Generation of Schwann cell derived melanocytes from hPSCs identifies pro-metastatic factors in melanoma

The neural crest (NC) is highly multipotent and generates diverse lineages in the developing embryo. However, spatiotemporally distinct NC populations display differences in fate potential, such as increased gliogenic and parasympathetic potential from later migrating, nerve-associated Schwann cell precursors (SCPs). Interestingly, while melanogenic potential is shared by both early migrating NC and SCPs, differences in melanocyte identity resulting from differentiation through these temporally distinct progenitors have not been determined. Here, we leverage a human pluripotent stem cell (hPSC) model of NC temporal patterning to comprehensively characterize human NC heterogeneity, fate bias, and lineage development. We captured the transition of NC differentiation between temporally and transcriptionally distinct melanogenic progenitors and identified modules of candidate transcription factor and signaling activity associated with this transition. For the first time, we established a protocol for the directed differentiation of melanocytes from hPSCs through a SCP intermediate, termed trajectory 2 (T2) melanocytes. Leveraging an existing protocol for differentiating early NC-derived melanocytes, termed trajectory 1 (T1), we performed the first comprehensive comparison of transcriptional and functional differences between these distinct melanocyte populations, revealing differences in pigmentation and unique expression of transcription factors, ligands, receptors and surface markers. We found a significant link between the T2 melanocyte transcriptional signature and decreased survival in melanoma patients in the cancer genome atlas (TCGA). We performed an in vivo CRISPRi screen of T1 and T2 melanocyte signature genes in a human melanoma cell line and discovered several T2-specific markers that promote lung metastasis in mice. We further demonstrated that one of these factors, SNRPB, regulates the splicing of transcripts involved in metastasis relevant functions such as migration, cell adhesion and proliferation. Overall, this study identifies distinct developmental trajectories as a source of diversity in melanocytes and implicates the unique molecular signature of SCP-derived melanocytes in metastatic melanoma.

Single-cell analyses of axolotl telencephalon organization, neurogenesis, and regeneration

Salamanders are tetrapod models to study brain organization and regeneration; however, the identity and evolutionary conservation of brain cell types are largely unknown. We delineated the cell populations in the axolotl telencephalon during homeostasis and regeneration using single-cell genomic profiling. We identified glutamatergic neurons with similarities to amniote neurons of hippocampus, dorsal and lateral cortex, and conserved γ-aminobutyric acid-releasing (GABAergic) neuron classes. We inferred transcriptional dynamics and gene regulatory relationships of postembryonic, region-specific neurogenesis and unraveled conserved differentiation signatures. After brain injury, ependymoglia activate an injury-specific state before reestablishing lost neuron populations and axonal connections. Together, our analyses yield insights into the organization, evolution, and regeneration of a tetrapod nervous system.

Proteomic changes associated with predator-induced morphological defenses in oysters

Inducible prey defenses occur when organisms undergo plastic changes in phenotype to reduce predation risk. When predation pressure varies persistently over space or time, such as when predator and prey co-occur over only part of their biogeographic ranges, prey populations can become locally adapted in their inducible defenses. In California estuaries, native Olympia oyster (Ostrea lurida) populations have evolved disparate phenotypic responses to an invasive predator, the Atlantic oyster drill (Urosalpinx cinerea). In this study, oysters from an estuary with drills, and oysters from an estuary without drills, were reared for two generations in a laboratory common garden, and subsequently exposed to cues from Atlantic drills. Comparative proteomics was then used to investigate molecular mechanisms underlying conserved and divergent aspects of their inducible defenses. Both populations developed smaller, thicker, and harder shells after drill exposure, and these changes in shell phenotype were associated with up-regulation of calcium transport proteins that could influence biomineralization. Inducible defenses evolve in part because defended phenotypes incur fitness costs when predation risk is low. Immune proteins were down-regulated by both oyster populations after exposure to drills, implying a trade-off between biomineralization and immune function. Following drill exposure, oysters from the population that co-occurs with drills grew smaller shells than oysters inhabiting the estuary not yet invaded by the predator. Variation in the response to drills between populations was associated with isoform-specific protein expression. This trend suggests that a stronger inducible defense response evolved in oysters that co-occur with drills through modification of an existing mechanism.

Human melanocyte development and melanoma dedifferentiation at single-cell resolution

In humans, epidermal melanocytes are responsible for skin pigmentation, defence against ultraviolet radiation and the deadliest common skin cancer, melanoma. Although there is substantial overlap in melanocyte development pathways between different model organisms, species-dependent differences are frequent and the conservation of these processes in human skin remains unresolved. Here, we used a single-cell enrichment and RNA-sequencing pipeline to study human epidermal melanocytes directly from the skin, capturing transcriptomes across different anatomical sites, developmental age, sexes and multiple skin tones. We uncovered subpopulations of melanocytes that exhibit anatomical site-specific enrichment that occurs during gestation and persists through adulthood. The transcriptional signature of the volar-enriched subpopulation is retained in acral melanomas. Furthermore, we identified human melanocyte differentiation transcriptional programs that are distinct from gene signatures generated from model systems. Finally, we used these programs to define patterns of dedifferentiation that are predictive of melanoma prognosis and response to immune checkpoint inhibitor therapy.

Abstract 3112: Human melanocyte development and melanoma dedifferentiation at single cell resolution

In humans, epidermal melanocytes are responsible for skin pigmentation, defense against ultraviolet radiation, and the deadliest common skin cancer, melanoma. While there is substantial overlap in melanocyte development pathways between different model organisms, species dependent differences are frequent and the conservation of these processes in human skin remains unresolved. Thus, the biology of developing and adult human melanocytes remains largely uncharacterized. Here, we used a single-cell enrichment and RNA-sequencing pipeline to study human epidermal melanocytes derived directly from skin, capturing transcriptomes across different anatomic sites, developmental age, sexes, and multiple skin tones. Using donor-matched skin from distinct volar and non-volar anatomic locations, we uncovered subpopulations of melanocytes exhibiting site-specific enrichment that occurs during gestation and persists through adulthood. In addition, we identified human melanocyte differentiation transcriptional programs that are distinct from gene signatures generated from model systems. Finally, we use these programs to define patterns of dedifferentiation that are predictive of melanoma prognosis. Overall, the characterization of human melanocytes fresh from skin revealed new subpopulations, human-specific transcriptional programs, and valuable insights into melanoma dedifferentiation.

Citation Format: Rachel L. Belote, Daniel Le, Ashley Maynard, Ursula E. Lang, Adriane Sinclair, Vincente Planells-Palop, Laurence S. Baskin, Aaron D. Tward, Spyros Darmanis, Robert L. Judson-Torres. Human melanocyte development and melanoma dedifferentiation at single cell resolution [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3112.

Longitudinal characterisation of haematological and biochemical parameters in cancer patients prior to and during COVID-19 reveals features associated with outcome

BACKGROUND

Cancer patients are at increased risk of death from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Cancer and its treatment affect many haematological and biochemical parameters, therefore we analysed these prior to and during coronavirus disease 2019 (COVID-19) and correlated them with outcome.

PATIENTS AND METHODS

Consecutive patients with cancer testing positive for SARS-CoV-2 in centres throughout the United Kingdom were identified and entered into a database following local governance approval. Clinical and longitudinal laboratory data were extracted from patient records. Data were analysed using Mann-Whitney U test, Fisher's exact test, Wilcoxon signed rank test, logistic regression, or linear regression for outcomes. Hierarchical clustering of heatmaps was performed using Ward's method.

RESULTS

In total, 302 patients were included in three cohorts: Manchester (n = 67), Liverpool (n = 62), and UK (n = 173). In the entire cohort (N = 302), median age was 69 (range 19-93 years), including 163 males and 139 females; of these, 216 were diagnosed with a solid tumour and 86 with a haematological cancer. Preinfection lymphopaenia, neutropaenia and lactate dehydrogenase (LDH) were not associated with oxygen requirement (O2) or death. Lymphocyte count (P < 0.001), platelet count (P = 0.03), LDH (P < 0.0001) and albumin (P < 0.0001) significantly changed from preinfection to during infection. High rather than low neutrophils at day 0 (P = 0.007), higher maximal neutrophils during COVID-19 (P = 0.026) and higher neutrophil-to-lymphocyte ratio (NLR; P = 0.01) were associated with death. In multivariable analysis, age (P = 0.002), haematological cancer (P = 0.034), C-reactive protein (P = 0.004), NLR (P = 0.036) and albumin (P = 0.02) at day 0 were significant predictors of death. In the Manchester/Liverpool cohort 30 patients have restarted therapy following COVID-19, with no additional complications requiring readmission.

CONCLUSION

Preinfection biochemical/haematological parameters were not associated with worse outcome in cancer patients. Restarting treatment following COVID-19 was not associated with additional complications. Neutropaenia due to cancer/treatment is not associated with COVID-19 mortality. Cancer therapy, particularly in patients with solid tumours, need not be delayed or omitted due to concerns that treatment itself increases COVID-19 severity.

Ageing compromises mouse thymus function and remodels epithelial cell differentiation

Ageing is characterised by cellular senescence, leading to imbalanced tissue maintenance, cell death and compromised organ function. This is first observed in the thymus, the primary lymphoid organ that generates and selects T cells. However, the molecular and cellular mechanisms underpinning these ageing processes remain unclear. Here, we show that mouse ageing leads to less efficient T cell selection, decreased self-antigen representation and increased T cell receptor repertoire diversity. Using a combination of single-cell RNA-seq and lineage-tracing, we find that progenitor cells are the principal targets of ageing, whereas the function of individual mature thymic epithelial cells is compromised only modestly. Specifically, an early-life precursor cell population, retained in the mouse cortex postnatally, is virtually extinguished at puberty. Concomitantly, a medullary precursor cell quiesces, thereby impairing maintenance of the medullary epithelium. Thus, ageing disrupts thymic progenitor differentiation and impairs the core immunological functions of the thymus.

Transcriptomic responses to extreme low salinity among locally adapted populations of Olympia oyster (Ostrea lurida)

The Olympia oyster (Ostrea lurida) is a foundation species inhabiting estuaries along the North American west coast. In California estuaries, O. lurida is adapted to local salinity regimes and populations differ in low salinity tolerance. In this study, oysters from three California populations were reared for two generations in a laboratory common garden and subsequently exposed to low salinity seawater. Comparative transcriptomics was then used to understand species-level responses to hyposmotic stress and population-level mechanisms underlying divergent salinity tolerances. Gene expression patterns indicate Olympia oysters are sensitive to hyposmotic stress: All populations respond to low salinity by up-regulating transcripts indicative of protein unfolding, DNA damage and cell cycle arrest after sub-lethal exposure. Among O. lurida populations, transcriptomic profiles differed constitutively and in response to low salinity. Despite two generations in common-garden conditions, transcripts encoding apoptosis modulators were constitutively expressed at significantly different levels in the most tolerant population. Expression of cell death regulators may facilitate cell fate decisions when salinity declines. Following low salinity exposure, oysters from the more tolerant population expressed a small number of mRNAs at significantly higher levels than less tolerant populations. Proteins encoded by these transcripts regulate ciliary activity within the mantle cavity and may function to prolong valve closure and reduce mortality in low salinity seawater. Collectively, gene expression patterns suggest sub-lethal impacts of hyposmotic stress in Olympia oysters are considerable and that even oysters with greater low salinity tolerance may be vulnerable to future freshwater flooding events.

Single-cell transcriptomics of 20 mouse organs creates a Tabula Muris

Here we present a compendium of single-cell transcriptomic data from the model organism Mus musculus that comprises more than 100,000 cells from 20 organs and tissues. These data represent a new resource for cell biology, reveal gene expression in poorly characterized cell populations and enable the direct and controlled comparison of gene expression in cell types that are shared between tissues, such as T lymphocytes and endothelial cells from different anatomical locations. Two distinct technical approaches were used for most organs: one approach, microfluidic droplet-based 3'-end counting, enabled the survey of thousands of cells at relatively low coverage, whereas the other, full-length transcript analysis based on fluorescence-activated cell sorting, enabled the characterization of cell types with high sensitivity and coverage. The cumulative data provide the foundation for an atlas of transcriptomic cell biology.

Evolution and clinical impact of co-occurring genetic alterations in advanced-stage EGFR-mutant lung cancers

A widespread approach to modern cancer therapy is to identify a single oncogenic driver gene and target its mutant-protein product (for example, EGFR-inhibitor treatment in EGFR-mutant lung cancers). However, genetically driven resistance to targeted therapy limits patient survival. Through genomic analysis of 1,122 EGFR-mutant lung cancer cell-free DNA samples and whole-exome analysis of seven longitudinally collected tumor samples from a patient with EGFR-mutant lung cancer, we identified critical co-occurring oncogenic events present in most advanced-stage EGFR-mutant lung cancers. We defined new pathways limiting EGFR-inhibitor response, including WNT/β-catenin alterations and cell-cycle-gene (CDK4 and CDK6) mutations. Tumor genomic complexity increases with EGFR-inhibitor treatment, and co-occurring alterations in CTNNB1 and PIK3CA exhibit nonredundant functions that cooperatively promote tumor metastasis or limit EGFR-inhibitor response. This study calls for revisiting the prevailing single-gene driver-oncogene view and links clinical outcomes to co-occurring genetic alterations in patients with advanced-stage EGFR-mutant lung cancer.

Burdens and difficulties experienced by caregivers of children and adolescents with schizophrenia-spectrum disorders: a qualitative study

AIM

The purpose of this qualitative study was to investigate the burdens and difficulties associated with the experience of caring for youth with schizophrenia-spectrum disorders.

METHODS

Ten caregivers participated in a modified version of the Knowledge about Schizophrenia Illness interview.

RESULTS

The most common areas of general difficulties reported by caregivers were emotional burdens and the everyday practical demands and sacrifices required in caring for their dependents. RESULTS also suggested high levels of burden for caregivers concerning difficulties with mental health services.

CONCLUSION

Additional work is needed to learn more about the challenges that caregivers of youth with schizophrenia-spectrum disorders are facing, as well as to develop empirically based strategies for helping these caregivers and their dependents.

Inhalation vs. aspiration of single-walled carbon nanotubes in C57BL/6 mice: inflammation, fibrosis, oxidative stress, and mutagenesis

Nanomaterials are frontier technological products used in different manufactured goods. Because of their unique physicochemical, electrical, mechanical, and thermal properties, single-walled carbon nanotubes (SWCNT) are finding numerous applications in electronics, aerospace devices, computers, and chemical, polymer, and pharmaceutical industries. SWCNT are relatively recently discovered members of the carbon allotropes that are similar in structure to fullerenes and graphite. Previously, we (47) have reported that pharyngeal aspiration of purified SWCNT by C57BL/6 mice caused dose-dependent granulomatous pneumonia, oxidative stress, acute inflammatory/cytokine responses, fibrosis, and decrease in pulmonary function. To avoid potential artifactual effects due to instillation/agglomeration associated with SWCNT, we conducted inhalation exposures using stable and uniform SWCNT dispersions obtained by a newly developed aerosolization technique (2). The inhalation of nonpurified SWCNT (iron content of 17.7% by weight) at 5 mg/m(3), 5 h/day for 4 days was compared with pharyngeal aspiration of varying doses (5-20 microg per mouse) of the same SWCNT. The chain of pathological events in both exposure routes was realized through synergized interactions of early inflammatory response and oxidative stress culminating in the development of multifocal granulomatous pneumonia and interstitial fibrosis. SWCNT inhalation was more effective than aspiration in causing inflammatory response, oxidative stress, collagen deposition, and fibrosis as well as mutations of K-ras gene locus in the lung of C57BL/6 mice.

The economics of drug use and abuse

The markets for drugs such as cocaine are characterized by much ignorance about the nature of trading relationships, in particular the volumes and prices exhibited by overlapping national and international networks of buyers and sellers (i.e. markets), and by severe regulation by the State. The regulation of illegal markets is expensive; for example, in 1988 in the UK, over 5000 Customs officers and 1800 CID and uniformed policemen were involved in enforcing the law at a cost of about 140 million pounds. The size of the markets can be only 'guesstimated': in 1989 just over 520 kg of cocaine was seized. If this is assumed to be 10% of the market, the total size of the cocaine market was somewhere in excess of 5000 kg. The 'cost-effectiveness' of both Customs and the police in enforcing the law may have declined in the late 1980s. What economic arguments are there for sustaining illegality and an expensive enforcement effort? Some arguments for State regulation are explored; for example, the drug user harms 'innocent' third parties, the drug user is less productive and reduces national income, the drug user will impose costs on the National Health Service, the drug user's behaviour is offensive, and the drug user should be protected from his own stupidity. Where do these arguments leave the case for maintaining public policy towards illicit drugs? Would it be cost effective to move towards the liberalization of these markets?

Fine particle number and mass concentration measurements in urban Indian households

Fine particle number concentration (D(p)>10 nm, cm(-3)), mass concentrations (approximation of PM(2.5), microg m(-3)) and indoor/outdoor number concentration ratio (I/O) measurements have been conducted for the first time in 11 urban households in India, 2002. The results indicate remarkable high indoor number and mass concentrations and I/O number concentration ratios caused by cooking. Besides cooking stoves that used liquefied petroleum gas (LPG) or kerosene as the main fuel, high indoor concentrations can be explained by poor ventilation systems. Particle number concentrations of more than 300,000 cm(-3) and mass concentrations of more than 1000 microg m(-3) were detected in some cases. When the number and mass concentrations during cooking times were statistically compared, a correlation coefficient r>0.50 was observed in 63% of the households. Some households used other fuels like wood and dung cakes along with the main fuel, but also other living activities influenced the concentrations. In some areas, outdoor combustion processes had a negative impact on indoor air quality. The maximum concentrations observed in most cases were due to indoor combustion sources. Reduction of exposure risk and health effects caused by poor indoor air in urban Indian households is possible by improving indoor ventilation and reducing penetration of outdoor particles.

Thoracic size-selective sampling of fibres: performance of four types of thoracic sampler in laboratory tests

The counting of fibres on membrane filters could be facilitated by using size-selective samplers to exclude coarse particulate and fibres that impede fibre counting. Furthermore, the use of thoracic size selection would also remove the present requirement to discriminate fibres by diameter during counting. However, before thoracic samplers become acceptable for sampling fibres, their performance with fibres needs to be determined. This study examines the performance of four thoracic samplers: the GK2.69 cyclone, a Modified SIMPEDS cyclone, the CATHIA sampler (inertial separation) and the IOM thoracic sampler (porous foam pre-selector). The uniformity of sample deposit on the filter samples, which is important when counts are taken on random fields, was examined with two sizes of spherical particles (1 and 10 microm) and a glass fibre aerosol with fibres spanning the aerodynamic size range of the thoracic convention. Counts by optical microscopy examined fields on a set scanning pattern. Hotspots of deposition were detected for one of the thoracic samplers (Modified SIMPEDS with the 10 microm particles and the fibres). These hotspots were attributed to the inertial flow pattern near the port from the cyclone pre-separator. For the other three thoracic samplers, the distribution was similar to that on a cowled sampler, the current standard sampler for fibres. Aerodynamic selection was examined by comparing fibre concentration on thoracic samples with those measured on semi-isokinetic samples, using fibre size (and hence calculated aerodynamic diameter) and number data obtained by scanning electron microscope evaluation in four laboratories. The size-selection characteristics of three thoracic samplers (GK2.69, Modified SIMPEDS and CATHIA) appeared very similar to the thoracic convention; there was a slight oversampling (relative to the convention) for d(ae) < 7 microm, but that would not be disadvantageous for comparability with the cowled sampler. Only the IOM thoracic sampler tended to undersample the fibres relative to the thoracic convention. With the data divided into four classes based on fibre length, the size-selection characteristics appeared to be unaffected by fibre length for GK2.69, Modified SIMPEDS and CATHIA. Only the IOM thoracic sampler (with the foam selector) showed slightly lower selection for longer length classes of fibres. These results indicate that the tested samplers follow the thoracic sampling convention for fibres, and may be used to improve the quality and reliability of samples that are taken when there is likely to be significant background dust.

Cultural pathways through universal development

We focus our review on three universal tasks of human development: relationship formation, knowledge acquisition, and the balance between autonomy and relatedness at adolescence. We present evidence that each task can be addressed through two deeply different cultural pathways through development: the pathways of independence and interdependence. Whereas core theories in developmental psychology are universalistic in their intentions, they in fact presuppose the independent pathway of development. Because the independent pathway is therefore well-known in psychology, we focus a large part of our review on empirically documenting the alternative, interdependent pathway for each developmental task. We also present three theoretical approaches to culture and development: the ecocultural, the sociohistorical, and the cultural values approach. We argue that an understanding of cultural pathways through human development requires all three approaches. We review evidence linking values (cultural values approach), ecological conditions (ecocultural approach), and socialization practices (sociohistorical approach) to cultural pathways through universal developmental tasks.

Predicting within-family variability in juvenile height growth of Salix based upon similarity among parental AFLP fingerprints

Willow is being developed as a crop for biomass plantations in the Northeast and North-central United States, but has only recently been the subject of controlled breeding to generate improved genotypes. Maximizing variability among progeny within full-sib families produced by controlled pollination may increase the probability of producing willow clones exhibiting desirable extreme phenotypes. Yet, predicting combinations of parents yielding highly variable progeny is not currently possible. Controlled pollinations were completed among 15 Salix eriocephala clones and the resulting progeny were vegetatively propagated and planted in a greenhouse progeny test. Heights of rooted cuttings were measured after 4 months of growth. Genetic similarity among parents was estimated based on 77 polymorphic AFLP bands. Strong negative correlation ( r = -0.88) was detected between mean female-parent similarity indices and the standard deviation of height among half-sib progeny from those females. Parent combinations that had relatively low similarity indices tended to produce progeny that had greater variability in height. This negative relationship suggests that AFLP fingerprints of S. eriocephala parents may be useful for predicting parent combinations that will yield families with large variability.

Translating evidence into practice. The case of influenza vaccination

A problem common to all health care systems remains the translation of robust evidence into effective practice. Influenza vaccination has been reported to be an effective public health care intervention, but guidelines on coverage and subsequent uptake rates for vaccination across European countries vary substantially. One challenge therefore is to evaluate how effective different implementation mechanisms may be in improving overall vaccination rates for target populations across Europe.

Ethics and health care 'underfunding'

There are continual "crises" in health care systems worldwide as producer and patient groups unify and decry the "underfunding" of health care. Sometimes this cacophony is the self interest of profit seeking producers and often it is advocacy of unproven therapies. Such pressure is to be expected and needs careful management by explicit rationing criteria which determine who gets access to what health care. Science and rationality, however, are unfortunately, rarely the rules of conduct in the medical market-place. Key Words: Underfunding • rationing • efficiency • equity • accountability

Money or your life? The health-wealth trade-off in pharmaceutical regulation

For decades the development of pharmaceuticals has been regulated by safety, efficacy and quality rules for product registration. In public health care systems, these three 'hurdles' are increasingly being supplemented by a fourth: the mandatory requirement to demonstrate economic efficiency in order to obtain reimbursement. This requirement challenges the wealth creation ethic of industry (money) with the population health ethic of public health and health economics (your life). Despite practical and methodological obstacles to the use of economic evidence in decisions, the logic of this development is evident: in order to maximise improvements in population health, scarce resources must be targeted towards developing and applying technologies that deliver the greatest health gains per unit cost. The impact of this policy change on industry practice and profits will be considerable, and companies that fail to demonstrate the economic efficiency of their products will stumble at the fourth hurdle.

Workforce productivity and incentive structures in the UK National Health Service

The UK National Health Service (NHS) is a labour-intensive service, yet the productivity of one of the largest labour forces in the world has been relatively ignored over the last 50 years. The data available to measure productivity over time are limited and focus on inputs and activity, not outcome. However, what data there are indicate that, despite major increases in NHS funding and staffing, changes in technology and continuous reorganisation of structures, productivity tends to show little or no change over successive decades. The challenges to policy-makers are how to improve the measurement of productivity and how to alter the behaviour of hospital clinicians and general practitioners by reform of incentive structures in the UK NHS.

Health technology assessment in Europe. Improving clarity and performance

This paper discusses the challenges facing health technology assessment (HTA) in Europe, based on an explicit analysis of the characteristics of an "optimal" HTA system. It has three objectives: a) to elaborate an explicit system of policy goals and the characteristics of an optimal HTA system that facilitates the achievement of these goals; b) to identify the general institutional incentive barriers (government and market failures) that prevent the attainment of an optimal HTA system in Europe; and c) to argue that evaluation of the implications of health technologies for equity and inequality in health is an essential part of this optimal system and a considerable challenge for HTA decision makers, especially as national governments realign policy toward equity goals.

Disease management. A global cost-containing initiative?

Disease management has been marketed by healthcare industry providers as a way of improving resource allocation in healthcare and containing costs. However, to achieve improved efficiency in healthcare requires the guidelines and protocols in the disease management process to be based on sound evidence of effectiveness and cost effectiveness. This has not always been the case. The approach itself has an inadequate evidence base in terms of randomised controlled trials, other rigorous methods of evaluation and the results of economic evaluation. Disease management can be viewed as an attempt by pharmaceutical companies to undertake forward vertical integration into other parts of the healthcare process. This could reduce uncertainty for purchasers and reduce transaction costs, thereby potentially facilitating both healthcare expenditure control and efficiency. However, such cost savings may be outweighed by a concentration of power in disease management (pharmaceutical) companies, and the exploitation of such power to inflate expenditure and misallocate resources. Disease management must be appraised with care.

Ibuprofen versus other non-steroidal anti-inflammatory drugs: use in general practice and patient perception

OBJECTIVE

To investigate whether ibuprofen was as well-regarded by patients as other non-steroidal anti-inflammatory drugs (NSAIDs).

DESIGN

Questionnaire sent to 1137 consecutive recipients of an NSAID prescription from 21 doctors in six general practices with computerized records. Patient responses were subsequently linked to data held on the practice records.

SETTING

General practices in and around Nottingham, selected to reflect local variations in number of partners, list size, geographical location, deprivation, prescribing burden and prescribing rate.

SUBJECTS

Unselected patients receiving NSAIDs prescribed for all indications for use.

MAIN OUTCOME MEASURES

Effectiveness of ibuprofen and other NSAIDs, possible drug related adverse events, patients' overall satisfaction with ibuprofen and other NSAIDs, factors associated with choice of ibuprofen, drug costs of ibuprofen and other NSAIDs.

RESULTS

The main NSAIDs used were ibuprofen, diclofenac and naproxen. Ibuprofen use ranged from 1.0% of prescriptions in one practice to 69.1% in another. Although ibuprofen was generally prescribed in low doses, it was perceived by patients as being as effective as the other NSAIDs used, even after allowing for severity of the pre-treatment condition. Overall, 50.5% of patients rated their NSAID the best treatment they had received for their condition with no differences between individual drugs.

CONCLUSIONS

Ibuprofen is as highly regarded as other NSAIDs when used in similar circumstances. Switching patients to ibuprofen may be a realistic way of reducing financial and medical costs associated with NSAIDs.

Pharmacoepidemiology of non-steroidal anti-inflammatory drug use in Nottingham general practices

AIM

To investigate the pharmacoepidemiology of NSAID usage in Nottingham general practices.

DESIGN

Questionnaire sent to 1137 consecutive recipients of an NSAID prescription from 21 doctors in six general practices with computerized records. Patient responses were subsequently linked to data held on the practice records.

SETTING

General practices in and around Nottingham, selected to reflect local variations in number of partners, list size, geographical location, deprivation, prescribing burden and prescribing rate.

SUBJECTS

Unselected patients receiving NSAIDs prescribed for all indications.

MAIN OUTCOME MEASURES

Indication for treatment, differences in prescribing to different age groups, compliance and overall scheme drug exposure, drug effectiveness and tolerability, possible drug-related adverse events, patients' overall satisfaction with treatment and estimated costs of care.

RESULTS

NSAIDs were used for a wide range of conditions and only a small number of patients had rheumatoid arthritis. The main drugs used were ibuprofen, diclofenac and naproxen. Patients making short-term use of NSAIDs had low compliance if they experienced adverse drug effects, whilst conversely in long-term users, those with high compliance reported more adverse drug effects. Calculated compliance did not vary with age although older patients (over 65 years) claimed in their questionnaires to be more compliant than younger patients. Half the patients reported good or complete symptom relief. Half of those questions (and two thirds of those with good or complete symptom relief) rated their NSAID as the best treatment they had received for their current condition. The frequency of gastrointestinal adverse events was higher in the young and the old, which correlated with the use of anti-ulcer drugs, and increased with the total number of medications used.

CONCLUSIONS

NSAIDs are used for a wide-range of conditions. They give symptom relief to, and are perceived as effective by, most patients taking them.

Air movement visualization in the workplace: current methods and new approaches

Airflow visualization in the workplace to assess containment, ventilation, or general air movements is often carried out using smoke tracers. The most prevalent method uses a disposable smoke tube that generates a plume of concentrated sulfuric acid fume. However, use of the smoke tube exposes occupational hygienists to the risk of sulfuric acid exposure through inhalation or dermal contact, as well as injury from sharps. Following concern over the potential health hazard associated with smoke tube usage, alternative flow visualization methods and technologies have been reviewed. Methods of generating smoke or bubbles other than using smoke tubes suitable for visualizing air movements include heated element smoke generators, combustion generators, generation of metallic chlorides and ammonium chloride, generation of neutral density bubbles, and water fog generation. Some of these methods are applicable in specific workplace situations. However, there is no commercially available smoke or bubble generator currently available that matches the smoke tube for cost effectiveness, ease of use, and wide applicability, while also reducing the potential health risks associated with smoke tube usage. Despite this, certain technologies, in particular water/glycerol smoke generation using heated element generators, have the potential to be developed into viable alternatives to the smoke tube. Thus, with further development, an air movement visualization method that poses a significantly lower health hazard than the smoke tube is feasible.

Public opinion and rationing in the United Kingdom

In the United Kingdom and as in all other countries, health care professionals ration access to diagnosis and treatment. Throughout its history there has been a reluctance to acknowledge the existence, let alone the nature of rationing processes and public opinion about them. Several health policy reforms are discussed with reference to their approach to dealing with the scarcity of health care resources. Data taken form the 1998 Eurobarometer Survey are analysed to examine public opinion regarding rationing issues, such as funding for health care, the need to set limits in health coverage, the role of stakeholders in setting priorities, and the use of age, and other factors, as a criteria for setting priorities.

Rationing health care: an exploration

Rationing involves a failure to offer care, or the denial of care, from which patients would benefit. Rationing involves definition of efficiency (benefit) and equity (fairness) allocation criteria and a recognition of a trade-off between the two. However, accountability for rationing choices also requires careful governance of the agents of society, doctors, who judge the health needs of competing patients. An integrated rationing system requires management of patient access criteria, the knowledge base which informs practice and clinical practices.

Naturally occurring CCR5 extracellular and transmembrane domain variants affect HIV-1 Co-receptor and ligand binding function

Analysis of CCR5 variants in human immunodeficiency virus, type 1 (HIV-1), high risk cohorts led to the identification of multiple single amino acid substitutions in the amino-terminal third of the HIV-1 co-receptor CCR5 suggesting the possibility of protective and permissive genotypes; unfortunately, the low frequency of these mutations did not led to correlation with function. Therefore, we used analytical methods to assess the functional and structural significance of six of these variant receptors in vitro. These studies showed three categories of effects on CCR5 function. 1) Mutations in the first extracellular domain of CCR5 severely reduce specific ligand binding and chemokine-induced chemotaxis. 2) An extracellular domain variant, A29S, when co-expressed with CD4, supported HIV-1 infection whereas the others do not. 3) The transmembrane region variants of CCR5 support monotropic HIV-1 infection that is blocked by addition of some receptor agonists. Mutations in the first and second transmembrane domains increase RANTES (regulated on activation normal T-cell expressed) binding affinity but did not affect MIP1beta binding affinity presumably based on differences in ligand-receptor interaction sites. Furthermore, the CCR5 transmembrane mutants do not respond to RANTES with the classical bell-shaped chemotactic response curve, suggesting that they are resistant to RANTES-induced desensitization. These data demonstrate that single amino acid changes in the extracellular domains of CCR5 can have profound effects on both HIV-1 co-receptor and specific ligand-induced functions, whereas mutations in the transmembrane domain only affect the response to chemokine ligands.

Universal coverage and cost control: the United Kingdom National Health Service

The UK NHS has a number of important strengths. Its costs are relatively low compared to the health care systems of other developed countries due in part to cash limited central budgeting. It is extremely popular with the electorate and surveys show overall satisfaction with the NHS despite some dissatisfaction with waiting lists and a public perception of underfunding. The NHS model of general medical care provided by independent contractors has been acclaimed as "a British success" (General Medical Services Council, 1983). The role of the UK GP combines providing primary care and acting as a gatekeeper to secondary care. This increases equitable access to care for the population and assists in cost containment. As a model, it is currently being emulated in other countries including Sweden and US Health Maintenance Organizations but, as in these countries, the UK primary care model has been evaluated poorly. There are of course continuing weaknesses in the UK health care system. There is insufficient knowledge upon which to base health care services and increase efficiency. In the future, if a knowledge-based health care service is to be created, a considerable amount of research and evaluation is required to identify "what works" in health care (i.e., what is effective) and also the cost effective ways of altering provider behaviour to maximise the amount of health gain which can be achieved using a limited budget. The NHS reforms created a lot of enthusiasm and energy but its effects are difficult to disentangle from the simultaneous increases in funding. There is little evidence from the UK or elsewhere that competition in health care produces efficiency or improvements in resource allocation. Evaluation is required to identify which of the reforms are increasing efficiency. Competition needs to be used with caution and recognised as a mean and not an end in itself. It is remarkable how both clinical practice and health policy reform, in the UK and elsewhere, is poorly evaluated. Medical practice varies substantially locally, regionally, and internationally, e.g., patients with similar age and stage of cancer receive very different levels of radiotherapy across Europe. For most interventions, the appropriate level of treatment may be asserted but is not based on cost effectiveness knowledge. Health policy analysts, like clinicians, make assertions about competition and other health care reforms which are value- rather than knowledge-based. Both groups of decision-makers should be more cautious, informing their choices with research rather than relying on unsubstantiated optimism!

Synthesis and biological properties of novel pyridinioalkanoyl thiolesters (PATE) as anti-HIV-1 agents that target the viral nucleocapsid protein zinc fingers

Nucleocapsid p7 protein (NCp7) zinc finger domains of the human immunodeficiency virus type 1 (HIV-1) are being developed as antiviral targets due to their key roles in viral replication and their mutationally nonpermissive nature. On the basis of our experience with symmetrical disulfide benzamides (DIBAs; Rice et al. Science 1995, 270, 1194-1197), we synthesized and evaluated variants of these dimers, including sets of 4,4'- and 3,3'-disubstituted diphenyl sulfones and their monomeric benzisothiazolone derivatives (BITA). BITAs generally exhibited diminished antiviral potency when compared to their disulfide precursors. Novel, monomeric structures were created by linking haloalkanoyl groups to the benzamide ring through -NH-C(=O)- (amide) or -S-C(=O)- (thiolester) bridges. Amide-linked compounds generally lacked antiviral activity, while haloalkanoyl thiolesters and non-halogen-bearing analogues frequently exhibited acceptable antiviral potency, thus establishing thiolester benzamides per se as a new anti-HIV chemotype. Pyridinioalkanoyl thiolesters (PATEs) exhibited superior anti-HIV-1 activity with minimal cellular toxicity and appreciable water solubility. PATEs were shown to preferentially target the NCp7 Zn finger when tested against other molecular targets, thus identifying thiolester benzamides, and PATEs in particular, as novel NCp7 Zn finger inhibitors for in vivo studies.