Genomic and Metabolomic Polymorphism among Experimentally Selected Paromomycin-Resistant Leishmania donovani Strains.

Understanding the mechanism(s) underpinning drug resistance could lead to novel treatments to reverse the increased tolerance of a pathogen. In this study, paromomycin (PMM) resistance (PMMr) was induced in three Nepalese clinical strains of Leishmania donovani with different inherent susceptibilities to antimony (Sb) drugs by stepwise exposure of promastigotes to PMM. Exposure to PMM resulted in the production of mixed populations of parasites, even though a single cloned population was used at the start of selection. PMM 50% inhibitory concentration (IC50) values for PMMr parasites varied between 104 and 481 µM at the promastigote stage and 32 and 195 µM at the intracellular amastigote stage. PMM resistance was associated with increased resistance to nitric oxide at the amastigote stage but not the promastigote stage (P < 0.05). This effect was most marked in the Sb-resistant (Sbr) PMMr clone, in which PMM resistance was associated with a significant upregulation of glutathione compared to that in its wild type (P < 0.05), although there was no change in the regulation of trypanothione (detected in its oxidized form). Interestingly, PMMr strains showed an increase in either the keto acid derivative of isoleucine (Sb intermediate PMMr) or the 2-hydroxy acids derived from arginine and tyrosine (Sb susceptible PMMr and Sbr PMMr). These results are consistent with the recent finding that the upregulation of the branched-chain amino acid aminotransferase and d-lactate dehydrogenase is linked to PMMr In addition, we found that PMMr is associated with a significant increase in aneuploidy during PMM selection in all the strains, which could allow the rapid selection of genetic changes that confer a survival advantage.

In vitro selection of miltefosine resistance in promastigotes of Leishmania donovani from Nepal: genomic and metabolomic characterization.

In this study, we followed the genomic, lipidomic and metabolomic changes associated with the selection of miltefosine (MIL) resistance in two clinically derived Leishmania donovani strains with different inherent resistance to antimonial drugs (antimony sensitive strain Sb-S; and antimony resistant Sb-R). MIL-R was easily induced in both strains using the promastigote-stage, but a significant increase in MIL-R in the intracellular amastigote compared to the corresponding wild-type did not occur until promastigotes had adapted to 12.2 µM MIL. A variety of common and strain-specific genetic changes were discovered in MIL-adapted parasites, including deletions at the LdMT transporter gene, single-base mutations and changes in somy. The most obvious lipid changes in MIL-R promastigotes occurred to phosphatidylcholines and lysophosphatidylcholines and results indicate that the Kennedy pathway is involved in MIL resistance. The inherent Sb resistance of the parasite had an impact on the changes that occurred in MIL-R parasites, with more genetic changes occurring in Sb-R compared with Sb-S parasites. Initial interpretation of the changes identified in this study does not support synergies with Sb-R in the mechanisms of MIL resistance, though this requires an enhanced understanding of the parasite's biochemical pathways and how they are genetically regulated to be verified fully.

Topical fibronectin in an alkali burn model of corneal ulceration in rabbits.

We studied the effect of topical fibronectin on epithelial wound healing and ulceration in alkali-burned rabbit corneas. After the first 56 hours, fibronectin accelerated complete surface reepithelialization to 4.3 +/- 2.3 days. Control alkali-burned corneas treated with phosphate-buffered saline or albumin did not resurface for 6.7 +/- 3.7 days and 6.2 +/- 2.5 days, respectively. When recurrent epithelial defects occurred, the time required for healing was also significantly accelerated by fibronectin treatment. Corneal ulceration developed in 25 of 28 and 15 of 18 saline and albumin-treated control eyes, respectively; only nine of 18 fibronectin-treated eyes ultimately ulcerated. Immunohistologic studies showed that the initially deposited fibronectin-fibrinogen matrix on the surface of burned corneas had disintegrated by 72 to 96 hours after wounding, corresponding clinically to the time of secondary epithelial breakdown. A prominent fibronectin-fibrinogen matrix remained on the surface of fibronectin-treated corneas, presumably aiding surface reepithelialization and decreasing corneal ulceration.

Scanning electron microscopy of conjunctival surfaces in patients with ocular cicatricial pemphigoid.

The conjunctival surfaces of ten patients with active, ocular cicatricial pemphigoid, three patients with drug-controlled ocular cicatricial pemphigoid, and six patients with normal conjunctivas were studied using scanning electron microscopy. A homogeneous granular sheet of amorphous mucin-like material was observed covering extensive areas of the conjunctiva in eight of ten patients with active ocular cicatricial pemphigoid. This sheet of amorphous material was absent on drug-controlled ocular cicatricial pemphigoid and normal conjunctival specimens. Our study demonstrates that patients with active ocular cicatricial pemphigoid possess ocular surface mucus that appears thicker and more continuous than normal ocular mucus when observed with scanning electron microscopy. This observation is in agreement with clinical observations of thick mucus strands in the inferior fornix of patients with active ocular cicatricial pemphigoid.

Synthesis and influenza virus sialidase inhibitory activity of analogues of 4-Guanidino-Neu5Ac2en (Zanamivir) modified in the glycerol side-chain.

Analogues of 4-Guanidino-Neu5Ac2en (Zanamivir) have been prepared containing carbamate substituents at the 7-hydroxy position. (4S,5R,6R)-5-Acetylamino-6-[1R-[(6-aminohexyl)carbamoyloxy]-2R,3-dihydroxypropyl]-4-guanidino-5,6-dihydro-4H-pyran-2carboxylic acid and (4S,5R,6R)-5-Acetylamino-6-[1R-[heptylcarbamoyloxy]-2R,3-dihydroxypropyl]-4-guanidino-5,6-dihydro4H-pyran2-carboxylic acid were the two analogues possessing activity comparable to Zanamivir, showing potent inhibition of influenza virus sialidases and good antiviral activity in vitro.

Variations in perinatal mortality in Gloucestershire: preliminary communication.

The perinatal mortality rate (PNMR) was calculated for each rural parish in Gloucestershire for the years 1968-79. The characteristics of high- and low-rate parishes (each set comprising about 10% of all births) were contrasted according to routinely recorded fetal, maternal and environmental variables. The overall PNMR in the high-rate set was six times higher than in the low-rate set; congenital malformations and low birth weight distribution could explain about one-third of this difference but the residue was not attributable to fetal gestation, maternal age or parity or social class as may have been expected. However, there was a strong association with population and housing density. It is suggested that comparisons within districts may provide more sensitive associations with PNMR than comparisons between districts, regions and countries.

Guidelines for medical audit: seven principles.

The government, general managers, and professional bodies all agree that medical audit should be implemented throughout the United Kingdom. Nevertheless, it is not yet decided either nationally or locally how audit should be defined and what its implications will be. In an analysis to find ways of measuring the design and effectiveness of hospital audit, therefore, seven main measures emerged that might serve as practical criteria. These were the definition of medical and managerial responsibilities; medical organisation; scope of audit; essential characteristics; resources needed; record keeping; and evaluation. Though generally consistent with the proposals of the government and the Department of Health, these seven principles offer some alternative approaches.

Health service accreditation: report of a pilot programme for community hospitals.

Voluntary accreditation in the United Kingdom is being used by health care providers to improve and market their services and by commissioners to define and monitor service contracts. In a three year pilot scheme in the south west of England, 43 out of 57 eligible community hospitals volunteered to be surveyed; 37 of them were ultimately accredited for up to two years by the hospital accreditation programme. The main causes for non-accreditation related to safety, clinical records, and medical organisation. Follow up visits in 10 hospitals showed that, overall, 69% of recommendations were implemented. An independent survey of participating hospitals showed the perceived benefits to include team building, review of operational policies, improvement of data systems, and the generation of local prestige. Purchasers are increasingly influenced by accreditation status but are mostly unwilling to finance the process directly. None the less, the concept may become an important factor moderating the quality of service in the new NHS.

[External quality assessment of clinical services in Europe]. / La valutazione esterna della qualità dei servizi clinici in Europa.

All countries and clinical specialties have some elements of systems for quality improvement, but their aims, configurations, models standards and assessments are often not formally recognised or integrated. External programmes to assess service delivery in Europe include the International Standardisation Organisation (ISO) and Excellence (EFQM - European Foundation Quality Management) models (industry based, management focus), peer review and accreditation (health care based, professional focus) and inspection (regulatory, safety-focused). Patient surveys and disease registers also contribute to assessment and benchmarking best performance. There are legal, cultural, professional and commercial reasons to adopt common core standards but there is little legislative framework to allow formal harmonisation within and between countries and clinical specialties. Examples are given of various approaches to the definition, assessment and improvement of standards for clinical services in Europe in order to encourage specialist associations to develop self-regulations based on the experience of others. Clinical practice and clinical services could be more efficiently and effectively harmonised by the professions than by their respective governments.

Drug delivery: lessons to be learnt from Leishmania studies.

BACKGROUND: Leishmaniasis is a disease caused by infection with the protozoan parasite Leishmania, which is responsible for three main types of disease: cutaneous leishmaniasis, visceral leishmaniasis and mucocutaneous leishmaniasis based to the site of infection for the particular species. This presents a major challenge to successful drug treatment, as a drug must not only reach antileishmanial concentrations in infected macrophages, the parasites' host cell, but also reach infected cells in locations specific to the type of disease. In this paper we discuss how studies using Leishmania have contributed to our knowledge on how drug delivery systems can be used to improve drug efficacy and delivery.

The efficacy of aerosol treatment with non-ionic surfactant vesicles containing amphotericin B in rodent models of leishmaniasis and pulmonary aspergillosis infection.

Amphotericin B (AMB) is used to treat both fungal and leishmanial infections, which are of major significance to human health. Clinical use of free AMB is limited by its nephrotoxicity, whereas liposomal AMB is costly and requires parenteral administration, thus development of novel formulations with enhanced efficacy, minimal toxicity and that can be applied via non-invasive routes is required. In this study we analysed the potential of non-ionic surfactant vesicles (NIV) given by nebulisation to deliver AMB to the lungs, liver and skin. Treatment with AMB-NIV resulted in significantly higher drug levels in the lungs and skin (p<0.05) compared to similar treatment with AMB solution but significantly lower plasma levels (p<0.05). Treatment with AMB-NIV resulted in a significant reduction in fungal lung burdens in a rat model of invasive pulmonary aspergillosis (p<0.05) compared to treatment with the carrier alone. Treatment with AMB-NIV but not AMB solution significantly suppressed Leishmania donovani liver parasite burdens (p<0.05) but could not inhibit the growth of cutaneous Leishmania major lesions. The results of this study indicate that aerosolised NIV enhanced pulmonary and hepatic delivery whilst minimising systemic exposure and toxicity.

Impact of quality strategies on hospital outputs.

CONTEXT: This study was part of the Methods of Assessing Response to Quality Improvement Strategies (MARQuIS) research project on patients crossing borders, a study to investigate quality improvement strategies in healthcare systems across the European Union (EU). AIM: To explore the association between the implementation of quality improvement strategies in hospitals and hospitals' success in meeting defined quality requirements that are considered intermediate outputs of the care process. METHODS: Data regarding the implementation of seven quality improvement strategies (accreditation, organisational quality management programmes, audit and internal assessment of clinical standards, patient safety systems, clinical practice guidelines, performance indicators and systems for obtaining patients' views) and four dimensions of outputs (clinical, safety, patient-centredness and cross-border patient-centredness) were collected from 389 acute care hospitals in eight EU countries using a web-based questionnaire. In a second phase, 89 of these hospitals participated in an on-site audit by independent surveyors. Pearson correlation and linear regression models were used to explore associations and relations between quality improvement strategies and achievement of outputs. RESULTS: Positive associations were found between six internal quality improvement strategies and hospital outputs. The quality improvement strategies could be reasonably subsumed under one latent index which explained about half of their variation. The analysis of outputs concluded that the outputs can also be considered part of a single construct. The findings indicate that the implementation of internal as well as external quality improvement strategies in hospitals has beneficial effects on the hospital outputs studied here. CONCLUSION: The implementation of internal quality improvement strategies as well as external assessment systems should be promoted.

Learning from MARQuIS: future direction of quality and safety in hospital care in the European Union.

This article summarises the significant lessons to be drawn from, and the policy implications of, the findings of the Methods of Assessing Response to Quality Improvement Strategies (MARQuIS) project--a part of the suite of research projects intended to support policy established by the European Commission through its Sixth Framework Programme. The article first reviews the findings of MARQuIS and their implications for healthcare providers (and particularly for hospitals), and then addresses the broader policy implications for member states of the European Union (EU) and for the commission itself. Against the background of the European Commission's Seventh Framework Programme, it then outlines a number of future areas for research to inform policy and practice in quality and safety in Europe. The article concludes that at this stage, a unique EU-wide quality improvement system for hospitals does not seem to be feasible or effective. Because of possible future community action in this field, attention should focus on the use of existing research on quality and safety strategies in healthcare, with the aim of combining soft measures to accelerate mutual learning. Concrete measures should be considered only in areas for which there is substantial evidence and effective implementation can be ensured.

Clinical outcome indicators.

The difficulties of collecting comparable outcome data emphasise the reliance of managers and information officers on their clinical colleagues. Only by involving doctors, nurses and paramedical staff in clinical data collection can the scope and accuracy of outcome indicators be significantly improved.

Perioperative and perinatal death as measures for quality assurance.

The concept of avoidable death is increasingly used both epidemiologically and clinically as an indicator of the quality of health services. This paper examines practical experience, particularly in Britain and Europe, of the organisation and impact of collaborative mortality studies in improving patient care in surgery and perinatal services. It suggests that the technical inadequacies of such studies are small compared with their benefits--as long as their message is translated into local practice. It offers some key ingredients for effective collaborative mortality studies.

Health-care league tables in the United Kingdom.

There is a global search for performance indicators for health services as a basis for quality improvement, external assessment, management control and public accountability and information. This requires agreement on what constitutes good performance as perceived by a disparate range of potential users, and on what aggregated or tracer data faithfully reflect policy objectives. To these challenges are added the technical problems of collating comparisons which are complete, accurate, timely and statistically valid, as well as behavioural problems of their interpretation and use. Examples are given of the Patients' Charter (National Health Service in England) and the Scottish outcome indicators. This experience from the UK may well have some relevance in other countries.

Medical audit in Britain: what now and what next?

Public, political and professional pressure for formal medical audit is mounting in Britain, as in other countries. Within the National Health Service, the government has proposed that audit should be established by 1991 in hospitals and by 1992 in general practice. Prior to this proposal considerable progress had already been made by individual doctors and by national professional bodies. If this medical initiative is to be retained, doctors must be able to demonstrate that audit is universal, systematic and effective.

Quality assurance in the United Kingdom.

In short, quality assurance in UK healthcare has developed since the mid-1980s driven by a series of national policy initiatives in the NHS, by increasing determination of the clinical professions to maintain standards, and by a general consumer movement to know more about public and professional services. Much has been achieved but there remains substantial debate about quality assurance leadership, coordination, funding and evaluation--or even what to call it.