Establishment of the 1st International Genetic Reference Panel for Factor V Leiden, human gDNA

Forty-one laboratories participated in an international collaborative study to assess the suitability of a panel of three genomic DNA samples as the 1st International Genetic Reference Panel for the Factor V Leiden (FVL) variant.The code numbers of the materials were 03/254 (FV wild type), 03/260 (FVL homozygote) and 03/248 (FVL heterozygote).The participants evaluated the panel against their in-house controls which were known patient samples and commercial controls. In total, 859 genotype tests were carried out on the panel, with an error rate of 0.7%.The errors were not related to specific samples of the panel or to any specific techniques.The findings of this study have indicated that this panel is suitable to be used as a reference material for genotyping of factor V Leiden. It was therefore recommended that the three genomic DNA samples be established as the 1st International Genetic Reference Panel for Factor V Leiden, Human gDNA, 04/224. This recommendation was approved by the Scientific and Standardization Committee (SSC) of the ISTH (International Society on Thrombosis and Haemostasis) in June 2004 and the Expert Committee on Biological Standardization (ECBS) of theWorld Health Organization (WHO) in November 2004.

Aplastic anemia in two consecutive pregnancies: obstetric and anesthetic management

Aplastic anemia is a serious condition occasionally coexisting with pregnancy. This pathological process is associated with significant maternal and neonatal morbidity and mortality. Obstetric and anesthetic management are particularly challenging, and treatment requires knowledge of pathophysiologic mechanisms in order to provide safe care to this group of patients. We describe the successful obstetric management and labor analgesia of a patient with a diagnosis of aplastic anemia in two consecutive pregnancies.

A Home-Based Type 2 Diabetes Self-Management Intervention in Rural Guatemala

INTRODUCTION

Diabetes self-management education (DSME) is a fundamental element of type 2 diabetes care. Although 75% of adults with diabetes worldwide live in low-income and middle-income countries (LMICs), limited DSME research has been conducted in LMICs. The objective of this study was to evaluate a home-based DSME intervention in rural Guatemala.

METHODS

We conducted a prospective study of a DSME intervention using a quasi-experimental, single-group pretest-posttest design. We enrolled 90 participants in the intervention, which consisted of 6 home visits (May 2014-July 2016) conducted by a diabetes educator using a curriculum culturally and linguistically tailored to rural Mayan populations. Primary outcomes were changes in mean hemoglobin A1c (HbA1c) and mean systolic and diastolic blood pressure at baseline and at 12 months. Secondary outcomes were diabetes knowledge and self-care activities at baseline and intervention completion.

RESULTS

HbA1c decreased significantly from baseline to 12 months (absolute mean change, -1.5%; 95% confidence interval [CI], -1.9% to -1.0%; P < .001). Systolic blood pressure also improved significantly at 12 months (-6.2 mm Hg; 95% CI, -10.1 to -2.2 mm Hg; P = .002); changes in diastolic blood pressure were not significant (-1.6 mm Hg; 95% CI, -3.9 to -0.7 mm Hg; P = .17). We also found significant improvements in diabetes knowledge and self-care activities from baseline to intervention completion.

CONCLUSION

DSME interventions can be successfully delivered in a setting with an underresourced health system, high poverty rate, and unique cultural characteristics like Mayan Guatemala. Our findings point to the need for more DSME research in resource-limited settings globally.

The effect of hospital biocide sodium dichloroisocyanurate on the viability and properties of Clostridium difficile spores

Clostridium difficile is the primary cause of healthcare-associated diarrhoea globally and produces spores which are resistant to commonly used biocides and are able persist on contaminated surfaces for months. This study examined the effect of sublethal concentrations of the biocide sodium dichloroisocyanurate (NaDCC) on the viability of spores produced by 21 clinical isolates of C. difficile representing a range of PCR ribotypes. Spores exposed to 500 ppm NaDCC for 10 min exhibited between a 4-6 log₁₀ reduction in viability which was independent of spore PCR ribotype. The effect of sublethal concentrations of biocide on the surface properties of exosporium positive and negative clinical isolates was determined using a spore adhesion to hydrocarbon (SATH) assay. These isolates differed markedly in their responses suggesting that exposure to biocide can have a profound effect on hydrophobicity and thus the ability of spores to adhere to surfaces. This raises the intriguing possibility that sublethal exposure to NaDCC could inadvertently promote the spread of the pathogen in healthcare facilities.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study is the first to report on changes in Clostridium difficile spore surface property after exposure to sublethal levels of the commonly used biocide sodium dichloroisocyanurate. The implications of these changes to the spore surface include increased adherence of the spores to inorganic surfaces which can directly contribute to persistence and spread of spores within the hospital environment.

Effect of MTA particle size on periapical healing

AIM

To examine the effect of reduction in MTA particle size on dento-alveolar and osseous healing in dogs.

METHODOLOGY

Root canals of 24 mandibular premolars in four 2-year-old beagles were prepared and filled with gutta-percha and sealer. Two to four weeks later, during periapical surgery, the root-end cavity preparations in these teeth were filled with either grey ProRoot MTA or modified (reduced particle sizes with faster setting time) MTA. The animals were sacrificed 4 months later. Degrees of inflammation, type of inflammatory cells, fibrous connective tissue adjacent to the root-end filling materials, cementum formation over the resected roots and root-end filling materials and bone healing were examined. Data were analysed using the McNemar test.

RESULTS

No significant differences in healing of periapical tissues were found when comparing ProRoot MTA to a modified MTA containing reduced particle sizes.

CONCLUSION

Reducing the particle sizes of MTA did not impact its biological properties.

Case characteristics among Middle East respiratory syndrome coronavirus outbreak and non-outbreak cases in Saudi Arabia from 2012 to 2015

OBJECTIVES

As of 1 November 2015, the Saudi Ministry of Health had reported 1273 cases of Middle East respiratory syndrome (MERS); among these cases, which included 9 outbreaks at several hospitals, 717 (56%) patients recovered, 14 (1%) remain hospitalised and 543 (43%) died. This study aimed to determine the epidemiological, demographic and clinical characteristics that distinguished cases of MERS contracted during outbreaks from those contracted sporadically (ie, non-outbreak) between 2012 and 2015 in Saudi Arabia.

DESIGN

Data from the Saudi Ministry of Health of confirmed outbreak and non-outbreak cases of MERS coronavirus (CoV) infections from September 2012 through October 2015 were abstracted and analysed. Univariate and descriptive statistical analyses were conducted, and the time between disease onset and confirmation, onset and notification and onset and death were examined.

RESULTS

A total of 1250 patients (aged 0-109 years; mean, 50.825 years) were reported infected with MERS-CoV. Approximately two-thirds of all MERS cases were diagnosed in men for outbreak and non-outbreak cases. Healthcare workers comprised 22% of all MERS cases for outbreak and non-outbreak cases. Nosocomial infections comprised one-third of all Saudi MERS cases; however, nosocomial infections occurred more frequently in outbreak than non-outbreak cases (p<0.001). Patients contracting MERS during an outbreak were significantly more likely to die of MERS (p<0.001).

CONCLUSIONS

To date, nosocomial infections have fuelled MERS outbreaks. Given that the Kingdom of Saudi Arabia is a worldwide religious travel destination, localised outbreaks may have massive global implications and effective outbreak preventive measures are needed.

The diagnostic utility and cost-effectiveness of selective nerve root blocks in patients considered for lumbar decompression surgery: a systematic review and economic model

BACKGROUND

Diagnostic selective nerve root block (SNRB) involves injection of local anaesthetic, sometimes in conjunction with corticosteroids, around spinal nerves. It is used to identify symptomatic nerve roots in patients with probable radicular pain that is not fully concordant with imaging findings.

OBJECTIVES

(1) Determine the diagnostic accuracy of SNRB in patients with low back and radiating pain in a lower limb; (2) evaluate whether or not accuracy varies by patient subgroups; (3) review injection-related adverse events; and (4) evaluate the cost-effectiveness of SNRB.

DATA SOURCES

MEDLINE, EMBASE, Science Citation Index, Bioscience Information Service (BIOSIS), Latin American and Caribbean Health Sciences Literature (LILACS) and grey literature databases were searched from inception to August 2011. Reference lists of included studies were screened.

METHODS

A systematic review (SR) of studies that assessed the accuracy of SNRB or adverse events in patients with low back pain and symptoms in a lower limb for the diagnosis of lumbar radiculopathy. Study quality was assessed using the quality assessment of diagnostic accuracy studies (QUADAS)-2 checklist. We used random-effects meta-analysis to pool diagnostic accuracy data. Decision tree and Markov models were developed, combining SR results with information on the costs and outcomes of surgical and non-surgical care. Uncertainty was assessed using probabilistic and deterministic sensitivity analyses.

RESULTS

Five studies assessed diagnostic accuracy: three diagnostic cohort and two within-patient case-control studies. All were judged to be at high risk of bias and had high concerns regarding applicability. In individual studies, sensitivity ranged from 57% [95% confidence interval (CI) 43% to 70%] to 100% (95% CI 76% to 100%) and specificity from 9.5% (95% CI 1% to 30%) to 86% (95% CI 76% to 93%). The most reliable estimate was judged to come from two cohort studies that used post-surgery outcome as the reference standard; summary sensitivity and specificity were 93% (95% CI 86% to 97%) and 26% (95% CI 5% to 68%), respectively. No study provided sufficient detail to judge whether or not accuracy varied by patient subgroup. Seven studies assessed adverse events. There were no major or permanent complications; minor complications were reported in 0-6% of patients. The addition of SNRB to the diagnostic work-up was not cost-effective with an incremental cost per quality-adjusted life-year of £1,576,007. Sensitivity analyses confirmed that SNRB was unlikely to be a cost-effective method for diagnosis and planning surgical therapy.

LIMITATIONS

We identified very few studies; all were at high risk of bias. The conduct and interpretation of SNRBs varied and there was no gold standard for diagnosis. Limited information about the impact of SNRB on subsequent care and the long-term costs and benefits of surgery increased uncertainty about cost-effectiveness.

CONCLUSIONS

There were few studies that estimated the diagnostic accuracy of SNRB in patients with radiculopathy and all were limited by the difficulty of making a reference standard diagnosis. Summary estimates suggest that specificity is low, but results are based on a small number of studies at a high risk of bias. Based on current weak evidence, it is unlikely that SNRB is a cost-effective method for identifying the symptomatic nerve root prior to lumbar spine surgery. Future research should focus on randomised controlled trials to evaluate whether or not SNRB improves patient outcomes at acceptable cost.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

AID dysregulation in lupus-prone MRL/Faslpr/lpr mice promotes interchromosomal c-Myc/IgH loci translocations, increased class switch DNA recombination and production of anti-dsDNA IgG autoantibodies: modulation by HoxC4 (148.25)

Activation-induced cytidine deaminase (AID) initiates immunoglobulin (Ig) gene somatic hypermutation (SHM) and class switch DNA recombination (CSR), which are critical in the generation of pathogenic autoantibodies. In these studies, we addressed the regulation of AID by HoxC4 in lupus. We found that SLE patients and lupus-prone MRL/Faslpr/lpr mice displayed increased expression of HoxC4, which directly activates the promoter of the AID gene, and increased expression of AID. Dysregulation of these proteins was associated with increased CSR in B cells of MRL/Faslpr/lpr mice. In the HoxC4-/- MRL/Faslpr/lpr mice we generated, HoxC4-deficiency resulted in reduced AID expression, impaired CSR and decreased serum anti-dsDNA IgG, particularly IgG2a production, in association with a reduction in IgG deposition in kidney glomeruli. Consistent with our previous findings that upregulated AID expression is associated with extensive DNA lesions, we found a high frequency of c-Myc to IgH translocations in MRL/Faslpr/lpr mice. The frequency of c-Myc to IgH translocations was significantly reduced in autoimmune MRL/Faslpr/lpr mice deficient in HoxC4. Our findings showed that HoxC4 is upregulated in lupus B cells, and this plays a major role in dysregulating AID expression, increasing CSR and autoantibody production, and promoting c-Myc to IgH translocations.

East pacific rise: hot springs and geophysical experiments

Hydrothermal vents jetting out water at 380 degrees +/- 30 degrees C have been discovered on the axis of the East Pacific Rise. The hottest waters issue from mineralized chimneys and are blackened by sulfide precipitates. These hydrothermal springs are the sites of actively forming massive sulfide mineral deposits. Cooler springs are clear to milky and support exotic benthic communities of giant tube worms, clams, and crabs similar to those found at the Galápagos spreading center. Four prototype geophysical experiments were successfully conducted in and near the vent area: seismic refraction measurements with both source (thumper) and receivers on the sea floor, on-bottom gravity measurements, in situ magnetic gradiometer measurements from the submersible Alvin over a sea-floor magnetic reversal boundary, and an active electrical sounding experiment. These high-resolution determinations of crustal properties along the spreading center were made to gain knowledge of the source of new oceanic crust and marine magnetic anomalies, the nature of the axial magma chamber, and the depth of hydrothermal circulation.

Colour vision testing for diabetic retinopathy: a systematic review of diagnostic accuracy and economic evaluation

OBJECTIVE

To determine the diagnostic performance and cost-effectiveness of colour vision testing (CVT) to identify and monitor the progression of diabetic retinopathy (DR).

DATA SOURCES

Major electronic databases including MEDLINE, EMBASE, Cumulative Index to Nursing and Allied Health Literature, and Cochrane Database of Systematic Reviews were searched from inception to September 2008.

REVIEW METHODS

A systematic review of the evidence was carried out according to standard methods. An online survey of National Screening Programme for Diabetic Retinopathy (NSPDR) clinical leads and programme managers assessed the diagnostic tools used routinely by local centres and their views on future research priorities. A decision tree and Markov model was developed to estimate the incremental costs and effects of adding CVT to the current NSPDR.

RESULTS

In total, 25 studies on CVT met the inclusion criteria for the review, including 18 presenting 2 x 2 diagnostic accuracy data. The quality of studies and reporting was generally poor. Automated or computerised CVTs reported variable sensitivities (63-97%) and specificities (71-95%). One study reported good diagnostic accuracy estimates for computerised CVT plus retinal photography for detection of sight-threatening DR, but it included few cases of retinopathy in total. Results for pseudoisochromatic plates, anomaloscopes and colour arrangement tests were largely inadequate for DR screening, with Youden indices (sensitivity + specificity - 100%) close to zero. No studies were located that addressed patient preferences relating to CVT for DR. Retinal photography is universally employed as the primary method for retinal screening by centres responding to the online survey; none used CVT. The review of the economic evaluation literature found no previous studies describing the cost and effects of any type of CVT. Our economic evaluation suggested that adding CVT to the current national screening programme could be cost-effective if it adequately increases sensitivity and is relatively inexpensive. The deterministic base-case analysis indicated that the cost per quality-adjusted life-year gained may be 6364 pounds and 12,432 pounds for type 1 and type 2 diabetes respectively. However, probabilistic sensitivity analysis highlighted the substantial probability that CVT is not diagnostically accurate enough to be either an effective or a cost-effective addition to current screening methods. The results of the economic model should be treated with caution as the model is based on only one small study.

CONCLUSIONS

There is insufficient evidence to support the use of CVT alone, or in combination with retinal photography, as a method for screening for retinopathy in patients with diabetes. Better quality diagnostic accuracy studies directly comparing the incremental value of CVT in addition to retinal photography are needed before drawing conclusions on cost-effectiveness. The most frequently cited preference for future research was the use of optical coherence tomography for the detection of clinically significant macular oedema.

Utility of atypical antipsychotics in the treatment of resistant unipolar depression

Many patients fail to achieve an adequate response to antidepressant medication. Growing evidence suggests that atypical antipsychotics may augment antidepressant effects, resulting in a greater potential for response. Atypical antipsychotics possess pharmacological actions that are associated with antidepressant properties, including serotonin 5-HT(2) receptor antagonist and 5-HT(1A) and dopamine receptor partial agonist activity. In fact, the term 'atypical antipsychotic' is an unfortunate remnant of the early indication of these drugs in the treatment of schizophrenia. Soon after their introduction, the usefulness of atypical antipsychotics in bipolar disorder was firmly established and their use in the treatment of mood disorders has far outpaced their use in schizophrenia and other psychotic disorders. Aripiprazole has become the first agent to receive US FDA approval for the adjunctive treatment of unipolar depression. Most recently, Symbyax, a fluoxetine/olanzapine combination, received FDA approval for the acute treatment of treatment-resistant depression. This is the first medication to be FDA approved for this indication. In the present article, the usefulness of antipsychotics in the treatment of resistant unipolar depression is reviewed.

A virtual look at Epstein-Barr virus infection: simulation mechanism

Epstein-Barr virus (EBV) is an important human pathogen that establishes a life-long persistent infection and for which no precise animal model exists. In this paper, we describe in detail an agent-based model and computer simulation of EBV infection. Agents representing EBV and sets of B and T lymphocytes move and interact on a three-dimensional grid approximating Waldeyer's ring, together with abstract compartments for lymph and blood. The simulation allows us to explore the development and resolution of virtual infections in a manner not possible in actual human experiments. Specifically, we identify parameters capable of inducing clearance, persistent infection, or death.

How infrastructure procurement can enhance social development

This paper reports the findings of a study by Engineers Against Poverty and the Institution of Civil Engineers into the factors in infrastructure procurement that are currently inhibiting the achievement of social development objectives. The paper explores the impact/performance of the asset and the service it delivers (the product), and the opportunities during the project's construction and operation (the process). The study adopted a very broad definition of ‘procurement’ to embrace all stages from project identification to the final monitoring, enforcement and evaluation. Methods included reviews of procurement documentation and practice in four case-study countries (India, Indonesia, Kenya and Nigeria), round-table discussions and in-depth interviews with stakeholders. This yielded a long list of inhibiting factors but also some encouraging efforts at reform. The paper concludes that procurement procedures and contract agreement have the potential to promote social objectives. However, the objectives should be clearly identified in the project design; the budget and procurement strategy have to be appropriate; and implementation must be monitored and enforced.