Why surveys are 'very hard': exploring challenges and insights for collection of authentic patient experience information with speakers of Australian First Nations languages

INTRODUCTION

Health services collect patient experience data to monitor, evaluate and improve services and subsequently health outcomes. Obtaining authentic patient experience information to inform improvements relies on the quality of data collection processes and the responsiveness of these processes to the cultural and linguistic needs of diverse populations. This study explores the challenges and considerations in collecting authentic patient experience information through survey methods with Australians who primarily speak First Nations languages.

METHODS

First Nations language experts, interpreters, health staff and researchers with expertise in intercultural communication engaged in an iterative process of critical review of two survey tools using qualitative methods. These included a collaborative process of repeated translation and back translation of survey items and collaborative analysis of video-recorded trial administration of surveys with languages experts (who were also receiving dialysis treatment) and survey administrators. All research activities were audio- or video-recorded, and data from all sources were translated, transcribed and inductively analysed to identify key elements influencing acceptability and relevance of both survey process and items as well as translatability.

RESULTS

Serious challenges in achieving equivalence of meaning between English and translated versions of survey items were pervasive. Translatability of original survey items was extensively compromised by the use of metaphors specific to the cultural context within which surveys were developed, English words that are familiar but used with different meaning, English terms with no equivalent in First Nations languages and grammatical discordance between languages. Discordance between survey methods and First Nations cultural protocols and preferences for seeking and sharing information was also important: the lack of opportunity to share the 'full story', discomfort with direct questions and communication protocols that preclude negative or critical responses constrained the authenticity of the information obtained through survey methods. These limitations have serious implications for the quality of information collected and result in frustration and distress for those engaging with the survey.

CONCLUSION

Profound implications for the acceptability of a survey tool as well as data quality arise from differences between First Nations cultural and communication contexts and the cultural context within which survey methods have evolved. When data collection processes are not linguistically and culturally congruent there is a risk that patient experience data are inaccurate, miss what is important to First Nations patients and have limited utility for informing relevant healthcare improvement. Engagement of First Nations cultural and language experts is essential in all stages of development, implementation and evaluation of culturally safe and effective approaches to support speakers of First Nations languages to share their experiences of health care and influence change.

Simplified gestational diabetes screening with a triaging fasting plasma glucose reduces the burden of oral glucose tolerance tests during pregnancy - A large tertiary comparative cohort study

AIMS

The study aimed to evaluate the impact of a simplified screeningapproach for gestational diabetes (GDM) compared to conventional screening on OGTT rates, GDM prevalence, and perinatal outcomes.

METHOD

A retrospective comparative cohort study included singleton births from 20 weeks' gestation. Pregnancies without diagnostic glucose results from 13 weeks' gestation or incomplete screenings were excluded. Simplified screening consisted of a triaging fasting plasma glucose (FPG), where only those with FPG levels between 4.7 and 5.0 mmol/L proceeded to the 2hr 75 g oral glucose tolerance test (OGTT).The study period was divided into conventional screening (1st January 2019-30th June 2020) and simplified screening (1st January 2021-31st December 2021).

RESULTS

Out of 15,138 pregnancies, 12,035 met the inclusion criteria: 7385 underwent conventional and 4650 underwent simplified screening. In the simplified group, 82.9 % avoided an OGTT. The simplified screening group also had a lower GDM prevalence compared to the conventional group ((18.7 % vs. 21.7 %, p < 0.001). Perinatal outcomes, including the rate of large-for-gestational-age infants, were similar between the groups.

CONCLUSION

The simplified GDM screening strategy for significantly reduced OGTTs by over 80% without impacting perinatal outcomes. It suggests that prospective studies are necessary to further evaluate this approach.

Electronic alerts and a care bundle for acute kidney injury-an Australian cohort study

BACKGROUND

Early recognition of hospital-acquired acute kidney injury (AKI) may improve patient management and outcomes.

METHODS

This multicentre study was conducted at three hospitals (H1-intervention; H2 and H3-controls) served by a single laboratory. The intervention bundle [an interruptive automated alerts (aAlerts) showing AKI stage and baseline creatinine in the eMR, a management guide and junior medical staff education] was implemented only at H1. Outcome variables included length-of-stay (LOS), all-cause in-hospital mortality and management quality.

RESULTS

Over 6 months, 639 patients developed AKI (265 at H1 and 374 at controls), with 94.7% in general wards; 537 (84%) patients developed Stage 1, 58 (9%) Stage 2 and 43 (7%) Stage 3 AKI. Median LOS was 9 days (IQR 4-17) and was not different between intervention and controls. However, patients with AKI stage 1 had shorter LOS at H1 [median 8 versus 10 days (P = 0.021)]. Serum creatinine had risen prior to admission in most patients. Documentation of AKI was better in H1 (94.8% versus 83.4%; P = 0.001), with higher rates of nephrology consultation (25% versus 19%; P = 0.04) and cessation of nephrotoxins (25.3 versus 18.8%; P = 0.045). There was no difference in mortality between H1 versus controls (11.7% versus 13.0%; P = 0.71).

CONCLUSIONS

Most hospitalized patients developed Stage 1 AKI and developed AKI in the community and remained outside the intensive care unit (ICU). The AKI eAlert bundle reduced LOS in most patients with AKI and increased AKI documentation, nephrology consultation rate and cessation of nephrotoxic medications.

Do remote dialysis services really cost more? An economic analysis of hospital and dialysis modality costs associated with dialysis services in urban, rural and remote settings

Background

Rates of end-stage kidney disease in Australia are highest in the Northern Territory (NT), with the burden of disease heaviest in remote areas. However, the high cost of delivering dialysis services in remote areas has resulted in centralisation, requiring many people to relocate for treatment. Patients argue that treatment closer to home improves health outcomes and reduces downstream healthcare use. Existing dialysis cost studies have not compared total health care costs associated with treatment in different locations.

Objective

To estimate and compare, from a payer perspective, the observed health service costs (all cause hospital admissions, emergency department presentations and maintenance dialysis) associated with different dialysis models in urban, rural and remote locations.

Methods

Using cost weights attributed to diagnostic codes in the NT Department of Health’s hospital admission data set (2008–2014), we calculated the mean (SD) total annual health service costs by dialysis model for 995 dialysis patients. Generalized linear modeling with bootstrapping tested the marginal cost differences between different explanatory variables to estimate ‘best casemix’/‘worst casemix’ cost scenarios.

Results

The mean annual patient hospital expenditure was highest for urban models at $97 928 (SD $21 261) and $43 440 (SD $5 048) and lowest for remote at $19 584 (SD $4 394). When combined with the observed maintenance dialysis costs, expenditure was the highest for urban models at $148 510 (SD $19 774). The incremental cost increase of dialysing in an urban area, compared with a rural area, for a relocated person from a remote area, was $5 648 more and increased further for those from remote and very remote areas to $10 785 and $15 118 respectively.

Conclusions

This study demonstrates that dialysis treatment in urban areas for relocated people has health and cost implications that maybe greater than the cost of remote service delivery. The study emphasises the importance of considering all health service costs and cost consequences of service delivery models.

Key points for decision makers

Relocation for dialysis treatment has serious health and economic consequences. Relocated people have low dialysis attendance and high hospital costs in urban areas. While remote dialysis service models are more expensive than urban models, the comparative cost differences are significantly reduced when all health service costs are included. The delivery of equitable and accessible dialysis service models requires a holistic approach that incorporates the needs of the patient; hence dialysis cost studies must consider the full range of cost impacts beyond the dialysis treatments alone.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-021-06612-z.

Most people requiring ongoing treatment for end-stage kidney disease in the Northern Territory (NT) identify as Aboriginal with the majority residing in areas classified as remote or very remote. Unlike other jurisdictions in Australia, haemodialysis in a satellite unit is the most common form of treatment. However, there is a geographic mismatch between demand and service provision, with services centralised in urban areas. Patients and communities have long advocated for services at or closer to home, maintaining that the consequences of relocation and dislocation have far reaching health, psychosocial and economic ramifications. We analysed retrospective hospital data for 995 maintenance dialysis patients, stratified by the model of care they received in urban, rural and remote locations. Using cost weights attributed to diagnosis codes, we costed hospital admissions, emergency department presentations and maintenance dialysis attendances, to provide a mean total health service cost/patient/year for each model of care. We found that urban services were associated with low observed maintenance dialysis and high hospital costs, but the inverse was true for remote and very remote models. Remote models had high maintenance dialysis costs (due to expense of remote service delivery and good dialysis attendance) but low hospital usage and costs. When adjusted for other variables such as age, dialysis vintage and comorbidities, lower total hospital costs were associated with rural and remote service provision. In an environment of escalating demand and constrained budgets, this study underlines the need for policy decisions to consider the full cost consequences of different dialysis service models.

Merkel Cell Carcinoma - Current Controversies and Future Directions

Merkel cell carcinoma is a rare, aggressive neuroendocrine skin malignancy. Evidence for management comes from case series and single-arm trials. Optimal outcomes require assessment of the patient in a multidisciplinary team setting. Rapid diagnosis and staging are essential for locoregional control and may reduce metastasis. Sentinel lymph node biopsy (SLNB) adds prognostic information. FDG-positron emission tomography has high sensitivity and specificity and affects management in a quarter of cases. Surgical excision and radiotherapy provide good locoregional control even with positive margins. Wide surgical margins are needed if adjuvant radiotherapy is not used. It is uncertain whether adjuvant radiotherapy or elective surgery for uninvolved nodes or for patients selected by positive SLNB improves survival. Total doses of 50 Gy provide high levels of control for microscopic disease but at least 60 Gy should be given for macroscopic disease. Chemotherapy can be given safely with radiotherapy, but the benefit of adjuvant chemotherapy remains uncertain. Trials of adjuvant immune therapy are underway. Unresectable primaries might be controlled with radiotherapy alone or combination systemic therapy, radiotherapy and surgery. Metastatic disease often responds to chemotherapy, but the response duration can be short. Immunity is central to disease control. Immune checkpoint inhibitor treatment resulted in high response rates in chemotherapy-naive patients and lower rates in chemotherapy-refractory patients. Durable responses are observed.

Gender Parity Remains To Be Achieved for the Range of Editorial Roles Associated with Current Australasian Medical Journals

With gender parity of medical school graduates having been achieved for well over two decades, it is timely to assess whether this has translated into gender parity for all of the editorial type roles of Australasian medical journals, reflecting a move toward gender equity. Data analysis was undertaken of the gender ratios of the current editorial roles of Australasian medical journals as compared to available Australian Health Workforce data. This reveals some variation in the gender ratios for all of the current range of editorial type positions and, hence, an absence of parity. There are no women holding formal editorial positions at all for 27.7% of these journals, whilst 77.7% of the chief editors' roles are occupied by men. For five out of 18 (27.7%) of the journals, gender parity has been or is close to having been achieved for these particular roles. These gender ratios do not mirror the gender ratios of the wider community of practice for at least 50% of the journals. Hence, it can be seen that gender parity is yet to be achieved for the range of editorial roles of Australasian medical journals, which carries implications for gender equity initiatives.

Chronic kidney disease and socio-economic status: a cross sectional study

Objective: This cross-sectional study investigated the relationship between individual-level markers of disadvantage, renal function and cardio-metabolic risk within an Indigenous population characterised by a heavy burden of chronic kidney disease and disadvantage.Design: Using data from 20 Indigenous communities across Australia, an aggregate socio-economic status (SES) score was created from individual-level socio-economic variables reported by participants. Logistic regression was used to assess the association of individual-level socio-economic variables and the SES score with kidney function (an estimated glomerular function rate (eGFR) cut-point of <60 ml/min/1.73 m²) as well as clinical indicators of cardio-metabolic risk.Results: The combination of lower education and unemployment was associated with poorer kidney function and higher cardio-metabolic risk factors. Regression models adjusted for age and gender showed that an eGFR < 60 ml/min/1.73 m² was associated with a low socio-economic score (lowest vs. highest 3.24 [95% CI 1.43-6.97]), remote living (remote vs. highly to moderately accessible 3.24 [95% CI 1.28-8.23]), renting (renting vs. owning/being purchased 5.76[95% CI 1.91-17.33]), unemployment (unemployed vs employed 2.85 [95% CI 1.31-6.19]) and receiving welfare (welfare vs. salary 2.49 [95% CI 1.42-4.37]). A higher aggregate socio-economic score was inversely associated with an eGFR < 60 ml/min/1.73 m² (0.75 [95% CI 063-0.89]).Conclusion: This study extends upon our understanding of associations between area-level markers of disadvantage and burden of end stage kidney disease amongst Indigenous populations to a detailed analysis of a range of well-characterised individual-level factors such as overall low socio-economic status, remote living, renting, unemployment and welfare. With the increasing burden of end-stage kidney disease amongst Indigenous people, the underlying socio-economic conditions and social and cultural determinants of health need to be understood at an individual as well as community-level, to develop, implement, target and sustain interventions.

Projecting demands for renal replacement therapy in the Northern Territory: a stochastic Markov model

Objective The aim of the present study was to evaluate the potential effects of different health intervention strategies on demand for renal replacement therapy (RRT) services in the Northern Territory (NT). Methods A Markov chain simulation model was developed to estimate demand for haemodialysis (HD) and kidney transplantation (Tx) over the next 10 years, based on RRT registry data between 2002 and 2013. Four policy-relevant scenarios were evaluated: (1) increased Tx; (2) increased self-care dialysis; (3) reduced incidence of end-stage kidney disease (ESKD); and (4) reduced mortality. Results There were 957 new cases of ESKD during the study period, with most patients being Indigenous people (85%). The median age was 50 years at onset and 57 years at death, 12 and 13 years younger respectively than Australian medians. The prevalence of RRT increased 5.6% annually, 20% higher than the national rate (4.7%). If current trends continue (baseline scenario), the demand for facility-based HD (FHD) would approach 100000 treatments (95% confidence interval 75000-121000) in 2023, a 5% annual increase. Increasing Tx (0.3%), increasing self-care (5%) and reducing incidence (5%) each attenuate demand for FHD to ~70000 annually by 2023. Conclusions The present study demonstrates the effects of changing service patterns to increase Tx, self-care and prevention, all of which will substantially attenuate the growth in FHD requirements in the NT. What is known about the topic? The burden of ESKD is projected to increase in the NT, with demand for FHD doubling every 15 years. Little is known about the potential effect of changes in health policy and clinical practice on demand. What does this paper add? This study assessed the usefulness of a stochastic Markov model to evaluate the effects of potential policy changes on FHD demand. What are the implications for practitioners? The scenarios simulated by the stochastic Markov models suggest that changes in current ESKD management practices would have a large effect on future demand for FHD.

Does delay in planned diabetes care influence outcomes for aboriginal Australians? A study of quality in health care

BACKGROUND

To examine the association between delay in planned diabetes care and quality of outcomes.

METHODS

A retrospective analysis of primary care and inpatient records for 2567 Aboriginal patients, with diabetes, living in 49 remote communities in the Northern Territory of Australia. Poisson regression was used to estimate the association between delay from diagnosis to documented diabetes care plan and three outcome measures: mean HbA1c level, most recent blood pressure and number of diabetes-related hospital admissions.

RESULTS

Compared with no delay (< 60 days), patients with delay had increased risk of elevated mean HbA1c: 60 days to < 2 years, incidence rate ratio (IRR), 1.2 (95% CI:1.07-1.39); 2 years to < 4 years, incidence rate ratio (IRR), 1.2 (95% CI:1.04-1.45); 4 years and over, incidence rate ratio (IRR), 1.3 (95% CI:1.12-1.52). There was no evidence of association between delay and optimal blood pressure control. Risk of diabetes-related admission increased with increased delay. Compared with no delay the IRRs for delay were: 60 days to < 2 years, 1.2 (95% CI:1.07-1.42); 2 to < 4 years, 1.3 (95% CI: 1.15-1.58): and 4 years and over, 2.6 (95% CI,2.28-3.08).

CONCLUSION

The study found that a timely diabetes care plan was associated with better short-term blood glucose control and fewer diabetes-related admissions but not with improved blood pressure control. Delays may be a result of both patient and service-related factors.

Socioeconomic status and dialysis quality of care

AIM

Lower socioeconomic status (SES) has been associated with increased dialysis mortality. This study aimed to determine if the quality of care (QOC) delivered to dialysis patients varied by SES.

METHODS

All non-Indigenous adults commencing haemodialysis (HD) or peritoneal dialysis (PD) registered with the Australia and New Zealand Dialysis and Transplant Registry between 2002 and 2012 were included. Each patient's location at dialysis start was classified into SES quartiles of advantaged to disadvantaged. Guidelines were used to determine attainment of adequate QOC at 6-<18 months and 18-<30 months after dialysis start, using logistic regression models. QOC measures included pre-dialysis phosphate, calcium, haemoglobin, transferrin saturation and ferritin. HD-related parameters included single pool Kt/V and percentage with functioning arteriovenous fistula/graft. PD-related parameters included weekly Kt/V and percentage transferring to HD.

RESULTS

Of 19 486 commencing dialysis, the median age was 65 years (interquartile range 53-74), 62.2% were male and 85.1% were Caucasian. At 6-<18 months after dialysis start, there were no significant differences by SES in attainment of biochemical targets, PD or HD adequacy. The disadvantaged quartile was less likely to achieve haemoglobin targets (odds ratio 0.88, 0.80-0.96, P = 0.01) or have a functioning arteriovenous fistula or graft (odds ratio 0.79, 0.68-0.92, P = 0.003) compared with the most advantaged group. Vascular access differences persisted at 18-<30 months.

CONCLUSION

Other than vascular access, area-level SES has minimal impact on QOC attainment among non-Indigenous dialysis patients in Australia. Increased mortality in lower SES groups may be due to pre-dialysis factors and other variables such as health-related behaviours, lifestyle and literacy.

Estimating the total prevalence and incidence of end-stage kidney disease among Aboriginal and non-Aboriginal populations in the Northern Territory of Australia, using multiple data sources

Background

Most estimates for End Stage Kidney Disease (ESKD) prevalence and incidence are based on renal replacement therapy (RRT) registers. However, not all people with ESKD will commence RRT and estimates based only on RRT registry data will underestimate the true burden of ESKD in the community. This study estimates the total number of Northern Territory (NT) residents with ESKD including: those receiving RRT, those diagnosed but not receiving RRT and an estimate of “undiagnosed” cases.

Methods

Four data sources were used to identify NT residents with a diagnosis of ESKD: public hospital admissions, Australia and New Zealand Dialysis and Transplant Registry registrations, death registrations and, for the Aboriginal population only, electronic primary care records. Three data sources contained information recorded between 1 July 2008 and 31 December 2013, death registration data extended to 31 December 2014 to capture 2013 prevalent cases. A capture–recapture method was used to estimate both diagnosed and undiagnosed cases by making use of probability patterns of overlapping multiple data sources.

Results

In 2013, the estimated ESKD prevalence in the NT Aboriginal population was 11.01 (95% confidence interval (CI) 10.24–11.78) per 1000, and 0.90 (95% CI 0.76–1.05) per 1000 in the NT non-Aboriginal population. The age-adjusted rates were 17.97 (95% CI 17.82–18.11) and 1.07 (95% CI 1.05–1.09) per 1000 in the NT Aboriginal and non-Aboriginal populations respectively. The proportion of individuals receiving RRT was 71.4% of Aboriginal and 75.5% of non-Aboriginal prevalent ESKD cases. The age-adjusted ESKD incidence was also greater for the Aboriginal (5.26 (95% CI 4.44–6.08) per 1000 population) than non-Aboriginal population (0.36 (95% CI 0.25–0.47) per 1000).

Conclusion

This study provides comprehensive estimates of the burden of ESKD including those cases that are not identified in relevant health data sources. The results are important for informing strategies to reduce the total burden of ESKD and to manage the potential unmet demand, particularly from comparatively young Aboriginal patients who may be suitable for RRT but do not currently access the services for social, geographic or cultural reasons.

Electronic supplementary material

The online version of this article (doi: 10.1186/s12882-017-0791-3) contains supplementary material, which is available to authorized users.

Economic and quality of care evaluation of dialysis service models in remote Australia: protocol for a mixed methods study

Background

Australia’s Northern Territory (NT) has the country’s highest incidence and prevalence of kidney disease. Indigenous people from remote areas suffer the heaviest disease burden. Concerns regarding cost and sustainability limit the provision of dialysis treatments in remote areas and most Indigenous people requiring dialysis relocate to urban areas. However, this dislocation of people from their family, community and support networks may prove more costly when the broader health, societal and economic consequences for the individual, family and whole of government are considered.

Methods

The Dialysis Models of Care Study is a large cross organisation mixed methods study. It includes a retrospective (2000–2014) longitudinal data linkage study of two NT cohorts: Renal Cohort 1- comprising approximately 2000 adults who received dialysis and Renal Cohort 2- comprising approximately 400 children of those adults. Linkage of administrative data sets from the Australian and New Zealand Dialysis and Transplant Registry, NT Departments of Health, Housing and Education by a specialist third party (SA/NT Datalink) will enable extraction of activity, financial and outcome data. Interviews with patients, clinicians and service providers, using a snowball technique, will canvass relevant issues and assist in determining the full costs and impacts of the five most used dialysis Models of Care.

Discussion

The study uses a mixed methods approach to investigate the quantitative and qualitative dimensions of the full costs and outcomes associated with the choice of particular dialysis models of care for any given patient. The study includes a large data linkage component that for the first time links health, housing and education data to fully analyse and evaluate the impact on patients, their families and the broader community, resulting from the relocation of people for treatment. The study will generate a large amount of activity, financial and qualitative data that will investigate health costs less directly related to dialysis treatment, costs to government such as housing and/or education and the health, social and economic outcomes experienced by patients. This approach fills an evidence gap critical to health service planners.

Electronic supplementary material

The online version of this article (doi:10.1186/s12913-017-2273-5) contains supplementary material, which is available to authorized users.

Serum vitamin D levels, diabetes and cardio-metabolic risk factors in Aboriginal and Torres Strait Islander Australians

BACKGROUND

Low levels of serum 25-hydroxy vitamin D (25(OH)D), have been associated with development of type 2 diabetes and cardiovascular disease (CVD); however there are limited data on serum 25(OH)D in Indigenous Australians, a population at high risk for both diabetes and CVD. We aimed to assess levels of serum 25(OH)D in Aboriginal and Torres Strait Islander Australians and to explore relationships between 25(OH)D and cardio-metabolic risk factors and diabetes.

METHODS

592 Aboriginal and/or Torres Strait Islander Australian participants of The eGFR (estimated glomerular filtration rate) Study, a cross-sectional analysis of a cohort study performed in 2007-2011, from urban and remote centres within communities, primary care and tertiary hospitals across Northern Territory, Far North Queensland and Western Australia. Assessment of serum 25(OH)D, cardio-metabolic risk factors (central obesity, diabetes, hypertension, history of cardiovascular disease, current smoker, low HDL-cholesterol), and diabetes (by history or HbA1c ≥6.5%) was performed. Associations were explored between 25(OH)D and outcome measures of diabetes and number of cardio-metabolic risk factors.

RESULTS

The median (IQR) serum 25(OH)D was 60 (45-77) nmol/L, 31% had 25(OH)D <50 nmol/L. For participants with 25(OH)D < 50 vs ≥50 nmol/L, cardio-metabolic risk profile differed for: diabetes (54%, 36% p < 0.001), past history of cardiovascular disease (16%, 9%, p = 0.014), waist-hip ratio (0.98, 0.92, p < 0.001), urine albumin-creatinine ratio (2.7, 1.5 mg/mmol, p < 0.001). The OR (95% CI) for diabetes was 2.02 (1.03 - 3.95) for people in the lowest vs highest tertiles of 25(OH)D (<53 vs >72 nmol/L, respectively) after adjusting for known cardio-metabolic risk factors.

CONCLUSION

The percentage of 25(OH)D levels <50 nmol/L was high among Aboriginal and Torres Strait Islander Australians from Northern and Central Australia. Low 25(OH)D level was associated with adverse cardio-metabolic risk profile and was independently associated with diabetes. These findings require exploration in longitudinal studies.

The relationship between number of primary health care visits and hospitalisations: evidence from linked clinic and hospital data for remote Indigenous Australians

BACKGROUND

Primary health care (PHC) is widely regarded as essential for preventing and treating ill health. However, the evidence on whether improved PHC reduces hospitalisations has been mixed. This study examines the relationship between PHC and hospital inpatient care in a population with high health need, high rates of hospitalisation and relatively poor PHC access.

METHODS

The cross-sectional study used linked individual level PHC visit and hospitalisation data for 52 739 Indigenous residents from 54 remote communities in the Northern Territory of Australia between 1 July 2007 and 30 June 2011. The association between PHC visits and hospitalisations was modelled using simple and spline quadratic regression for key demographics and disease groups including potentially avoidable hospitalisations.

RESULTS

At the aggregate level, the average annual number of PHC visits per person had a U-shaped association with hospitalisations. For all conditions combined, there was an inverse association between PHC visits and hospitalisations for people with less than four clinic visits per year, but a positive association for those visiting the clinic four times or more. For patients with diabetes, ischaemic heart disease or renal disease, the minimum level of hospitalisation was found when there was 20-30 PHC visits a year, and for children with otitis media and dental conditions, 5-8 visits a year.

CONCLUSIONS

The results of this study demonstrate a U-shape relationship between PHC visits and hospitalisations. Under the conditions of remote Indigenous Australians, there may be an optimal level of PHC at which hospitalisations are at a minimum. The authors propose that the effectiveness of a health system may hinge on a refined balance, rather than a straight-line relationship between primary health care and tertiary care.

Multisite randomised controlled trial to evaluate polypropylene clips applied to the breech of lambs as an alternative to mulesing. I: effects on body weight, breech bare area measurements and scores, wrinkle scores and faecal and urine staining

OBJECTIVE

 To assess the effects of application of occlusive polypropylene clips to lambs on body weight, breech bare area measurements and scores, wrinkle scores, and faecal and urine stain scores.

PROCEDURES

 A randomised controlled trial using 32,028 lambs was conducted on 208 properties across Australia. Polypropylene clips were applied at lamb marking. At each site, 160 lambs were weighed, measured for breech bare area and scored for bare area, wrinkle, dag and urine staining, and skin type and thickness. Lambs were allocated to a control (no clips) or treatment (breech and tail clips) group. Lambs were assessed on days 14 (range 10-19) and 55 (range 34-129) after clip application for body weight, breech bare area measurements and scores. On day 55 the operators also scored wrinkling and urine staining.

RESULTS

 At an average of 55 days after treatment, treated ewe and wether lambs had 16% and 21% greater horizontal bare area measurements, and 31.7% and 32.7% higher bare area scores than control lambs, respectively. The ewes and wether lambs also had lower wrinkle (6.8% and 5.8%, respectively) and dag scores (12% and 12.3%, respectively) than controls. Treated ewes had lower urine stain scores (18.8%) than controls. However, body weight was slightly lower in clip-treated lambs compared with controls by 0.320 kg (1.2%) and 0.430 kg (1.6%) for ewes and wethers, respectively.

CONCLUSION

 Polypropylene clips applied to the breech and tail of lambs increased breech bare area and reduced dag, urine and wrinkle scores. Improvements in these measures of factors that predispose to blowfly strike suggest that the application of clips may reduce the risk of breech flystrike.

Heparin leak from a hemodialysis catheter causing major bleeding, ultimately leading to transplant rejection and death

Leakage of hemodialysis catheter-locking solutions into the circulation has been reported in in vitro and in vivo studies, although there have been few reports of serious clinical adverse events. We describe a case of heparin leak from a hemodialysis catheter, which caused significant clinical bleeding requiring multiple transfusions and may have ultimately been responsible for the patient's death after transplantation.

Thrombotic microangiopathy from Australian brown snake (Pseudonaja) envenoming

BACKGROUND

Australian brown snake (genus Pseudonaja) envenoming causes a venom-induced consumptive coagulopathy (VICC). A proportion of cases go on to develop thrombotic microangiopathy characterized by thrombocytopenia, microangiopathic haemolytic anaemia (MAHA) and acute renal failure (ARF).

AIM

The aim of the study was to define better the natural history and empirical treatments for thrombotic microangiopathy in brown snake envenoming.

METHODS

A review of brown snake bites recruited to the Australian Snakebite Project (ASP), a national multicentre study of snake envenoming was undertaken. Serial data are recorded on clinical effects and laboratory results, including measurement of venom concentrations. We describe cases of thrombotic microangiopathy and compare these to cases without thrombotic microangiopathy.

RESULTS

From 32 cases of brown snake envenoming with severe VICC, four (13%) developed thrombotic microangiopathy, we also included two cases of thrombotic microangiopathy from prior to ASP. All six developed severe thrombocytopenia (<20 x 10(-9)/L), worst 3 days after the bite and resolving over a week, MAHA with fragmented red blood cells on the blood film and five developed anuric ARF requiring dialysis and lasting 2-8 weeks. All six received antivenom, which was delayed compared with other brown snake-envenoming cases. Four were treated with plasmapheresis. The severity and recovery of the thrombocytopenia, anaemia and renal function were similar with and without plasmapheresis. The median length of stay for MAHA cases was 14 days (interquartile range (IQR) 12-14) compared to 1.8 days (IQR 1.3-2) for all other cases.

CONCLUSION

Thrombotic microangiopathy resulting from brown snake bite appears to have a good prognosis and management should focus on early antivenom therapy and supportive care including dialysis. The role of plasmapheresis is yet to be defined.

High dose chemotherapy and autologous stem cell transplantation as adjuvant therapy for primary breast cancer patients with four or more lymph nodes involved: long-term results of an international randomised trial

BACKGROUND

The purpose of this study was to assess whether a short course of anthracycline containing chemotherapy followed by high dose therapy with autologous stem-cell support improves disease-free and overall survival as compared with conventional, anthracycline containing chemotherapy, in patients with primary breast cancer and four or more histologically involved lymph nodes.

PATIENTS AND METHODS

Two hundred and eighty one patients entered into a randomised clinical trial were allocated to receive standard, conventional treatment (5-fluorouracil, epirubicin and cyclophosphamide-FEC for six cycles) or FEC for three cycles followed by high dose therapy consisting of cyclophosphamide, thiotepa and carboplatin and stem cell rescue (HDT). To be eligible, patients had to be free of overt metastatic disease and be < or =60 years of age. Analyses were according to intention to treat.

RESULTS

At a median follow up of 68 months, 118 patients have experienced a relapse or death from breast cancer (62 in the FEC followed by HDT arm and 56 in the conventional FEC arm) and a total of 100 patients have died (54 in the FEC followed by HDT arm and 46 in the conventional FEC arm). No significant difference was observed in relapse-free survival [hazard ratio 1.06, 95% CI 0.74-1.52, p = 0.76] or overall survival [hazard ratio 1.18, 95% CI 0.80-1.75, p = 0.40]. Five patients died from treatment related causes, three as a consequence of HDT and two in the conventional FEC arm.

CONCLUSIONS

At the present time, no benefit has been observed from replacing three cycles of conventional chemotherapy with the HDT regimen described here. Patients should continue to receive conventional chemotherapy as adjuvant therapy for breast cancer.

Prediction of failure of native arteriovenous fistulas using 'on-line' fistula flow measurements

BACKGROUND

Measurement of blood flow within native arteriovenous fistula during haemodialysis is recommended to detect incipient fistula failure. In the present study the value of such flow measurements was assessed in a group of patients on maintenance haemodialysis, with access via native arteriovenous fistulas.

METHODS

Flow was measured using the 'on-line' thermodilution technique, on three separate occasions, and correlated with subsequent fistula failure within 6 months.

RESULTS

Of the 53 patients studied, there were six failures (three thromboses and three inadequate dialysis filtration rates). Flow rates in patients who progressed to fistula failure were significantly less than flow rates in patients whose fistulas did not fail (U = 13.0, P < 0.0003). Failure was no more common in one type of fistula than another (type fistula: F = 0.29, P = 0.88; flow predicting failure: F = 7.22, P = 0.010). Receiver operating characteristic (ROC) curve analyses confirmed flow measurement to be a useful predictor of fistula failure (area under ROC curve 0.91). The optimal threshold of 576 mL/min flow gave a sensitivity of 89% and a specificity of 81%. Measurement of access resistance was less useful in predicting failure (area under ROC curve 0.87). Measurement of fall in flow from the previous measurement was of no use (area under ROC curve 0.535).

CONCLUSION

On-line thermodilution measurement of flow within established native arteriovenous fistula is useful in surveillance and early prediction of fistula failure. Fistula flow <576 mL/min may indicate incipient native fistula failure, and should prompt further investigation.

Registration and regulation of health informatics professionals in the UK National Health Service

Whilst good health informatics can contribute directly to the delivery of effective patient care, bad informatics can kill. The UK is establishing a regulatory body to register health informatics specialists who can demonstrate that they meet agreed standards of professional practice: the UK Council for Health Informatics Professions (UKCHIP). UKCHIP will also manage the introduction of a Code of Conduct (based on the IMIA Code) and processes for continuous professional development, appeals, and removal from the Register. The challenge has been to design a process that provides a suitable structure for all informatics staff, including records, coding, audit, library and knowledge management, ICT, systems, information management and clinical management specialists. The contention is that this inclusive model of regulation has international applicability.

In vitro effects of isoprinosine and a dipeptide methyl ester on Echinococcus multilocularis protoscoleces

A protoscoleces/vesicles in vitro maintenance test with assessment of viability by eosin exclusion was used to evaluate the quantitative and qualitative activities of isoprinosine, its active component inosine and the dipeptide methylester L-Phe-Phe-OMe on isolated protoscoleces of Echinococcus multilocularis for 24 and 48 h. Isoprinosine and inosine showed dose- and time-dependent activity, the latter displaying a more rapid effect than the former. A high activity was shown with L-Phe-Phe-OMe, when compared to praziquantel. Ultrastructural alterations were much more striking with L-Phe-Phe-OMe, with an effect similar to that of praziquantel, whereas the chemotherapeutic activity of inosine and isoprinosine appeared to be directed against a metabolic target, with a lethal effect not immediately visible at the ultrastructural level. Thus, the previously reported in vivo activities of these drugs result largely from a direct effect on the parasite.

Echinococcus multilocularis alkaline phosphatase as a marker for metacestode damage induced by in vitro drug treatment with albendazole sulfoxide and albendazole sulfone

Alveolar echinococcosis (AE) is caused by the metacestode stage of the fox tapeworm Echinococcus multilocularis. The disease affects the human liver and occasionally other organs and is fatal if treatment is unsuccessful. The present chemotherapy of AE is based on the administration of benzimidazole carbamate derivatives, such as mebendazole and albendazole. Albendazole treatment has been found to be ineffective in some cases, parasitostatic rather than parasiticidal, and the recurrence rate is rather high. Therefore, chemotherapy usually involves the lifelong uptake of massive doses of albendazole and new treatment options are urgently needed. In order to avoid costly and time-consuming animal experimentation, a first step in searching for novel parasiticidal compounds could be the in vitro drug screening of novel compounds by employing metacestode cultivation. However, presently used techniques (e.g., transmission electron microscopy) for determination of parasite viability involve costly equipment and time-consuming preparation of rather large amounts of parasite material. We therefore searched for a parasite marker which can be easily traced and the presence or absence of which is indicative of parasite viability. In this study we show that the increase of E. multilocularis alkaline phosphatase activity in culture supernatants during in vitro drug treatment with albendazole derivatives correlates with the progressive degeneration and destruction of the metacestode tissue. The inexpensive and rapid assay presented here will serve as an ideal tool for performing first-round in vitro tests on the efficacy of a large number of antiparasitic compounds.

Use of Percoll for the infection of cells in vitro with Cryptosporidium parvum oocysts

A method for the infection of non-adherent THP-1 cells and adherent MDBK cells with Cryptosporidium parvum oocysts using isotonic Percoll solutions was developed. Excystation was maximal after 2 h, but toxicity increased with the oocyst/cell ratio and the incubation time. The infection rates did not increase with the oocyst/cell ratio and both cell types were equally parasitized.

Electroconvulsive therapy is associated with superior symptomatic and functional change in depressed patients after psychiatric hospitalization

BACKGROUND

Major depressive episode is associated with quality of life (QOL) deficits, and QOL improves following remission of depression. We conducted an observational study of the relationship between depressive symptoms and QOL for 1 year after psychiatric hospitalization, and compared QOL in patients who received ECT against those who did not.

METHODS

We examined 88 patients with major depressive disorder (53.4+/-15.4 years old; 69 women) upon admission, with repeated measurements at discharge, 1, 3, 6, and 12 months after discharge. Depression severity was measured with the Beck Depression Inventory. QOL measurements encompassed ADLs, IADLs, performance in major roles, and satisfaction with relationships. Treatment for depression was at the discretion of the respective physicians.

RESULTS

Depression severity dropped dramatically by discharge, and changed little thereafter. QOL measures showed improvement at the first month, with additional improvement at the third month. Improvement in QOL was closely tied to improvement in depression severity. ECT during the index hospitalization was associated with greater improvement in depressive symptoms and in most measures of QOL.

LIMITATIONS

The results of this study may not apply to the treatment of outpatients, and the large number of statistical comparisons may have resulted in some spurious associations.

CONCLUSIONS

Inpatient treatment of depression is followed by improvement in QOL. Novel findings in this study include evidence that maximum improvement in QOL does not occur until an average of 3 months after discharge, and that ECT-treated patients had superior outcomes.

Mice transgenic for BAFF develop lymphocytic disorders along with autoimmune manifestations

The cause of many autoimmune and inflammatory diseases is unresolved, although dysregulated production of tumor necrosis factor (TNF) family members appears to be important in many cases. BAFF, a new member of the TNF family, binds to B cells and costimulates their growth in vitro. Mice transgenic for BAFF have vastly increased numbers of mature B and effector T cells, and develop autoimmune-like manifestations such as the presence of high levels of rheumatoid factors, circulating immune complexes, anti-DNA autoantibodies, and immunoglobulin deposition in the kidneys. This phenotype is reminiscent of certain human autoimmune disorders and suggests that dysregulation of BAFF expression may be a critical element in the chain of events leading to autoimmunity.

Effects of mood and age on quality of life in depressed inpatients

BACKGROUND

Prior investigations have demonstrated a link between quality of life (QOL) deficits and depression. This report elaborates on prior investigations findings by implementation of formal assignment of the diagnosis of depression and a hierarchical approach to assessment of QOL.

METHODS

A masters or doctoral level mental health clinician used the SCID to confirm a diagnosis of major depression in ninety psychiatric inpatients. Function was assessed with the PSMS (a measure of ADL), the IADL scale, and the "daily living and role functioning" and the "relation to self and others" subscales of the Basis-32.

RESULTS

Patient age and severity of depression were the most consistent predictors of QOL deficits, although the direction of the age-effect on QOL depended on the specific measure of QOL. Increasing severity of depression was consistently associated with worse QOL, and remained significant after adjusting for age.

LIMITATIONS

The cross-sectional method of this study limits the inference of causality between depression severity and poor QOL.

CONCLUSIONS

QOL deficits in acutely depressed hospitalized patients occur at multiple strata in the hierarchy of behavior and are most consistently influenced by age and severity of depression. The effect of age on QOL in depressed inpatients is complex, and age is not uniformly associated with poor QOL.

Pretreatment differences in specific symptoms and quality of life among depressed inpatients who do and do not receive electroconvulsive therapy: a hypothesis regarding why the elderly are more likely to receive ECT

Electroconvulsive therapy (ECT) is among the most commonly performed medical procedures requiring general anesthesia in the United States. Nevertheless, very little is known about the characteristics of depressed patients who receive ECT and how they differ from depressed patients receiving psychotropic medication. We conducted a detailed examination of demographic, clinical, and quality-of-life (QOL) measurements in a group of 90 depressed inpatients, and we then used these measurements to contrast the 31 patients who received ECT with the 59 who received alternative therapies. The ECT group did not differ from the non-ECT group in gender composition, marital status, race, education, employment status, overall severity of depression, chronicity of depression, adequacy of prehospitalization antidepressant treatment, extent of physical illness, or extent of social support. The ECT group was older. Furthermore, the ECT group had greater weight loss, worse functioning in activities of daily living (ADLs), and worse functioning in instrumental activities of daily living (IADLs). The differences in weight loss, ADL, and IADL scores disappeared after age adjustment. However, statistical adjustment for age revealed that the ECT group reported worse capacity in their daily living and role functioning than did the non-ECT group. We conclude that the decision to pursue ECT is based in part on the perceived effect of the depression on QOL, as well as the severity of specific symptoms such as weight loss. The elderly seem particularly vulnerable to depression-related functional deficits and weight loss, and this may explain why prior studies showed a differential use of ECT in the elderly.

BAFF, a novel ligand of the tumor necrosis factor family, stimulates B cell growth

Members of the tumor necrosis factor (TNF) family induce pleiotropic biological responses, including cell growth, differentiation, and even death. Here we describe a novel member of the TNF family, designated BAFF (for B cell activating factor belonging to the TNF family), which is expressed by T cells and dendritic cells. Human BAFF was mapped to chromosome 13q32-34. Membrane-bound BAFF was processed and secreted through the action of a protease whose specificity matches that of the furin family of proprotein convertases. The expression of BAFF receptor appeared to be restricted to B cells. Both membrane-bound and soluble BAFF induced proliferation of anti-immunoglobulin M-stimulated peripheral blood B lymphocytes. Moreover, increased amounts of immunoglobulins were found in supernatants of germinal center-like B cells costimulated with BAFF. These results suggest that BAFF plays an important role as costimulator of B cell proliferation and function.

Both the lymphotoxin and tumor necrosis factor pathways are involved in experimental murine models of colitis

BACKGROUND & AIMS

Membrane lymphotoxin (LT) alpha/beta, a member of the tumor necrosis factor (TNF) family of immune regulatory molecules, is involved both in the development of secondary lymphoid tissues and the maintenance of organized lymphoid tissues in the adult. Defects observed in the mucosal immune system in animals with a genetically disrupted LTalpha/beta pathway coupled with the expression of LTalpha/beta in activated T cells motivated an examination of the importance of this pathway in experimental colitis.

METHODS

Soluble LTbeta receptor (LTbetaR) immunoglobulin fusion protein was used to inhibit the LTalpha/beta/light axis in two independent rodent models of colitis: CD45RBhi CD4(+)-reconstituted SCID mice and bone marrow-transplanted tg26 mice (BM --> tg26).

RESULTS

Treatment with LTbetaR immunoglobulin attenuated the development of both the clinical and histological manifestations of the disease in these two murine models of colitis. Given the success of TNF inhibitors in the treatment of human Crohn's disease, the effects of LTbetaR immunoglobulin have been compared with antibody to TNF in the BM --> tg26 model, and both treatments were equally efficacious.

CONCLUSIONS

The LT pathway plays a role in the development of colitis as important as that of the TNF system and, therefore, represents a potential novel intervention point for the treatment of inflammatory bowel disease.

Alterations of Toxoplasma gondii induced by 2',3'-dideoxyinosine in vitro

The time-course of action of the antiviral agent 2',3'-dideoxyinosine (ddI) against Toxoplasma gondii tachyzoites in vitro and its effects at the ultrastructural level were investigated. The very short latency of effect and high efficacy of ddI were evidenced by the fact that the drugs' effects on parasite growth occurred 2 hr after addition to the culture medium, and that an IL90 value of 0.5 microg/ml was reached after 72 hr. Although without apparent effect on uninfected cells, ddI clearly acted on the intracellular parasites, which tended to disappear. Remaining tachyzoites were almost exclusively extracellularly located and often exhibited a clustering of mitochondria-like bodies and subsequent deep alterations of their plasma membranes. These results confirm previous findings and emphasize the potential usefulness of ddI in the management of cerebral toxoplasmosis, a major health problem in acquired immune deficiency syndrome patients.

In vitro cultivation of Cryptosporidium parvum in the non-adherent human monocytic THP-1 cell line

This study shows that the human monocytic cell line THP-1 supports the growth of C. parvum. Immunofluorescence controls showed that only scarce oocysts remained after infection and disappeared within the first 24 h of culture. A continuous asexual life cycle proceeded throughout the experiments, with at least 15-d cultures. This model provides a useful tool for studies on the biology of C. parvum in cells involved in its transport in immunocompromised host.

Characterization of lymphotoxin-alpha beta complexes on the surface of mouse lymphocytes

The lymphotoxin-alpha beta complex (LT alpha beta) is found on the surface of activated lymphocytes and binds to a specific receptor called the LT beta receptor (LT beta R). In the mouse, signaling through this pathway is important for lymph node development and splenic organization, yet the biochemical properties of murine LT alpha and LT beta are essentially unknown. Here we have used soluble receptor-Ig forms of LT beta R and TNF-R55 and mAbs specific for murine LT alpha, LT beta, and LT beta R to characterize the appearance of surface LT alpha beta complexes and LT beta R on several common murine cell lines. Cells that bound LT beta R also bound anti-LT alpha and anti-LT beta mAbs in a FACS analysis. The ability of these reagents to discriminate between surface TNF and LT was verified by analysis of surface TNF-positive, LPS-activated murine RAW 264.7 monocytic cells. Primary mouse leukocytes from spleen, thymus, lymph node, and peritoneum were activated in vitro, and CD4+ and CD8+ T cells as well as B cells expressed surface LT ligand but not the LT beta R. Conversely, elicited peritoneal monocytes/macrophages were surface LT negative yet LT beta R positive. This study shows that on mononuclear cells, surface LT complexes and receptor are expressed similarly in mice and man, and the tools described herein form the foundation for study of the functional roles of the LT system in the mouse.

Cytotoxic activities of recombinant soluble murine lymphotoxin-alpha and lymphotoxin-alpha beta complexes

Human lymphotoxin-alpha (LT alpha) is found in a secreted form and on the surface of lymphocytes as a complex with a second related protein called lymphotoxin-beta (LT beta). Both secreted human LT alpha and TNF have similar biological activities mediated via the TNF receptors, whereas the cell surface LT alpha beta complex binds to a separate receptor called the LT beta receptor (LT beta R). The murine LT alpha and LT beta (mLT alpha and mLT beta) proteins have never been characterized. When recombinant mLT alpha was produced by either of several methods, the protein had a very low specific activity relative to that of human LT alpha in the conventional WEHI 164 cytotoxicity bioassay. The weak activity observed was inhibited by a soluble murine TNF-R55 Ig fusion protein (mTNF-R55-Ig), but not by mLT beta R-Ig. Coexpression of both mLT alpha and a soluble version of mLT beta in insect cells led to an LT alpha beta form that was cytotoxic in the WEHI 164 assay via the LT beta R. To determine whether natural mLT alpha-like forms with cytotoxic activity comparable to that of secreted human LT alpha were secreted from primary spleen cells, splenic lymphocytes were activated in various ways, and their supernatants were analyzed for cytotoxic activity. Using specific Abs to distinguish between mTNF and mLT, a TNF component was readily detected; however, there was no evidence for a secreted mLT alpha cytotoxic activity using this assay. Combined, these observations suggest that secreted mLT alpha may not play a role in the mouse via interactions with TNF-R55, and the ramifications of this hypothesis are discussed.

Echinococcus multilocularis metacestodes: immunological and immunocytochemical analysis of the relationships between alkaline phosphatase and the Em2 antigen

Echinococcus multilocularis metacestodes possess an alkaline phosphatase (EmAP) which has been extensively characterized at the biochemical level in previous studies. The apparent molecular weight of the enzyme monomer and its isoelectric point matched those originally described for the Em2 antigen, a reference antigen currently used for the immunodiagnosis of E. multilocularis infection. These observations raised questions about the molecular relationship between the two molecules. In order to investigate the relations between EmAP and the Em2 antigen, immunoblotting and ELISA were carried out using polyclonal and monoclonal antibodies directed against EmAP and the Em2 antigen, respectively. In addition, the localization of EmAP and the Em2 antigen was compared by immunofluorescence and immunogold electron microscopy in in vitro-generated E. multilocularis metacestodes. The results show that common epitopes between EmAP and Em2 exist, which are predominantly of a peptidic nature. Both antigens are localized in an acellular parasite structure, the laminated layer, with additional locations for the EmAP on the glycocalyx and in the central region of invaginated protoscoleces. These results suggest a putative functional relationship between the two antigens and that Em2 could originate from EmAP.

Cytotoxic activities of recombinant soluble murine lymphotoxin-alpha and lymphotoxin-alpha beta complexes

Human lymphotoxin-alpha (LT alpha) is found in a secreted form and on the surface of lymphocytes as a complex with a second related protein called lymphotoxin-beta (LT beta). Both secreted human LT alpha and TNF have similar biological activities mediated via the TNF receptors, whereas the cell surface LT alpha beta complex binds to a separate receptor called the LT beta receptor (LT beta R). The murine LT alpha and LT beta (mLT alpha and mLT beta) proteins have never been characterized. When recombinant mLT alpha was produced by either of several methods, the protein had a very low specific activity relative to that of human LT alpha in the conventional WEHI 164 cytotoxicity bioassay. The weak activity observed was inhibited by a soluble murine TNF-R55 Ig fusion protein (mTNF-R55-Ig), but not by mLT beta R-Ig. Coexpression of both mLT alpha and a soluble version of mLT beta in insect cells led to an LT alpha beta form that was cytotoxic in the WEHI 164 assay via the LT beta R. To determine whether natural mLT alpha-like forms with cytotoxic activity comparable to that of secreted human LT alpha were secreted from primary spleen cells, splenic lymphocytes were activated in various ways, and their supernatants were analyzed for cytotoxic activity. Using specific Abs to distinguish between mTNF and mLT, a TNF component was readily detected; however, there was no evidence for a secreted mLT alpha cytotoxic activity using this assay. Combined, these observations suggest that secreted mLT alpha may not play a role in the mouse via interactions with TNF-R55, and the ramifications of this hypothesis are discussed.

Characterization of lymphotoxin-alpha beta complexes on the surface of mouse lymphocytes

The lymphotoxin-alpha beta complex (LT alpha beta) is found on the surface of activated lymphocytes and binds to a specific receptor called the LT beta receptor (LT beta R). In the mouse, signaling through this pathway is important for lymph node development and splenic organization, yet the biochemical properties of murine LT alpha and LT beta are essentially unknown. Here we have used soluble receptor-Ig forms of LT beta R and TNF-R55 and mAbs specific for murine LT alpha, LT beta, and LT beta R to characterize the appearance of surface LT alpha beta complexes and LT beta R on several common murine cell lines. Cells that bound LT beta R also bound anti-LT alpha and anti-LT beta mAbs in a FACS analysis. The ability of these reagents to discriminate between surface TNF and LT was verified by analysis of surface TNF-positive, LPS-activated murine RAW 264.7 monocytic cells. Primary mouse leukocytes from spleen, thymus, lymph node, and peritoneum were activated in vitro, and CD4+ and CD8+ T cells as well as B cells expressed surface LT ligand but not the LT beta R. Conversely, elicited peritoneal monocytes/macrophages were surface LT negative yet LT beta R positive. This study shows that on mononuclear cells, surface LT complexes and receptor are expressed similarly in mice and man, and the tools described herein form the foundation for study of the functional roles of the LT system in the mouse.

Lymphotoxin but not tumor necrosis factor functions to maintain splenic architecture and humoral responsiveness in adult mice

To compare the function of the tumor necrosis factor (TNF) and lymphotoxin (LT)alpha/beta systems in the mature immune system, these two pathways were blocked with soluble receptor-immunoglobulin (R-Ig) fusion proteins in normal adult mice. Inhibition of LT alpha/beta signaling using LT betaR-Ig or a blocking monoclonal antibody against murine LT beta had profound effects. The spleen lacked discrete B cell follicles and the marginal zone was altered. Less marked changes were detected in lymph nodes. LT alpha/beta inhibition also prevented germinal center formation in the spleen and impaired Ig production in response to sheep red blood cells (SRBC) immunization. These results show that the LT alpha/beta system is required for the maintenance of splenic architecture and normal immune responses, and not simply for the development of peripheral immune organs during ontogeny. In contrast, inhibition of the TNF/LT alpha pathway with TNF-R55-Ig did not affect the splenic architecture or the anti-SRBC response. Splenic defects and impaired antibody responses are seen in TNF-deficient mice, suggesting that TNF is important during development. Therefore relative to TNF, the LT system has the dominant influence on splenic organization and anti-SRBC Ig formation in the adult mouse.

Effects of 2',3'-dideoxyinosine on Toxoplasma gondii cysts in mice

The activity against Toxoplasma gondii of 2',3' dideoxyinosine (ddI), an anti-human immunodeficiency virus drug, was examined in an in vitro and in vivo study. Cell cultures infected with a strain known to cause chronic infections were used to show the dose-dependent effect of this drug compared with spiramycin and sulfadiazine. When a dose of 4 microg/ml was used, no infected THP-1 cells or parasites were found after 60 h of incubation. An electron-microscopic study confirmed that after 12 h at 1 microg/ml, the few parasites observed were severely altered. The treatment of chronically infected mice 3 months postinfection showed that a 30-day treatment with 2 mg of ddI/ml induced a significant reduction in the number of T. gondii cysts in the cerebral tissue. These cysts were not viable, as confirmed by immunofluorescence and reinfection experiments. These experiments suggest a possible role for ddI in the treatment of toxoplasmosis, and this possibility deserves further investigation.

Distinct roles in lymphoid organogenesis for lymphotoxins alpha and beta revealed in lymphotoxin beta-deficient mice

Lymphotoxin alpha (LT alpha)-deficient mice revealed critical roles for LT alpha in lymphoid organogenesis, but it is not clear whether LT alpha functions through an LT alpha homotrimer (LT alpha3) or LT alpha/beta heterotrimers. We generated LTbeta-deficient mice and found them to lack Peyer's patches, peripheral lymph nodes, splenic germinal centers, and follicular dendritic cells. Unlike LT alpha-deficient mice, LT beta-deficient mice had cervical and mesenteric lymph nodes. Furthermore, the mesenteric lymph nodes had germinal center-like regions, although these structures appeared to lack follicular dendritic cells. The absence of cervical and mesenteric lymph nodes in LT alpha-deficient mice, and yet their presence in LT beta-deficient mice and in mice deficient in tumor necrosis factor receptor types I and II, suggest that LT alpha3 may signal via an as yet unidentified receptor.

Antibodies against Echinococcus multilocularis alkaline phosphatase as markers for the specific diagnosis and the serological monitoring of alveolar echinococcosis

The immunological properties of the purified alkaline phosphatase (pAP) of Echinococcus multilocularis metacestodes have been investigated using alveolar echinococcosis (AE) patient sera in ELISA tests. A comparative study was done with EmC-Ag (crude antigen) and pAP-Ag (purified antigen). When the parasite purified enzyme pAP was used as antigen, the specificity of the ELISA was markedly increased since it reached 100% without any decrease of its sensitivity (100%). The serologic follow-up of AE patients was conducted during several months with these two antigens in three categories of patients: cured, stabilized and aggravated. There was a good correlation between clinical and serologic data when the pAP was used as antigen in ELISA tests. The anti-pAP antibodies titres did change more rapidly than anti-EmC antibodies titres when a recurrence occurred. Modifications of the anti-pAP antibodies levels were also observed during the patient's therapy: mebendazole, albendazole and Isoprinosine. These results suggest that pAP-Ag should be used for the diagnosis and the follow-up of AE patients.

Echinococcus granulosus, E. multilocularis and mammalian liver-type alkaline phosphatases: a comparative study

The alkaline phosphatases (EC 3.1.3.1) from Echinococcus granulosus and E. multilocularis (Cestoda) were compared to each other and to a liver-type enzyme. The purified proteins (210 and 220 kDa, respectively) had a tetrameric structure composed of 4, 56/53 kDa subunits. Enzymatic removal of their N-linked sugar moieties abolished the differences in their apparent molecular weight under reducing conditions. After phase separation in Triton X-114, the E. multilocularis enzyme was the most amphiphilic, and treatment with PI-P1C reduced the amount of the parasite alkaline phosphatases that were in a hydrophobic form by about 50%. Both parasite enzymes were highly resistant to heat denaturation and insensitive to the inhibitors L-phenylalanine and L-leucine. In addition, L-homoarginine, levamisole and ZnCl2 can be used to differentiate the parasite and mammalian liver-type enzymes from each other. The Echinococcus alkaline phosphatases have original biochemical properties when compared to the mammalian liver-type enzyme.

Characterization of the mouse lymphotoxin-beta gene

Lymphotoxin-beta (LT-beta) is a member of the TNF family of ligands which when expressed with lymphotoxin-alpha (LT-alpha, i.e., the original LT or TNF-beta) forms a heteromeric complex with LT-alpha on the cell surface. The mouse gene structure was determined by both cDNA cloning and analysis of a genomic DNA fragment encompassing the TNF/LT locus in the H-2 region of chromosome 17. The mouse and human genomic structures were found to be similar in terms of location in the class III region of the MHC; however, the mouse gene lacks one intron found in most members of the family. Both the cDNA and the genomic sequences revealed an altered splice donor in the conventional intron 2 position, rendering it nonfunctional. The altered gene retains an open reading frame such that an additional 66 amino acids are inserted into the stalk region connecting the transmembrane domain with the receptor binding domain encoded by exon 4 in this type II membrane protein. Northern analysis showed that this gene is expressed predominantly in lymphoid organs. The outlining of the complete mouse TNF locus will further studies of the relationship between these genes and immune function.