Liver biopsy histopathology for diagnosis of Johne's disease in sheep

Sheep with Johne's disease develop epithelioid macrophage microgranulomas, specific to Mycobacterium avium subsp. paratuberculosis (Map) infection, in the terminal ileum, mesenteric lymph nodes, and organs distant to the alimentary tract such as the liver. The objectives of this study were to determine whether liver pathology was present in ewes affected by Map and whether liver cores provide adequate tissue for this potential diagnostic marker. One hundred and twenty-six adult, low body condition ewes were euthanized, necropsied, and underwent simulated liver biopsy. Ileal lesions typical of Map were found in 60 ewes. Hepatic epithelioid microgranulomas were observed in all ewes with Type 3b (n = 40) and 82% (n = 11) with Type 3c ileal lesions. None were found in ewes unaffected by Map or with Type 1, 2, or 3a ileal lesions. Liver biopsy core samples provided adequate tissue for histopathology with a sensitivity and specificity of 96% (95% confidence interval [CI], 0.87-0.99) and 100% (95% CI, 0.95-1), respectively for detection of types 3b and 3c ileal lesions.

Intrusive fathering, children's self-regulation and social skills: a mediation analysis

BACKGROUND

Fathers have unique influences on children's development, and particularly in the development of social skills. Although father-child relationship influences on children's social competence have received increased attention in general, research on fathering in families of children with developmental delays (DD) is scant. This study examined the pathway of influence among paternal intrusive behaviour, child social skills and child self-regulatory ability, testing a model whereby child regulatory behaviour mediates relations between fathering and child social skills.

METHODS

Participants were 97 families of children with early identified DD enrolled in an extensive longitudinal study. Father and mother child-directed intrusiveness was coded live in naturalistic home observations at child age 4.5, child behaviour dysregulation was coded from a video-taped laboratory problem-solving task at child age 5, and child social skills were measured using independent teacher reports at child age 6. Analyses tested for mediation of the relationship between fathers' intrusiveness and child social skills by child behaviour dysregulation.

RESULTS

Fathers' intrusiveness, controlling for mothers' intrusiveness and child behaviour problems, was related to later child decreased social skills and this relationship was mediated by child behaviour dysregulation.

CONCLUSIONS

Intrusive fathering appears to carry unique risk for the development of social skills in children with DD. Findings are discussed as they related to theories of fatherhood and parenting in children with DD, as well as implications for intervention and future research.

Rituximab for the first-line treatment of stage III-IV follicular lymphoma (review of Technology Appraisal No. 110): a systematic review and economic evaluation

BACKGROUND

Follicular lymphoma (FL) is a non-Hodgkin's lymphoma which typically presents when the disease is at an advanced stage. The majority of patients receive first-line therapy of rituximab in combination with chemotherapy, with two-thirds receiving cyclophosphamide, vincristine and prednisolone. The clinical and cost-effectiveness of other chemotherapies in combination with rituximab in first-line therapy is not known.

OBJECTIVE

To systematically evaluate and appraise the clinical effectiveness and cost-effectiveness of rituximab (MabThera(®), Roche Products) in combination with chemotherapy, compared with chemotherapy alone, for the first-line treatment of symptomatic stage III-IV FL.

DATA SOURCES

A systematic review of literature and an economic evaluation were carried out. Key databases [including MEDLINE In-Process & Other Non-Indexed Citations; Cumulative Index to Nursing and Allied Health Literature (CINAHL); EMBASE; The Cochrane Library, including the Cochrane Database of Systematic Reviews (CDSR), Cochrane Central Register of Controlled Trials (CENTRAL), Database of Abstracts of Reviews of Effects (DARE), NHS Economic Evaluation Database (NHS EED) and Health Technology Assessment (HTA) databases; Science Citation Index (SCI); and BIOSIS], plus research registers and conference proceedings, were searched for relevant studies from inception up to October 2010.

REVIEW METHODS

One reviewer assessed titles and abstracts of studies identified by the search strategy, obtained the full text of relevant papers and screened them against inclusion criteria. Data from included studies were extracted by one reviewer using a standardised data extraction form and checked by a second reviewer. The quality of included studies was assessed by one reviewer and checked by a second. A patient-level simulation model was developed to estimate the costs and quality-adjusted life-year (QALY) gains from the perspective of the UK NHS and Personal Social Services, with costs and benefits discounted at 3.5% annually.

RESULTS

Four randomised controlled trials comparing rituximab plus chemotherapy (R-chemotherapy) with chemotherapy alone in untreated, symptomatic patients with stage III-IV FL were identified. R-chemotherapy compared with chemotherapy alone increased the likelihood of a response to treatment in all four trials, with no additional toxicity of clinical relevance. Overall response rates were significantly improved in all four trials, with a difference between the R-chemotherapy and chemotherapy arms of between 5% and 24%, respectively. Complete response rates were also improved, with a difference between the R-chemotherapy and chemotherapy arms of between 2% and 25%, respectively. Exploratory meta-analyses were conducted; the level of statistical heterogeneity was very high and thus we believe the response rates from the individual trials to be a more robust estimator of the efficacy of the specific R-chemotherapy regimens. Over a follow-up period of 4-5 years, R-chemotherapy significantly increased the overall survival rate compared with chemotherapy alone in three trials, although data for two trials were compromised owing to the use of additional treatments. The incremental cost-effectiveness ratio (ICER) for the addition of rituximab to CVP (cyclophosphamide, vincristine and prednisolone), CHOP (cyclophosphamide, doxorubicin/adriamycin, vincristine and prednisolone) and MCP [mitoxantrone, chlorambucil (Leukeran(®), Aspen) and prednisolone] was £7720, £10,834 and £9316 per QALY gained, respectively, when it was assumed that first-line rituximab maintenance was not used. A scenario analysis is also presented, assuming that responders to R-chemotherapy in first-line induction receive maintenance with rituximab, increasing the ICER to £14,959, £21,687 and £20,493 per QALY gained, respectively.

LIMITATIONS

These relate to the sources of data used for the effectiveness in first and second line and the assumed utility values; there is uncertainty about the effect of salvage treatment on patients who had been previously treated with an anthracycline regimen. There is uncertainty whether or not rituximab is as effective in second-line treatment when patients have been previously treated with rituximab.

CONCLUSIONS

The results from four randomised trials comparing R-chemotherapy with chemotherapy alone showed an improvement in clinical effectiveness outcomes, with minimal clinically relevant additional adverse events or toxicity. The cost per QALY gained is estimated to be < £25,000 for all three comparisons under our base-case assumption and is considerably lower if first-line rituximab maintenance is not assumed. More data on patients pre-treated with rituximab and on the effect of first-line maintenance with rituximab is required for future work.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Descriptive results of a prospective cohort study of avian influenza in the Mekong River Delta of Viet Nam

A prospective cohort study of avian influenza infection in poultry flocks was carried out in the Mekong River Delta of Viet Nam between December 2008 and April 2010. Our objectives were to (i) estimate the prevalence and incidence of avian influenza virus infection and (ii) assess the efficacy of H5N1 vaccination programmes as indicated by the presence of H5 antibody in vaccinated and unvaccinated poultry. Real-time PCR and H5 multiplex assays were used to detect the antigen of avian influenza viruses from swab samples. The haemagglutination inhibition test was used to detect H5 antibody. A total of 17 968 swab and 14 878 blood samples were collected from 5476 birds over the study period. The overall incidence rate of influenza type A virus infection was 5 (95% CI 4-7) positive birds per 100 bird-months at risk. The overall incidence rate of H5 virus infection was 0.2 (95% CI 0.1-0.5) positive birds per 100 bird-months at risk. Fifty (95% CI 48-52) birds per 100 tested birds were H5 HI positive in the unvaccinated group compared with 71 (95% CI 69-73) birds per 100 in the vaccinated group. Influenza type A and H5 viruses were circulating in village poultry throughout the study period with no recorded signs of clinical disease. This implies that interventions need to be carried out continuously throughout the year rather than only focusing on the established high-risk periods. Broiler ducks had an incidence rate of influenza H5 virus infection approximately four times greater than that of layer ducks and in-contact species. We conclude that broiler ducks are likely to be the main entry route for H5 virus into poultry flocks in the MRD. Control efforts would benefit from understanding why there is a difference between villages in H5 incidence and developing strategies to provide greater protection to broiler ducks.

The Microbial Database for Danish wastewater treatment plants with nutrient removal (MiDas-DK) - a tool for understanding activated sludge population dynamics and community stability

Since 2006 more than 50 Danish full-scale wastewater treatment plants with nutrient removal have been investigated in a project called 'The Microbial Database for Danish Activated Sludge Wastewater Treatment Plants with Nutrient Removal (MiDas-DK)'. Comprehensive sets of samples have been collected, analyzed and associated with extensive operational data from the plants. The community composition was analyzed by quantitative fluorescence in situ hybridization (FISH) supported by 16S rRNA amplicon sequencing and deep metagenomics. MiDas-DK has been a powerful tool to study the complex activated sludge ecosystems, and, besides many scientific articles on fundamental issues on mixed communities encompassing nitrifiers, denitrifiers, bacteria involved in P-removal, hydrolysis, fermentation, and foaming, the project has provided results that can be used to optimize the operation of full-scale plants and carry out trouble-shooting. A core microbial community has been defined comprising the majority of microorganisms present in the plants. Time series have been established, providing an overview of temporal variations in the different plants. Interestingly, although most microorganisms were present in all plants, there seemed to be plant-specific factors that controlled the population composition thereby keeping it unique in each plant over time. Statistical analyses of FISH and operational data revealed some correlations, but less than expected. MiDas-DK (www.midasdk.dk) will continue over the next years and we hope the approach can inspire others to make similar projects in other parts of the world to get a more comprehensive understanding of microbial communities in wastewater engineering.

Multisite randomised controlled trial to evaluate polypropylene clips applied to the breech of lambs as an alternative to mulesing. II: multivariate analysis of relationships between clip treatment and operator, sheep, farm and environmental factors

OBJECTIVE

A multivariate analysis approach was used to evaluate both the effects of application of occlusive polypropylene clips to the breech on bare area measurements and scores of lambs, and the influence of operator, region, sheep, farm and environmental factors on outcomes.

PROCEDURES

A randomised controlled trial using 32,028 lambs was conducted on 208 commercial wool-growing properties across Australia. Differences in bare area measurements and scores between groups were estimated and analysed using a mixed model to investigate the effects of operator differences, farm and environmental factors and the interactions among these factors.

RESULTS

Clip-treated lambs with higher body weight at visit 1 had higher bare area measures and scores, but lower changes in dag and urine scores. Lambs with tight skin showed improved response in bare area scores and measurements after clip treatment, but lambs with a high wrinkle score at visit 1 showed less response to the treatment in their urine, dag and wrinkle and bare area scores. These effects of the clip treatment were not significantly influenced by estimated fleece fibre diameter, operator or region, but were significantly influenced by farm.

CONCLUSIONS

The effect of occlusive clips on breech measurements and scores was significantly influenced by body weight, skin type and thickness, wrinkle score and sex of the lamb, but not by region, operator or estimated fibre diameter. The clip treatment significantly improved characteristics that influence the susceptibility of lambs to flystrike under most conditions.

A soft x-ray transmission grating imaging-spectrometer for the National Ignition Facility

A soft x-ray transmission grating spectrometer has been designed for use on high energy-density physics experiments at the National Ignition Facility (NIF); coupled to one of the NIF gated x-ray detectors it records 16 time-gated spectra between 250 and 1000 eV with 100 ps temporal resolution. The trade-off between spectral and spatial resolution leads to an optimized design for measurement of emission around the peak of a 100-300 eV blackbody spectrum. Performance qualification results from the NIF, the Trident Laser Facility and vacuum ultraviolet beamline at the National Synchrotron Light Source, evidence a <100 μm spatial resolution in combination with a source-size limited spectral resolution that is <10 eV at photon energies of 300 eV.

What is the clinical effectiveness and cost-effectiveness of using drugs in treating obese patients in primary care? A systematic review

BACKGROUND

Obesity [defined as a body mass index (BMI) ≥ 30 kg/m(2)] represents a considerable public health problem and is associated with a significant range of comorbidities and an increased mortality risk. The primary aim of the management of obesity is to achieve weight reduction in the interests of health. For obese patients who cannot achieve or maintain a healthy weight by non-pharmacological means, drug therapy is recommended in combination with non-pharmacological interventions such as dietary modifications and exercise.

OBJECTIVE

To evaluate the clinical effectiveness and cost-effectiveness of three pharmacological interventions in obese patients.

DATA SOURCES

Clinical effectiveness data used in the meta-analysis were sourced from articles identified in a systematic review of the literature. Data used to inform transitions to obesity-related comorbidities were derived from the General Practice Research Database (GPRD). The results of the meta-analysis and GPRD analyses informed the economic model supplemented by data from the Health Survey for England and other UK-specific data sourced from the literature.

REVIEW METHODS

A systematic literature review was conducted of the clinical effectiveness and cost-effectiveness of orlistat, sibutramine and rimonabant within their licensed indications for the treatment of obese patients. Electronic bibliographic databases including MEDLINE, MEDLINE In-Process & Other Non-Indexed Citations, EMBASE, The Cochrane Library databases and Cumulative Index to Nursing and Allied Health Literature (CINAHL) were searched in January 2009, and the reference lists of relevant articles were checked. Studies were included if they compared orlistat, sibutramine or rimonabant with lifestyle and/or exercise advice (standard care), placebo or metformin.

RESULTS

Overall, 94 studies involving 24,808 individuals were included in the clinical meta-analysis. Eighty-three trials included data on weight change, 41 included data on BMI change and 45 and 36 studies reported on 5% and 10% body weight loss, respectively. Overall, the results show that the active drug interventions are all effective at reducing weight and BMI compared with placebo. In the case of sibutramine, the higher dose (15 mg) resulted in a greater reduction than the lower dose (10 mg). Generally, the data quality of the trials included was low with poor reporting of standard errors and standard deviations. Results from the BMI risk models derived from the GPRD showed consistent increases in risk with increasing BMI. Adjustments for key confounders, such as age, sex and smoking status, were found to be statistically significant at the 5% level, in all risk models. Applying linear models to estimate BMI trajectories, for the diabetic cohort, an average increase in BMI of 0.040 per year for both men and women was observed. The non-diabetic cohort model showed an increase in BMI of 0.175 per year for women and 0.145 per year for men. The results of the cost-effectiveness analyses suggest that sibutramine 15 mg dominates the other three active interventions and the net benefit analyses show that sibutramine 15 mg is the most cost-effective alternative for thresholds > £2000 per quality-adjusted life-year (QALY). However, both sibutramine and rimonabant have been withdrawn because of safety concerns relating to potential treatment-induced fatal adverse events. If the proportion of patients who experienced a fatal adverse event was > 1.8% (1.5%, 1.0%) for sibutramine 15 mg (sibutramine 10 mg, rimonabant) the treatment would not be considered cost-effective when using a threshold of £20,000 per QALY.

LIMITATIONS

The clinical review did not include all possible lifestyle comparators, with the inclusion limited to only those trials included one of the active drug interventions. We also excluded all studies not reported in English. Although the clinical review included data from 94 studies, the quality of data was generally low, particularly in terms of the reporting of standard deviation. There was also inconsistency between the results of the mixed-treatment comparison (MTC) and the pair-wise analyses.

CONCLUSION

The MTC of anti-obesity treatments shows that all the active treatments are effective at reducing weight and BMI. The economic results show that, compared with placebo, the treatments are all cost-effective when using a threshold of £20,000 per QALY, and, within the limitations of the data available, sibutramine 15 mg dominates the other three interventions. This work has highlighted many areas of methodological research that could be explored, including assessing inconsistencies within a network to determine differences between the results of pair-wise and MTC analyses; the use of meta-regression methods to look for effect modifiers; exploring the effect of local publication bias; and the use of joint models to analyse the repeated measures of BMI and the time-to-event processes simultaneously.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Non-invasive diagnostic assessment tools for the detection of liver fibrosis in patients with suspected alcohol-related liver disease: a systematic review and economic evaluation

BACKGROUND

Excessive alcohol consumption may lead to the development of alcohol-related liver disease (ALD). Liver biopsy may be used in patients with suspected ALD to confirm the diagnosis, exclude other or additional liver pathologies, and provide accurate staging of the degree of liver injury in order to enable the prediction of prognosis and inform treatment decisions. However, as it is an invasive procedure that carries the risk of morbidity and mortality, current UK guidance recommends that biopsy is not required to confirm the diagnosis in patients with a high clinical suspicion of ALD in whom blood tests have excluded other causes of liver disease, unless it is necessary to confirm a diagnosis of acute alcoholic hepatitis in order to inform specific treatment decisions.

OBJECTIVES

To evaluate the diagnostic accuracy, cost-effectiveness, and effect on patient outcomes of four non-invasive tests for liver fibrosis [the Enhanced Liver Fibrosis (ELF™) test (Siemens Healthcare Diagnostic Inc., Tarrytown, NY, USA), FibroTest (BioPredictive, Paris, France), FibroMAX (BioPredictive, Paris, France) and transient elastography (FibroScan(®); produced by EchoSens, Paris, France and distributed in the UK by Artemis Medical Ltd, Kent, UK)] in patients suspected of having ALD.

DATA SOURCES

A systematic review was undertaken to identify studies reporting the diagnostic and prognostic accuracy of the ELF test, FibroTest, FibroMAX, and FibroScan for the identification of liver fibrosis and associated conditions in patients with suspected ALD. The following databases were searched in January 2010: MEDLINE (from 1950 to January 2010), MEDLINE In-Process & Other Non-Indexed Citations (from 1950 to January 2010), EMBASE (from 1980 to January 2010), Cochrane Database of Systematic Reviews (from 1996 to January 2010), Cochrane Central Register of Controlled Trials (from 1898 to January 2010), Cochrane Methodology Register (from 1904 to January 2010), Database of Abstracts of Reviews of Effects (from 1995 to January 2010), HTA Database (from 1995 to January 2010), NHS Economic Evaluation Database (from 1995 to January 2010), Cumulative Index to Nursing and Allied Health Literature (from 1982 to January 2010), Web of Knowledge and Science Citation Index (from 1969 to January 2010).

REVIEW METHODS

Study quality was assessed using the QUADAS (Quality Assessment of Diagnostic Accuracy Studies) checklist. Owing to the heterogeneity of the studies, no formal meta-analysis was undertaken. A de novo mathematical model was constructed to estimate the incremental costs and incremental quality-adjusted life-years (QALYs) associated with alternative strategies compared with a biopsy-all strategy. The tests are assessed first as a replacement for liver biopsy, and secondly as an additional test prior to liver biopsy. Thirty-six scenarios were assessed for each non-invasive test strategy, which varied the sensitivity of biopsy, the anxiety associated with biopsy, sensitivity and specificity values and whether or not the biopsy was percutaneous or transjugular. For each scenario, threshold levels were reported where biopsying all patients was more cost-effective than the strategy for two parameters (the decreased level of abstinence associated with the strategy compared with biopsying all and the level of incidental QALY gain associated with biopsy).

RESULTS

No studies were identified that specifically assessed the ELF test, although a study was identified that evaluated the diagnostic accuracy of the European Liver Fibrosis Test (essentially, the ELF test with the addition of age to the algorithm) compared with biopsy. Three studies of FibroTest, no relevant studies of FibroMax, and six studies of FibroScan assessing accuracy compared with biopsy in patients with known or suspected alcohol-related liver disease were identified. In all studies, the number of patients with suspected ALD was small, meaning that the estimated sensitivities and specificities were not robust. No conclusive estimate of the cost per QALY of each non-invasive test could be provided. Scenarios exist in which each of the strategies analysed is more cost-effective than biopsying all patients and, in contrast, scenarios exist in which each strategy is less cost-effective than biopsying all patients.

LIMITATIONS

Study selection and data analysis were undertaken by one reviewer.

CONCLUSIONS

No conclusive result can be provided on the most cost-effective strategy until further data are available. A large number of parameters require data; however, the following are selected as being of most importance: (1) the sensitivity and specificity of each non-invasive liver test (NILT) against biopsy at validated and pre-selected cut-off thresholds; (2) the influence of potential confounding variables such as current drinking behaviour and the degree of hepatic inflammation on the performance of NILTs; and (3) the likelihood, and magnitude, of decreases in abstinence rates associated with a diagnosis of significant ALD by diagnostic modality and the incidental gains in QALYs that may be associated with biopsy.

FUNDING

The National Institute for Health Research Technology Assessment programme.