Diagnostic yield from symptomatic lower gastrointestinal endoscopy in the UK: A British Society of Gastroenterology analysis using data from the National Endoscopy Database

BACKGROUND

The value of lower gastrointestinal endoscopy (LGIE; colonoscopy or sigmoidoscopy) relates to its ability to detect clinically relevant findings, predominantly cancers, preneoplastic polyps or inflammatory bowel disease. There are concerns that many LGIEs are performed on low-risk patients with limited benefit.

AIMS

To determine the diagnostic outcomes of LGIE for common symptoms.

METHODS

We performed a cross-sectional study of diagnostic LGIE between March 2019 and February 2020 using the UK National Endoscopy Database. We used mixed-effects logistic regression models, incorporating random (endoscopist) and fixed (symptoms, patient age, and sex) effects upon two dependent variables (large polyp [≥10 mm] and cancer diagnosis). Adjusted positive predictive values (aPPVs) were calculated.

RESULTS

We analysed 384,510 LGIEs; 33.2% were performed on patients aged under 50 and 53.6% on women. Regarding colonoscopies, the unadjusted PPV for cancer was 1.5% (95% CI: 1.4-1.5); higher for men than women (1.9% vs. 1.1%, p < 0.01). The PPV for large polyps was 3.2% (95% CI: 3.1-3.2). The highest colonoscopy cancer aPPVs were in the over 50s (1.9%) and in those with rectal bleeding (2.5%) or anaemia (2.1%). Cancer aPPVs for other symptoms were <1% despite representing 54.3% of activity. In patients under 50, aPPVs were 0.4% for cancer and 1.6% for large polyps. Results were similar for sigmoidoscopy.

CONCLUSIONS

Most colonoscopies were performed on patients with low-risk symptoms, where cancer risk was similar to the general population. Cancer and large polyp yield was highest in elderly patients with rectal bleeding or anaemia, although still fell short of FIT-based screening yields.

Current and projected number of years of life lost due to prostate cancer: A global study

BACKGROUND

Prostate cancer is an important cause of death worldwide. The number of years of life lost (YLL) due to prostate cancer is a metric of the toll of prostate cancer and using projections of demographic changes, can be used to measure future burden.

METHODS

Prostate cancer mortality data by country and world region was retrieved from the Global Cancer Observatory and the World Health Organization mortality data set, and life expectancy was from the United Nations Department of Economic and Social Affairs. We estimated YLL as the difference between age at death in people with prostate cancer and remaining life expectancy for people of the same age in the general population. We also estimated the age-standardized YLL rates per 100,000 males over 50 and the average annual percentage change in YLL rates over the period 2000-2019 and the number of YLL for the year 2040 by applying population projections to the 2020 YLL rates.

RESULTS

In 2020, 3.5 million person-years of life were lost due to prostate cancer in males over 50, and 40% of YLL were in those aged over 75. Age-standardized rates varied greatly between and within regions. Over the last two decades, rates of YLL have increased in many Asian and African countries while they have decreased in northern American and European countries. Globally, YLL are anticipated to double by 2040 to reach 7.5 million, with the greatest increases in Africa, Asia, and Latin America and the Caribbean.

CONCLUSION

There are wide variations in the burden of prostate cancer globally as measured by YLL. The burden of prostate cancer is projected to increase over time and appears to be highest in Sub-Saharan Africa, Eastern Europe, and Latin America and the Caribbean. It will be critical to plan and implement programs to reduce the burden of prostate cancer globally.

A systematic review and thematic synthesis of qualitative studies exploring GPs' and nurses' perspectives on discussing weight with patients with overweight and obesity in primary care

Guidelines and evidence suggest primary care clinicians should give opportunistic interventions to motivate weight loss, but these rarely occur in practice. We sought to examine why by systematically reviewing qualitative research examining general practitioners' ('GPs') and nurses' views of discussing weight with patients. We systematically searched English language publications (1945-2018) to identify qualitative interview and focus group studies. Thematic methods were used to synthesise the findings from these papers. We synthesised the studies by identifying second-order themes (explanations offered by the original researchers) and third-order constructs (new explanations which went beyond those in the original publications). Quality assessment using the Joanna Briggs checklist was undertaken. We identified 29 studies (>601 GPs, nurses and GP trainees) reporting views on discussing weight with patients. Key second-order themes were lack of confidence in treatments and patients' ability to make changes, stigma, interactional difficulty of discussing the topic and a belief of a wider societal responsibility needed to deal with patients with overweight and obesity. The third-order analytical theme was that discussions about weight were not a priority, and other behavioural interventions, including those relating to smoking, often took precedent. GPs and nurses reported that noting body mass index measurements at every consultation alongside a framework to deliver interventions would likely increase the frequency and perceived efficacy of behavioural weight interventions. GPs and nurses acknowledge the importance of obesity as a health issue, but this is insufficient, particularly amongst GPs, for them to construe this as a medical problem to address with patients in consultations. Strategies to implement clinical guidelines need to make tackling obesity a clinical priority. Training to overcome interactional difficulties, regular weighing of patients and changing expectations and understanding of weight loss interventions are also probably required.

Digital labour platforms in Pakistan: institutional voids and solidarity networks

Purpose

While digital labour platforms are being increasingly studied across the Global South, the existing literature does not conceptualise the theoretical link between such platforms and socio-economic development. This paper theorises such a link drawing on the notion of institutional voids defined, as in Khanna and Palepu (2010), as “the absence of intermediaries to efficiently connect buyers and sellers” in an economy. We frame digital labour platforms as means to fill institutional voids, seeking to create “development” in the form of earning opportunities in contexts of deprivation.

Design/methodology/approach

We draw on an interpretive case study of an online work training project in a deprived region of Pakistan, where members of marginalised communities were trained to become freelancers for global digital labour platforms. We use the notion of market-enabling institutions aimed at filling institutional voids as a lens to study the project's declared goals, examining the extent to which these were met in practice for the workers who participated in the training.

Findings

Our analysis reveals three types of market-enabling institutions–credibility enhancers, aggregators and distributors, and transaction facilitators–through which digital labour platforms seek to fill institutional voids. However, workers' narratives reveal that institutional voids are only partially filled by these platforms, and their perpetuation results in diverse forms of power asymmetries leveraged by clients and owners of the platforms. We also observe the formation of solidarity networks among workers, networks that are intra-familial and societal rather than characterised by formal unionisation.

Originality/value

The paper offers a novel perspective to theorise the link between digital labour and socio-economic development. Applying such a perspective in a Global South context, it also finds the limits of the digital platforms' institutional void-filling potential, highlighting the emergence of power asymmetries and the emerging formation of worker solidarity networks.

Electronic cigarettes as a smoking cessation aid for patients with cancer: beliefs and behaviours of clinicians in the UK

OBJECTIVES

To explore UK clinicians' beliefs and behaviours around recommending e-cigarettes as a smoking cessation aid for patients with cancer.

DESIGN

Cross-sectional online survey.

SETTING

England, Wales, Scotland and Northern Ireland.

PARTICIPANTS

Clinicians involved in the care of patients with cancer.

PRIMARY AND SECONDARY OUTCOMES

Behavioural Change Wheel capability, opportunity and motivation to perform a behaviour, knowledge, beliefs, current practice around e-cigarettes and other smoking cessation practices.

METHOD

Clinicians (n=506) completed an online survey to assess beliefs and behaviours around e-cigarettes and other smoking cessation practices for patients with cancer. Behavioural factors associated with recommending e-cigarettes in practice were assessed.

RESULTS

29% of clinicians would not recommend e-cigarettes to patients with cancer who continue to smoke. Factors associated with recommendation include smoking cessation knowledge (OR 1.56, 95% CI 1.01 to 2.44) and e-cigarette knowledge (OR 1.64, 95% CI 1.06 to 2.55), engagement with patients regarding smoking cessation (OR 2.12, 95% CI 1.12 to 4.03), belief in the effectiveness of e-cigarettes (OR 2.36 95% CI 1.61 to 3.47) and belief in sufficient evidence on e-cigarettes (OR 2.08 95% CI 1.10 to 4.00) and how comfortable they felt discussing e-cigarettes with patients (OR 1.57 95% CI 1.04 to 2.36).

CONCLUSION

Many clinicians providing cancer care to patients who smoke do not recommend e-cigarettes as a smoking cessation aid and were unaware of national guidance supporting recommendation of e-cigarettes as a smoking cessation aid.

Disparities in the excess risk of mortality in the first wave of COVID-19: Cross sectional study of the English sentinel network

OBJECTIVES

Few studies report contributors to the excess mortality in England during the first wave of coronavirus disease 2019 (COVID-19) infection. We report the absolute excess risk (AER) of mortality and excess mortality rate (EMR) from a nationally representative COVID-19 sentinel surveillance network including known COVID-19 risk factors in people aged 45 years and above.

METHODS

Pseudonymised, coded clinical data were uploaded from contributing primary care providers (N = 1,970,314, ≥45years). We calculated the AER in mortality by comparing mortality for weeks 2 to 20 this year with mortality data from the Office for National Statistics (ONS) from 2018 for the same weeks. We conducted univariate and multivariate analysis including preselected variables. We report AER and EMR, with 95% confidence intervals (95% CI).

RESULTS

The AER of mortality was 197.8/10,000 person years (95%CI:194.30-201.40). The EMR for male gender, compared with female, was 1.4 (95%CI:1.35-1.44, p<0.00); for our oldest age band (≥75 years) 10.09 (95%CI:9.46-10.75, p<0.00) compared to 45-64 year olds; Black ethnicity's EMR was 1.17 (95%CI: 1.03-1.33, p<0.02), reference white; and for dwellings with ≥9 occupants 8.01 (95%CI: 9.46-10.75, p<0.00). Presence of all included comorbidities significantly increased EMR. Ranked from lowest to highest these were: hypertension, chronic kidney disease, chronic respiratory and heart disease, and cancer or immunocompromised.

CONCLUSIONS

The absolute excess mortality was approximately 2 deaths per 100 person years in the first wave of COVID-19. More personalised shielding advice for any second wave should include ethnicity, comorbidity and household size as predictors of risk.

The Oxford Royal College of General Practitioners Clinical Informatics Digital Hub: Protocol to Develop Extended COVID-19 Surveillance and Trial Platforms

BACKGROUND

Routinely recorded primary care data have been used for many years by sentinel networks for surveillance. More recently, real world data have been used for a wider range of research projects to support rapid, inexpensive clinical trials. Because the partial national lockdown in the United Kingdom due to the coronavirus disease (COVID-19) pandemic has resulted in decreasing community disease incidence, much larger numbers of general practices are needed to deliver effective COVID-19 surveillance and contribute to in-pandemic clinical trials.

OBJECTIVE

The aim of this protocol is to describe the rapid design and development of the Oxford Royal College of General Practitioners Clinical Informatics Digital Hub (ORCHID) and its first two platforms. The Surveillance Platform will provide extended primary care surveillance, while the Trials Platform is a streamlined clinical trials platform that will be integrated into routine primary care practice.

METHODS

We will apply the FAIR (Findable, Accessible, Interoperable, and Reusable) metadata principles to a new, integrated digital health hub that will extract routinely collected general practice electronic health data for use in clinical trials and provide enhanced communicable disease surveillance. The hub will be findable through membership in Health Data Research UK and European metadata repositories. Accessibility through an online application system will provide access to study-ready data sets or developed custom data sets. Interoperability will be facilitated by fixed linkage to other key sources such as Hospital Episodes Statistics and the Office of National Statistics using pseudonymized data. All semantic descriptors (ie, ontologies) and code used for analysis will be made available to accelerate analyses. We will also make data available using common data models, starting with the US Food and Drug Administration Sentinel and Observational Medical Outcomes Partnership approaches, to facilitate international studies. The Surveillance Platform will provide access to data for health protection and promotion work as authorized through agreements between Oxford, the Royal College of General Practitioners, and Public Health England. All studies using the Trials Platform will go through appropriate ethical and other regulatory approval processes.

RESULTS

The hub will be a bottom-up, professionally led network that will provide benefits for member practices, our health service, and the population served. Data will only be used for SQUIRE (surveillance, quality improvement, research, and education) purposes. We have already received positive responses from practices, and the number of practices in the network has doubled to over 1150 since February 2020. COVID-19 surveillance has resulted in tripling of the number of virology sites to 293 (target 300), which has aided the collection of the largest ever weekly total of surveillance swabs in the United Kingdom as well as over 3000 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serology samples. Practices are recruiting to the PRINCIPLE (Platform Randomised trial of INterventions against COVID-19 In older PeopLE) trial, and these participants will be followed up through ORCHID. These initial outputs demonstrate the feasibility of ORCHID to provide an extended national digital health hub.

CONCLUSIONS

ORCHID will provide equitable and innovative use of big data through a professionally led national primary care network and the application of FAIR principles. The secure data hub will host routinely collected general practice data linked to other key health care repositories for clinical trials and support enhanced in situ surveillance without always requiring large volume data extracts. ORCHID will support rapid data extraction, analysis, and dissemination with the aim of improving future research and development in general practice to positively impact patient care.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/19773.

Indigena Solutions, Tensions in an Aboriginal IT Impact Sourcing Firm

This paper explores the role of cultural tensions in the operations of an Information Technology Impact Sourcing (ITIS) venture called Indigena Solutions. The company was based in Vancouver Canada and was intended to provide meaningful careers to a marginalized group, namely Canadian Indigenous Peoples. The company provided on-shore IT services such as help-desk support and software testing. With the support of Accenture and with initial success at high profile clients such as BC Hydro and Vancouver City Trust, the company lasted about seven years. Indigena was declared bankrupt in 2017. This research demonstrates the cultural tensions inherent in creating an Impact Sourcing venture, with challenges of location, the inability to attract Indigenous workers to a non-traditional career, and the underlying challenge of structural racism, despite the recognized social responsibility and commitment to help a marginalized group. The research was designed as a case study using an interpretive approach. The originality of this research rests on the exploration of why Impact Sourcing in a developed country failed to meet the needs of the marginalized Indigenous Peoples community. This research contributes to the body of work that explains tensions inherent in ITIS. Practitioners may find this research valuable as they consider the challenges of establishing and successfully operating an ITIS firm.

Low performance on mathematical tasks in preschoolers: the importance of domain-general and domain-specific abilities

BACKGROUND

Different domain-specific and domain-general cognitive precursors play a key role in the development of mathematical abilities. The contribution of these domains to mathematical ability changes during development. Primary school-aged children who show mathematical difficulties form a heterogeneous group, but it is not clear whether this also holds for preschool low achievers (LAs) and how domain-specific and domain-general abilities contribute to mathematical difficulties at a young age. The aim of this study was to explore the cognitive characteristics of a sample of preschool LAs and identify sub-types of LAs.

METHODS

81 children were identified as LAs from 283 preschoolers aged 3 to 5 years old and were assessed on a number of domain-general and domain-specific tasks.

RESULTS

Cluster analysis revealed four subgroups of LAs in mathematics: (1) a weak processing sub-type; (2) a general mathematical LAs sub-type; (3) a mixed abilities sub-type; and (4) a visuo-spatial deficit sub-type. Whilst two of the groups showed specific domain-general difficulties, none showed only domain-specific difficulties.

CONCLUSIONS

Current findings suggest that preschool LAs constitute a heterogeneous group and stress the importance of domain-general factors for the development of mathematical abilities during the preschool years.

Erratum to: Methods for evaluating medical tests and biomarkers

[This corrects the article DOI: 10.1186/s41512-016-0001-y.].

Pilot Trial of Intravenous Lipid Emulsion Treatment for Severe Nifedipine-Induced Shock

Animal studies and human case reports show promise in using lipid rescue to treat refractory calcium channel antagonist toxicity. However, the majority of research and clinical experience has focused on non-dihydropyridine agents. Thus, we sought to investigate the value of lipid emulsion (ILE) therapy for dihydropyridine-induced shock. This IACUC-approved study utilized seven swine that were sedated with alpha-chloralose, mechanically ventilated, and instrumented for drug delivery and hemodynamic measures. After stabilization and basal measures, nifedipine (0.01875 mg/kg/min) was infused until imminent cardiac arrest (seizure, end tidal CO2 < 10 mmHg, bradydysrhythmia, or pulseless electrical activity). Animals then received a 7 mL/kg bolus of 20% lipid emulsion via central catheter. Lipid circulation was visually confirmed by the presence of fat in peripheral arterial blood. Hemodynamics were continuously monitored until 10 min after lipid bolus. Surviving animals were euthanized. Pre- and post-lipid treatment parameters were analyzed using the Wilxocon signed rank test (p <0.05 significant). Nifedipine toxicity was characterized by vasodilatory hypotension, impaired vascular contractility, and tachycardia with terminal bradycardia. The median time to imminent cardiac arrest from start of nifedipine infusion was 218 min. Lipid treatment did not improve hemodynamics or restore circulation in any animal. There was no benefit from lipid rescue in this model of nifedipine toxicity. Further study of ILE for dihydropyridine toxicity is warranted but initial animal model results are not promising.

Differential evolution of peripheral cytokine levels in symptomatic and asymptomatic responses to experimental influenza virus challenge

Exposure to influenza virus triggers a complex cascade of events in the human host. In order to understand more clearly the evolution of this intricate response over time, human volunteers were inoculated with influenza A/Wisconsin/67/2005 (H3N2), and then had serial peripheral blood samples drawn and tested for the presence of 25 major human cytokines. Nine of 17 (53%) inoculated subjects developed symptomatic influenza infection. Individuals who will go on to become symptomatic demonstrate increased circulating levels of interleukin (IL)-6, IL-8, IL-15, monocyte chemotactic protein (MCP)-1 and interferon (IFN) gamma-induced protein (IP)-10 as early as 12-29 h post-inoculation (during the presymptomatic phase), whereas challenged patients who remain asymptomatic do not. Overall, the immunological pathways of leucocyte recruitment, Toll-like receptor (TLR)-signalling, innate anti-viral immunity and fever production are all over-represented in symptomatic individuals very early in disease, but are also dynamic and evolve continuously over time. Comparison with simultaneous peripheral blood genomics demonstrates that some inflammatory mediators (MCP-1, IP-10, IL-15) are being expressed actively in circulating cells, while others (IL-6, IL-8, IFN-α and IFN-γ) are probable effectors produced locally at the site of infection. Interestingly, asymptomatic exposed subjects are not quiescent either immunologically or genomically, but instead exhibit early and persistent down-regulation of important inflammatory mediators in the periphery. The host inflammatory response to influenza infection is variable but robust, and evolves over time. These results offer critical insight into pathways driving influenza-related symptomatology and offer the potential to contribute to early detection and differentiation of infected hosts.

Discovery of Therapeutic Deubiquitylase Effector Molecules

The approval of proteasome inhibitors bortezomib and carfilzomib and the E3 ligase antagonist thalidomide and its analogs, lenalidomide and pomalidomide, validates the ubiquitin–proteasome pathway as a source of novel drugs for treating cancer and, potentially, a variety of devastating illnesses, including inflammation, cardiovascular disease, and neurodegenerative disease. All elements of this critical regulatory pathway—the proteasome itself, E3 ligases (which conjugate ubiquitin to target proteins), and deubiquitylating enzymes (which deconjugate ubiquitin, reversing ligase action)—are potential therapeutic targets, and all have been worked on extensively during the past decade. No deubiquitylase inhibitors or activators have yet progressed to clinical trial, however, despite compelling target validation and several years of high-throughput screening and preclinical development of hits by numerous pharmaceutical companies, biotechnology organizations, and academic groups. The appropriateness of deubiquitylases as therapeutic targets in many disease areas is reviewed, followed by evidence that selective inhibitors of these cysteine proteases can be discovered. Because the lack of progress in drug-discovery efforts with deubiquitylases suggests a need for improved discovery methodologies, currently available platforms and strategies are analyzed, and improved or completely novel, unrelated approaches are considered in terms of their likelihood of producing clinically viable effectors of deubiquitylases.

Regulation of amino acid transport in the renal epithelial cell line NBL-1

The activities of the transport systems A, B° and XAG- are induced by various forms of stress in renal epithelial cells. Amino acid deprivation induces System A and XAG- in a protein-synthesis dependent process. In the case of System XAG- evidence is presented that induction of transport does not involve an increase in the amount of mRNA for the transporter or of the amount of transport protein. Preliminary evidence for the existence of a novel glycoprotein which is induced in parallel to the induction of these transport systems is presented. It is suggested that the induction of amino acid transport proteins and of some of the so-called stress proteins may be triggered by a common molecular mechanism.

Managing Knowledge Transfer in Offshore Software Development

The aim of this article is to examine the role of copresent interaction and the extent to which this can be supplanted by information and communication technology-based interaction for managing knowledge transferin distributed settings. This study draws on two case studies of small UK firms sourcing software development from India and Bangladesh. Using Nonaka and Konno’s knowledge creation theory, the role of copresent and ICT-based interactions in managing knowledge transfer is explained. The article contributes an extension of the concepts of knowledge creation theory by providing evidence of the role of copresent and ICT-based interaction for knowledge transfer in the context of offshore software development.

Profiling bladder cancer organ site-specific metastasis identifies LAMC2 as a novel biomarker of hematogenous dissemination

Little is known about which genes mediate metastasis in bladder cancer, which accounts for much of the mortality of this disease. We used human bladder cancer cell lines to develop models of two clinically common metastatic sites, lung and liver, and evaluated their gene expression with respect to human tumor tissues. Parental cells were injected into either the murine spleen to generate liver metastases or tail vein to generate lung metastases with sequential progeny derived by re-injection and comparisons made of their organ-specific nature by crossed-site injections. Both genomic and transcriptomic analyses of organ-selected cell lines found salient differences and shared core metastatic profiles, which were then screened against gene expression data from human tumors. The expression levels of laminin V gamma 2 (LAMC2) contained in the core metastatic signature were increased as a function of human tumor stage, and its genomic location was in an area of gain as measured by comparative genomic hybridization. Using immunohistochemistry in a human bladder cancer tissue microarray, LAMC2 expression levels were associated with tumor grade, but inversely with nodal status. In contrast, in node-negative patients, LAMC2 expression was associated with visceral metastatic recurrence. In summary, LAMC2 is a novel biomarker of bladder cancer metastasis that reflects the propensity of cells to metastasize via either lymphatic or hematogenous routes.

Sequence diversity of gap junction proteins

This paper summarizes our understanding of the molecular organization of gap junction proteins. There appear to be overall similarities in the organization of heart and liver junctions in terms of general domains, even though the molecular sizes of the two proteins are quite different. Sequence data on the amino-terminal regions of these two proteins show 43% of the residues to be identical and 25% more to be homologous. The major intrinsic protein of lens (MIP), believed by many to be the lens-fibre junction protein, does not show such sequence homology with the known portions of junction proteins from either heart or liver. Yet the sequence of MIP, which is completely known, suggests a conformation for this molecule quite compatible with a junctional role. It thus appears that molecules potentially involved in junction formation will prove to form a rather diverse family, with special characteristics of organ-specific molecules that may well be related to their function.

Small Firms and Offshore Software Outsourcing

It seems surprising that small firms engage in offshore outsourcing given that they lack the resources that large firms possess to overcome the difficulties involved. We examine these factors using transaction cost theory’s three stages: contact costs, contract costs, and control costs. Then, using our field data from small client firms (in the United States and the United Kingdom), intermediaries, and offshore vendors, we analyze the mitigation approaches that reduce transaction costs for small firms. We identify nine such approaches: three for client firms and six for suppliers. For the small client firm, they are liaisons of knowledge flows, gaining experience, and overcoming opportunism; and, for the service providers, they are onshore presence, reducing contact costs, simplifying contracting, providing control channels, expert intermediaries, and standardization of services.

Combination Antiangiogenic and Androgen Deprivation Therapy for Prostate Cancer

PURPOSE

Androgen ablation therapy leads to mild regression or stabilization of prostate cancer, followed by progression to the fatal androgen-independent state. Whereas androgen ablation diminishes tumor angiogenesis by suppressing vascular endothelial growth factor (VEGF) production, androgen-independent disease is marked by androgen-independent VEGF expression. We examined combined androgen ablation and inhibition of VEGF signaling in an androgen-sensitive human prostate cancer xenograft model (LNCaP) that is known to develop androgen-independent growth after androgen ablation.

EXPERIMENTAL DESIGN

N-(4-Bromo-2-fluorophenyl)-6-methoxy-7-[(1-methylpiperidin-4-yl)methoxy]quinazolin-4-amine (ZD6474) is an orally active inhibitor of VEGF receptor tyrosine kinase activity, with additional activity against epidermal growth factor receptor tyrosine kinase. ZD6474 (50 mg/kg/d, per os) was administered to groups of castrated and noncastrated athymic mice bearing established (4-616 mm3) LNCaP xenografts. To evaluate the extent of tumor regrowth after ZD6474, treatment was stopped after 40 days of continuous dosing, and subsequent tumor growth was monitored. Prostate-specific antigen expression was assessed to determine the effect of ZD6474 on androgen-regulated genes.

RESULTS

In comparison with orchiectomy, ZD6474 treatment produced greater tumor growth inhibition (P < 0.001), inducing complete cytostasis for the duration of dosing. An analysis of serum prostate-specific antigen concentration and tumor weight indicated that ZD6474 did not have a direct effect on androgen-related gene expression. Combination therapy (castration plus ZD6474) produced a comparable therapeutic effect to treatment with ZD6474 alone (in noncastrated mice), for the duration of ZD6474 administration. However, when ZD6474 treatment was discontinued, the rate of tumor regrowth was significantly less in the combination group. Tumors from mice receiving combined treatment were also found to be more necrotic than tumors from mice receiving either androgen ablation or ZD6474 alone.

CONCLUSIONS

These data indicate that inhibition of VEGF signaling produces a highly significant inhibition of tumor growth in a human androgen-dependent prostate tumor model, which far exceeds that produced by androgen ablation alone. However, when ZD6474 treatment is removed, concurrent androgen ablation produces a greater inhibition of tumor regrowth than is observed in mice without androgen ablation. Increased necrosis observed in tumors from orchiectomized mice receiving ZD6474 also suggests benefit from combining anti-androgen and anti-VEGF signaling approaches.

Angiogenesis and prostate cancer tumor growth

The initiation of new blood vessels through angiogenesis is critical to tumor growth. Tumor cells release soluble angiogenic factors that induce neovascularization, without which nutrients and oxygen would not be available to allow tumors to grow more than 2-3 mm in diameter. This "angiogenic switch" or angiogenic phenotype requires an imbalance between proangiogenic and antiangiogenic factors since the formation of new blood vessels is highly regulated. This review discusses angiogenesis mediators, and the potential for manipulation of angiogenic factors as a practical cancer therapy, particularly in prostate cancer.

Chromosomal instability is demonstrated by fibroblasts derived from the tunica of men with Peyronie's disease

Peyronie's disease is a fibrotic disorder, a condition characterized by cellular proliferation and excess extracellular matrix production. Previous work in related conditions has demonstrated chromosomal instability. This investigation was undertaken to analyze fibroblasts derived from Peyronie's disease tunical tissue for abnormalities of chromosome number and progression of cytogenetic aberrations during cell culture. Tunical tissue was excised from men with Peyronie's disease from both plaque and nonplaque tissue and cells were explanted in culture. Control cells were derived from both neonatal foreskins and normal tunica from men with congenital penile curvature. Fluorescent in situ hybridization was used to probe for chromosomes 7, 8, 17, 18, X and Y. Control cells demonstrated normal copy number for all chromosomes analyzed. In contrast, Peyronie's disease plaque-derived fibroblasts demonstrated frequent aneusomies in chromosomes 7, 8, 17, 18 and X and recurrent deletions of chromosome Y. Peyronie's disease nonplaque tunica-derived fibroblasts demonstrated infrequent chromosomal changes early in culture; however, with repeated passaging the majority of cell cultures demonstrated aneusomies in at least one chromosome. These data indicate that Peyronie's disease plaque-derived fibroblasts have consistent aneusomies even at early passage and that nonplaque tunica-derived cells from men with Peyronie's disease also demonstrate chromosomal instability. This suggests that the tunica albuginea of men with Peyronie's disease may be predisposed to undergoing unregulated fibrosis. These findings confirm the transformed nature of the Peyronie's disease tunical fibroblasts studied in this analysis. While the etiology of these findings is not clear, it is likely that these pathobiological characteristics contribute to the pathophysiology of this disease process.

Evaluation of an osteoporosis self-referral program to enhance management outcomes

Osteoporosis is a common but undertreated condition. While bone density is known to predict fracture risk, there is currently no economical way of measuring general population risk. This study examined whether an economical screening technique could improve diagnosis and lead to appropriate outcomes in the management of osteoporosis. A self-referral program was established to provide women with information about osteoporosis and an individualized risk assignment. A high-risk designation was provided for postmenopausal women below the lower tertile of a calcaneal broadband ultrasound attenuation (BUA) (< or = 58 db/MHz) or those with a SCORE value > or = 6. A telephone survey was conducted 6 mo after program registration to evaluate osteoporosis management outcomes. Of 271 women surveyed, 181 (67%) were postmenopausal and thus potential candidates for estrogen replacement, and 21% and 63% were assigned a high-risk profile by either calcaneal ultrasound or SCORE, respectively. Women at higher risk were significantly more likely to discuss osteoporosis with their family physician (p < 0.001), and to undergo further testing with dual X-ray absorptiometry measurement (p < 0.005). Utilization of estrogen replacement by postmenopausal women at time of survey was significantly increased compared to registration (p = 0.01). The self-referral program positively impacted decisions women made about preventing osteoporosis, particularly if they considered themselves at higher risk.

Molecular therapeutics in prostate cancer

The purpose of this review is to provide information on the molecular basis of prostate cancer biology and to identify some of the targets for therapy, and highlight some potential strategies for molecular treatment. Here we give a synopsis of what we have learned regarding molecular biology of cancer in general and the directions research might take in the future in order to impact prostate cancer specifically. This work is certainly not encyclopedic in nature and we apologize in advance to colleagues whose work we were no able to include. Hope lies in learning to utilize some of these molecular workings for better prevention, diagnosis, and treatment of the most common solid organ cancer in men. Prostate cancer is a formidable disease and at current rates of diagnosis will affect one-in-six men living in the United States (Greenlee et al., 2000) Many of these men are diagnosed at an early stage of the disease and can be effectively treated by surgery or radiation. However, a significant fraction of men are diagnosed with later stage disease or progress despite early curative therapeutic attempts. Unfortunately, many of these men succumb to prostate cancer, as management options are limited and not always successful. Through an understanding of the molecular processes that occur in the development and progression of prostate cancer, novel therapies will arise that will provide longer survival, better quality of life, and a chance for cure in men afflicted with this disease.

Angiogenesis in prostate cancer: biology and therapeutic opportunities

Tumor growth is limited in size without the incorporation of new blood vessels. Tumor cells release soluble factors (angiogenic factors) that induce neovascularization and allow subsequent growth beyond 2-3 mm in diameter meeting the need for cellular uptake of oxygen and nutrients. This process is referred to as the 'angiogenic switch' and indicates the acquisition of an angiogenic phenotype. Tumor angiogenesis requires an imbalance between proangiogenic and antiangiogenic factors with formation of new vessels being a highly regulated process. In this review we discuss the mediators of angiogenesis, the strategies for manipulating angiogenic factors, and possible therapeutic applications with a special emphasis on prostate cancer.

Transgenic Polyoma middle-T mice model premalignant mammary disease

Mice transgenic for the Polyomavirus middle T (PyV-mT) gene have been widely used to study mammary tumorigenesis and metastasis. Although numerous molecular insights were gained from the analysis of these transgenic malignant tumors, the early events leading to malignant transformation have not been systematically investigated nor has the biological potential of hyperplastic lesions been documented. This paper presents the first comprehensive histopathological characterization of transgenic PyV-mT hyperplasias together with classical transplantation experiments designed to test the growth potential of these lesions. Moreover, stable hyperplastic outgrowth lines were established as a tool to study premalignant PyV-mT-induced hyperplasias in detail. Each line has a different tumor latency, indicating that PyV-mT-induced hyperplasias, like early proliferative lesions seen in the human breast, are heterogeneous with respect to their malignant potential. Our results settle a controversy; they establish that PyV-mT gene expression alone is insufficient to induce tumors and that additional events are required for tumorigenesis and metastasis. These results support the use of PyV-mT transgenic mice as a model for investigating the multistep progression of malignant mammary tumorigenesis and metastasis.

Pheromones cause disease: pheromone/odourant transduction

This paper compares two models of the sense of smell and demonstrates that the new model has advantages over the accepted model with implications for medical research. The accepted transduction model had an odourant or pheromone contacting an aqueous sensory lymph then movement through it to a receptor membrane beneath. If the odourant or pheromone were non-soluble, the odourant/pheromone supposedly would be bound to a soluble protein in the lymph to be carried across. Thus, an odourant/carrier protein complex physically moved through the receptor lymph/mucus to interact with a membrane bound receptor. After the membranous receptor interaction, the molecule would be deactivated and any odourant/pheromone-binding protein recycled. This new electrical chemosensory model being proposed here has the pheromone or other odourant generating an electrical event in the extra-cellular mucus. Before the pheromone arrives, proteins of the 'carrier class' dissolved in the receptor mucus slowly and continuously sequester ions. A sensed pheromonal chemical species sorbs to the mucus and immediately binds to the now ion-holding dissolved protein. The binding of the pheromone to the protein causes a measurable conformational change in the pheromone/odourant-binding protein, desequestering ions. Releasing the bound ions changes the potential differences across a nearby super-sensitive dendritic membrane resulting in dendrite excitation. Pheromones will be implicated in the aetiology of the infectious, psychiatric and autoimmune diseases. This is the third article in a series of twelve to systematically explore this contention (see references 1-9).

Lipopolysaccharide-induced apoptosis of macrophages determines the up-regulation of concentrative nucleoside transporters Cnt1 and Cnt2 through tumor necrosis factor-alpha-dependent and -independent mechanisms

In murine bone marrow macrophages, lipopolysaccharide (LPS) induces apoptosis through the autocrine production of tumor necrosis factor-alpha (TNF-alpha), as demonstrated by the fact that macrophages from TNF-alpha receptor I knock-out mice did not undergo early apoptosis. In these conditions LPS up-regulated the two concentrative high affinity nucleoside transporters here shown to be expressed in murine bone marrow macrophages, concentrative nucleoside transporter (CNT) 1 and 2, in a rapid manner that is nevertheless consistent with the de novo synthesis of carrier proteins. This effect was not dependent on the presence of macrophage colony-stimulating factor, although LPS blocked the macrophage colony-stimulating factor-mediated up-regulation of the equilibrative nucleoside transport system es. TNF-alpha mimicked the regulatory response of nucleoside transporters triggered by LPS, but macrophages isolated from TNF-alpha receptor I knock-out mice similarly up-regulated nucleoside transport after LPS treatment. Although NO is produced by macrophages after LPS treatment, NO is not involved in these regulatory responses because LPS up-regulated CNT1 and CNT2 transport activity and expression in macrophages from inducible nitric oxide synthase and cationic amino acid transporter (CAT) 2 knock-out mice, both of which lack inducible nitric oxide synthesis. These data indicate that the early proapoptotic responses of macrophages, involving the up-regulation of CNT transporters, follow redundant regulatory pathways in which TNF-alpha-dependent- and -independent mechanisms are involved. These observations also support a role for CNT transporters in determining extracellular nucleoside availability and modulating macrophage apoptosis.

Sustained nitric oxide production in macrophages requires the arginine transporter CAT2

The aberrant production of nitric oxide (NO) contributes to the pathogenesis of diseases as diverse as cancer and arthritis. Sustained NO production via the inducible enzyme, nitric-oxide synthase 2 (NOS2), requires extracellular arginine uptake. Three closely related cationic amino acid transporter genes (Cat1-3) encode the transporters that mediate most arginine uptake in mammalian cells. Because CAT2 is induced coordinately with NOS2 in numerous cell types, we investigated a possible role for CAT2-mediated arginine transport in regulating NO production. The complexity of arginine transport systems and their biochemically similar transport properties called for a genetic approach to determine the role of CAT2. CAT2-deficient mice were generated and found to be healthy and fertile in contrast to Cat1(-/-) animals. Analysis of cytokine-activated macrophages from Cat2(-/-) mice revealed a 92% reduction in NO production and a 95% reduction in l-Arg uptake. The reduction in NO production was not due to differences in NOS2 protein expression, NOS2 activity, or intracellular l-arginine content. In conclusion, our results show that sustained abundant NO synthesis by macrophages requires arginine transport via the CAT2 transporter.

Ozonation of NOM and algal toxins in four treated waters

The occurrence of cyanobacteria (blue-green algae) blooms and the possibility of production of cyanotoxins (algal toxins) have become major concerns for drinking water providers worldwide. Ozone has been shown to be effective for the destruction of some classes of toxins under specific conditions, although most researchers agree that the dose and contact time required will depend on water quality. The clarification of the relative effects of water quality parameters such as dissolved organic carbon concentration and character, and alkalinity, has not been previously attempted. In this study the cyanotoxins microcystin LR and LA and anatoxin-a were ozonated at a range of ozone doses in four treated waters with very different water quality. For both the toxins, 100% destruction was related to a residual ozone concentration present after 5 min. This was, in turn, related to the water quality and indicated that a direct reaction with molecular ozone could be responsible for the destruction. The results confirmed that both the toxins would be destroyed under conditions usually utilised for ozonation prior to granular activated carbon (GAC) filtration. This will apply under a range of water quality conditions but not necessarily a range of temperatures. The saxitoxin class of compounds was very resistant to oxidation by ozone and would require further treatment such as GAC filtration.

Taxonomy of pain

Research on the pathophysiology of chronic pain has begun to challenge the traditional diagnostic and treatment paradigms for the patient with neuropathic pain. The heterogeneous nature of neuropathic pain indicates that more than one anatomic lesion is most likely responsible for the clinical presentation of a particular syndrome. Numerous pharmacologic agents that have shown improved efficacy in the treatment of neuropathic pain have been developed over the past decade. For the practicing clinician, an important concern is whether the current paradigm for classification of neuropathic pain syndromes is comprehensive enough to address this rapidly expanding body of knowledge.

Gabapentin use in neuropathic pain syndromes

The development of neuropathic pain involves a series of changes including primary and secondary hyperalgesia, peripheral and central sensitization, and wind-up phenomena. Neurotransmitters play a critical role in this process. For example, glutaminergic subtypes of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) and neurokinin prime the N-methyl-D-aspartate (NMDA) receptor by triggering the release of intracellular calcium ions, thus unblocking the magnesium ion plug on the NMDA receptor and allowing Ca2+ influx into the cell. Ca2+ ions acting as secondary messengers initiate protein kinase C activation, phospholipase C and nitric oxide synthetase production, and proto-oncogene expression. The activation of the NMDA receptor thereby increases the responsiveness of the nociceptive system. Anticonvulsant drugs--including carbamazepine, phenytoin, and felbamate--have been used to treat neuropathic pain. Gabapentin is a novel anticonvulsant that may have a unique effect on voltage-dependent Ca2+ channel currents at postsynaptic dorsal horn neurons. Thus, gabapentin may interrupt an entire series of events, not just a single process, that lead to the development of neuropathic pain. Preclinical models of anti-inflammatory and neuropathic pain indicate that gabapentin effectively antagonizes the maintenance of this pain. Additionally, in preemptive surgical models, gabapentin has been shown to prevent the induction of pain. Gabapentin has been shown to be efficacious in numerous smaller clinical studies, case reports, and chart reviews in a variety of neuropathic pain syndromes. Two large multicenter studies, one in postherpetic neuralgia (PHN) and one in diabetic peripheral neuropathy (DPN), support preclinical findings. In the PHN study, patients treated with gabapentin demonstrated a significant difference (P<0.001) in their average daily pain score at endpoint compared to placebo patients. In the DPN trial, mean weekly pain was significantly (P<0.001) different for gabapentin-treated patients compared to placebo-treated patients at endpoint. Consistent with the known side-effect profile of gabapentin, the most common adverse events noted in both studies were dizziness and somnolence. Gabapentin should be considered an important addition to the management of neuropathic pain syndromes.