Antibody landscape of C57BL/6 mice cured of B78 melanoma via a combined radiation and immunocytokine immunotherapy regimen

Sera of immune mice that were previously cured of their melanoma through a combined radiation and immunocytokine immunotherapy regimen consisting of 12 Gy of external beam radiation and the intratumoral administration of an immunocytokine (anti-GD2 mAb coupled to IL-2) with long-term immunological memory showed strong antibody-binding against melanoma tumor cell lines via flow cytometric analysis. Using a high-density whole-proteome peptide array (of 6.090.593 unique peptides), we assessed potential protein-targets for antibodies found in immune sera. Sera from 6 of these cured mice were analyzed with this high-density, whole-proteome peptide array to determine specific antibody-binding sites and their linear peptide sequence. We identified thousands of peptides that were targeted by these 6 mice and exhibited strong antibody binding only by immune (after successful cure and rechallenge), not naïve (before tumor implantation) sera and developed a robust method to detect these differentially targeted peptides. Confirmatory studies were done to validate these results using 2 separate systems, a peptide ELISA and a smaller scale peptide array utilizing a slightly different technology. To the best of our knowledge, this is the first study of the full set of germline encoded linear peptide-based proteome epitopes that are recognized by immune sera from mice cured of cancer via radio-immunotherapy. We furthermore found that although the generation of B-cell repertoire in immune development is vastly variable, and numerous epitopes are identified uniquely by immune serum from each of these 6 immune mice evaluated, there are still several epitopes and proteins that are commonly recognized by at least half of the mice studied. This suggests that every mouse has a unique set of antibodies produced in response to the curative therapy, creating an individual "fingerprint." Additionally, certain epitopes and proteins stand out as more immunogenic, as they are recognized by multiple mice in the immune group.

Antibody landscape of C57BL/6 mice cured of B78 melanoma via immunotherapy

Hoefges et al. utilized a whole-proteome peptide array approach to show that C57BL/6 mice develop a large repertoire of antibodies against linear peptide sequences of their melanoma after receiving a curative immunotherapy regimen consisting of radiation and an immunocytokine. Antibodies can play an important role in innate and adaptive immune responses against cancer, and in preventing infectious disease. Flow cytometry analysis of sera of immune mice that were previously cured of their melanoma through a combined immunotherapy regimen with long-term memory showed strong antibody-binding against melanoma tumor cell lines. Using a high-density whole-proteome peptide array, we assessed potential protein-targets for antibodies found in immune sera. Sera from 6 of these cured mice were analyzed with this high-density, whole-proteome peptide array to determine specific antibody-binding sites and their linear peptide sequence. We identified thousands of peptides that were targeted by 2 or more of these 6 mice and exhibited strong antibody binding only by immune, not naive sera. Confirmatory studies were done to validate these results using 2 separate ELISA-based systems. To the best of our knowledge, this is the first study of the "immunome" of protein-based epitopes that are recognized by immune sera from mice cured of cancer via immunotherapy.

Abstract 1377: Endogenous antibodies recognize multiple proteins on B78 melanoma in mice cured via immunotherapy

Introduction: Antibodies can play an important role in innate and adaptive immune responses against cancer. By using a high-density whole mouse proteome peptide array, we were able to assess potential protein-targets for antibodies present in mice cured of their melanoma by a combination immunotherapy regimen of 12Gy local radiation and intratumoral administration of a tumor-specific immunocytokine (anti-GD2 antibody linked to IL-2). This regimen can induce an “in situ vaccine” effect (ISV) enabling mice to be cured of their tumors with long-term immune memory.

Methods: Immunocompetent C57/BL6 mice bearing large B78 (GD2-expressing) melanoma tumors were treated with ISV. Sera were collected at different timepoints (before tumor implantation, after implantation before treatment, after completion of treatment, after the mouse was rendered tumor-free and after a rejected rechallenge). Tumor cell surface binding of these serum samples was assessed via flow cytometry and showed a strong increase in binding of sample obtained following immunotherapy, and after rejection of a tumor rechallenge. Binding was assessed against the original tumor line, B78, as well as B16 (parental to B78 without GD2 expression).We used the naïve and immune sera on a Nimble Therapeutics whole mouse proteome peptide array to determine specific antibody-binding sites. Whole proteome data was analyzed using a newly developed algorithm which scans adjacent peptides to detect differential binding between naïve and immune samples.

Results: Multiple proteins were selectively identified by immune sera which were not well detected by sera from naïve mice. Hundreds of proteins were targeted by 3 or more of 6 mice and exhibited strong antibody binding only by immune sera. Some proteins were recognized via the same binding epitopes, others via different epitopes in separate mice. Some of the whole protein peptide array results were validated via JPT multi-well peptide array and some via independent peptide ELISA. Results from Nimble peptide array and ELISA validated well.

Conclusions: We were able to detect antibody in immune sera binding selectively to specific linear epitopes and identify proteins of interest for further investigation as potential targets for antibody-based or cellular therapies. Results from our whole proteome peptide array were validated in separate assays via peptide ELISA. We are also exploring if some of the identified tumor-specific endogenous antibodies could be used as biomarkers to predict response to our ISV regimen and potentially other immunotherapy treatments.

Citation Format: Anna Hoefges, Sean J. McIlwain, Amy K. Erbe, Trang Q. Le, Kaitlin Tetreault, Nicholas Mathers, Alexander L. Rakhmilevich, Jacquelyn A. Hank, Jigar Patel, Brad Garcia, Zachary S. Morris, Irene M. Ong, Paul M. Sondel. Endogenous antibodies recognize multiple proteins on B78 melanoma in mice cured via immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1377.

Thousands of new antigens are recognized in mice via endogenous antibodies after being cured of a B78 melanoma via immunotherapy

Antibodies can play an important role in innate and adaptive immune responses against cancer. Using a high-density peptide array, we assessed potential protein-targets for antibodies activated in mice cured of their melanoma through a combined immunotherapy regimen. Our goal was to determine the linear peptide sequences recognized by anti-tumor antibodies produced in mice cured of their melanoma with immunotherapy.

Mice with GD2-expressing syngeneic B78 melanoma were treated with a combination immunotherapy capable of inducing an “in situ vaccine” effect (ISV), enabling mice to be cured of their tumors with long-term immune memory. Naïve and immune sera were collected from these mice. Using flow cytometry, immune sera showed strong antibody-binding against B16 (parental cell line of B78 without GD2 expression). These sera were then used on a Nimble Therapeutics’ peptide-array (either whole proteome or a curated list of ~650 proteins) to determine specific antibody-binding sites, and data were analyzed using a probabilistic model. Using the “curated list” peptide array, proteins were selected if the protein was bound in immune sera but not bound in the sera from naïve or non-responding tumor-bearing mice. When focusing on the whole mouse proteome data, thousands of peptides were targeted by 2 or more mice and exhibited strong antibody binding only by immune sera.

We are continuing to refine our analytical methods and are further investigating all identified proteins. These peptides may be new targets for antibody-based or cellular therapies and some of the tumor-specific endogenous antibodies that we have identified may be used as biomarkers to predict response to our ISV regimen and potentially other immunotherapy treatments.

The Toxicogenome of Hyalella azteca: A Model for Sediment Ecotoxicology and Evolutionary Toxicology

Hyalella azteca is a cryptic species complex of epibenthic amphipods of interest to ecotoxicology and evolutionary biology. It is the primary crustacean used in North America for sediment toxicity testing and an emerging model for molecular ecotoxicology. To provide molecular resources for sediment quality assessments and evolutionary studies, we sequenced, assembled, and annotated the genome of the H. azteca U.S. Lab Strain. The genome quality and completeness is comparable with other ecotoxicological model species. Through targeted investigation and use of gene expression data sets of H. azteca exposed to pesticides, metals, and other emerging contaminants, we annotated and characterized the major gene families involved in sequestration, detoxification, oxidative stress, and toxicant response. Our results revealed gene loss related to light sensing, but a large expansion in chemoreceptors, likely underlying sensory shifts necessary in their low light habitats. Gene family expansions were also noted for cytochrome P450 genes, cuticle proteins, ion transporters, and include recent gene duplications in the metal sequestration protein, metallothionein. Mapping of differentially expressed transcripts to the genome significantly increased the ability to functionally annotate toxicant responsive genes. The H. azteca genome will greatly facilitate development of genomic tools for environmental assessments and promote an understanding of how evolution shapes toxicological pathways with implications for environmental and human health.

The Toxicogenome of Hyalella azteca: A Model for Sediment Ecotoxicology and Evolutionary Toxicology

Hyalella azteca is a cryptic species complex of epibenthic amphipods of interest to ecotoxicology and evolutionary biology. It is the primary crustacean used in North America for sediment toxicity testing and an emerging model for molecular ecotoxicology. To provide molecular resources for sediment quality assessments and evolutionary studies, we sequenced, assembled, and annotated the genome of the H. azteca U.S. Lab Strain. The genome quality and completeness is comparable with other ecotoxicological model species. Through targeted investigation and use of gene expression data sets of H. azteca exposed to pesticides, metals, and other emerging contaminants, we annotated and characterized the major gene families involved in sequestration, detoxification, oxidative stress, and toxicant response. Our results revealed gene loss related to light sensing, but a large expansion in chemoreceptors, likely underlying sensory shifts necessary in their low light habitats. Gene family expansions were also noted for cytochrome P450 genes, cuticle proteins, ion transporters, and include recent gene duplications in the metal sequestration protein, metallothionein. Mapping of differentially expressed transcripts to the genome significantly increased the ability to functionally annotate toxicant responsive genes. The H. azteca genome will greatly facilitate development of genomic tools for environmental assessments and promote an understanding of how evolution shapes toxicological pathways with implications for environmental and human health.

Perceptions of the causes of childhood disability among Pakistani families living in the UK

It has been well documented that South Asian families caring for a child with a disability experience discrimination and disadvantage in accessing health and social care services. This gives increasing cause for concern as the number of South Asian people with severe learning impairments in the UK continues to rise. Mainstream services are ill-equipped to provide individual services to parents who choose to define and address disability differently, and whose concerns and solutions may differ from the majority population, despite the fact that these parents possess many strengths and may present alternative ways of addressing their needs. This study aimed to provide a detailed account of the ways that Pakistani parents living in a northern city in the UK and caring for a child with a disability, account for and understand their child's disability. Sixteen in-depth interviews were carried out between October 2002 and July 2003, with Pakistani parents and one grandparent of children with a disability. All final transcripts were in English, and a thematic analysis was undertaken. Results include a detailed account of parents' understanding of the causes of their child's disability. All parents made reference to theological explanations as to why they had a child with a disability; however, most parents also gave biomedical or other explanations. The relationship between theological and biomedical explanations was explored along with the consequences of the different beliefs for individuals and families. Parents also spoke vividly about the impact of negative and stigmatizing beliefs about causes of disability which they felt were prevalent in the Pakistani community, and they used a biomedical discourse to refute these ideas. The authors suggest that knowledge of individual and family beliefs, and awareness of the impact of these beliefs, can provide a valuable conceptual lens for health and social care practitioners to use when working in family-centred, culturally congruent ways with parents.

Young people of minority ethnic origin in England and early parenthood: views from young parents and service providers

The paper explores the phenomenon of early parenthood in minority ethnic communities in England. The data were collected using focus group interviews, in-depth semi-structured interviews and a telephone survey. The sample consisted of 139 participants (41 service providers, 10 grandmothers, 88 young parents). The findings map out the complexity and diversity of experience of early parenthood amongst young people of minority ethnic origin, not least the multiple attachments many experience in relation to their social groups, religious affiliations and the traditional patterns of parenting within their immediate and extended family. Both the young parents and professionals in this study constructed early parenthood in more positive terms than is currently portrayed in the contemporary policy. The findings are analysed and discussed in relation to ethnic identity, social inclusion and exclusion. We explore participants' attempts to counter negative 'deficit' models of early parenthood with reference to perspectives on youth, parenthood and contemporary strategic policy. In conclusion, we suggest an unambiguous focus on the reduction of pregnancy is not a credible message when teenage pregnancy is a social norm for a particular ethnic or cultural group. For young parents of Muslim faith in particular, teenage parenting within marriage is not necessarily considered a 'problem' or seen as a distinctive event. Most participants did not view early parenthood as a barrier to re-establishing career and educational aspirations. A wide diversity of experience amongst young parents is evidenced in the communities studied; this needs to be reflected more comprehensively both in UK policy and in support services.

Psychological treatment for insomnia in the regulation of long-term hypnotic drug use

OBJECTIVES

To evaluate the clinical and cost impact of providing, in routine general practice settings, a cognitive-behaviour therapy (CBT) package for insomnia to long-term hypnotic drug users with chronic sleep difficulties; and to identify factors associated with variations in clinical outcomes.

DESIGN

A pragmatic cluster randomised controlled trial with two treatment arms (a CBT-treated 'sleep clinic' group, and a 'no additional treatment' control group), with post-treatment assessments starting at 3, 6 and 12 months.

SETTING

Twenty-three general practices in Sheffield, UK.

PARTICIPANTS

In total, 209 patients (aged 31-92 years) with chronic sleep problems who had been receiving repeat hypnotic drug prescriptions for at least 1 month (mean = 13.4 years) were recruited into the trial.

INTERVENTIONS

The intervention consisted of six 50-minute sessions as follows: introduction and sleep assessment, basic sleep hygiene, stimulus control and sleep restriction procedures, progressive relaxation, cognitive treatments, and review and discharge.

MAIN OUTCOME MEASURES

These included: global sleep quality [as measured by the Pittsburgh Sleep Quality Index (PSQI)], frequency of hypnotic drug use, mean dose of hypnotics consumed, health-related quality of life [as measured by the Short-Form 36 (SF-36)], NHS service costs and overall cost utility.

RESULTS

At 3- and 6-month follow-ups, patients treated with CBT showed improved global PSQI scores as well as improvements in the SF-36 dimensions of vitality at 3 months and physical functioning and mental health at 6 months. CBT-treated patients also reported reductions in the frequency of hypnotic drug use compared with the control group, with many CBT-treated patients reporting zero drug use at the follow-up assessments. Clinical improvements were maintained within the CBT group at the 12-month follow-up, with PSQI scores and the frequency of hypnotic drug use continuing to show significant reductions relative to the control group. Multiple regression analyses of PSQI scores within the sleep clinic group alone indicated that the magnitude of pre- to post-treatment change in overall sleep quality was closely related to Hospital Anxiety and Depression Scale depression scores at 3-, 6-and 12-month follow-ups. In each model higher depression scores at baseline were associated with poorer treatment outcomes. No significant relationship was found between the patient's age and PSQI outcomes in any of these analyses. Within the sleep clinic group, reductions in drug use showed no significant association with the hypnotic product consumed. At the 3-month follow-up low-frequency drug use was reported by 22.9% (8/35) of temazepam users, 33.3% (5/15) of nitrazepam users and 38.9% (7/18) of zopiclone users. The total cost of service provision was GBP154.40 per patient (1999/2000 prices). The mean incremental cost per quality-adjusted life-year (QALY) at 6 months was GBP3418; this figure was insensitive to changes in costs. A simple model also showed that extending the evaluation period beyond 6 months may improve the cost-effectiveness of CBT. The incorporation of hidden costs associated with hypnotic drug treatment (e.g. accidents) also reduces the cost per QALY ratio, although to a much lesser degree.

CONCLUSIONS

In routine general practice settings, psychological treatment for insomnia can improve sleep quality, reduce hypnotic drug use, and improve health-related quality of life at a favourable cost among long-term hypnotic users with chronic sleep difficulties. These positive outcomes appear robust over time, persisting for at least 1 year among the more treatment-adherent patients. While these benefits may be reduced among those patients presenting with higher levels of psychological distress, the present study clearly indicates that older age per se presents no barrier to successful treatment outcomes. Further research should assess the long-term clinical and cost-effectiveness of psychological treatments for insomnia among non-hypnotic-using patients, and establish the minimum psychological treatment input required.

Residential rehabilitation for drug users: a review of 13 months' intake to a therapeutic community

BACKGROUND

Residential rehabilitation based on 'therapeutic community' treatment for drug users is a treatment option which is attractive to GPs and others referring drug users for treatment. Whilst there is evidence that maintenance-based programmes for drug users are effective, there have been fewer attempts to evaluate the effectiveness of abstinence-based programmes which are relatively more intensive and expensive interventions.

OBJECTIVE

This paper reports and evaluates the outcomes for 13 months' intake of 138 drug users to a residential community.

METHODS

We carried out a retrospective cohort study using existing clinical and residential record data. The setting is a residential rehabilitation centre run by the charity Phoenix House in Sheffield, UK, offering a 1-year programme for heroin addicts including community detoxification overseen by primary care specialist doctors and residential rehabilitation. Participants were all patients who entered treatment between 1 February 1998 and 28 February 1999 inclusive. An analysis was carried out of clinical records and other records kept by clinicians and staff at the centre. Outcome measures were numbers of days of retention in treatment and reasons for departure, categorized as completed treatment, planned or unplanned departure and expulsion from the programme. For patients who underwent in-house detoxification, a further outcome measure was whether or not detoxification was complete at discharge.

RESULTS

Heroin was the main drug of abuse in 85% of admissions. Mean length of time for which individuals had been drug dependent was 8 years (range 1.3-20.1 years). The mean length of stay was 80.2 days (range 1-394, 95% confidence interval 61.8-98.6). Thirty-four individuals (25%) completed 90 days or more. No association was found between length of stay and age, sex, route of administration, polydrug use, length of time addicted or age of first addiction. Sixty-five per cent of those who received in-house detoxification completed the detoxification period. When patients were classified as 'successes' or 'failures' by reason for departure from the programme, 94 (68.1%) were classified as failures and 18 (13.0%) as successes. Data were unavailable for 26 patients. Success was not associated with any characteristic at entry apart from being drug free as opposed to requiring detoxification (P = 0.048, chi-square = 6.06, df = 2).

CONCLUSION

This study shows overall low levels of programme completion and high levels of unplanned departure and eviction from the programme amongst these long-term drug users. On the other hand, the importance of abstinence for those who achieve it in residential rehabilitation should not be underestimated, nor should the possibility that long-term outcomes are influenced by the learning process involved in the intervention. It may be possible to operate better selection procedures in order to optimize outcomes.

Deaths from drugs of abuse in Sheffield, 1998: the role of prescribed medication

Characteristics of recent drug abuse-related deaths in the city of Sheffield were examined from the coroner's records. Almost all of those who died of poisoning from a drug of abuse were known to be dependent on heroin yet less than half were receiving treatment. Benzodiazepines were frequently detected alongside opiates during toxicology, the source of which was likely to be the deceased's own prescription.

Supporting GPs whose performance gives cause for concern: the North Trent experience

BACKGROUND

The North Trent scheme to address the problem of GPs whose performance gives cause for concern was implemented in 1997. This paper describes the structure and process of the scheme and evaluates the main outcomes.

METHODS

We used non-participant observation and semi-structured interviews with representatives of the seven Health Authorities (HAs) of North Trent including medical and prescribing advisors and senior primary care managers. Twenty-one GPs who were members of the Performance Review Quartets (PRQs) were also interviewed. Qualitative data were analysed using a constant comparative method to identify emergent themes.

RESULTS

Performance indicators were agreed between HAs and the profession in the seven North Trent localities. The scheme identified 18 GPs whose performance gave cause for concern, of whom 15 GPs in six practices received a formal visit. Educational plans were agreed and implemented with three GPs. The remaining 12 received administrative and clinical support. Three of the 18 GPs initially refused to co-operate with the scheme. Two of these have since agreed a practice visit following a visit by a senior local medical committee representative. The performance indicators used in the scheme have not been specific to individual GPs except those in single-handed practices. Some indicators used by PRQs related to cost effectiveness rather than quality of care for individual patients. Current resources were adequate for the small number of underperforming GPs identified by the scheme.

CONCLUSIONS

The North Trent scheme has identified a number of underperforming GPs, 83% of whom have been willing to participate in a supportive intervention. The scheme will need some modification with the advent of primary care trusts and the proposed assessment and support centres.

Postnatal depression -- biological or cultural? A comparative study of postnatal women in the UK and Taiwan

AIM

The aim of the study was to compare the factors which are associated with postnatal depression in the UK (United Kingdom) and Taiwan.

BACKGROUND/RATIONALE

A comparative study of postnatal women in the UK and Taiwan was undertaken to investigate postnatal care and the prevalence of postnatal depression.

DESIGN/METHODS

The Edinburgh Postnatal Depression Scale (EPDS) was used to determine the prevalence of postnatal depression. A semistructured interview and validated questionnaire were used to collect data on maternal satisfaction with postnatal care and the factors associated with postnatal depression. A one in three random sample of women from two community midwife teams in Sheffield, UK and three public health stations in Keelung, Taiwan took part in the study.

RESULTS/FINDINGS

Fifty (94% response rate) women from Sheffield and 101 (83% response rate) women from Keelung, who were at low risk for maternal or foetal problems during labour and the postnatal period, agreed to participate. The prevalence of postnatal depression in the British and Taiwanese women was almost equal; 18% in the UK and 19% in Taiwan. In Taiwan, the prevalence of postnatal depression had a negative association with relationship with partner (Spearman correlation=-0.34, P < 0.001) and self-confidence (Spearman correlation=-0.28, P < 0.01, Spearman correlation). In addition Taiwanese women who felt more anxious after birth (10.9 +/- 7.9, P < 0.001, t-test) had a higher chance of postnatal depression. In the UK, there was a significant negative association between adaptation to the new role of motherhood and score on the EPDS (Spearman correlation=-0.47, P < 0.001). The overall scores for maternal satisfaction were 28.1 and 24.3 in the UK and Taiwan, respectively (P < 0.001, t-test). British women reported a better quality of care during the postnatal period in terms of emotional support and physical care.

CONCLUSIONS

The findings of this study suggest that further cross cultural investigation could shed light on the relative balance of biological and cultural factors which may be associated with the onset of postnatal depression. As the prevalence of postnatal depression is similar in both cultures despite large differences in culture and postnatal care systems, some support is given to a hypothesis that postnatal depression has at least some biological determinants as well as cultural/social ones.

Keeping families of heroin addicts together: results of 13 months' intake for community detoxification and rehabilitation at a family centre for drug users

BACKGROUND

Heroin addiction is a major public health problem affecting both the addicted individuals and their children, who have been shown to have poor social, educational and health status and to be at higher risk of abuse than their peers. Whilst the antenatal effects of parental drug use and the overall poor outcomes for these children have been widely studied, there has been little emphasis on the effectiveness of treatment interventions and even less emphasis on evaluating the effect on children of the standard treatments aimed at their parents' drug use.

OBJECTIVES

The aim of the present study was to evaluate the effect on heroin-addicted parents and their children of a family-based drug treatment intervention using a records-based methodology, and to identify any factors at admission which may influence outcome. This study is a pilot for a prospective Europe-wide study using a similar methodology prospectively in several treatment modalities.

METHODS

A retrospective cohort study was carried out using existing clinical and residential record data. The setting was a residential family centre run by the charity Phoenix House in Sheffield, UK, offering a 6-month (180 days) family-based programme for heroin addicts including community detoxification overseen by primary care specialist doctors and residential rehabilitation. All adults and children who entered the centre between July 1997 and July 1998 were included in the study (26 adults and 33 children, in 23 family groups). An analysis was made of clinical records and records kept on the adults and children by the clinicians and staff at the centre. The main outcome measures for the adults were length of stay and reason for departure (treatment complete, early planned discharge, unplanned discharge, eviction); and for the children were reason for departure and discharge destination (with parent or taken into care).

RESULTS

Mean length of stay was 110 days, and only 11 children (33%) and nine adults (35%) completed 150 days or more. Length of stay was found to be significantly correlated with parental age at admission (P < 0.01). Twelve children (37%) and nine adults (35%) were deemed to have completed treatment successfully. Of the remainder, 14 children (42%) and 11 adults (42%) left because of definite treatment failure. Successful treatment completion was found to be correlated with increased parental age (Pearson's r = 0.612, P = 0. 001). Poly-drug users were significantly less likely to complete treatment successfully (Fisher's exact test, P = 0.012). Twenty children were in the care of their parents on admission, and 24 were able to go home with their parents. There was no association between residence with parents pre- and post-admission (McNemar's chi-squared test = 1.6, P > or = 0.1).

CONCLUSIONS

Whilst overall high rates of treatment success are not expected in abstinence-based programmes, the outcomes for the adults in this setting are comparable with published results in other residential settings, and there is some evidence that some families may have stayed together who might otherwise have been separated. Older adults who were not poly-drug users had significantly better outcomes. The records-based methodology proved successful, but centres need to keep detailed and preferably long-term records on children if their outcomes are to be evaluated more fully.

Can methadone maintenance for heroin-dependent patients retained in general practice reduce criminal conviction rates and time spent in prison?

A retrospective analysis was made of the criminal records of 57 patients successfully retained in methadone maintenance at two general practices in Sheffield. Their criminal conviction rates and time spent in prison per year were compared for the periods before and after the start of their methadone programme. Overall, patients retained on methadone programmes in the general practices studied had significantly fewer convictions and cautions, and spent significantly less time in prison than they had before the start of treatment.

Empowering research: statistical power in general practice research

BACKGROUND

Statistical power is a measure of the extent to which a study is capable of discerning differences or associations which exist within the population under investigation, and is of critical importance whenever a hypothesis is tested by statistics. Conventionally, studies should reach a power level of 0.8, such that four times out of five a false null hypothesis will be rejected by a study. Statistical power may most easily be increased by increasing sample size.

OBJECTIVE

We aimed to assess the level of statistical power of general practice research.

METHODS

A total of 1422 statistical tests in 85 quantitative original papers in the British Journal of General Practice were analysed for statistical power.

RESULTS

The median power of tests analysed was 0.71, representing a slightly greater than two-thirds likelihood of rejecting false null hypotheses. Of 85 studies, 37 (44%) attained power of 0.8 or more. Ten studies had power of more than 0.99 suggesting 'over-powering'. Twenty-one of the papers surveyed (25%) had a likelihood of gaining significant results poorer than that obtained by tossing a coin when a null hypothesis is false.

CONCLUSION

While achieving higher power than studies in similar surveys of other disciplines, the power of general practice research falls short of the 0.8 convention. Adequate power is essential so that effects which exist are not missed. Recommendations are made concerning power calculations prior to the start of research and reporting of results in journal articles.

General practice--a post-modern specialty?

The 'modern' view of the world is based on the premise that we can discover the essential truth of the world using scientific method. The assumption is made that knowledge so acquired has been 'uncontaminated' by the mind of the investigator. Post-modern theory, however, is concerned with the process of knowing and how our minds are part of the process, i.e. our perceptions of reality and the relationships between different concepts are important influences on our ways of knowing. The values of post-modern theory are those of uncertainty, many different voices and experiences of reality and multifaceted descriptions of truth. These values are closer to our experience of general practice than the 'modern' values of scientific rationalism and should be reflected in a new curriculum for general practice.

Heartsink patients: a study of their general practitioners

BACKGROUND

A number of attempts have been made to investigate the heartsink, difficult, dysphoric or problem patient. Most studies have emphasized the role which the patient plays in evoking despair, anger and frustration in the doctor. However, one doctor's list of difficult patients may not necessarily be the same as another's.

AIM

A study was undertaken to determine if the individual characteristics of general practitioners are associated with the number of heartsink patients they report on their patient lists.

METHOD

Sixty out of 137 urban general practitioners drawn at random from the Sheffield Family Health Services Authority list were surveyed by structured interview and questionnaires in 1990. Outcome measures were interview data and scores on the 12-item general health questionnaire, Warr-Cook-Wall job satisfaction scale and the Bortner personality profile measure.

RESULTS

Sixty per cent of the variance in the number of heartsink patients that general practitioners reported on their lists could be accounted for by the following four explanatory variables: greater perceived workload; lower job satisfaction; lack of training in counselling and/or communication skills; and lack of appropriate postgraduate qualifications. No other variables considered could account for the variance in the number of heartsink patients reported by general practitioners.

CONCLUSION

The individual characteristics of doctors are associated with the number of heartsink patients reported by general practitioners. To reduce the number of such patients experienced, it may be necessary for general practitioners to reduce their workload and increase their job satisfaction and their level of relevant postgraduate training.

The wizard and the gatekeeper: of castles and contracts

The wizards and the gatekeepers were unhappy. There were many reasons for their unhappiness. They worked hard but felt that too much was being demanded of them. The poorly people's charter was resulting in unrealistic expectations, and changes in the apprenticeship for wizards were putting great strain on their mentors. The wizards enjoyed their work less and less, and it was getting difficult to find new gatekeepers. On the other hand, the way the system worked meant that there had to be plenty of goblins and the number of scrolls that had to be filled in was rising sharply. The wizards and gatekeepers tried to point out ways to improve things that would ensure that poorly people were better treated, but there was no easy solution. With the ominous sign that the recruitment of wizards and gatekeepers was becoming more difficult, an answer was needed--and soon.

Assessment of training in psychosexual medicine

The Institute of Psychosexual Medicine offers training in the treatment of psychosexual problems to medically qualified doctors. Training takes place in fortnightly seminars in which trainees present and discuss real cases. Assessment of cases presented at the beginning and end of the six term basic training showed appreciable improvement in doctors' abilities. The proportion of doctors meeting each of the 14 predetermined clinical objectives rose. Factors which affected the amount of improvement were the initial score, the number of cases presented at the seminars, the occupation of the leader, and the duration of training. Accreditation by the Institute of Psychosexual Medicine was shown to be an appropriate outcome measure for the achievement of the required standards for practising psychosexual medicine.

The gatekeeper and the wizard revisited

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Bone mineral content of appropriate and light for gestational age preterm and term newborn infants

Bone mineral content was measured by single photon absorptiometry at the right mid humerus of 122 appropriate and 35 light for gestational age newborn infants born after 26 to 42 weeks of gestation. Bone mineral content was 2.4 times greater at the mid humerus than at the distal radius. Even in extremely low birth weight infants reproducible measurements were possible at the mid humerus. Light for gestational age infants showed a lower bone mineral content than appropriate for gestational age infants when bone mineral content was related to gestational age. When related to birthweight (g) bone mineral content showed a similar linear relationship in light for gestational age (mg/cm = 44.2 + 0.037 weight) and appropriate for gestational age (mg/cm = 39.4 + 0.040 weight) infants. For all 177 infants the relationship was mg/cm = 32.3 + 0.045 weight (r = 0.91). It is concluded that in growing preterm infants bone mineral content should be assessed in relation to weight rather than to age.

An audit of the care of post-gastrectomy patients

The records of 26 patients in one practice who had had a partial gastrectomy were studied to see if a stated policy of follow-up had been successful. The policy aimed to detect by annual blood tests (birthday follow-up) the consequences of malabsorption of iron, folate, vitamin B12, and calcium. Of 198 possible tests (nine for each patient when seen for the first screening), only 87 (44 per cent) were done; 16 (18.2 per cent) were abnormal. At the 39 opportunities for annual follow-up, 71 per cent of the possible tests were done; 11 of the 62 tests (17.5 per cent) were abnormal. The most common abnormality was deficiency of iron (12 tests), followed by folate (four tests), serum B12 (two tests), and serum calcium (two tests). Appropriate action according to the review criteria was taken for 24 out of the 27 abnormalities found. The result of the review was to suggest a modified annual follow-up, with fewer than nine tests per year.