Rheumatic Heart Disease Severity, Progression and Outcomes: A Multi-State Model

Background

Rheumatic heart disease (RHD) remains a disease of international importance, yet little has been published about disease progression in a contemporary patient cohort. Multi‐state models provide a well‐established method of estimating rates of transition between disease states, and can be used to evaluate the cost‐effectiveness of potential interventions. We aimed to create a multi‐state model for RHD progression using serial clinical data from a cohort of Australian patients.

Methods and Results

The Northern Territory RHD register was used to identify all Indigenous residents diagnosed with RHD between the ages of 5 and 24 years in the time period 1999–2012. Disease severity over time, surgeries, and deaths were evaluated for 591 patients. Of 96 (16.2%) patients with severe RHD at diagnosis, 50% had proceeded to valve surgery by 2 years, and 10% were dead within 6 years. Of those diagnosed with moderate RHD, there was a similar chance of disease regression or progression over time. Patients with mild RHD at diagnosis were the most stable, with 64% remaining mild after 10 years; however, 11.4% progressed to severe RHD and half of these required surgery.

Conclusions

The prognosis of young Indigenous Australians diagnosed with severe RHD is bleak; interventions must focus on earlier detection and treatment if the observed natural history is to be improved. This multi‐state model can be used to predict the effect of different interventions on disease progression and the associated costs.

A quantitative analysis of attitudes and behaviours concerning sustainable parasite control practices from Scottish sheep farmers

Nematode control in sheep, by strategic use of anthelmintics, is threatened by the emergence of roundworms populations that are resistant to one or more of the currently available drugs. In response to growing concerns of Anthelmintic Resistance (AR) development in UK sheep flocks, the Sustainable Control of Parasites in Sheep (SCOPS) initiative was set up in 2003 in order to promote practical guidelines for producers and advisors. To facilitate the uptake of 'best practice' approaches to nematode management, a comprehensive understanding of the various factors influencing sheep farmers' adoption of the SCOPS principles is required. A telephone survey of 400 Scottish sheep farmers was conducted to elicit attitudes regarding roundworm control, AR and 'best practice' recommendations. A quantitative statistical analysis approach using structural equation modelling was chosen to test the relationships between both observed and latent variables relating to general roundworm control beliefs. A model framework was developed to test the influence of socio-psychological factors on the uptake of sustainable (SCOPS) and known unsustainable (AR selective) roundworm control practices. The analysis identified eleven factors with significant influences on the adoption of SCOPS recommended practices and AR selective practices. Two models established a good fit with the observed data with each model explaining 54% and 47% of the variance in SCOPS and AR selective behaviours, respectively. The key influences toward the adoption of best practice parasite management, as well as demonstrating negative influences on employing AR selective practices were farmer's base line understanding about roundworm control and confirmation about lack of anthelmintic efficacy in a flock. The findings suggest that improving farmers' acceptance and uptake of diagnostic testing and improving underlying knowledge and awareness about nematode control may influence adoption of best practice behaviour.

European Pharmacopoeia biological reference preparation for poliomyelitis vaccine (inactivated): collaborative study for the establishment of batch No. 3

Inactivated poliomyelitis vaccines are an important part of the World Health Organization (WHO) control strategy to eradicate poliomyelitis. Requirements for the quality control of poliomyelitis vaccines (inactivated) include the use of an in vitro D antigen quantification assay for potency determination on the final lot as outlined in the European Pharmacopoeia (Ph. Eur.) monograph 0214. Performance of this assay requires a reference preparation calibrated in International Units (IU). A Ph. Eur. biological reference preparation (BRP) for poliomyelitis vaccine (inactivated) calibrated in IU has been established for this purpose. Due to the dwindling stocks of batch 2 of the BRP a collaborative study was run as part of the European Directorate for the Quality of Medicines & HealthCare (EDQM) Biological Standardisation Programme to establish BRP batch 3 (BRP3). Twelve laboratories including Official Medicines Control Laboratories (OMCLs) and manufacturers participated. The candidate BRP3 (cBRP3) was from the same source and had the same characteristics as BRP batch 2 (BRP2). During the study the candidate was calibrated against the 3^rd International Standard for inactivated poliomyelitis vaccine using in-house D antigen ELISA assays in line with the Ph. Eur. monograph 0214. The candidate was also compared to BRP2 to evaluate the continuity. Based on the results of the study, values of 320 DU/mL, 78 DU/mL and 288 DU/mL (D antigen units/mL) (IU) for poliovirus type 1, 2 and 3 respectively were assigned to the candidate. In June 2016, the Ph. Eur. Commission adopted the material as Ph. Eur. BRP for poliomyelitis vaccine (inactivated) batch 3.

EDQM biological reference preparation for rabies vaccine (inactivated) for veterinary use

Rabies is a deadly zoonotic disease. Control of rabies in animals by vaccination is an important strategy to protect humans from infection and control the spread of the disease. Requirements for the quality control of rabies vaccines (inactivated) for veterinary use include an in vivo quantitative potency determination as outlined in the Ph. Eur. monograph 0451. Performance of this assay requires a reference preparation calibrated in International Units (IU). A European Pharmacopeia (Ph. Eur.) Biological Reference Preparation (BRP) for rabies vaccines (inactivated) for veterinary use, calibrated in IU, has been established for this purpose. Due to the dwindling stocks of the current batch (batch 4) of Ph. Eur. BRP for rabies vaccines (inactivated) for veterinary use, a collaborative study was run as part of the EDQM Biological Standardisation Programme to establish BRP batch 5. Ten laboratories, including Official Medicines Control Laboratories and manufacturers, participated. The candidate BRP5 was assayed against the 6(th) International Standard for rabies vaccine using the in vivo vaccination-challenge assay (monograph 0451) to assign a potency value. The candidate was also compared to BRP batch 4 to establish continuity. Taking into account the results from the comparisons a potency of 10 IU/vial was assigned and in March 2015 the Ph. Eur. Commission adopted the material as Ph. Eur. BRP for rabies vaccines (inactivated) for veterinary use batch 5. In addition to the in vivo assay 3 laboratories tested the candidate material using their in-house in vitro assays for information.

Economic and clinical benefit of collagenase ointment compared to a hydrogel dressing for pressure ulcer debridement in a long-term care setting

INTRODUCTION

The purpose of this study is to determine the cost-effectiveness of collagenase ointment relative to autolysis with a hydrogel dressing when debriding necrotic pressure ulcers in a long-term care setting.

METHODS

A Markov decision process model with 2 states (necrotic nonviable wound bed transitioning to a granulated viable wound bed) was developed using data derived from a prospective, randomized, 6-week, single-center trial of 27 institutionalized subjects with pressure ulcers that were ≥ 85% necrotic nonviable tissue. Direct medical costs from the payer perspective included study treatments, wound treatment supplies, and nursing time. Clinical benefit was measured as "granulation days" and was derived from the time-dependent debridement rates of the alternative products.

RESULTS

The average cost per patient for 42 days of pressure ulcer care was $1,817 in 2012 for the collagenase group and $1,611 for the hydrogel group. Days spent with a granulated wound were 3.6 times higher for collagenase (23.4 vs 6.5) than with the hydrogel. The estimated cost per granulation day was > 3.2 times higher for hydrogel ($249) vs collagenase ($78).

CONCLUSIONS

In this economic analysis based on a randomized, controlled clinical trial, collagenase ointment resulted in a faster time to complete debridement and was more cost-effective than hydrogel autolysis for pressure ulcers in a long-term care setting. Even though collagenase ointment has a higher acquisition cost than hydrogel, the clinical benefit offsets the initial cost difference, resulting in lower cost per granulation day to the nursing home over the course of the 42-day analysis.

Evaluation of the impact and control of enzootic abortion of ewes

Despite the availability of effective management and treatment strategies, Chlamydia abortus remains the single most frequently diagnosed cause of infectious ovine abortion (enzootic abortion of ewes, EAE) in the UK and one of the most significant causes of lamb mortality world-wide. In 2007, a survey of UK farmers, veterinarians and other farm animal holders was conducted to gather information on their perceptions of the risk of acquiring infection and the management practices employed to control the disease. The survey indicated that the preferred options for controlling EAE are either through vaccination and/or keeping flocks closed. However, further analysis of data indicates that implementation of these strategies does not provide a guarantee of exclusion of disease from flocks and thus further work is required to improve on current intervention strategies.

New BRP for human plasma calibrated for coagulation factors V, VIII, XI and XIII - collaborative study for establishment of batches 1 and 2

A human plasma reference preparation in International Units (IU) must be used in each potency assay of the human coagulation factors V, VIII and XI in human plasma pooled and treated for virus inactivation, according to the European Pharmacopoeia (Ph. Eur.) monograph 1646 and general chapters 2.7.4 and 2.7.22 respectively, and in the potency assay of human coagulation factor XIII in fibrin sealant kits, according to Ph. Eur. monograph 0903. International reference standards for all of these factors are now established, however, regional reference standards were not available for the required routine use. It was therefore proposed by European OMCLs and manufacturers to establish a European reference preparation, and it was the goal of this study to accomplish that. Two candidate biological reference preparations (BRPs), separate lyophilisation lots of the same normal human plasma bulk material, were calibrated against the International Standards (ISs) for human coagulation factors V, VIII, XI and XIII. Twelve European laboratories including OMCLs and manufacturers participated. The candidate material was tested against the ISs in 4 separate assays for each factor using the methods described in the relevant Ph. Eur. monographs and general chapters. No discernable difference was noted between the activities of the 2 candidates. They were shown to be suitable for their intended use and it was recommended to assign to both batches a potency of 0.73 IU/mL for factor V, 0.74 IU/mL for factor VIII, 0.59 IU/mL for factor XI and 0.79 IU/mL for factor XIII. Candidate batch B is proposed to be used first as lot 1, followed upon its depletion by candidate batch A (lot 2). The BRP batches will be monitored regularly for potency throughout their lifetime. EDQM BRP batches 1 and 2 of coagulation factors V, VIII, XI and XIII plasma were formally adopted by the Ph. Eur. Commission at their session in June 2011.

Nonthermal melting of a charge density wave in TiSe2

We use time-resolved optical reflectivity and x-ray diffraction with femtosecond resolution to study the dynamics of the structural order parameter of the charge density wave phase in TiSe2. We find that the energy density required to melt the charge density wave nonthermally is substantially lower than that required for thermal suppression and is comparable to the charge density wave condensation energy. This observation, together with the fact that the structural dynamics take place on an extremely fast time scale, supports the exciton condensation mechanism for the charge density wave in TiSe2.

Collaborative study for validation of a serological potency assay for rabies vaccine (inactivated) for veterinary use

European Pharmacopoeia (Ph. Eur.) monograph 0451 on Rabies vaccine (inactivated) for veterinary use describes an in vivo batch potency test that is based on the NIH test. This assay uses a large number of mice and results in a significant degree of suffering. In the interest of replacement, reduction and refinement of animal tests (3R) a serological potency assay for Rabies vaccine (inactivated) for animal use, developed and validated at the Paul-Ehrlich-Institut, has been assessed in a collaborative study organised by the EDQM (European Directorate for the Quality of Medicines & HealthCare). The goal was to demonstrate the wider transferability of the proposed assay and confirm its suitability. The study involved 13 laboratories and assessed 4 different vaccines from the EU market. Results of the study confirm that a limit test using a relatively small number of animals in a serological assay is possible, reproducible and reliable. The optimal number of animals per vaccine is product specific but may roughly be indicated to be between 8 and 10 for the products included in this study. Non-responders should be included in the analysis because they may reflect sub-potent vaccines. However, there may be a need to impose a maximum on the number of non-responders allowed for the reference vaccine as a monitor for assay validity. This assay provides a significant 3R improvement in terms of both the number of animals used and the amount of suffering entailed and provides a more reliable and reproducible assay format than the vaccination challenge assay. It also reduces the time required as compared to the vaccination challenge assay. It has been recommended to the Ph. Eur. group of experts 15V that this assay be included as an alternative to the batch potency assay in the Ph. Eur. monograph 0451.

Establishment of the Ph. Eur. BRP for varicella vaccine batch 1

The European Pharmacopoeia (Ph. Eur.) monograph for varicella vaccine (live) (0648) requires a vial of an appropriate reference material to be titred in triplicate to validate each assay and the virus concentration of the reference preparation is monitored using a control chart to determine the assay consistency. An international collaborative study involving 9 participants from 7 countries and including both OMCLs and manufacturers was carried out to establish a common reference material for this purpose and establish a Ph. Eur. Biological Reference Preparation. Two candidate reference preparations (X and Y), obtained from 2 different EU manufacturers, were assayed by the participants using their in-house PFU assay methods. Both candidates were found to be suitable for this purpose. Based on logistical considerations, candidate X (4.37 log(10)0 PFU/vial) has been established as BRP batch 1 of varicella vaccine (live) and was adopted at the June 2009 session of the European Pharmacopoeia Commission for immediate use. Candidate Y (3.82 log(10) PFU/vial) will be established as BRP batch 2 upon depletion of BRP batch 1 provided that the stability data supports this.

Non-steroidal anti-inflammatory drugs in sports medicine: guidelines for practical but sensible use

INTRODUCTION

Non-steroidal anti-inflammatory drugs (NSAID) are commonly used in sports medicine. NSAID have known anti-inflammatory, analgesic, antipyretic and antithrombotic effects, although their in-vivo effects in treating musculoskeletal injuries in humans remain largely unknown. NSAID analgesic action is not significantly greater than paracetamol for musculoskeletal injury but they have a higher risk profile, with side-effects including asthma exacerbation, gastrointestinal and renal side-effects, hypertension and other cardiovascular diseases.

DISCUSSION

The authors recommend an approach to NSAID use in sports medicine whereby simple analgesia is preferentially used when analgesia is the primary desired outcome. However, based both on the current pathophysiological understanding of most injury presentations and the frequency that inflammation may actually be a component of the injury complex, it is premature to suppose that NSAID are not useful to the physician managing sports injuries. The prescribing of NSAID should be cautious and both situation and pathology specific. Both dose and duration minimisation should be prioritized and combined with simple principles of protection, rest, ice, compression, elevation (PRICE), which should allow NSAID-sparing. NSAID use should always be coupled with appropriate physical rehabilitation.

CONCLUSION

NSAID are probably most useful for treating nerve and soft-tissue impingements, inflammatory arthropathies and tenosynovitis. They are not generally indicated for isolated chronic tendinopathy, or for fractures. The use of NSAID in treating muscle injury is controversial. Conditions in which NSAID use requires more careful assessment include ligament injury, joint injury, osteoarthritis, haematoma and postoperatively.

Femtosecond XANES study of the light-induced spin crossover dynamics in an iron(II) complex

X-ray absorption spectroscopy is a powerful probe of molecular structure, but it has previously been too slow to track the earliest dynamics after photoexcitation. We investigated the ultrafast formation of the lowest quintet state of aqueous iron(II) tris(bipyridine) upon excitation of the singlet metal-to-ligand-charge-transfer (1MLCT) state by femtosecond optical pump/x-ray probe techniques based on x-ray absorption near-edge structure (XANES). By recording the intensity of a characteristic XANES feature as a function of laser pump/x-ray probe time delay, we find that the quintet state is populated in about 150 femtoseconds. The quintet state is further evidenced by its full XANES spectrum recorded at a 300-femtosecond time delay. These results resolve a long-standing issue about the population mechanism of quintet states in iron(II)-based complexes, which we identify as a simple 1MLCT-->3MLCT-->5T cascade from the initially excited state. The time scale of the 3MLCT-->5T relaxation corresponds to the period of the iron-nitrogen stretch vibration.

Establishment of European pharmacopoeia Mycoplasma reference strains

European Pharmacopoeia (Ph. Eur.) general chapter 2.6.7. Mycoplasma requires for the culture test reference strains of mycoplasma field isolates with fewer than 15 passages for validation and run control and in the test for inhibitory substances. Low passage field isolates of 5 mycoplasma strains (Mycoplasma hyorhinis, Mycoplasma synoviae, Mycoplasma fermentans, Mycoplasma orale and Acholeplasma laidlawii) have been prepared for this purpose and a small scale collaborative study involving European laboratories was carried out to confirm the suitability of the material for the intended purpose. Strains were prepared as 1 ml samples in frozen format and are stored below -60 degrees C. Each laboratory determined a titre for the material on their in-house media. A secondary part of the study also compared the growth of prediluted samples on the different culture media. Results of the study confirm that the material is suitable for use as a biological reference preparation (BRP) and an estimated titre has been provided for each strain based on the results of the study. It was noted that differences in the culture media used in the different laboratories did not have a detrimental effect on titre estimation. The estimated titre is intended as a guide for users to validate the use of the reference material in house. The candidate BRPs were adopted by the European Pharmacopoeia Commission on June 28, 2006 and are available for use from EDQM. A revision to chapter 2.6.7, including reference to the use of nucleic acid amplification techniques (NAT) was also adopted in June 2006 and will appear in the European Pharmacopoeia version 5.8 in January 2007 and come into force the 1st of July 2007. While it was not part of the study a number of participants also performed in-house NAT assays on the study material. Preliminary findings from these studies are presented.