Inflammation but not autoimmunity occurs in transgenic mice expressing constitutive levels of interleukin-2 in islet beta cells

Transgenic mice expressing murine interleukin (IL)-2 constitutively in islet beta cells were generated (RIP-IL-2 mice). They died at an early age, when higher levels of IL-2 were produced, because of a predominant macrophage inflammatory response that destroyed the exocrine pancreas. Animals with lower levels of IL-2 survived and had islets that became increasingly infiltrated with lymphocytes over time. However, in spite of the presence of impressive peri- and intra-islet infiltrates, autoimmunity to islet antigens was not seen. Autoimmunity was also not induced to extrathymic H-2Kb molecules known to induce tolerance by a peripheral mechanism when the RIP-IL-2 mice were mated to other mice expressing H-2Kb in islet beta cells (RIP-Kb mice). Apparently, IL-2 can act only on activated T cells and is unable to reverse tolerance in T cells that have been made unresponsive through inappropriate presentation of antigen.

Augmentation of killing of Escherichia coli O157 by combinations of lactate, ethanol, and low-pH conditions

The acid tolerance of Escherichia coli O157:H7 strains can be overcome by addition of lactate, ethanol, or a combination of the two agents. Killing can be increased by as much as 4 log units in the first 5 min of incubation at pH 3 even for the most acid-tolerant isolates. Exponential-phase, habituated, and stationary-phase cells are all sensitive to incubation with lactate and ethanol. Killing correlates with disruption of the capacity for pH homeostasis. Habituated and stationary-phase cells can partially offset the effects of the lowering of cytoplasmic pH.

Overexpression of beta 2-microglobulin in transgenic mouse islet beta cells results in defective insulin secretion

Overexpression of heavy chains of the class I major histocompatibility complex in islet beta cells of transgenic mice is known to induce nonimmune diabetes. We have now overexpressed the secretory protein beta 2-microglobulin in beta cells. Transgenic mice of one lineage had normal islets. Mice of another lineage did not become overtly diabetic but showed significant depletion of beta-cell insulin. When mice were made homozygous for the transgene locus, they developed diabetes. Introduction of the beta 2-microglobulin chain into class I heavy chain transgenic mice resulted in a significant improvement in their islet morphology and insulin content, and the female mice remained normoglycemic. These results suggest that different transgene molecules overexpressed in beta cells can cause islet dysfunction, though not necessarily overt diabetes, and that this effect is mediated by the level of transgene expression. Evidence is provided to show that beta-cell disruption by transgene overexpression occurs at the level of protein and involves a defect in insulin secretion.

Identification of childhood disability in Jamaica: the ten question screen

This is the first in a series of papers that report the testing of two instruments for the identification and assessment of childhood disability by community workers (CWs) in Third World countries. It is part of the International Epidemiologic Study on Childhood Disability. The Ten Question Screen (TQ) was used as the main instrument to identify disability in a two stage population-based survey of 5478 children aged 2-9 years in Clarendon, Jamaica. In the second stage, TQ positive and 8% of the screen negative controls were professionally assessed by a doctor and a psychologist using standard criteria based on the main classification system of the ICIDH. Sensitivity of the TQ as a whole varied in different strata of the group and amongst different disabilities, from perfect in girls under 6 years, fits and motor disabilities and for serious disability in all group except boys over 5 years with cognitive disability. Specificity was good but the false positive rate was unacceptably high at 74%. It was concluded, firstly, that the validation of a simple questionnaire of perceptions of behaviour against objective measurements of impairments was perhaps not fair to the TQ. In spite of this, the TQ would be a very useful instrument in collecting disability data or for identifying people in need of rehabilitation help, if a way of reducing false positives could be found.

IncD, a genetic locus in F responsible for incompatibility with several plasmids of the IncFI group

Cloning of mini-F DNA segments has led to the identification and mapping of a locus, incD, involved in incompatibility reactions with many IncFI plasmids. The cloned incD locus expressed incompatibility with F, R386, and six other IncFI plasmids but not with ColV3-K30 or pHH507 which lack sequence homology with the incD region. A sequence of 360 bp (48.66-49.02 FKB) was found to be sufficient for expression of incD incompatibility. Multicopy vectors containing incD are compatible with each other, but can be displaced by mini-F plasmids deleted for incD. These results indicate that incD-mediated incompatibility reactions require the presence of replication genes to which incD is normally linked. The degree of incompatibility exercised by incD is moderate compared with that of other inc loci in F, suggesting that incD is involved in an aspect of plasmid maintenance, such as partition, different from the functions of the other inc loci.

New Zealand's health providers in an emerging market

Services have almost completely replaced hospitals as the organisational units in the reformed New Zealand health care system. Within the secondary service provider sector service management, the decentralisation of general management to budget-holding clinical groupings has been an important factor in achieving a population focus, cost containment, accountability and integration. It is being further developed within the 23 newly formed Crown health enterprises (CHEs), the main providers of secondary, hospital and related services. The CHEs are evolving roles beyond a narrow definition of 'providers', taking initiatives to collaborate with other providers, or rejecting those elements of competition that might interfere with effective local co-ordination of services. Service management is also being extended to the demand-driven, fee-for-service primary care sector, where inflation-adjusted expenditure over the last decade has grown at more than 6%, compared with zero growth in the capitation-financed secondary sector. This is being achieved in both general practice and community budget-holder groupings through what might be called managed primary health care. The current health reform process has also created four regional health authorities (RHAs), responsible, within capped and capitated budgets, for the fully integrated purchasing of services from both primary and secondary providers. The success of these innovative arrangements, which could be of international significance, will depend upon the quality of the developing relationships between providers and their purchasing RHAs.

Molecular homology and incompatibility in the IncFI plasmid Group

The usual grounds for the inclusion of a plasmid in a particular incompatibility group are its mutual incompatibility with a type plasmid of that group, and, in some cases, the demonstration of shared regions of specific homology, presumed to be related to DNA replication. We have found that some plasmids classified as IncFI on genetical grounds share no homology with the previously described incompatibility regions of F on the basis of hybridization of specific radioactive probes to restriction enzyme digests of DNA from these plasmids. Others show homology with some or all of the regions of the F plasmid that can express incompatibility. The incompatibility behaviour of these plasmids has been examined to determine the relationship between the possession of regions of homology and the expression of incompatibility. Three plasmids, ColV3-K30, pHH507 and Entp307, show homology only with the secondary replicon of F and appear to use sequences homologous with the secondary F replicon in their replication. The results are consistent with the propositions that some contemporary IncFI plasmids arose by the integration of several replicons, and, in general, the replicon not being used for replicon expresses its incompatibility, as does the replicon being used for replication. We conclude that incompatibility of two plasmids with F does not necessarily demonstrate relatedness of the plasmids to each other, and that inclusion within the IncFI group can result from the possession of any of several combinations of inc sequences.

Decentralisation, integration and accountability: perceptions of New Zealand's top health service managers

This paper reports on the findings of a representative survey of senior managers within New Zealand's health system. Respondents report most favourably upon the implementation of a new organisational structure, service management, which appears to have largely replaced the traditional division of health services into hospitals and community services. Service management, which is the decentralisation of decision making to integrated patient groupings, i.e. medicine, surgery, mental health, women's health, primary health care etc., appears to have been remarkably successful, in the view of the respondents, in achieving greater efficiencies, better quality care, better decision making about priorities and greater accountability of doctors. A majority of respondents consider that services have replaced hospitals as organisational entities. Significant progress is reported in the integration of hospital and community services, primary and secondary care, preventive and treatment services and of public, private and voluntary services through service management. The findings point to a new paradigm which may be of fundamental significance in the future organisation of health services.

Service management: New Zealand's model of resource management

The health system in New Zealand, which in many respects is similar to that of the United Kingdom NHS, is currently undergoing massive change. In 1989 fourteen area health boards were formed, each board being accountable to the minister of health for achieving health goals and providing comprehensive health services for its defined population. This process has been assisted by the promulgation of a set of national health goals and a national health charter. Within area health boards the principle of general management is being implemented. Organisational structures are moving away from hospitals to services in a process which is being called service management which may be defined as the decentralisation of general management to the clinical workface. Similar in many respects to the resource management initiatives in the NHS it brings together medical, nursing and business management at the operational level with one person being accountable for the achievement of quality of care objectives within a budgetary framework. Budgetary restraints in excess of 10% have been achieved in the last 12 months partly through the service management process. Service management is seen to be a major paradigm shift in health services organisation and could be of international significance in its potential for achieving medical accountability for cost containment and quality assurance, and for coordinating care across agency and disciplinary boundaries.

Beyond ideology: the emerging roles of New Zealand's crown health enterprises

New Zealand has experienced radical public sector restructuring over the last decade, including the corporatization and subsequent privatization of state trading units and the reform of social services, including health. In 1991 a new government proposed and then implemented more radical health reforms, which included the corporatization of state-owned provider units (23 crown health enterprises) and the creation of an internal market with purchasers (four regional health authorities) separated from providers. Interviews with chief executives of crown health enterprises suggest that provider units are seeking a wider role than envisaged, with an interest in the health needs of their populations and undertaking some purchasing on their behalf. The purchasers see a narrower role for crown health enterprises. Both purchasers and providers report that competition between providers is not particularly helpful (and with only limited opportunities for this to occur), with collaboration being seen as more useful. Providers are critical of purchasers ability to adopt a strategic approach. Unlike other aspects of New Zealand's restructuring, there appears to be a retreat from some of the more radical facets of the reforms, reflecting both the resistance of the health sector and a newly uncertain political climate.

Expression of T cell antigen receptor and immunoglobulin genes in lymphoid organs visualized by in situ hybridization

In situ hybridization techniques were used to detect expression within lymphoid tissues of genes encoding T cell receptor (TCR) alpha, beta and gamma chains, as well as immunoglobulin kappa light chain. Transcripts of these genes were specifically detected in frozen sections of thymus, spleen and lymph node but not in non-lymphoid tissues. Differences in the level of beta chain gene transcription were observed within and between the thymus cortex and medulla, with approximately 60% and 34% of cells in these areas labelled, respectively. Expression of the TCR alpha chain genes was more homogeneous, while amongst the cells transcribing the gamma chain gene, there was a subpopulation of 0.2% of heavily labelled cortical thymocytes. Labelling of T cell dependent areas of spleen and lymph nodes was observed with each of the TCR probes, but neither alpha nor beta gene expression was seen in lymphoid tissues of athymic nude mice. The gamma chain gene was, however, expressed in both spleen and lymph nodes of these mice. These results indicate that TCR gene expression is not limited to a small subpopulation of T cell precursors. They are discussed in relation to T cell differentiation within the thymus.

Service management: a New Zealand model for shifting the balance from hospital to community care

New Zealand's health system has undergone a radical reform in recent years. A central feature of this reform is the area health board, a partly elected and partly appointed body responsible for all health services for its defined population. Within the area health board, the organizational structure which is based upon general management is moving away from institutional towards service or programme management. This is involving clinicians in the management process as service managers, within an accountability structure which cuts across the traditional hospital/community service boundaries. This is a major paradigm shift in health services management which could have major implications for a shift from hospital to community-based care and from secondary to primary health care.

Lost in the market? A survey of senior public health service managers in New Zealand's 'reforming' health system

In 1993, New Zealand implemented radical health sector reform, separating purchaser from provider and creating a competitive market. This paper reports on a 1994 survey of senior managers' perceptions of how well public health services were adapting to this more commercial environment. An initial questionnaire to chief executive officers of Crown health enterprises, the main providers of public health, as well as secondary treatment services, was followed by a telephone survey of managers of public health services. Chief executives expressed generally positive views about the importance of public health, especially health promotion, within their organisations. Public health managers indicated a wide range of negative and positive views about the new system. They were concerned especially about service fragmentation, diminished information-sharing and decreased collaboration, especially with Maori and general practice providers. Questions were raised about the compatibility of competition with the need for collaboration in public health. The major issue was the inefficient, costly, conflicting and fragmented purchasing arrangements for public health. Managers wanted united systems and fewer purchasers. More positive views were expressed on an improved focus on outputs and clearer directions, and none wanted to return to the former era of an entirely separate system for public health services. The abolition of the Public Health Commission during 1995 should lead to increased integration of purchasing and policy making, but important questions remain about the place of public health services, especially in their links with primary care.

Inherent beta-cell dysfunction induced by transgenic expression of allogeneic major histocompatibility complex class I antigen in islet cells

Insulin-dependent diabetes mellitus (IDDM) is generally believed to be an autoimmune disease resulting from T-cell dysfunction that produces beta-cell damage, but it is conceivable that some forms of IDDM are not immunologically mediated. The effect of the expression of a foreign transgenic MHC class I antigen (H-2Kb), restricted to pancreatic islet beta-cells, was tested in vitro and in nude (athymic) mice to determine whether beta-cell dysfunction was due to non-immune mechanisms. The models used clearly excluded immune involvement in beta-cell damage. Fetal pancreas from transgenic and littermate control mice was maintained in organ culture for up to 18 days and insulin secretion into the medium assessed. For the initial 3-4 days in vitro, fetal control and transgenic pancreas secreted similar amounts of insulin, but thereafter insulin secretion by the transgenic tissue decreased in comparison with the controls. When the cultured pancreas was transplanted into nude mice, the transgenic issue produced smaller grafts than the control pancreas, but there was wide variation in graft size. Expression of H-2Kb antigens in beta-cells of nude transgenic mice also resulted in early-onset diabetes. The insulin content in the pancreas of young H-2Kb transgenic euthymic mice, (previously shown not to have insulitis), was reduced but glucagon content was normal. The reduction in in vivo insulin production was similar chronologically to the reduced insulin production by transgenic islets in vitro. These data confirm the non-immune loss of beta-cell function in MHC-transgenic mice and they may be a model for atypical Type I diabetes.

Progress towards achieving health for all New Zealanders by the year 2000

New Zealand has been faced in recent years with a serious failure to maintain its relative position, in comparison to other OECD countries, in its social, economic and health status indicators. Although health costs so far have been successfully controlled, through a largely capitation funded service, its health organisational problems are typical of developed countries including major problems of equity and efficiency. Despite these problems some important recent initiatives give optimism for future health improvement. These include the spread of the service concept through service development groups and moves towards decentralisation through area health boards. Population-based funding of hospital and area health boards, supplemented with service planning guidelines, has proved to be an important lever for change. Maori health initiatives are beginning to show the way to improving the status of this disadvantaged section of society and perhaps for other New Zealanders as well. Important issues yet to be faced include establishing an effective central organisation for the health services, education and training for leadership and a more central place for the still largely fragmented and isolated primary health care services.

Decentralisation of general management within the New Zealand health system

The radical organisation changes implemented in the New Zealand health system in recent years are discussed and analysed in this study which is based upon a review of documents and interviews with general managers of area health boards. Service management, which involves the decentralisation of general management to programme or product groupings (medicine, child health etc) has been widely implemented in almost all boards completely replacing the traditional disciplinary hierarchies. It is also leading to a population-rather than an institutional-based system of management. General managers report positively on the achievements of service management including greater accountability and commitment of clinical staff, innovation and team building, improved performance and service quality, the integration of hospital and community-based care and a customer rather than an occupational orientation. There is an increasing trend towards the recognition of primary health care as a key service entity.

Murine models of autoimmune diabetes: nonspecific cytotoxic lymphocytes derived from pancreatic islets in the presence of IL-2

Our aim was to derive T lymphocyte lines that specifically recognize islet antigens in murine models of autoimmune diabetes. Islets of Langerhans infiltrated with lymphocytes were isolated either from mice previously injected with multiple low doses of streptozotocin or from NOD-WEHI mice and were cultured in the presence of the T cell growth factor, interleukin 2 (IL-2). With islets from both models of autoimmune diabetes, rapidly proliferating, large granular lymphocytes emerged after 7-10 days and destroyed the islets and other cells such as fibroblasts in the cultures. Cytotoxicity assays showed that these cells were capable of destroying both P815 and YAC-1 tumor cells. In contrast to lymphocytes present initially in the islet infiltrates which express predominantly the L3T4 marker, the large granular lymphocytes were shown to be Ly-2 positive. They also expressed the alpha beta T cell receptor and contained mRNA for the alpha beta T cell receptor demonstrable by in situ hybridization. While morphologically similar to NK cells these large granular lymphocytes bear T cell markers and destroy a broader range of targets. They may represent a minor population of T lymphocytes particularly responsive to IL-2 although other studies show that T cells generally can develop a similar phenotype after prolonged culture with IL-2. The lack of target cell specificity indicates that these IL-2-stimulated large granular lymphocytes are unlikely to mediate the immunopathogenesis of diabetes in these animal models.

Radical reforms for primary health care in New Zealand

Financial, social and political forces have combined to produce radical reforms in New Zealand's health system. These are characterized by decentralized management; the integration of services that have traditionally been kept separate, such as the hospital and the community, and public and personal health; and focusing on the population rather than institutions as the basis of the system. These changes are accompanied by a shift of emphasis from secondary towards primary health care.