Protocol for a multicentre, parallel-arm, 12-month, randomised, controlled trial of arthroscopic surgery versus conservative care for femoroacetabular impingement syndrome (FASHIoN)

INTRODUCTION

Femoroacetabular impingement (FAI) syndrome is a recognised cause of young adult hip pain. There has been a large increase in the number of patients undergoing arthroscopic surgery for FAI; however, a recent Cochrane review highlighted that there are no randomised controlled trials (RCTs) evaluating treatment effectiveness. We aim to compare the clinical and cost-effectiveness of arthroscopic surgery versus best conservative care for patients with FAI syndrome.

METHODS

We will conduct a multicentre, pragmatic, assessor-blinded, two parallel arm, RCT comparing arthroscopic surgery to physiotherapy-led best conservative care. 24 hospitals treating NHS patients will recruit 344 patients over a 26-month recruitment period. Symptomatic adults with radiographic signs of FAI morphology who are considered suitable for arthroscopic surgery by their surgeon will be eligible. Patients will be excluded if they have radiographic evidence of osteoarthritis, previous significant hip pathology or previous shape changing surgery. Participants will be allocated in a ratio of 1:1 to receive arthroscopic surgery or conservative care. Recruitment will be monitored and supported by qualitative intervention to optimise informed consent and recruitment. The primary outcome will be pain and function assessed by the international hip outcome tool 33 (iHOT-33) measured 1-year following randomisation. Secondary outcomes include general health (short form 12), quality of life (EQ5D-5L) and patient satisfaction. The primary analysis will compare change in pain and function (iHOT-33) at 12 months between the treatment groups, on an intention-to-treat basis, presented as the mean difference between the trial groups with 95% CIs. The study is funded by the Health Technology Assessment Programme (13/103/02).

ETHICS AND DISSEMINATION

Ethical approval is granted by the Edgbaston Research Ethics committee (14/WM/0124). The results will be disseminated through open access peer-reviewed publications, including Health Technology Assessment, and presented at relevant conferences.

TRIAL REGISTRATION NUMBER

ISRCTN64081839; Pre-results.

Temporal embryonic transcription of chicken fast skeletal myosin heavy chain isoforms in the single comb white leghorn

There are numerous factors that can significantly influence embryonic development in poultry and thus make simple days of incubation (chronological age) a less than perfect metric for studying embryonic physiology. The developmental fast skeletal muscle myosin (MyHC), the predominant protein in the Pectoralis major (PM), is temporally expressed as a cadre of highly specific developmental isoforms. In the study described herein, a novel molecular technology (NanoString) was used to characterize the myosin isoform transcriptional patterns in the PM of Single Comb White Leghorn (SCWL) embryos. NanoString technology is based on quantitative analysis of the transcriptome through digital detection and quantification of target mRNA transcripts. Total RNA was isolated and gene transcription quantified using NanoString in embryonic muscle samples collected daily from 6 through 19 days of incubation. Data were analyzed using the LOESS smoothing function at a 95% confidence level. The temporal transcription of MyHC isoforms obtained in this study was consistent with the literature at higher specificity and resolution, thus validating NanoString for use in gene transcription analyses. The results support a hypothesis that the transcription patterns of the embryonic MyHC isoforms may be used as molecular clocks to further investigate the developmental relationships underlying embryonic fast skeletal muscle growth and development.

The role of defensive ecological interactions in the evolution of conotoxins

Venoms comprise of complex mixtures of peptides evolved for predation and defensive purposes. Remarkably, some carnivorous cone snails can inject two distinct venoms in response to predatory or defensive stimuli, providing a unique opportunity to study separately how different ecological pressures contribute to toxin diversification. Here, we report the extraordinary defensive strategy of the Rhizoconus subgenus of cone snails. The defensive venom from this worm-hunting subgenus is unusually simple, almost exclusively composed of αD-conotoxins instead of the ubiquitous αA-conotoxins found in the more complex defensive venom of mollusc- and fish-hunting cone snails. A similarly compartmentalized venom gland as those observed in the other dietary groups facilitates the deployment of this defensive venom. Transcriptomic analysis of a Conus vexillum venom gland revealed the αD-conotoxins as the major transcripts, with lower amounts of 15 known and four new conotoxin superfamilies also detected with likely roles in prey capture. Our phylogenetic and molecular evolution analysis of the αD-conotoxins from five subgenera of cone snails suggests they evolved episodically as part of a defensive strategy in the Rhizoconus subgenus. Thus, our results demonstrate an important role for defence in the evolution of conotoxins.

Grain rotation and lattice deformation during perovskite spray coating and annealing probed in situ by GI-WAXS

Synchrotron grazing incidence WAXS is used to track CH₃NH₃PbI₃ precursor and perovskite crystallites rotation in situ during solution-deposition and thermal annealing.

Importance of risk factor management in diabetic patients and reduction in Stage B heart failure

BACKGROUND

A number of studies have demonstrated the presence of a diabetic cardiomyopathy, increasing the risk of heart failure development in this population. Improvements in present-day risk factor control may have modified the risk of diabetes-associated cardiomyopathy.

AIM

We sought to determine the contemporary impact of diabetes mellitus (DM) on the prevalence of cardiomyopathy in at-risk patients with and without adjustment for risk factor control.

DESIGN

A cross-sectional study in a population at risk for heart failure.

METHODS

Those with diabetes were compared to those with other cardiovascular risk factors, unmatched, matched for age and gender and then matched for age, gender, body mass index, systolic blood pressure and low density lipoprotein cholesterol.

RESULTS

In total, 1399 patients enrolled in the St Vincent's Screening to Prevent Heart Failure (STOP-HF) cohort were included. About 543 participants had an established history of DM. In the whole sample, Stage B heart failure (asymptomatic cardiomyopathy) was not found more frequently among the diabetic cohort compared to those without diabetes [113 (20.8%) vs. 154 (18.0%), P = 0.22], even when matched for age and gender. When controlling for these risk factors and risk factor control Stage B was found to be more prevalent in those with diabetes [88 (22.2%)] compared to those without diabetes [65 (16.4%), P = 0.048].

CONCLUSION

In this cohort of patients with established risk factors for Stage B heart failure superior risk factor management among the diabetic population appears to dilute the independent diabetic insult to left ventricular structure and function, underlining the importance and benefit of effective risk factor control in this population on cardiovascular outcomes.

Valganciclovir for symptomatic congenital cytomegalovirus disease

BACKGROUND

The treatment of symptomatic congenital cytomegalovirus (CMV) disease with intravenous ganciclovir for 6 weeks has been shown to improve audiologic outcomes at 6 months, but the benefits wane over time.

METHODS

We conducted a randomized, placebo-controlled trial of valganciclovir therapy in neonates with symptomatic congenital CMV disease, comparing 6 months of therapy with 6 weeks of therapy. The primary end point was the change in hearing in the better ear ("best-ear" hearing) from baseline to 6 months. Secondary end points included the change in hearing from baseline to follow-up at 12 and 24 months and neurodevelopmental outcomes, with each end point adjusted for central nervous system involvement at baseline.

RESULTS

A total of 96 neonates underwent randomization, of whom 86 had follow-up data at 6 months that could be evaluated. Best-ear hearing at 6 months was similar in the 6-month group and the 6-week group (2 and 3 participants, respectively, had improvement; 36 and 37 had no change; and 5 and 3 had worsening; P=0.41). Total-ear hearing (hearing in one or both ears that could be evaluated) was more likely to be improved or to remain normal at 12 months in the 6-month group than in the 6-week group (73% vs. 57%, P=0.01). The benefit in total-ear hearing was maintained at 24 months (77% vs. 64%, P=0.04). At 24 months, the 6-month group, as compared with the 6-week group, had better neurodevelopmental scores on the Bayley Scales of Infant and Toddler Development, third edition, on the language-composite component (P=0.004) and on the receptive-communication scale (P=0.003). Grade 3 or 4 neutropenia occurred in 19% of the participants during the first 6 weeks. During the next 4.5 months of the study, grade 3 or 4 neutropenia occurred in 21% of the participants in the 6-month group and in 27% of those in the 6-week group (P=0.64).

CONCLUSIONS

Treating symptomatic congenital CMV disease with valganciclovir for 6 months, as compared with 6 weeks, did not improve hearing in the short term but appeared to improve hearing and developmental outcomes modestly in the longer term. (Funded by the National Institute of Allergy and Infectious Diseases; ClinicalTrials.gov number, NCT00466817.).

Post-operative bilateral adrenal haemorrhage: A case report

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An unusual complication of intra-abdominal sepsis.

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A demonstration of diagnostic difficulty in the post-operative patient.

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A variation from the normal electrolyte profile observed in adrenal insufficiency.

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Highlights the clinical importance of a high index of suspicion for further investigation of ‘on-ward’ electrolyte abnormalities.

INTRODUCTION

Bilateral adrenal haemorrhage is a rare, but serious, illness carrying an estimated 15% mortality.^1,2 The majority of cases occur in patients with acute, stressful illness, however the exact mechanism underlying adrenal haemorrhage remains unclear. This medical emergency carries significant diagnostic difficulty⁴ with non-specific clinical symptoms and variations in electrolyte abnormalities. Timely treatment is important as it prevents both the acute and long-term sequelae of adrenal failure.

PRESENTATION OF CASE

This report describes a medical emergency in a surgical patient following emergency surgery for intra-abdominal sepsis. The patient reported non-specific symptoms of confusion, mild pyrexia and vague abdominal pain during the post-operative phase, with subtle electrolyte abnormalities and a low serum cortisol suggestive of adrenal crisis. Timely medical treatment, with intravenous hydrocortisone and intensive monitoring, and appropriate medical follow-up with addition of long-term fludrocortisone resulted in a satisfactory outcome.

DISCUSSION

This report describes a potentially life-threatening complication of intra-abdominal sepsis with adrenal crisis secondary to bilateral adrenal haemorrhage. In particular, this case highlights the diagnostic difficulty in such surgical patients due to vague symptoms and, in this case, the presence of a presentation variant with acute hyponatraemia and normal potassium.

CONCLUSION

This case highlights the importance of awareness of both the symptoms and signs and variation in electrolyte profile when assessing surgical patients post-operatively. In addition, this case highlights the benefit of early recognition and initiation of treatment and the importance of follow-up as long-term medical management is often required to prevent further relapse.

Proliferation, differentiation and amyloid-β production in neural progenitor cells isolated from TgCRND8 mice

The amyloid precursor protein (APP) and amyloid-β (Aβ) peptide play central roles in the pathology and etiology of Alzheimer's disease. Amyloid-induced impairments in neurogenesis have been investigated in several transgenic mouse models but the mechanism of action remains to be conclusively demonstrated. The changes in neurogenesis during this transition of increasing Aβ levels and plaque formation were investigated in the present study. We found that the proliferation of newborn cell in the dentate gyrus was enhanced prior to elevations in soluble Aβ production as well as amyloid deposition in 5-week-old TgCRND8 mice, which are well-established Alzheimer's disease models, compared to non-transgenic (Non-Tg) mice. The number of BrdU-positive cells remained higher in TgCRND8 vs Non-Tg mice for a period of 8weeks. The numbers of BrdU/NeuN-positive cells were not significantly different in TgCRND8 compared to Non-Tg mice. A significant decrease in BrdU/GFAP but not in BrdU/S100β was found in Tg vs Non-Tg at 6-weeks of age. In addition, a unique observation was made using isolated neuroprogenitor cells from TgCRND8 mice which were found to be less viable in culture and produced substantial amounts of secreted Aβ peptides. This suggests that the proliferation of neural progenitors in vivo may be modulated by high levels of APP expression and the resulting Aβ generated directly by the progenitor cells. These findings indicate that cell proliferation is increased prior to Aβ deposition and that cell viability is decreased in TgCRND8 mice over time.

Oral acyclovir suppression and neurodevelopment after neonatal herpes

BACKGROUND

Poor neurodevelopmental outcomes and recurrences of cutaneous lesions remain unacceptably frequent among survivors of neonatal herpes simplex virus (HSV) disease.

METHODS

We enrolled neonates with HSV disease in two parallel, identical, double-blind, placebo-controlled studies. Neonates with central nervous system (CNS) involvement were enrolled in one study, and neonates with skin, eye, and mouth involvement only were enrolled in the other. After completing a regimen of 14 to 21 days of parenteral acyclovir, the infants were randomly assigned to immediate acyclovir suppression (300 mg per square meter of body-surface area per dose orally, three times daily for 6 months) or placebo. Cutaneous recurrences were treated with open-label episodic therapy.

RESULTS

A total of 74 neonates were enrolled--45 with CNS involvement and 29 with skin, eye, and mouth disease. The Mental Development Index of the Bayley Scales of Infant Development (in which scores range from 50 to 150, with a mean of 100 and with higher scores indicating better neurodevelopmental outcomes) was assessed in 28 of the 45 infants with CNS involvement (62%) at 12 months of age. After adjustment for covariates, infants with CNS involvement who had been randomly assigned to acyclovir suppression had significantly higher mean Bayley mental-development scores at 12 months than did infants randomly assigned to placebo (88.24 vs. 68.12, P=0.046). Overall, there was a trend toward more neutropenia in the acyclovir group than in the placebo group (P=0.09).

CONCLUSIONS

Infants surviving neonatal HSV disease with CNS involvement had improved neurodevelopmental outcomes when they received suppressive therapy with oral acyclovir for 6 months. (Funded by the National Institute of Allergy and Infectious Diseases; CASG 103 and CASG 104 ClinicalTrials.gov numbers, NCT00031460 and NCT00031447, respectively.).

Ultrasound in regional anaesthesia

Ultrasound guidance is rapidly becoming the gold standard for regional anaesthesia. There is an ever growing weight of evidence, matched with improving technology, to show that the use of ultrasound has significant benefits over conventional techniques, such as nerve stimulation and loss of resistance. The improved safety and efficacy that ultrasound brings to regional anaesthesia will help promote its use and realise the benefits that regional anaesthesia has over general anaesthesia, such as decreased morbidity and mortality, superior postoperative analgesia, cost-effectiveness, decreased postoperative complications and an improved postoperative course. In this review we consider the evidence behind the improved safety and efficacy of ultrasound-guided regional anaesthesia, before discussing its use in pain medicine, paediatrics and in the facilitation of neuraxial blockade. The Achilles' heel of ultrasound-guided regional anaesthesia is that anaesthetists are far more familiar with providing general anaesthesia, which in most cases requires skills that are achieved faster and more reliably. To this ends we go on to provide practical advice on ultrasound-guided techniques and the introduction of ultrasound into a department.

Intramuscular interferon beta-1a in chronic inflammatory demyelinating polyradiculoneuropathy

OBJECTIVE

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) shares immunologic features with multiple sclerosis (MS). Because IM interferon beta-1a (IM IFNbeta-1a) is an effective and safe treatment for MS, we conducted a dose-ranging efficacy study of IFNbeta-1a in patients with CIDP.

METHODS

Adults with IV immunoglobulin (IVIg)-dependent CIDP (n = 67) were enrolled in this 32-week double-blind trial and randomized to IM IFNbeta-1a. Patients received 30 microg once weekly plus placebo (n = 12), IM IFNbeta-1a 60 microg once weekly plus placebo (n = 11), IM IFNbeta-1a 30 microg twice weekly (n = 11), IM IFNbeta-1a 60 microg twice weekly (n = 11), or placebo twice weekly (n = 22). Participants were maintained on IVIg through week 16, when IVIg was discontinued. Patients who worsened were restarted on IVIg. The primary outcome was total IVIg dose (g/kg) administered from week 16 to 32.

RESULTS

There was no difference in total IVIg dose administered after week 16 for patients treated with IFNbeta-1a (1.20 g/kg) compared with placebo (1.34 g/kg; p = 0.75). However, exploratory analyses suggested IFNbeta-1a significantly reduced total dose of IVIg compared with placebo for participants who required either high-dose IVIg (>0.95 g/kg per month) or had greater weakness at baseline (Medical Research Council sum score <51). Adverse events included flu-like symptoms, headache, and fatigue in the IFNbeta-1a groups.

CONCLUSIONS

Interferon beta-1a (IFNbeta-1a) therapy did not provide significant benefit over IV immunoglobulin (IVIg) therapy alone for patients with chronic inflammatory demyelinating polyradiculoneuropathy. However, IFNbeta-1a might be beneficial for patients with more severe disability or those needing high doses of IVIg.

LEVEL OF EVIDENCE

This study was designed to provide Class I evidence for the safety and efficacy of IM IFNbeta-1a in the treatment of CIDP but has been subsequently classified as Class II due to a >20% patient dropout rate. Thus, this randomized, controlled clinical trial provides Class II evidence of no effect on primary and secondary endpoints of 4 dosage regimens of IM IFNbeta-1a added to IVIg in persons with CIDP.

Safety of oseltamivir compared with the adamantanes in children less than 12 months of age

BACKGROUND

When oseltamivir is administered in extremely high doses (500-1000 mg/kg) to young juvenile rats, central nervous system toxicity and death occurred in some animals. Mortality was not observed in older juvenile rats, suggesting a possible relationship between neurotoxicity and an immature blood-brain barrier. To assess potential neurologic adverse effects of oseltamivir use in infants, a retrospective chart review was performed in infants less than 12 months of age who received oseltamivir, amantadine, or rimantadine.

METHODS

The primary objective was to describe the frequency of neurologic adverse events among children less than 12 months of age who received oseltamivir compared with those receiving adamantanes. Medical record databases, emergency department databases, and/or pharmacy records at 15 medical centers were searched to identify patients.

RESULTS

Of the 180 infants identified as having received antiviral therapy, 115 (64%) received oseltamivir, 37 (20%) received amantadine, and 28 (16%) received rimantadine. The median dose of oseltamivir was 2.0 mg/kg/dose in 3- to 5-month-old and 2.2 mg/kg/dose in 9- to 12-month-old infants. The maximum dose administered was 7.0 mg/kg/dose. There were no statistically significant differences in the occurrence of adverse neurologic events during therapy among subjects treated with oseltamivir versus those treated with the adamantanes (P = 0.13).

CONCLUSIONS

This is the largest report to date of oseltamivir use in children less than 12 months of age. Neurologic events were not more common with use of oseltamivir compared with that of the adamantanes. Dosing of oseltamivir was variable, illustrating the need for pharmacokinetic data in this younger population.

Caffeine ingestion and fluid balance: a review

BACKGROUND

Caffeine and related methylxanthine compounds are recognized as having a diuretic action, and consumers are often advised to avoid beverages containing these compounds in situations where fluid balance may be compromised. The aim of this review is to evaluate the available literature concerning the effect of caffeine ingestion on fluid balance and to formulate targeted and evidence-based advice on caffeinated beverages in the context of optimum hydration.

METHOD

A literature search was performed using the Medline database of articles published in the medical and scientific literature for the period of January 1966-March 2002. Subject headings and key words used in this search were: tea, coffee, caffeine, diuresis, fluid balance and water-electrolyte balance. A secondary search was performed using the bibliographies of publications identified in the initial search.

RESULTS

The available literature suggests that acute ingestion of caffeine in large doses (at least 250-300 mg, equivalent to the amount found in 2-3 cups of coffee or 5-8 cups of tea) results in a short-term stimulation of urine output in individuals who have been deprived of caffeine for a period of days or weeks. A profound tolerance to the diuretic and other effects of caffeine develops, however, and the actions are much diminished in individuals who regularly consume tea or coffee. Doses of caffeine equivalent to the amount normally found in standard servings of tea, coffee and carbonated soft drinks appear to have no diuretic action.

CONCLUSION

The most ecologically valid of the published studies offers no support for the suggestion that consumption of caffeine-containing beverages as part of a normal lifestyle leads to fluid loss in excess of the volume ingested or is associated with poor hydration status. Therefore, there would appear to be no clear basis for refraining from caffeine containing drinks in situations where fluid balance might be compromised.

Antiarrhythmic efficacy of amiodarone in recurrent ventricular tachycardia evaluated by multiple electrophysiological and ambulatory ECG recordings

Thirty-three patients with recurrent drug-refractory ventricular tachycardia were treated with oral amiodarone during an average period of 6.1 months. In-hospital monitoring for two weeks or more, electrophysiological tests and ambulatory ECG were used to evaluate the results. Twenty patients are still using the drug with complete control of the arrhythmia. Eleven have failed the drug, ten due to recurrence of documented ventricular tachycardia. Only three patients failed after the first month of therapy. Two patients died, one suddenly. The drug was discontinued in a further two patients due to side-effects. Other side-effects were tolerable or manageable by dose adjustments alone. Five patients showed evidence of inadequate arrhythmia control between days 15 and 32 of therapy but subsequently responded to the drug for 4-9 months, giving further support to the concept that in some patients at least 30 days of therapy is necessary for the full effect of the drug to appear. In 16 of the 20 patients tested by arrhythmia induction study while on the drug, ventricular tachycardia could still be induced. Seven (44%) of these eventually failed the drug. Arrhythmia recurred in one of those four in whom tachycardia could not be induced. Amiodarone is a valuable drug in the management of recurrent ventricular tachycardia, refractory to other antiarrhythmic drugs.

157 VIRAL RISK ASSESSMENT OF BOVINE OOCYTES HARVESTED FROM ABATTOIR ORIGIN

Bovine oocytes derived from abattoir origin are mainly used for artificial reproductive techniques in both agricultural and biomedical applications. Regulatory agencies have expressed concern for potential transmission of adventitious viruses by sourcing bovine oocytes from abattoir origin. To evaluate this concern, a viral risk assessment was conducted on batch samples collected from follicular fluid, cumulus cells, oocytes, and Day 8 embryos. These batch samples were collected from ovaries on seven randomly selected days in a 2-week period and they were frozen and stored at –80°C until tested. All samples were tested by 9 Code of Federal Regulations (9CFR) part 113.53c (animal viral testing) at a GLP compliant laboratory (American BioResearch Laboratories, Sevier, TN, USA). The 9CFR viral testing includes bovine viral diarrhea virus (BVDV), bovine parvovirus, bovine adenovirus type 3 and 5, bovine rabies virus, bovine bluetongue virus, bovine respiratory syncytial virus, bovine reovirus, viral cytopathic effect, and hemadsorption on permissive cell cultures. Batch samples were also tested for BVDV and bovine leukemia virus (BLV) by polymerase chain reaction (PCR) and follicular fluids for BVDV antibody neutralization activity at an accredited diagnostic laboratory (Animal Disease Research and Diagnostic Laboratory, SDSU, Brookings, SD, USA). The 9CFR viral testing results on all the batch samples were negative. The BVDV PCR test had a low positive (37.89 cycles) with one follicular fluid batch sample (1/7) and a low positive (37.9 cycles) on all cleaved embryos (7/7). However, BVDV virus isolation was negative for both batch samples by 9CFR testing. The BLV PCR had a positive follicular batch sample (1/7), with all other samples testing being negative. BVD serum neutralization antibody assay demonstrated that all follicular fluid had significant titers of 1:128–1:1024. Although some of the viral particles may have been detected in follicular fluid and cleaved embryos by PCR, none of the batch samples collected were positive for viral growth in this study. The BVDV PCR indicated low levels of BVDV RNA. It is speculated that the positive BVDV PCR results on cleaved embryos could possibly be attributed to the use of irradiated fetal calf serum (contaminated BVDV virus) used in culture media. Follicular fluids also have high titers to BVDV which may have neutralized the virus. These results indicate that virus-free bovine oocytes can be derived from the abattoir. Thus, with appropriately applied quality assurance testing, abattoir-origin oocytes might be used effectively in agricultural and biomedical applications. Table 1. Summary of test results on batch samples from abattoir-derived oocytes

Ganciclovir Population Pharmacokinetics in Neonates Following Intravenous Administration of Ganciclovir and Oral Administration of a Liquid Valganciclovir Formulation

Cytomegalovirus (CMV) is the most common viral congenital infection, producing both sensorineural hearing loss and mental retardation. Our objective was to assess the population pharmacokinetics of a research-grade oral valganciclovir solution in neonates with symptomatic congenital CMV disease. Twenty-four neonates received 6 weeks of antiviral therapy. Ganciclovir and valganciclovir were measured by liquid chromatography/tandem mass spectroscopy. NONMEM version VI beta was used for population analyses. All profiles were consistent with a one-compartment model. Postnatal age, body surface area, and gender did not improve the model fit after body weight was taken into account. The typical value of clearance (l/h), distribution volume (l), and bioavailability of ganciclovir were 0.146 x body weight (WT)(1.68), 1.15 x WT, and 53.6%, respectively. Although these results cannot be extrapolated to extemporaneously compounded valganciclovir preparations, they provide the foundation on which a commercial-grade valganciclovir oral solution may be a viable option for administration to neonates.

Genotyping of Mycobacterium bovis isolates from badgers in four areas of the Republic of Ireland by restriction fragment length polymorphism analysis

An analysis of the molecular epidemiology of Mycobacterium bovis in badgers was made in four selected areas of the Republic of Ireland in which an intensive badger removal programme was being carried out over a period of five years. Tissue samples from 2310 badgers were cultured. Restriction fragment length polymorphism (RFLP) analysis with IS6110, polymorphic GC-rich sequence (PGRS) and direct repeat sequence (DR) probes was applied to the isolates from 398 badgers, and 52 different rflp types were identified. Most of the isolates belonged to seven predominant types, and the other 45 types were represented by few isolates. An analysis suggests that some of these 45 types may have been introduced by the inward migration of badgers and others may have been the result of genetic changes to one of the prevalent types. The badgers were divided into groups on the basis of the sett at which they were captured, and RFLP typing was applied to isolates from two or more badgers from 85 groups. Multiple RFLP types were identified among isolates from 50 of these groups, suggesting that badgers probably moved frequently between group territories.