Driving delivery and uptake of catch-up vaccination among adolescent and adult migrants in UK general practice: a mixed methods pilot study

BACKGROUND

Migrants in the UK and Europe face vulnerability to vaccine-preventable diseases (VPDs) due to missed childhood vaccines and doses and marginalisation from health systems. Ensuring migrants receive catch-up vaccinations, including MMR, Td/IPV, MenACWY, and HPV, is essential to align them with UK and European vaccination schedules and ultimately reduce morbidity and mortality. However, recent evidence highlights poor awareness and implementation of catch-up vaccination guidelines by UK primary care staff, requiring novel approaches to strengthen the primary care pathway.

METHODS

The 'Vacc on Track' study (May 2021-September 2022) aimed to measure under-vaccination rates among migrants in UK primary care and establish new referral pathways for catch-up vaccination. Participants included migrants aged 16 or older, born outside of Western Europe, North America, Australia, or New Zealand, in two London boroughs. Quantitative data on vaccination history, referral, uptake, and sociodemographic factors were collected, with practice nurses prompted to deliver catch-up vaccinations following UK guidelines. Focus group discussions and in-depth interviews with staff and migrants explored views on delivering catch-up vaccination, including barriers, facilitators, and opportunities. Data were analysed using STATA12 and NVivo 12.

RESULTS

Results from 57 migrants presenting to study sites from 18 countries (mean age 41 [SD 7.2] years; 62% female; mean 11.3 [SD 9.1] years in UK) over a minimum of 6 months of follow-up revealed significant catch-up vaccination needs, particularly for MMR (49 [86%] required catch-up vaccination) and Td/IPV (50 [88%]). Fifty-three (93%) participants were referred for any catch-up vaccination, but completion of courses was low (6 [12%] for Td/IPV and 33 [64%] for MMR), suggesting individual and systemic barriers. Qualitative in-depth interviews (n = 39) with adult migrants highlighted the lack of systems currently in place in the UK to offer catch-up vaccination to migrants on arrival and the need for health-care provider skills and knowledge of catch-up vaccination to be improved. Focus group discussions and interviews with practice staff (n = 32) identified limited appointment/follow-up time, staff knowledge gaps, inadequate engagement routes, and low incentivisation as challenges that will need to be addressed. However, they underscored the potential of staff champions, trust-building mechanisms, and community-based approaches to strengthen catch-up vaccination uptake among migrants.

CONCLUSIONS

Given the significant catch-up vaccination needs of migrants in our sample, and the current barriers to driving uptake identified, our findings suggest it will be important to explore this public health issue further, potentially through a larger study or trial. Strengthening existing pathways, staff capacity and knowledge in primary care, alongside implementing new strategies centred on cultural competence and building trust with migrant communities will be important focus areas.

Defining drivers of under-immunization and vaccine hesitancy in refugee and migrant populations

BACKGROUND/OBJECTIVE

Some refugee and migrant populations globally showed lower uptake of COVID-19 vaccines and are also considered to be an under-immunized group for routine vaccinations. These communities may experience a range of barriers to vaccination systems, yet there is a need to better explore drivers of under-immunization and vaccine hesitancy in these mobile groups.

METHODS

We did a global rapid review to explore drivers of under-immunization and vaccine hesitancy to define strategies to strengthen both COVID-19 and routine vaccination uptake, searching MEDLINE, Embase, Global Health PsycINFO and grey literature. Qualitative data were analysed thematically to identify drivers of under-immunization and vaccine hesitancy, and then categorized using the 'Increasing Vaccination Model'.

RESULTS

Sixty-three papers were included, reporting data on diverse population groups, including refugees, asylum seekers, labour migrants and undocumented migrants in 22 countries. Drivers of under-immunization and vaccine hesitancy pertaining to a wide range of vaccines were covered, including COVID-19 (n = 27), human papillomavirus (13), measles or Measles-mumps-rubella (MMR) (3), influenza (3), tetanus (1) and vaccination in general. We found a range of factors driving under-immunization and hesitancy in refugee and migrant groups, including unique awareness and access factors that need to be better considered in policy and service delivery. Acceptability of vaccination was often deeply rooted in social and historical context and influenced by personal risk perception.

CONCLUSIONS

These findings hold direct relevance to current efforts to ensure high levels of global coverage for a range of vaccines and to ensure that marginalized refugee and migrant populations are included in the national vaccination plans of low-, middle- and high-income countries. We found a stark lack of research from low- and middle-income and humanitarian contexts on vaccination in mobile groups. This needs to be urgently rectified if we are to design and deliver effective programmes that ensure high coverage for COVID-19 and routine vaccinations.

Computational decision-support tools for urban design to improve resilience against COVID-19 and other infectious diseases: A systematic review

The COVID-19 pandemic highlighted the need for decision-support tools to help cities become more resilient to infectious diseases. Through urban design and planning, non-pharmaceutical interventions can be enabled, impelling behaviour change and facilitating the construction of lower risk buildings and public spaces. Computational tools, including computer simulation, statistical models, and artificial intelligence, have been used to support responses to the current pandemic as well as to the spread of previous infectious diseases. Our multidisciplinary research group systematically reviewed state-of-the-art literature to propose a toolkit that employs computational modelling for various interventions and urban design processes. We selected 109 out of 8,737 studies retrieved from databases and analysed them based on the pathogen type, transmission mode and phase, design intervention and process, as well as modelling methodology (method, goal, motivation, focus, and indication to urban design). We also explored the relationship between infectious disease and urban design, as well as computational modelling support, including specific models and parameters. The proposed toolkit will help designers, planners, and computer modellers to select relevant approaches for evaluating design decisions depending on the target disease, geographic context, design stages, and spatial and temporal scales. The findings herein can be regarded as stand-alone tools, particularly for fighting against COVID-19, or be incorporated into broader frameworks to help cities become more resilient to future disasters.

Code-Sharing in Cost-of-Illness Calculations: An Application to Antibiotic-Resistant Bloodstream Infections

Background: More data-driven evidence is needed on the cost of antibiotic resistance. Both Japan and England have large surveillance and administrative datasets. Code sharing of costing models enables reduced duplication of effort in research.

Objective: To estimate the burden of antibiotic-resistant Staphylococcus aureus bloodstream infections (BSIs) in Japan, utilizing code that was written to estimate the hospital burden of antibiotic-resistant Escherichia coli BSIs in England. Additionally, the process in which the code-sharing and application was performed is detailed, to aid future such use of code-sharing in health economics.

Methods: National administrative data sources were linked with voluntary surveillance data within the Japan case study. R software code, which created multistate models to estimate the excess length of stay associated with different exposures of interest, was adapted from previous use and run on this dataset. Unit costs were applied to estimate healthcare system burden in 2017 international dollars (I$).

Results: Clear supporting documentation alongside open-access code, licensing, and formal communication channels, helped the re-application of costing code from the English setting within the Japanese setting. From the Japanese healthcare system perspective, it was estimated that there was an excess cost of I$6,392 per S. aureus BSI, whilst oxacillin resistance was associated with an additional I$8,155.

Conclusions:S. aureus resistance profiles other than methicillin may substantially impact hospital costs. The sharing of costing models within the field of antibiotic resistance is a feasible way to increase burden evidence efficiently, allowing for decision makers (with appropriate data available) to gain rapid cost-of-illness estimates.

A multilevel neo-institutional analysis of infection prevention and control in English hospitals: coerced safety culture change?

Despite committed policy, regulative and professional efforts on healthcare safety, little is known about how such macro-interventions permeate organisations and shape culture over time. Informed by neo-institutional theory, we examined how inter-organisational influences shaped safety practices and inter-subjective meanings following efforts for coerced culture change. We traced macro-influences from 2000 to 2015 in infection prevention and control (IPC). Safety perceptions and meanings were inductively analysed from 130 in-depth qualitative interviews with senior- and middle-level managers from 30 English hospitals. A total of 869 institutional interventions were identified; 69% had a regulative component. In this context of forced implementation of safety practices, staff experienced inherent tensions concerning the scope of safety, their ability to be open and prioritisation of external mandates over local need. These tensions stemmed from conflicts among three co-existing institutional logics prevalent in the NHS. In response to requests for change, staff flexibly drew from a repertoire of cognitive, material and symbolic resources within and outside their organisations. They crafted 'strategies of action', guided by a situated assessment of first-hand practice experiences complementing collective evaluations of interventions such as 'pragmatic', 'sensible' and also 'legitimate'. Macro-institutional forces exerted influence either directly on individuals or indirectly by enriching the organisational cultural repertoire.

Articulating citizen participation in national anti-microbial resistance plans: a comparison of European countries

Background

National action plans determine country responses to anti-microbial resistance (AMR). These plans include interventions aimed at citizens. As the language used in documents could persuade certain behaviours, we sought to assess the positioning and implied responsibilities of citizens in current European AMR plans. This understanding could lead to improved policies and interventions.

Methods

Review and comparison of national action plans for AMR (NAP-AMR) obtained from the European Centre for Disease Prevention and Control (plans from 28 European Union and four European Economic Area/European Free Trade Association countries), supplemented by European experts (June-September 2016). To capture geographical diversity, 11 countries were purposively sampled for content and discourse analyses using frameworks of lay participation in healthcare organization, delivery and decision-making.

Results

Countries were at different stages of NAP-AMR development (60% completed, 25% in-process, 9% no plan). The volume allocated to citizen roles in the plans ranged from 0.3 to 18%. The term 'citizen' was used by three countries, trailing behind 'patients' and 'public' (9/11), 'general population' (6/11) and 'consumers' (6/11). Increased citizen awareness about AMR was pursued by ∼2/3 plans. Supporting interventions included awareness campaigns (11/11), training/education (7/11) or materials during clinical encounters (4/11). Prevention of infection transmission or self-care behaviours were much less emphasized. Personal/individual and social/collective role perspectives seemed more frequently stimulated in Nordic countries.

Conclusion

Citizen roles in AMR plans are not fully articulated. Documents could employ direct language to emphasise social or collective responsibilities in optimal antibiotic use.

Comparison of national strategies to reduce meticillin-resistant Staphylococcus aureus infections in Japan and England

BACKGROUND

National responses to healthcare-associated infections vary between high-income countries, but, when analysed for contextual comparability, interventions can be assessed for transferability.

AIM

To identify learning from country-level approaches to addressing meticillin-resistant Staphylococcus aureus (MRSA) in Japan and England.

METHODS

A longitudinal analysis (2000-2017), comparing epidemiological trends and policy interventions. Data from 441 textual sources concerning infection prevention and control (IPC), surveillance, and antimicrobial stewardship interventions were systematically coded for: (a) type: mandatory requirements, recommendations, or national campaigns; (b) method: restrictive, persuasive, structural in nature; (c) level of implementation: macro (national), meso (organizational), micro (individual) levels. Healthcare organizational structures and role of media were also assessed.

FINDINGS

In England significant reduction has been achieved in number of reported MRSA bloodstream infections. In Japan, in spite of reductions, MRSA remains a predominant infection. Both countries face new threats in the emergence of drug-resistant Escherichia coli. England has focused on national mandatory and structural interventions, supported by a combination of outcomes-based incentives and punitive mechanisms, and multi-disciplinary IPC hospital teams. Japan has focused on (non-mandatory) recommendations and primarily persuasive interventions, supported by process-based incentives, with voluntary surveillance. Areas for development in Japan include resourcing of dedicated data management support and implementation of national campaigns for healthcare professionals and the public.

CONCLUSION

Policy interventions need to be relevant to local epidemiological trends, while acceptable within the health system, culture, and public expectations. Cross-national learning can help inform the right mix of interventions to create sustainable and resilient systems for future infection and economic challenges.

Capacity of English NHS hospitals to monitor quality in infection prevention and control using a new European framework: a multilevel qualitative analysis

OBJECTIVE

(1) To assess the extent to which current English national regulations/policies/guidelines and local hospital practices align with indicators suggested by a European review of effective strategies for infection prevention and control (IPC); (2) to examine the capacity of local hospitals to report on the indicators and current use of data to inform IPC management and practice.

DESIGN

A national and local-level analysis of the 27 indicators was conducted. At the national level, documentary review of regulations/policies/guidelines was conducted. At the local level data collection comprised: (a) review of documentary sources from 14 hospitals, to determine the capacity to report performance against these indicators; (b) qualitative interviews with 3 senior managers from 5 hospitals and direct observation of hospital wards to find out if these indicators are used to improve IPC management and practice.

SETTING

2 acute English National Health Service (NHS) trusts and 1 NHS foundation trust (14 hospitals).

PARTICIPANTS

3 senior managers from 5 hospitals for qualitative interviews.

PRIMARY AND SECONDARY OUTCOME MEASURES

As primary outcome measures, a 'Red-Amber-Green' (RAG) rating was developed reflecting how well the indicators were included in national documents or their availability at the local organisational level. The current use of the indicators to inform IPC management and practice was also assessed. The main secondary outcome measure is any inconsistency between national and local RAG rating results.

RESULTS

National regulations/policies/guidelines largely cover the suggested European indicators. The ability of individual hospitals to report some of the indicators at ward level varies across staff groups, which may mask required improvements. A reactive use of staffing-related indicators was observed rather than the suggested prospective strategic approach for IPC management.

CONCLUSIONS

For effective patient safety and infection prevention in English hospitals, routine and proactive approaches need to be developed. Our approach to evaluation can be extended to other country settings.

Serious electronic games as behavioural change interventions in healthcare-associated infections and infection prevention and control: a scoping review of the literature and future directions

BACKGROUND

The uptake of improvement initiatives in infection prevention and control (IPC) has often proven challenging. Innovative interventions such as 'serious games' have been proposed in other areas to educate and help clinicians adopt optimal behaviours. There is limited evidence about the application and evaluation of serious games in IPC. The purposes of the study were: a) to synthesise research evidence on the use of serious games in IPC to support healthcare workers' behaviour change and best practice learning; and b) to identify gaps across the formulation and evaluation of serious games in IPC.

METHODS

A scoping study was conducted using the methodological framework developed by Arksey and O'Malley. We interrogated electronic databases (Ovid MEDLINE, Embase Classic + Embase, PsycINFO, Scopus, Cochrane, Google Scholar) in December 2015. Evidence from these studies was assessed against an analytic framework of intervention formulation and evaluation.

RESULTS

Nine hundred sixty five unique papers were initially identified, 23 included for full-text review, and four finally selected. Studies focused on intervention inception and development rather than implementation. Expert involvement in game design was reported in 2/4 studies. Potential game users were not included in needs assessment and game development. Outcome variables such as fidelity or sustainability were scarcely reported.

CONCLUSIONS

The growing interest in serious games for health has not been coupled with adequate evaluation of processes, outcomes and contexts involved. Explanations about the mechanisms by which game components may facilitate behaviour change are lacking, further hindering adoption.

Defining the user role in infection control

BACKGROUND

Health policy initiatives continue to recognize the valuable role of patients and the public in improving safety, advocating the availability of information as well as involvement at the point of care. In infection control, there is a limited understanding of how users interpret the plethora of publicly available information about hospital performance, and little evidence to support strategies that include reminding healthcare staff to adhere to hand hygiene practices.

AIM

To understand how users define their own role in patient safety, specifically in infection control.

METHODS

Through group interviews, self-completed questionnaires and scenario evaluation, user views of 41 participants (15 carers and 26 patients with recent experience of inpatient hospital care in London, UK) were collected and analysed. In addition, the project's patient representative performed direct observation of the research event to offer inter-rater reliability of the qualitative analysis.

FINDINGS

Users considered evidence of systemic safety-related failings when presented with hospital choices, and did not discount hospitals with high ('red' flagged) rates of meticillin-resistant Staphylococcus aureus. Further, users considered staff satisfaction within the workplace over and above user satisfaction. Those most dissatisfied with the care they received were unlikely to ask staff, 'Have you washed your hands?'

CONCLUSION

This in-depth qualitative analysis of views from a relatively informed user sample shows 'what matters', and provides new avenues for improvement initiatives. It is encouraging that users appear to take a holistic view of indicators. There is a need for strategies to improve dimensions of staff satisfaction, along with understanding the implications of patient satisfaction.

Making sense of evidence in management decisions: the role of research-based knowledge on innovation adoption and implementation in health care

Background

Although innovation can improve patient care, implementing new ideas is often challenging. Previous research found that professional attitudes, shaped in part by health policies and organisational cultures, contribute to differing perceptions of innovation ‘evidence’. However, we still know little about how evidence is empirically accessed and used by organisational decision-makers when innovations are introduced.

Aims and objectives

We aimed to investigate the use of different sources and types of evidence in innovation decisions to answer the following questions: how do managers make sense of evidence? What role does evidence play in management decision-making when adopting and implementing innovations in health care? How do wider contextual conditions and intraorganisational capacity influence research use and application by health-care managers?

Methods

Our research design comprised multiple case studies with mixed methods. We investigated technology adoption and implementation in nine acute-care organisations across England. We employed structured survey questionnaires, in-depth interviews and documentary analysis. The empirical setting was infection prevention and control. Phase 1 focused on the espoused use of evidence by 126 non-clinical and clinical hybrid managers. Phase 2 explored the use of evidence by managers in specific technology examples: (1) considered for adoption; (2) successfully adopted and implemented; and (3) rejected or discontinued.

Findings

(1) Access to, and use of, evidence types and sources varied greatly by profession. Clinicians reported a strong preference for science-based, peer-reviewed, published evidence. All groups called upon experiential knowledge and expert opinion. Nurses overall drew upon a wider range of evidence sources and types. Non-clinical managers tended to sequentially prioritise evidence on cost from national-level sources, and local implementation trials. (2) A sizeable proportion of professionals from all groups, including experienced staff, reported difficulty in making sense of evidence. Lack of awareness of existing implementation literature, lack of knowledge on how to translate information into current practice, and lack of time and relevant skills were reported as key reasons for this. (3) Infection outbreaks, financial pressures, performance targets and trusted relationships with suppliers seemed to emphasise a pragmatic and less rigorous approach in sourcing for evidence. Trust infrastructure redevelopment projects, and a strong emphasis on patient safety and collaboration, appeared to widen scope for evidence use. (4) Evidence was continuously interpreted and (re)constructed by professional identity, organisational role, team membership, audience and organisational goals. (5) Doctors and non-clinical managers sourced evidence plausible to self. Nursing staff also sought acceptance of evidence from other groups. (6) We found diverse ‘evidence templates’ in use: ‘biomedical-scientific’, ‘practice-based’, ‘rational-policy’. These represented shared cognitive models which defined what constituted acceptable and credible evidence in decisions. Nurses drew on all diverse ‘templates’ to make sense of evidence and problems; non-clinical managers drew mainly on the practice-based and rational-policy templates; and doctors drew primarily on the biomedical-scientific template.

Conclusions

An evidence-based management approach that inflexibly applies the principles of evidence-based medicine, our findings suggest, neglects how evidence is actioned in practice and how codified research knowledge inter-relates with other ‘evidence’ also valued by decision-makers. Local processes and professional and microsystem considerations played a significant role in adoption and implementation. This has substantial implications for the effectiveness of large-scale projects and systems-wide policy.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.

Bombyxin: An Insect Brain Peptide that Belongs to the Insulin Family

Bombyxin is a 5 kDa secretory brain peptide that belongs to the insulin family. Bombyxin of the silkmoth Bombyx mori can induce adult development when injected into brain-removed dormant pupae of the saturniid moth Samia cynthia ricini by activating the prothoracic glands to synthesize and release ecdysone. Bombyx bombyxin has been shown to lower the concentration of the major haemolymph sugar, trehalose, and to elevate the trehalase activity in the midgut and muscles in Bombyx, but the doses required to be effective are higher than the amounts in the feeding larvae. The exact physiological function of bombyxin in Bombyx itself is therefore still obscure, but its insulin-like structure suggests it has important roles. Bombyxin comprises a mixture of highly heterogeneous molecular forms whose amino acid sequences have 40% identity with human insulin. The Bombyx bombyxin gene encodes a precursor consisting of the signal peptide, B chain, C peptide, and A chain, in that order from the N terminus. So far, 32 bombyxin genes have been identified in Bombyx, and they are classified into 7 families, A to G, according to their sequence similarity. The bombyxin genes have no introns and cluster in unique distribution patterns. The gene arrangement in the cluster has been classified into three categories: gene pairs, gene triplets, and single genes. Nucleotide sequence analysis indicates that equal and unequal crossings-over and duplications may have generated these unique distribution patterns. The Bombyx bombyxin genes are expressed predominantly in the brain and at low levels in a number of other tissues. Genes of all 7 families are expressed in four pairs of the medial neurosecretory cells of the brain. Detailed examination indicated that only a limited number of genes in the A, B and C family members are expressed and that their expression shows a gene-arrangement-dependent pattern.

Identification and expression analysis of nervous wreck, which is preferentially expressed in the brain of the male silkworm moth, Bombyx mori

Sexually dimorphic neural circuits are essential for reproductive behaviour. The molecular basis of sexual dimorphism in the silkworm moth (Bombyx mori) brain, however, is unclear. We conducted cDNA subtraction screening and identified nervous wreck (Bmnwk), a synaptic growth regulatory gene, whose expression is higher in the male brain than in the female brain of the silkworm. Bmnwk was preferentially expressed in the brain at the late pupae and adult stages. In situ hybridization revealed that Bmnwk is highly expressed in the optic lobe of the male moth brain. These findings suggest that Bmnwk has a role in the development and/or maintenance of the optic lobe in the male silkworm brain.

Lessons from local engagement in Latin American health systems

OBJECTIVES

To examine the management of recent policies for stronger patient and public involvement in Latin American health systems, identifying common features and describing local practice examples of relevance to the UK.

CONTEXT

Participation is a core principle of many contemporary policies for health system reform. In Latin America, as in the UK, it is frequently associated with innovations in primary care services and their organizational developments. This shared interest in alternative models of local engagement offers new opportunities for collaborative research and policy development.

DESIGN

Commissioned by UK policy makers, a 4-year research programme was designed to promote exchanges with international counterparts focusing on how modern reform policies are being implemented. The selected countries possessed comparable principles and timeframes for their reforms. A series of individual country case studies were undertaken. Data were drawn from literature and documentary reviews; semi-structured interviews with national policy makers and expert advisers; and with management representatives at local exemplar sites. The aggregate data were subjected to thematic analysis applying a model for sustainable development.

RESULTS

Six common factors were identified in Latin American policies for stronger patient and public involvement. From these the most significant transferable learning for the UK relates to the position and status of professions and non-governmental agencies. Illustrative case exemplars were located in each of the eight countries studied.

20-Hydroxyecdysone regulation of two isoforms of the Ets transcription factor E74 gene in programmed cell death in the silkworm anterior silk gland

Programmed cell death of larval-specific tissues in insects is under the control of 20-hydroxyecdysone (20E). The ecdysteroid-regulated early genes are conserved in the programmed cell death of anterior silk glands (ASGs) in Bombyx mori and salivary glands in Drosophila melanogaster. We identified and characterized two isoforms of the Ets transcription factor E74 gene in B. mori (BmE74). In ASGs of B. mori last instar larvae, the Bm74A mRNA level increased concomitantly with an increase in haemolymph ecdysteroid titre after gut purge. The optimal 20E concentration for stimulation of Bm74A in ASGs was 4 microM, a similar value to the peak haemolymph ecdysteroid concentration after gut purge. In contrast, BmE74B expression peaked on day 5 of the feeding period, after which it did not increase again. These findings suggest that the BmE74 isoforms play different roles in the regulation of programmed cell death in B. mori ASGs.

The management of new primary care organizations: an international perspective

Management practice arising from parallel policies for modernizing health systems is examined across a purposive sample of 16 countries. In each, novel organizational developments in primary care are a defining feature of the proposed future direction. Semistructured interviews with national leaders in primary care policy development and local service implementation indicate that management strategies, which effectively address the organized resistance of medical professions to modernizing policies, have these four consistent characteristics: extended community and patient participation models; national frameworks for interprofessional education and representation; mechanisms for multiple funding and accountabilities; and the diversification of non-governmental organizations and their roles. The research, based on a two-year fieldwork programme, indicates that at the meso-level of management planning and practice, there is a considerable potential for exchange and transferable learning between previously unconnected countries. The effectiveness of management strategies abroad, for example, in contexts where for the first time alternative but comparable new primary care organizations are exercising responsibilities for local resource utilization, may be understood through the application of stakeholder analyses, such as those employed to promote parity of relationships in NHS primary care trusts.

Coordinate responses of transcription factors to ecdysone during programmed cell death in the anterior silk gland of the silkworm, Bombyx mori

Programmed cell death (PCD) in Bombyx mori anterior silk glands (ASGs) is triggered by 20-hydroxyecdysone (20E). We examined the expression profiles and effects of 20E on 11 transcription factor genes in the fifth instar to determine whether they demonstrate the hierarchical control seen in Drosophila PCD. Results indicate that EcR-A and usp-2, but not EcR-B1 or usp-1, may be components of the ecdysone receptor complex. Up-regulation of E75A, BHR3, and three BR-C isoforms, but not E75B, appeared to be associated with the induction of PCD. betaFTZ-F1 was not expressed during PCD execution. Thus, gene control in B. mori ASGs differs from that in Drosophila salivary glands, despite both tissues undergoing PCD in response to 20E at pupal metamorphosis.

Transferable learning from international primary care developments

Alternative approaches to the comparative analysis of international health systems developments are reviewed in relation to the advent of new primary care organizations in countries with parallel 'modernizing' policies. A framework for transferable learning between these is articulated and its design described. This is derived from priorities defined by lead policy and practice representatives in UK primary care. It points to the benefits of examining the interaction of critical new public management and planning functions as an effective vehicle for identifying both individual country role models and shared international experiences. Illustrative examples are provided in five subject areas ranging from local engagement to multiple forms of financing.

A CLAS act? Community-based organizations, health service decentralization and primary care development in Peru. Local Committees for Health Administration

In 1994 Peru embarked on a programme of health service reform, which combined primary care development and community participation through Local Committees for Health Administration (CLAS). They are responsible for carrying out local health needs assessments and identifying unmet health needs through regular household surveys. These enable them to determine local health provision and tailor services to local requirements. CLAS build on grassroots self-help circles that developed during the economic and political crises of the 1980s, and in which women have been prominent. However, they function under a 3 year contract with the Ministry of Health and within a framework of centrally determined guidelines and regulations. These reforms were implemented in the context of neo-liberal economic policies, which stressed financial deregulation and fiscal and monetary restraint, and were aimed at reducing foreign indebtedness and inflation. We evaluate the achievements of the CLAS and analyse the relationship between health and economic policy in Peru, with the aid of two contrasting models of the role of the state - 'agency' and 'stewardship'. We argue that Peru's experience holds valuable lessons for other countries seeking to foster community involvement. These include the need for community capacity building and partnership between community organizations and state (and other civil) agencies.

Pupal commitment and its hormonal control in wing imaginal discs

The timing of pupal commitment of the forewing imaginal discs of the silkworm, Bombyx mori, was determined by a transplantation assay using fourth instar larvae. The wing discs were not pupally committed at the time of ecdysis to the fifth instar. Pupal commitment began shortly after the ecdysis and was completed in 14 h. When the discs of newly molted larvae (0-h discs) were cultured in medium containing no hormone, they were pupally committed in 26 h. In vitro exposure of 0-h discs to 20-hydroxyecdysone accelerated the progression of pupal commitment. Methoprene, a juvenile hormone analog (JHA), did not suppress the change in commitment in vitro at physiological concentrations. Thus the wing discs at the time of the molt have lost their sensitivity to JH, and 20E is not a prerequisite for completion of pupal commitment. These results suggest that the change in commitment in the forewing discs may begin before the last larval molt.

Observation of fluorapatite formation under hydrolysis of tetracalcium phosphate in the presence of KF by means of soft X-ray emission and absorption spectroscopy

The effect of fluoride on the hydrolysis of tetracalcium phosphate (TTCP; Ca4(PO4)2O) in 0.1 mol/l KH2PO4 containing 62-83 mmol/l KF was studied with the help of X-ray fluorescence measurements. Fluorine X-ray emission and absorption spectra of the final product of hydrolysis and reference samples (CaF2 and Ca5(PO4)3F) were measured at Beamline BL-2C of Photon Factory (PF, Tsukuba). Based on these measurements we concluded that hydrolysis of TTCP in the presence of KF converts it into fluorapatite. Formation of CaF2, which is often found in the hydrolysis of hydroxyapatite at high fluoride concentration, was not observed.

Expression of arginine vasopressin and vasopressin V1a receptor mRNA in diabetic (db/db) mice

To assess the involvement of arginine vasopressin (AVP) in genetical diabetic (db/db) mice, we examined the mRNA expression levels of AVP and vasopressin V(1a) receptors (V(1a)R) in brain and liver of db/db mice. In 10 week-old db/db mice, a significant elevation in blood sugar levels and plasma osmolality were observed, showing obvious diabetic symptoms. There was a significant increase in brain AVP mRNA levels in db/db mice. The expression level of liver V(1a)R mRNA in db/db mice was significantly down-regulated, presumably as a consequence of ligand-receptor interaction. This is in contrast to results that show no significant reduction in brain V(1a)R mRNA levels when comparing db/db and control mice. Thus, it is possible that in the progress of genetic diabetes mellitus, AVP acts in liver than in brain through V(1a)R.

Ecdysteroid-inducible genes in the programmed cell death during insect metamorphosis

The anterior silk gland of the silkworm, Bombyx mori, undergoes programmed cell death (PCD) during pupal metamorphosis and PCD is triggered by 20-hydroxyecdysone (20E) in vitro. In order to identify the genes responsible for the PCD, we subtracted cDNAs prepared from the anterior silk glands incubated in the presence or absence of 20E in vitro. After a series of screenings by dot blot hybridization, DNA sequencing and reverse transcription polymerase chain reaction (RT-PCR), we obtained seven novel genes that were activated by 20E in vitro. Nucleotide sequence analysis indicated that two cDNAs (EN78 and EC08) did not have any obvious region to encode proteins, while five genes, designated EC74, EN86, EN03, EN10 and EN16, encoded proteins that are similar to inorganic phosphate cotransporter, TIA-1-like protein, chitinase-related protein, translation-initiation-factor subunit and annexin, respectively. Expression profiles of the genes after 20E stimulation indicated that four genes could be classified as early genes, while two are delayed early genes. The genes identified may provide insight into the PCD induced by a steroid hormone.

Development of hyperfimbriated strains of Vibrio cholerae O1

The Vibrio cholerae O1 and O139 fimbrillin genes (fimA or mshA) were amplified by polymerase chain reaction and cloned into an Escherichia coli pCR vector. These clones were sequenced. The fimA sequences were found to be identical between V cholerae O1 and O139. One of the plasmids was digested with EcoR I and inserted into the EcoR I site of pGEX-3X. The plasmid pVPP thus obtained was transferred into strains of wild-type V cholerae O1 Bgd17 (classical in biotype) and its fimbriated strain by electroporation. The recombinant plasmid pVPP overexpressed mature fimbriae following induction of the tac promoter with isopropyl-beta-D-thiogalactopyranoside. The cloned gene product was purified to homogeneity by sucrose-linear gradient centrifugation (7.8 mg of fimbriae/L-culture). All the properties of the recombinant fimbriae (e.g., subunit structure, hydrophobicity, hemagglutinating activity sensitive to D-mannose and D-glucose and immunogenicity) were identical to those of the wild-type fimbriae. This overexpression system will be extremely useful for rapid, inexpensive preparation of large amounts of fimbriae for vaccine design and development.

Involvement of adipokinetic hormone in the homeostatic control of hemolymph trehalose concentration in the larvae of Bombyx mori

Prior to wandering, 5th instar larvae of the silkworm, Bombyx mori, maintain constant hemolymph titers of trehalose. Head ligation of day 3, 5th instar larvae significantly decreased the hemolymph trehalose concentrations, but the concentrations did not decrease in starved larvae. After being diluted by replacement of larval hemolymph with insect Ringer's solution, the trehalose concentrations recovered the initial levels in 90 min in the non-ligated larvae, while they were not restored in 90 min in the neck-ligated larvae. These results suggest that a head factor(s) with hypertrehalosemic activity is involved in the homeostatic control of hemolymph trehalose concentration. When adipokinetic hormone (AKH) was injected into neck-ligated larvae, the trehalose concentrations increased in 2 h and decreased thereafter. Repeated injections of AKH every 4 h maintained the concentrations for 12 h. These findings suggest that AKH induces a hypertrehalosemic response and is involved in the homeostasis of hemolymph trehalose concentration in the larval feeding period.

Programmed cell death triggered by insect steroid hormone, 20-hydroxyecdysone, in the anterior silk gland of the silkworm, Bombyx mori

Silk gland is a larval specific tissue of lepidopteran insects and begins to degenerate shortly before pupation. Programmed cell death (PCD) of the anterior silk gland of Bombyx mori last instar larvae was studied in vivo and in vitro, focusing on the effects of 20- hydroxyecdysone (20E). The glands began to exhibit signs of PCD in vivo 2 days after gut purge and completed PCD by 48 h. In vitro, 20E prematurely induced PCD, and its completion took 144 h (6 days). An oligo-nucleosomal ladder pattern was observed in DNA extracted at the end of PCD. Caspase 3 inhibitor inhibited attainment of full PCD, but it did not block chromatin condensation as revealed by acridine orange staining. alpha-Amanitin inhibited the PCD induced by 20E in vitro if added to the culture in the first 8 h. Similarly, cycloheximide and emetine completely blocked PCD when applied in the first 18 h of culture with 20E. These results indicate that 20E-stimulated transcription and protein synthesis for PCD are completed in 8 h and 18 h, respectively. Nevertheless, withdrawal of 20E from the medium at different times showed that 20E must be present in vitro for 42 h to elicit full PCD. Current results indicate that the effects of 20E on the progression of PCD are mediated by two distinct processes - one through nuclear hormone receptors, and the other independent from de novo gene expression.

Heterotopia in microcephaly induced by cytosine arabinoside: hippocampus in the neocortex

Pregnant mice were injected intraperitoneally with cytosine arabinoside (Ara-C) on days 13.5 and 14.5 of pregnancy. The brains of their offspring were studied histologically and histochemically. In addition to dysgenic microcephaly, nodular structures consisting of cells with a relatively homogeneous morphology were observed in the depths of the cerebral cortex. The cell clusters were first seen around postnatal day 4, and had a cellular continuity with the disarrayed pyramidal cell layer in the CA 1 region of the hippocampus. Golgi-Cox staining showed a number of pyramidal-shaped cells in the clusters. Morphologically, they resembled the pyramidal neurons of the hippocampus. Immunohistochemical examination, using anti-serotonin or anti-tyrosine hydroxylase antibodies, also indicated similarities between the cell clusters and the pyramidal cell layer. It is, therefore, proposed that the cell clusters consisted of heterotopic pyramidal cells of the hippocampus. A few synaptic structures could already be detected in the heterotopic cell clusters on postnatal day 3 by electron microscopy. This early establishment of synaptic contact with related neurons may have caused the heterotopic localization of the pyramidal cells.

Nonpeptide mimic of bradykinin with long-acting properties

Kinins, members of a family of peptides released from kininogens by the action of kallikreins, have been implicated in a variety of biological activities including vasodilation, increased vascular permeability, contraction of smooth muscle cells and activation of sensory neurons. However, investigation of the physiological actions of kinins have been greatly hampered because its effects are curtailed by rapid proteolytic degradation. We examined the pharmacological characteristics of the first nonpeptide bradykinin receptor agonist 8-[2,6-dichloro-3-[N-[(E)-4-(N-methylcarbamoyl)cinnamidoacetyl+ ++]-N-methylamino]benzyloxy]-2-methyl-4-(2-pyridylmethoxy)quinolin e (FR190997). FR190997, whose structure is quite different from the natural peptide ligand, but is similar to the nonpeptide antagonists FR165649, FR167344 and FR173657, potently and selectively interacts with the human B2 receptor and markedly stimulates inositol phosphate formation in transfected Chinese hamster ovary (CHO) cells. FR190997 induces concentration-dependent contraction of isolated guinea pig ileum. In vivo, FR190997 mimics the biological action of bradykinin and induces hypotensive responses in rats with prolonged duration, presumably as a consequence of its resistance to proteolytic degradation. Therefore, FR190997 is a highly potent and subtype-selective nonpeptide agonist which displays high intrinsic activity at the bradykinin B2 receptor. This compound represents a powerful tool for further investigation of the physiology and pathophysiology of bradykinin receptors.

Essential tyrosine residues in 3-ketosteroid-delta(1)-dehydrogenase from Rhodococcus rhodochrous

Tetranitromethane treatment of 3-ketosteroid-Delta(1)-dehydrogenase of Rhodococcus rhodochrous caused loss of the catalytic activity in a time- and concentration-dependent manner. Peptides (P-81) and (PN-83) were isolated from tryptic digests of the native and tetranitromethane-treated enzyme proteins, respectively. PN-83 was the nitrated form of P-81. The amino acid sequence was GGAPLIDYLESDDDLEFMVYPWPDYFGK (positions 97-124 of the dehydrogenase sequence). PN-83 showed a low yield of PTH-Tyr of position 116, i.e. less than 5% of that of P-81, and instead a high yield of PTH-3-nitrotyrosine. This indicated that tetranitromethane modifies Y-116 under the experimental conditions used. Mutation of Y-104, Y-116, and Y-121 to smaller amino acid residues, Phe, Ser, or Ala, significantly changed the catalytic activity of the dehydrogenase. All of the mutants contained FAD and exhibited the same spectrophotometric properties as those of the wild type enzyme. The K(m) values for 4-androstene-3,17-dione of the Y-104, Y-116, and Y-121 mutants changed to large values. The most drastic change was observed for Y116A. The K(d) values for 1,4-androstadiene-3,17-dione of the Y116 mutants changed to 1.5-2.6-fold larger values than that of the recombinant enzyme. The Y-121 mutant enzymes exhibited catalytic activities like those of the recombinant enzyme, but the catalytic efficiencies of Y121F and Y121A drastically decreased to 0. 014-0.054% of that of the recombinant enzyme. The present results indicate that Y-121 plays an important role in the catalytic function, and that Y-116 and Y-104 act on binding of the substrate steroid.

Steroid monooxygenase of Rhodococcus rhodochrous: sequencing of the genomic DNA, and hyperexpression, purification, and characterization of the recombinant enzyme

Steroid monooxygenase of Rhodococcus rhodochrous is a Baeyer-Villigerase catalyzing the insertion of an oxygen atom between the C(17)- and C(20)-carbons of progesterone to produce testosterone acetate. The 5.1-kbp-long BamHI DNA fragment containing the steroid monooxygenase gene, smo, was cloned from the chromosomal DNA and sequenced. The smo gene is 1,650 nucleotides long, starts with a TTG codon, and ends with a TGA codon. The deduced amino acid sequence indicates that the enzyme protein consist of 549 amino acid residues with a molecular mass of 60,133. Thus, the molecular mass of the holoenzyme is 60,919. The amino acid sequence is highly homologous (41.2% identity) to that of cyclohexanone monooxygenase of Acinetobacter sp. In the upstream of the smo gene, the genes of heat shock proteins, dnaK, grpE, and dnaJ, located on the complementary strand, and the DNA-inserts of pSMO and pD1, which contains the ksdD gene, were joined at the BamHI site of the dnaJ gene. The smo gene was modified at the initiation codon to ATG and ligated with an expression vector to construct a plasmid, pSMO-EX, and introduced into Escherichia coli cells. The transformed cells hyperexpressed the steroid monooxygenase as an active and soluble protein at more than 40 times the level in R. rhodochrous cells. Purification of the recombinant monooxygenase from the E. coli cells by simplified procedures yielded about 2.3 mg of enzyme protein/g wet cells. The purified recombinant steroid monooxygenase exhibited indistinguishable molecular and catalytic properties from those of the R. rhodochrous enzyme.

Gene transfer into insect brain and cell-specific expression of bombyxin gene

A transgene reporter consisting of the bombyxin gene promoter and the green fluorescent protein coding region was introduced into intact brains of the silkworm Bombyx mori by in vitro electroporation. After in vitro culture of the brains, the fluorescence derived from the introduced reporter gene was observed in all cases in eight neurosecretory cells that had previously been identified as bombyxin-producing cells (BPCs). Although the fluorescence was not always observed in all cells, it was specific to BPCs, indicating that the reporter was under the control of the bombyxin gene promoter in a BPC-specific manner. Electroporatical introduction of a reporter gene was therefore found to be a suitable method for analyzing cell-specific expression in intact tissues and to be substitute for germ-line transmission of reporters in the transgenic system. Application of this technique enables us to analyze the cell-specific expression of transgene reporters within a few days and treat more than several dozens of the reporters within 1 month, which is difficult to do with the transgenic system.

3-Ketosteroid-delta1-dehydrogenase of Rhodococcus rhodochrous: sequencing of the genomic DNA and hyperexpression, purification, and characterization of the recombinant enzyme

The gene encoding 3-ketosteroid-Delta1-dehydrogenase from Rhodococcus rhodochrous was cloned and sequenced. The gene (ksdD) consists of 1,536 nucleotides and encodes an enzyme protein of 511 amino acid residues. The amino terminal methionine residue was deleted in the mature protein. The amino acids involved in the flavin binding site are conserved in the dehydrogenase sequence. The deduced amino acid sequence is highly homologous to that from Arthrobacter simplex but less so to that from Pseudomonas testosteroni. Upstream of the gene was located a heat shock protein gene, dnaJ, and downstream, a gene of a hypothetical protein. The enzyme gene was ligated with an expression vector to construct a plasmid pDEX-3 and introduced into Escherichia coli cells. The transformed cells hyperexpressed the 3-ketosteroid-Delta1-dehydrogenase as an active and soluble protein at more than 30 times the level of R. rhodochrous cells. Purification of the recombinant 3-ketosteroid-Delta1-dehydrogenase from the E. coli cells by a simplified procedure yielded about 13 mg of enzyme protein/liter of the bacterial culture. The purified recombinant dehydrogenase exhibited identical molecular and catalytic properties to the R. rhodochrous enzyme.

A novel member of the bombyxin gene family: structure and expression of bombyxin G1 gene, an insulin-related peptide gene of the silkmoth Bombyx mori

Bombyxin G1 gene, a novel insulin-related peptide gene of the silkmoth Bombyx mori, has been identified. The G1 gene encodes a precursor peptide which shows 41-56% and 28% sequence identities with preprobombyxins previously characterized and human preproinsulin, respectively. The G1 gene forms a pair with bombyxin C2 gene with opposite transcriptional orientation in a bombyxin gene cluster. The bombyxin G1 mRNA in Bombyx brain was shown to locate in four pairs of medial neurosecretory cells.

Ocular involvement and visual sequelae in hemophagocytic lymphohistiocytosis in association with congenital dyfsfibrinogenemia

We report a 7-year-old girl with hemophagocytic lymphohistiocytosis and an uncommon complication of vascular retinopathy and visual sequelae. She was also verified to be complicated with dysfibrinogenemia. The patient was treated with etoposide, dexamethasone, and cyclosporin A. During the fifth hospital week, a generalized tonic-clonic convulsion developed followed by deep coma. When she regained full consciousness, she complained of a visual disturbance. The ophthalmologic examination showed bilateral extensive retinal edema with numerous cotton-wool spots, indicative of vaso-occlusive retinopathy. This is inconsistent with the main finding of previous cases with ocular involvement, namely papilledema. Severely reduced visual acuity and visual field defects remained in both eyes even after systemic therapy. An awareness of this rare but serious complication is important because it may be preventable by early institution of chemotherapy. The pathogenesis of the retinopathy is also discussed.

Induction of fimbriated Vibrio cholerae O139

Several fimbriated phases of Vibrio cholerae O139 strains were selectively induced and compared immunologically and biochemically with those of V. cholerae O1. Fimbrial antigens were detected on the surfaces of vibrio cells colonizing the epithelial cells of a rabbit small intestine. Convalescent-phase sera from six individuals infected with V. cholerae O139 revealed the development of antibody against the fimbrillin. These findings suggest that the fimbriae of V. cholerae O1 and O139 are expressed in vivo during infection and that consideration must be given to the use of fimbrial antigens as components of vaccines against cholera.

Bombyxin F1 gene: structure and expression of a new bombyxin family gene that forms a pair with bombyxin B10 gene

Bombyxin F1 gene, a new bombyxin family gene, has been identified. The F1 gene forms a pair with bombyxin B10 gene with an opposite transcriptional orientation and the gene pair F1/B10 is located between bombyxin gene pairs B9/C1 and A7/B7 in a bombyxin gene cluster. The nucleotide sequence of the F1 gene and its deduced amino acid sequence deviate moderately from those characterized previously for the family-A, family-B, family-C, family-D, and family-E bombyxin genes; the bombyxin F1 gene and preprobombyxin F1 share no more than 62% and 53% sequence identities with other bombyxin members, respectively. Harr-plot analysis indicated that the spacer of the F1/B10 gene pair has low sequence similarity with that of other bombyxin gene pairs characterized. The bombyxin F1 mRNA in Bombyx mori brain was shown to locate in four pairs of medial neurosecretory cells, which also produce other bombyxin family mRNAs. Genomic Southern hybridization indicated that the Bombyx haploid genome contains a single copy of the family-F bombyxin gene.

Structure and expression of bombyxin E1 gene: a novel family gene that encodes bombyxin-IV, an insect insulin-related neurosecretory peptide

A bombyxin gene encoding precursor molecule for bombyxin-IV, one of the insulin-related neurosecretory peptide of the silkmoth Bombyx mori, has been cloned and characterized. The nucleotide sequence of this gene and its deduced amino acid sequence deviate moderately from those characterized previously for the family A, B, C and D bombyxin genes. The gene encoding the bombyxin-IV precursor was therefore defined into a novel family E and designated as gene E1. The bombyxin E1 transcript in Bombyx brain was shown to locate in four pairs of medial neurosecretory cells, which also produce other bombyxin family mRNAs, and the amount of the E1 transcript did not change markedly during the fifth larval instar. Genomic Southern hybridization indicated that the Bombyx haploid genome contained a single copy of the bombyxin family E gene.

Novel subtype-selective nonpeptide bradykinin receptor antagonists FR167344 and FR173657

We describe the receptor binding and antagonistic properties of two novel nonpeptide antagonists, FR167344 (3-bromo-8-[2,6-dichloro-3-[N-[(E)-4-(N,N-dimethylcarbamoyl)cinnamido acetyl]-N-methylamino]benzyloxy]-2-methylimidazo[1,2-a]pyridine hydrochloride) and FR173657 (8-[3-[N-[(E)-3-(6-acetamidopyridin-3-yl)acryloylglycyl]-N-m ethylamino]-2,6-dichlorobenzyloxy]-2-methylquinoline), for the human bradykinin receptor subtypes (B1 and B2). In competitive experiments using membranes prepared from Chinese hamster ovary cells expressing the bradykinin receptor subtypes, FR167344 and FR173657 showed a high affinity binding to the B2 receptor with IC50 values of 65 and 8.9 nM, respectively, and no binding affinity for the B1 receptor. FR167344 and FR173657 inhibited the B2 receptor-mediated phosphatidylinositol (PI) hydrolysis and produced a concentration-dependent rightward shift in the dose-response curve to bradykinin. This shift was accompanied by a progressive reduction of maximal response. Estimated pA2 values for the antagonism of bradykinin-induced PI hydrolysis by FR167344 and FR173657 were 8.0 and 9.0, respectively. FR167344 and FR173657 showed no stimulatory effects on PI hydrolysis. Therefore, FR167344 and FR173657 are potent, highly selective, and insurmountable antagonists for the human bradykinin B2 receptor.

Bombyxin gene expression in tissues other than brain detected by reverse transcription-polymerase chain reaction (RT-PCR) and in situ hybridization

Bombyxin is a 5 kDa insulin-related peptide produced in four pairs of medial neurosecretory cells in the brain of the silkmoth Bombyx mori. We demonstrate here the presence of bombyxin mRNA in tissues other than brain: ganglia, epidermis, testis, ovary, fat body, silk gland, Malpighian tubule, midgut, and hindgut of the Bombyx fifth instar larvae. Bombyxin mRNA was detected by Oligotex reverse transcription-polymerase chain reaction (RT-PCR), a rapid and simple procedure of reverse transcription-PCR, and in situ hybridization. The Oligotex RT-PCR method effectively eliminated the contaminating DNA in RNA samples and amplified bombyxin mRNA efficiently. In situ hybridization of the Bombyx ovary clearly demonstrated the localization of the bombyxin mRNA in the ovariole. The present study is the first demonstration of expression of brain neurosecretory peptide in tissues other than the central nervous system in insects at RNA level.

Multiple gene copies for bombyxin, an insulin-related peptide of the silkmoth Bombyx mori: structural signs for gene rearrangement and duplication responsible for generation of multiple molecular forms of bombyxin

Thirty-eight genes that encode bombyxin, the insulin-related brain secretory peptide of the silkmoth Bombyx mori, have been cloned and characterized. These genes have been classified into four families, A, B, C and D, according to their sequence similarity. All the bombyxin genes lack introns. Five of them have structural features of pseudogenes. The 38 genes cluster in the three DNA segments of Bombyx in unique distribution patterns. Their arrangement has been classified into three categories: gene pairs, gene triplets and single genes. In the pairs, two bombyxin genes belonging to families B and A (B/A) or to families B and C (B/C) are apposed with opposite transcriptional orientation. All triplets are arranged in the order of the family-B, family-C and family-A genes, and the transcriptional directions of the family-C and family-A genes are opposite to the direction of the family-B gene. The bombyxin gene triplets may have been generated by an unequal crossing-over between two gene pairs, B/A and B/C. Crossing-over may have occurred in the bombyxin family-B genes to increase their structural diversity. Duplications may have served to multiply the bombyxin gene triplets. These genomic rearrangements are thought to have led to the generation of multiple bombyxin gene copies and their diversity in structure and genomic organization.

Bombyxin-related peptides: cDNA structure and expression in the brain of the hornworm Agrius convolvuli [corrected]

We have cloned three cDNAs from the sweet potato hornworm Agrius convolvuli that encode precursor molecules for peptides structurally related to bombyxin, an insulin-related brain secretory peptide in Bombyx mori. The Agrius bombyxin-related peptide (ABRP) cDNAs are classified into type A and B according to their sequence similarity. The prepro-ABRPs deduced from the cDNA sequences have the insulin-like domain organization of signal peptide/B chain/C peptide/A chain. The ABRP transcripts in Agrius brain were shown to locate in four pairs of medial neurosecretory cells, the homologous group of neurosecretory cells that produce bombyxins in Bombyx brain. Genomic Southern analysis indicated the presence of multiple copies of ABRP gene in the Agrius genome. Results showed that the ABRP genes are remarkably different from the vertebrate insulin genes in the number of copy and spatial localization of the transcripts.

Insect prothoracicotropic hormone: a new member of the vertebrate growth factor superfamily

Prothoracicotropic hormone (PTTH) is a brain neurosecretory protein that controls insect development. PTTH of the silkmoth Bombyx mori is a homodimeric protein, the subunit of which consists of 109 amino acids. Clear-cut sequence similarity to any other proteins has not been observed. By disulfide-bond pattern analysis and modeling of the PTTH structure based on the known three-dimensional (3D) structures of growth factor family with cystine-knot motif, we propose that the PTTH protomer adopts the fold unique to the structural superfamily of the growth factors, beta-nerve growth factor (beta-NGF), transforming growth factor-beta 2 (TGF-beta 2), and platelet-derived growth factor-BB (PDGF-BB). The insect neurohormone PTTH appears to be a member of the growth factor superfamily, sharing a common ancestral gene with the three vertebrate growth factors, beta-NGF, TGF-beta 2 and PDGF-BB.

Human calgizzarin; one colorectal cancer-related gene selected by a large scale random cDNA sequencing and northern blot analysis

A cDNA library was constructed from COLO 205 and 1056 clones randomly selected from this library were partially sequenced. Two hundred and two (38.4%) out of 526 independent genes had more than 80% similarity to the genes reported in GenBank. In Northern blot analysis, 96 out of 98 genes were shown to be expressed at the same level in colon and lung carcinoma cell lines and control fibroblasts. Only two clones, including human synovial phospholipase A-2 and a homologue to rabbit calgizzarin, were expressed at different levels among these cell lines. The full sequence of human calgizzarin was determined and its expression was remarkably elevated in colorectal cancers compared with that in normal colorectal mucosa.

Subtype- and species-selectivity of a tachykinin receptor antagonist, FK888, for cloned rat and human tachykinin receptors

We investigated the receptor-binding properties and potencies of FK888 (N2-[(4R)-4-hydroxy-1-(1-methyl-1H-indol-3-yl)carbonyl-L-prolyl]-N- phenylmethyl-3-(2-naphthyl)-L-alaninamide), a tachykinin receptor antagonist, for the rat and human tachykinin receptor subtypes (NK1, NK2 and NK3) expressed in transfected mammalian cells. In displacement analyses, using membrane preparations derived from monkey kidney COS-7 cells transiently expressing tachykinin receptor subtypes, FK888 showed a subtype selectivity for NK1 receptor and its affinity for the human NK1 receptor was 320-fold higher than that for the rat NK1 receptor, demonstrating species difference in its binding affinity. This was in marked contrast to FK224 (N-[N2-[N-[N-[N-[2,3-didehydro-N-methyl-N-[N-[3-(2-pentylphenyl )- propionyl]-L-threonyl]tyrosyl-L-leucynyl]-D-phenylalanyl]-L- allothreonyl]-L-asparaginyl]-L-serine-n-lactone) that was selective for NK1 and NK2 receptors with similar affinities for the rat and human receptors. In Chinese hamster ovary cells permanently expressing the human NK1 receptor, FK888 inhibited the substance P-induced phosphatidylinositol hydrolysis and produced a parallel shift in the dose-response curve for substance P. Schild analysis of the antagonism of phosphatidylinositol hydrolysis by FK888 yielded a pA2 value of 8.9 and a slope of 0.97 of the regression line. FK888 itself showed no stimulatory effect on phosphatidylinositol hydrolysis in Chinese hamster ovary cells expressing the human NK1 receptor. Thus, FK888 is a potent, competitive and selective antagonist for human NK1 receptor.

Structure and expression of the gene for the prothoracicotropic hormone of the silkmoth Bombyx mori

We cloned and characterized two allelic variants of the gene for the Bombyx mori prothoracicotropic hormone (PTTH), a homodimeric 30-kDa brain secretory protein. These PTTH genes contain five exons that encode a precursor protein consisting of 224 amino acid residues whose C-terminal 109 residues represent the PTTH subunit. The Bombyx haploid genome contains a single copy of the PTTH gene. The major site of PTTH expression is the brain but expression at a very low level occurs in the gut. One Bombyx brain at day 0 of the fifth larval instar contained 2.4-2.8 pg PTTH mRNA, and this amount did not change markedly during larval-pupal development.