-related changes and limitations that need to be reflected in their medication management strategies. Geriatric drug therapy remains a multidisciplinary task. The health care industry, physicians, pharmacists, nurses and care givers provide and guide the patient's therapy according to individual needs, while the health care system and regulatory authorities build the necessary framework of support and resources.Any realistic and significant enhancement to the elderly patients' medicines and medication management needs to be addressed by all disciplines and stakeholders involved since the absence of any of the stakeholders in the overall process negatively impacts the achievable enhancement in geriatric drug therapy.

When poor solubility becomes an issue: from early stage to proof of concept

Drug absorption, sufficient and reproducible bioavailability and/or pharmacokinetic profile in humans are recognized today as one of the major challenges in oral delivery of new drug substances. The issue arose especially when drug discovery and medicinal chemistry moved from wet chemistry to combinatorial chemistry and high throughput screening in the mid-1990s. Taking into account the drug product development times of 8-12 years, the apparent R&D productivity gap as determined by the number of products in late stage clinical development today, is the result of the drug discovery and formulation development in the late 1990s, which were the early and enthusiastic times of the combinatorial chemistry and high throughput screening. In parallel to implementation of these new technologies, tremendous knowledge has been accumulated on biological factors like transporters, metabolizing enzymes and efflux systems as well as on the physicochemical characteristics of the drug substances like crystal structures and salt formation impacting oral bioavailability. Research tools and technologies have been, are and will be developed to assess the impact of these factors on drug absorption for the new chemical entities. The conference focused specifically on the impact of compounds with poor solubility on analytical evaluation, prediction of oral absorption, substance selection, material and formulation strategies and development. The existing tools and technologies, their potential utilization throughout the drug development process and the directions for further research to overcome existing gaps and influence these drug characteristics were discussed in detail.

Migraine and asthma in childhood: evidence for specific asymmetric parent-child interactions in migraine and asthma families

In spite of the fact that migraine often manifests as a familial disorder, the role of the family in migraine has not been adequately explored. In this study parent-child interactions in 20 families with a child suffering from migraine were analysed and compared with 20 healthy families and 20 families with an asthma child. The families had to solve a puzzle within a limited time. Parent-child interactions within migraine and asthma families were asymmetric, revealing a disease-specific interpersonal context in the family. Communication with the affected child in migraine families was significantly more directive, with more specific instructions and less help, towards migraineurs than with the healthy siblings. Dominance of parents and submissive behaviour of children were the main features of interactions. In asthma families interactions were more conflicting and less cooperative. This study demonstrated a specific, asymmetric, pattern of family interactions predisposing children either to migraine or asthma.

Influence of a stationary magnetic field on acetylcholinesterase in murine bone marrow cells

A thirty-minute exposure of mice to a homogeneous stationary magnetic field (SMF) of 1.4 Tesla at either 27 degrees C or 37 degrees C body temperature causes an inhibition of about 20 per cent of acetylcholinesterase (AChE, E.C. 3.11.7) in murine bone marrow cells (BMC) after 3.5 and 2 h, respectively, at the two aforementioned body temperatures. The extent of enzyme inhibition is independent of ambient temperature, but dependent on the time after exposure. This initial inhibition of AChE activity is followed by a limited recovery which is dependent upon the temperature during exposure to the SMF and remains incomplete even 15 h afterwards. We describe here certain enzymologic properties of AChE in BMC as well as inhibition studies with diisopropylfluorophosphate (DFP) to differentiate between AChE and nonspecific cholinesterases.