Beliefs about medicines in gout patients: results from the NOR-Gout 2-year study

OBJECTIVE

Adherence to urate-lowering therapy (ULT) in gout is challenging. This longitudinal study aimed to determine 2 year changes in beliefs about medicines during intervention with ULT.

METHOD

Patients with a recent gout flare and increased serum urate received a nurse-led ULT intervention with tight control visits and a treatment target. Frequent visits at baseline and 1, 2, 3, 6, 9, 12, and 24 months included the Beliefs about Medicines Questionnaire (BMQ), and demographic and clinical variables. The BMQ subscales on necessity, concerns, overuse, harm, and the necessity-concerns differential were calculated as a measure of whether the patient perceived that necessity outweighed concerns.

RESULTS

The mean serum urate reduced from 500 mmol/L at baseline to 324 mmol/L at year 2. At years 1 and 2, 85.5% and 78.6% of patients, respectively, were at treatment target. The 2 year mean ± sd BMQ scores increased for the necessity subscale from 17.0 ± 4.4 to 18.9 ± 3.6 (p < 0.001) and decreased for the concerns subscale from 13.4 ± 4.9 to 12.5 ± 2.7 (p = 0.001). The necessity-concerns differential increased from 3.52 to 6.58 (p < 0.001), with a positive change independent of patients achieving treatment targets at 1 or 2 years. BMQ scores were not significantly related to treatment outcomes 1 or 2 years later, and achieving treatment targets did not lead to higher BMQ scores.

CONCLUSION

Patient beliefs about medicines improved gradually over 2 years, with increased beliefs in the necessity of medication and reduced concerns, but this improvement was unrelated to better outcomes.

TRIAL REGISTRATION

ACTRN12618001372279.

Mechanisms of Change for Children Participating in Therapeutic Horse Riding: A Grounded Theory

AIM

To develop a model for understanding mechanisms of change in health outcomes for riders with disabilities participating in therapeutic horse riding (THR).

METHODS

Using grounded theory methods we collected and analyzed data from interviews with 16 child riders and 18 caregivers, teachers and primary therapists, and from participant-observation during THR sessions.

RESULTS

The central concept underpinning the model illustrating mechanisms of change was "gaining the tools to go on." Riders' experiences suggested the THR landscape (i.e., "where the tools are gathered") allowed for an expanded range of experiences in which riders could participate. Riders experienced an expansion of self-concept by learning to move, succeed, connect, and adapt (i.e., "the tools gathered") within the THR landscape. Riders then iteratively translated an expanded view of self into other environments, reflecting "how and where the tools are used."

CONCLUSION

Findings suggest that positive changes in health arise from riders' experiences of learning and agency within the THR therapeutic landscape, and from the influence of these experiences on a child's developing self-concept. This article considers the wider impact of THR on children's health, beyond a focus on changes in physical outcomes.

Crystal identification of synovial fluid aspiration by polarized light microscopy. An online test suggesting that our traditional rheumatologic competence needs renewed attention and training

Testing a reading exercise for identification of several typical crystal such as the negatively birefringent needle-shaped crystals that are under polarized light microscopy is the gold standard for diagnosing gout. The objective of this study was to assess current performance of crystal identification by professionals involved in examining synovial fluid in routine care. Rheumatologists, trainees, lab technicians, and other physicians with an interest in crystal arthritis completed an online test. The test consisted of 30 images: 8 monosodium urate (MSU) crystals, 5 calcium pyrophosphate (CPP), 4 cholesterol, 2 depot methylprednisolone, 2 calcium oxalate, 2 rice bodies, 1 hydroxyapatite, 1 liquid lipid, 1 fibrin, 1 Charcot-Leyden, and 5 different artifacts. Of the 22 non-MSU slides, a subset of 8 was pre-designated that were thought to be clinically important to be identified as non-MSU. The primary outcome was defined as the correct identification of all eight MSU slides plus the identification of all eight pre-defined non-MSU slides as non-MSU. The online test was completed by 110 participants. The primary outcome was achieved by 39%. Correct identification of all MSU images was achieved by 81%, correct identification of all 8 pre-defined non-MSU, CPP images, and all 22 non-MSU images as non-MSU by 68, 68, and 23%, respectively. MSU crystals were well identified, but incorrect identification of non-MSU crystals occurred frequently. This study suggests that there is room for improvement regarding crystal identification of particularly CPP and other non-MSU crystals even in this highly motivated group.

Systematic review of the prevalence of gout and hyperuricaemia in Australia

AIMS

Gout is a growing health problem worldwide especially in affluent countries, such as Australia. Gout and hyperuricaemia are associated with the metabolic syndrome, diabetes mellitus, obesity and hypertension. More importantly, Australia has a growing prevalence of these important health problems. The aim of this study was to systematically review published information regarding the prevalence of gout and hyperuricaemia in Australia.

METHODS

A systematic search was undertaken of the MEDLINE, EMBASE and Web of Science databases, as well as relevant websites for journal articles and reports relating to the prevalence of hyperuricaemia and gout in Australia.

RESULTS

Twenty-five journal articles and five reports were included in the review. Data collected in a standardised way show gout increased in prevalence from 0.5% population prevalence to 1.7% population prevalence from 1968 to 1995/1996. There has been a significant rise in the prevalence of gout in the Australian Aboriginal population from 0% in 1965 to 9.7% in men and 2.9% in women in 2002. Consistent with the rise in gout prevalence, serum uric acid in blood donors has increased from 1959 to 1980 (17% in 30- to 40-year-old men).

CONCLUSIONS

The rate of gout and hyperuricaemia in Australia is high in relation to comparable countries and is increasing. The prevalence of gout in elderly male Australians is second only to New Zealand, which has the highest reported rate in the world. Further research on Aboriginal and Torres Strait Islander gout and hyperuricaemia is required as a result of the lack of contemporary data.

Patient-reported outcomes in chronic gout: a report from OMERACT 10

OBJECTIVE

To summarize the endorsement of measures of patient-reported outcome (PRO) domains in chronic gout at the 2010 Outcome Measures in Rheumatology Meeting (OMERACT 10).

METHODS

During the OMERACT 10 gout workshop, validation data were presented for key PRO domains including pain [pain by visual analog scale (VAS)], patient global (patient global VAS), activity limitation [Health Assessment Questionnaire-Disability Index (HAQ-DI)], and a disease-specific measure, the Gout Assessment Questionnaire version 2.0 (GAQ v2.0). Data were presented on all 3 aspects of the OMERACT filters of truth, discrimination, and feasibility. One PRO, health-related quality of life measurement with the Medical Outcomes Study Short-form 36 (SF-36), was previously endorsed at OMERACT 9.

RESULTS

One measure for each of the 3 PRO of pain, patient global, and activity limitation was endorsed by > 70% of the OMERACT delegates to have appropriate validation data. Specifically, pain measurement by VAS was endorsed by 85%, patient global assessment by VAS by 73%, and activity limitation by HAQ-DI by 71%. GAQ v2.0 received 30% vote and was not endorsed due to several concerns including low internal consistency and lack of familiarity with the measure. More validation studies are needed for this measure.

CONCLUSION

With the endorsement of one measure each for pain, patient global, SF-36, and activity limitation, all 4 PRO for chronic gout have been endorsed. Future validation studies are needed for the disease-specific measure, GAQ v2.0. Validation for PRO for acute gout will be the focus of the next validation exercise for the OMERACT gout group.

Toward a valid definition of gout flare: results of consensus exercises using Delphi methodology and cognitive mapping

OBJECTIVE

To identify, in people known to have gout, the testable, key components of a standard definition of gout flare for use in clinical research.

METHODS

Consensus methodology was used to identify key elements of a gout flare. Two Delphi exercises were conducted among different groups of rheumatologists. A cognitive mapping technique among 9 gout experts with hierarchical cluster analysis provided a framework to guide the panel discussion, which identified the final set of items that should be tested empirically.

RESULTS

From the Delphi exercises, 21 items were presented to the expert panel. Cluster analysis and multidimensional scaling showed that these items clustered into 5 concepts (joint inflammation, severity of symptoms, stereotypical nature, pain, and gout archetype) distributed along 2 dimensions (objective to subjective features and general features to specific features of gout). Using this analysis, expert panel discussion generated a short list of potential features: joint swelling, joint tenderness, joint warmth, severity of pain, patient global assessment, time to maximum pain, time to complete resolution of pain, an acute-phase marker, and functional impact of the episode.

CONCLUSION

A short list of features has been identified and now requires validation against a patient- and physician-defined gout flare in order to determine the best combination of features.

Treatment recommendations for psoriatic arthritis

Objective:

To develop comprehensive recommendations for the treatment of the various clinical manifestations of psoriatic arthritis (PsA) based on evidence obtained from a systematic review of the literature and from consensus opinion.

Methods:

Formal literature reviews of treatment for the most significant discrete clinical manifestations of PsA (skin and nails, peripheral arthritis, axial disease, dactylitis and enthesitis) were performed and published by members of the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA). Treatment recommendations were drafted for each of the clinical manifestations by rheumatologists, dermatologists and PsA patients based on the literature reviews and consensus opinion. The level of agreement for the individual treatment recommendations among GRAPPA members was assessed with an online questionnaire.

Results:

Treatment recommendations were developed for peripheral arthritis, axial disease, psoriasis, nail disease, dactylitis and enthesitis in the setting of PsA. In rotal, 19 recommendations were drafted, and over 80% agreement was obtained on 16 of them. In addition, a grid that factors disease severity into each of the different disease manifestations was developed to help the clinician with treatment decisions for the individual patient from an evidenced-based perspective.

Conclusions:

Treatment recommendations for the cardinal physical manifestations of PsA were developed based on a literature review and consensus between rheumatologists and dermatologists. In addition, a grid was established to assist in therapeutic reasoning and decision making for individual patients. It is anticipated that periodic updates will take place using this framework as new data become available.

The Health Assessment Questionnaire Disability Index is a valid measure of physical function in gout

OBJECTIVE

There are no disability instruments that have specifically been validated for gout. The aim of this study was to determine the construct validity of the Health Assessment Questionnaire Disability Index (HAQ-DI) in gout and the internal validity using Rasch analysis.

METHODS

An observational cohort study of two groups of clinic patients with gout (n=20, n=53), in which clinical and functional measures were correlated with HAQ-DI scores. Rasch analysis was used to determine the internal validity of summated scores as a measure of physical disability.

RESULTS

The HAQ-DI items fitted a Rasch measurement model, confirming internal validity of the scale, although there was evidence of disordered thresholds and rescoring items as a 3-option response rather than a 4-option response improved model fit and resolved the disordered thresholds. HAQ-DI scores showed a bimodal distribution and evidence of floor effects. Clinical indices correlated highly with HAQ-DI scores in gout patients, particularly other measures of physical function. A strong relationship between days of sick leave and HAQ-DI was observed in gout patients (r2=0.44, p<0.001).

CONCLUSIONS

It is concluded that HAQ-DI has good construct and internal validity in gout but a modified scoring approach better fits a Rasch model.

A modified Delphi exercise to determine the extent of consensus with OMERACT outcome domains for studies of acute and chronic gout

OBJECTIVES

To reach consensus with recommendations made by an OMERACT Special Interest Group (SIG).

METHODS

Rheumatologists and industry representatives interested in gout rated and clarified, in three iterations, the importance of domains proposed by the OMERACT SIG for use in acute and chronic gout intervention studies. Consensus was defined as a value of less than 1 of the UCLA/RAND disagreement index.

RESULTS

There were 33 respondents (61% response rate); all agreed the initial items were necessary, except "total body urate pool". Additional domains were suggested and clarification sought for defining "joint inflammation" and "musculoskeletal function". Items that demonstrated no clear decision were re-rated in the final iteration. There were six highly rated items (rating 1-2) with four slightly lower rating items (rating 3) for acute gout; and 11 highly rated items with eight slightly lower ratings for chronic gout.

CONCLUSIONS

Consensus is that the following domains be considered mandatory for acute gout studies: pain, joint swelling, joint tenderness, patient global, physician global, functional disability; and for chronic gout studies: serum urate, gout flares, tophus regression, health-related quality of life, functional disability, pain, patient global, physician global, work disability and joint inflammation. Several additional domains were considered discretionary.

Assessment of outcome in clinical trials of gout a review of current measures

There has been renewed interest in the treatment of gout with recent reported intervention studies of new agents such as etoricoxib, febuxostat and pegylated-uricase. However, these studies have highlighted the relative paucity of validated outcome measures with which to judge efficacy. This review outlines the published information regarding which endpoints have been measured in randomized clinical trials, what should be measured, what tools or instruments are available for this and the technical properties of such instruments. It highlights recent work that validates measures of tophi, radiographic damage and patient-reported outcomes. The absence of a valid definition of gout-flare or how flare reduction defines response is problematic; this forms the basis for a current ACR-EULAR sponsored project.

Polyarticular psoriatic arthritis is more like oligoarticular psoriatic arthritis, than rheumatoid arthritis

BACKGROUND

and objective: Since the original description of psoriatic arthritis (PsA) subgroups by Moll and Wright, there has been some discrepancy in the precise prevalence of the different subgroups and in particular the proportion of patients with polyarthritis. The higher prevalence of the polyarthritis subgroup may be due to the inclusion of patients with seronegative rheumatoid arthritis with coincidental psoriasis. The classification of psoriatic arthritis (CASPAR) study database provided an opportunity to examine this question.

METHODS

The CASPAR study collected clinical, radiological and laboratory data on 588 patients with physician-diagnosed PsA and 525 controls with other inflammatory arthritis, 70% of whom had rheumatoid arthritis. Patients with PsA were divided into two groups: polyarthritis and non-polyarthritis (which included the Moll and Wright subgroups of spinal disease, distal interphalangeal predominant and arthritis mutilans) and were compared with patients with rheumatoid arthritis. Comparisons were made between all three groups and, if a significant difference occurred, between the two groups with PsA.

RESULTS

The three groups differed significantly with regard to all clinical and laboratory variables except duration of disease. Significant differences were also found between the two groups of PsA in terms of age, sex, total number of involved joints, disability score and symmetry. However, no differences were found between the groups of patients with PsA in terms of seropositivity for rheumatoid factor and antibodies to cyclic citrullinated peptide, enthesitis, and spinal pain and stiffness. Further, dactylitis was commonly seen in patients with PsA (57% in the polyarticular group and 45% in non-polyarticular group), and uncommonly found in patients with rheumatoid arthritis (5%). With the exception of entheseal changes, syndesmophytes and osteolysis, typical radiological features of PsA could not be used to distinguish between the PsA subgroups.

CONCLUSIONS

The evidence suggests that the changing prevalence of the polyarticular subgroup of PsA is not because doctors include patients with seronegative rheumatoid arthritis with coincidental psoriasis.

Psoriatic arthritis assessment tools in clinical trials

In order to measure disease activity, progression, and change with therapy in psoriatic arthritis (PsA), it is important to use accurate, reliable, and feasible outcome measures that can ideally be employed in longitudinal cohorts, clinical trials, and clinical practice. Until recently, there has been little focus on this methodology in PsA. Clinical trials and long term clinical registries have used disparate outcome measures. With emerging therapies, the focus on the methodology of outcome assessment has increased to ensure that discriminant and responsive instruments are used. The Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA), in conjunction with the society, Outcome Measures in Rheumatology (OMERACT), is focused on refining and developing outcome measures for a variety of disease domains reviewed in this report. Key domains to assess include joints, skin, enthesitis, dactylitis, spine, joint damage as assessed radiologically, quality of life, and function. These domains can be assessed by individual and composite measures. A number of measures have been "borrowed" from the fields of rheumatoid arthritis, ankylosing spondylitis, and psoriasis and adapted to PsA. Others are being developed specifically for PsA. Few are validated but most have been shown to perform well in distinguishing placebo from treatment response. This report reviews the current state of the art of assessment in PsA and points toward future directions of development of this field.

Classification and diagnostic criteria for psoriatic arthritis

BACKGROUND

The study of psoriatic arthritis is difficult and has lagged behind the study of other arthropathies in that there are no universally agreed or properly validated case definitions.

METHOD

This paper examined the validity and practicality of the original Moll and Wright criteria and subsequent criteria sets. Key features discriminating between psoriatic and other arthropathies were reviewed. A comparative study involving patients with psoriatic arthritis and rheumatoid arthritis was used to contrast the different classification methods.

RESULTS

Although the Moll and Wright criteria continue to be widely used, they have been shown to discriminate poorly between psoriatic and rheumatoid arthritis. In comparison, the most sensitive criteria were those of Vasey and Espinoza, McGonagle et al, and Gladman et al (99%), whereas the others were significantly less sensitive (between 56% and 94%). The specificity of all methods was high and statistically similar (between 93% and 99%). Models that had reasonably good accuracy even without such key variables as psoriasis or rheumatoid factor were developed. Spinal involvement continues to be a key feature of psoriatic arthritis, but dissimilarities with classic ankylosing spondylitis have been highlighted.

CONCLUSIONS

Further work is required to produce classification criteria for psoriatic arthritis. A prospective study collecting clinical, radiological, human leucocyte antigen (HLA) and immunological data from both psoriatic and non-psoriatic cases should provide agreed criteria for use in psoriatic arthritis studies in the future.

Preliminary identification of core domains for outcome studies in psoriatic arthritis using Delphi methods

OBJECTIVE

To develop a consensus based set of core domains for outcome studies in psoriatic arthritis.

METHODS

A list of 26 potential domains was prepared through literature review and email discussions amongst the GRAPPA steering committee members and scored by rheumatologists identified through membership of the CASPAR study and the steering committee. Each participant was emailed an up to date review of outcome measures in psoriatic arthritis and asked to distribute 100 points amongst each potential domain. In two subsequent rounds the group median, interquartile range, and earlier responses were emailed to each respondent to provide an opportunity to revise their scoring.

RESULTS

Thirty two participants responded to the first round, of whom 30 responded to the third round. For DC-ART, the highest scoring domains were actively inflamed joint count, radiological damage score, patient global assessment, pain, physical function, acute phase response, and quality of life (scores 7 to 12). For SMARD, the highest scoring domains were pain, patient global assessment, physical function, quality of life, and active joint count (scores 10 to 18). For clinical record keeping, three domains scored highly at 10 (pain, patient global assessment, and active joint count). For rehabilitation, the highest scoring domains were physical function, quality of life, pain, patient global assessment, work limitations, and work incapacity (scores 10 to 15).

CONCLUSION

Amongst rheumatologists with an interest in psoriatic arthritis, a reduced list of potential standard outcome domains have been defined by Delphi consensus methods.

Repetitive strain injury

Pain in the forearm is relatively common in the community. In the workplace forearm pain is associated with work involving frequent repetition, high forces, and prolonged abnormal postures. Nevertheless, other factors are involved in the presentation and the continuation of the pain. Notable among these factors are psychosocial issues and the workplace environment-the attitude to workers and their welfare, the physical conditions, and design of the job. Primary prevention may be effective but active surveillance is important with early intervention and an active management approach. Physical treatments have not been extensively evaluated. In the established case, management should be multidisciplinary, addressing physical aspects of the job but also addressing the "yellow, blue, and black flags" which should be viewed as obstacles to recovery. For the worker "on sick" a dialogue should be established between the worker, the primary care physician, and the workplace. Return to work should be encouraged and facilitated by medical interventions and light duty options. Rehabilitation programmes may be of use in chronic cases.

Evaluation of methods for recovery of Salmonella from dairy cattle, poultry, and swine farms

Current official methods for detection and isolation of Salmonella are mostly designed for foods. The objective of this study was to determine optimal methods for detection and isolation of Salmonella from animal and environmental samples of dairy, poultry, and swine farms. Preenrichment in lactose broth versus direct enrichment (no preenrichment) prior to selective enrichment in Rappaport-Vassiliadis, selenite cystine, and tetrathionate incubated at 35 and 42 degrees C and in four differential/selective plating media (brilliant green, bismuth sulfite, Hektoen enteric, and xylose-lysine-tergitol 4 agar base) were evaluated for their ability to recover Salmonella from artificially contaminated samples. The effects of pH adjustments to samples on Salmonella recovery were determined. A pH adjustment of the enrichment broth to 6.8 +/- 0.2 after addition of samples significantly improved recovery of Salmonella. The most effective medium combinations for isolation of Salmonella from farm samples depended on the type of samples. Generalizations of protocols for recovery of Salmonella from farm samples might result in poor recovery, increased recovery time, and increased sample processing costs.

Should asymptomatic patients with hereditary haemorrhagic telangiectasia (HHT) be screened for cerebral vascular malformations? Data from 22,061 years of HHT patient life

BACKGROUND

The frequency of haemorrhage in individuals with hereditary haemorrhagic telangiectasia (HHT), 10% of whom will have cerebral arteriovenous (AV) malformations, could be high enough to justify screening. This would allow presymptomatic treatment to prevent early onset stroke in a condition that affects at least 1 in 8000 individuals. This is an important issue in view of the contrast between transatlantic management approaches, the worldwide dissemination of patient information, and the ethical implications of the diagnosis for the untreated patient.

OBJECTIVES

To define the annual incidence of haemorrhagic stroke in individuals with HHT.

METHODS

Retrospective study on stroke incidence in individuals with HHT and their immediate families (n = 674; 22,061 HHT patient years), specifically analysing patients under 46 years of age (17,515 patient years). The results were compared with stroke risk in the general population.

RESULTS

In the majority of cases, the haemorrhage was the first significant neurological event. Overcorrecting for any bias towards overestimation that would be introduced in excluding non-penetrant family members, cerebral haemorrhages were more than 20 times more common in male HHT subjects under the age of 45 years than in the general population (standardised ratio 22.99; 95% confidence interval, 13.14 to 37.33). Haemorrhages were also six times more common in female HHT subjects (6.18; 2.27 to 13.45). The incidence ratio of cerebral haemorrhage in male patients (1.84; 1.05 to 2.99) yielded a haemorrhage rate in individuals with cerebral AV malformations of 1.4-2.0% per annum, comparable to figures in the non-HHT cerebral AV malformation population.

CONCLUSIONS

These data contradict accepted wisdom in many countries that asymptomatic HHT patients are at a low (and acceptable) risk of haemorrhage. The data justify a more aggressive screening approach to identify small causative lesions amenable to treatment.

Living with arthritis--what is important?

PURPOSE

Demonstrating the effectiveness of health care interventions requires valid measurement of the impact of those interventions. However, outlining precisely what constitutes a 'good outcome' in the field of rehabilitation is no easy task and tends to rely on models proposed by 'experts' rather than people with the disabling conditions. This paper describes a study exploring outcomes that those people with a disabling condition (arthritis) consider important.

METHOD

A qualitative study, interviewing 10 women with rheumatoid arthritis was carried out. The narratives were explored for categories and themes that encapsulated the perspective of the participants.

RESULTS

A range of categories was identified and collated into five themes (personal/intrinsic factors, external/extrinsic factors, future issues, perceptions of normality and taking charge).

CONCLUSIONS

The research supports in part, but also challenges more commonly used models of understanding the important consequences of disease and disability. The findings of the study may assist health professionals to reflect on current practice and reconsider processes used, and outcomes aimed for, in light of what patients/clients consider important.

EuroQol EQ-5D may not adequately describe the health of people with disabilities

PURPOSE

To assess whether life-circumstances and factors other than those described in the EuroQol EQ-5D instrument have a systematic influence on how the same EuroQol health-state is valued.

METHOD

A simulation exercise whereby health professionals were asked to rate the health-state of 16 case-scenarios. Each case-scenario was designed to describe the same EuroQol health-state but was varied systematically using a 4 by 2 factorial design, in terms of ability to work, ability to perform usual leisure activity, age and type of disability. A convenience sample of 41 health professionals studying towards a postgraduate Diploma in Rehabilitation formed the study group.

RESULTS

The average valuation was significantly higher than that derived from a social tariff model. The following factors contributed to a model which explained 10% of the variability in valuation scores: characteristics of the assessor--years of experience, experience with musculoskeletal disorders, and characteristics of the scenario--disability type, ability to work and ability to perform usual leisure activities (beta weights ranged from 0.093 to 0.253). Ability to perform usual leisure activities was associated with the greatest influence on the valuation rating. Additionally, professional type had a significant influence on rating with general practitioners giving significantly lower valuations.

CONCLUSIONS

The same health-state, as defined by EuroQol EQ-5D cannot be regarded as describing similar life-circumstances, sufficient to be valued in the same way. Factors specific to the 'valuer' (experience and professional type) and specific to the 'valuee' (disability type, ability to work or perform usual leisure activities) that are not included in the EQ-5D description are significantly associated with different valuation scores. Caution should be used in applying valuations obtained from social tariff models to a disabled population.

Comparing the performance of mono- and biplane fluoroscopy systems in diagnostic and interventional neuroangiography using the dose-area product

Biplane digital imaging systems are favoured in neurointerventional practice since they are believed to contribute to safer, quicker and more efficacious procedures. Our aim was to establish if such equipment exposes patients to the same level of ionising radiation as monoplane systems. We reviewed monoplane and biplane fluoroscopy screening times and dose-area products (DAP) for 267 diagnostic cerebral angiograms and 56 neurointerventional cases. Significantly lower DAP for the latter were recorded on the biplane equipment, demonstrating an important reduction in patient exposure to radiation. There were no significant differences between the two systems for diagnostic cerebral angiography.

Nannocystis exedens: a potential biocompetitive agent against Aspergillus flavus and Aspergillus parasiticus

This study examined the potential for controlling toxigenic Aspergillus flavus and Aspergillus parasiticus by biological means using a myxobacterium commonly found in soil. The ability of Nannocystis exedens to antagonize A. flavus ATCC 16875, A. flavus ATCC 26946, and A. parasiticus NRRL 3145 was discovered. Cultures of aflatoxigenic fungi were grown on 0.3% Trypticase peptone yeast extract agar for 14 days at 28 degrees C. When N. exedens was grown in close proximity with an aflatoxigenic mold, zones of inhibition (10 to 20 mm) developed between the bacterium and mold colony. A flattening of the mold colony on the sides nearest N. exedens and general stunting of growth of the mold colony were also observed. When N. exedens was added to the center of the cross-streak of a mold colony, lysis of the colony by the bacterium was observed after 24 h. Microscopic observations revealed that N. exedens grew on spores, germinating spores, hyphae, and sclerotia of the molds. These results indicate that N. exedens may be a potential biocontrol agent against A. flavus and A. parasiticus.

Enigma of raised intracranial pressure in patients with complex craniosynostosis: the role of abnormal intracranial venous drainage

OBJECT

In this study the authors investigated whether patterns of intracranial venous drainage in children with complex craniosynostosis associated with raised intracranial pressure (ICP) were abnormal and, thus, could support the theory that venous hypertension is a major contributor to raised ICP that can lead to impaired visual function or even blindness in these patients.

METHODS

The authors analyzed the anatomy of intracranial venous drainage as demonstrated in the results of 24 angiography studies obtained in 23 patients, all of whom had either a craniosynostosis-related syndrome (18 patients) or a nonsyndromic multisutural synostosis (five patients). Twenty-one patients had experienced raised ICP (in 19 patients diagnosis was based on invasive ICP monitoring and in two patients on clinical grounds alone) 1 to 6 weeks before undergoing angiography. Of the two remaining patients (both with Apert syndrome) whose ICP monitoring was normal immediately before angiography, each had undergone two previous cranial vault expansion procedures. On results of 18 angiography studies a 51 to 99% stenosis or no flow at all could be observed in the sigmoid-jugular sinus complex either bilaterally (11 patients) or unilaterally (seven patients). In 11 of these patients a florid collateral circulation through the stylomastoid emissary venous plexus was also seen. Two angiography studies were performed in one patient with Crouzon syndrome. A comparison of the two studies demonstrated a progression of the abnormal venous anatomy in that case. The authors found no obvious correlation between each patient's baseline ICP and the degree of abnormality of their venous anatomy, as judged on the basis of a venous-phase angiography severity score.

CONCLUSIONS

Based on their findings, the authors assert that in children with complex forms of craniosynostosis in whom other factors, such as hydrocephalus, are absent, abnormalities of venous drainage that particularly affect the sigmoid-jugular sinus complex produce a state of venous hypertension that, in turn, is responsible for the majority of cases of raised ICP. The incidence of these changes is unknown, but an analysis of the ages of the children in this study indicated that the period of particular vulnerability to the effects of venous hypertension lasts until the affected child is approximately 6 years old. After that age the collateral venous drainage through the stylomastoid plexus will likely become sufficient to allow ICP to normalize.

Contrast-enhanced MR angiography of intracranial giant aneurysms

BACKGROUND AND PURPOSE

Intravoxel phase dispersion and flow saturation often prevent adequate depiction of intracranial giant aneurysms on 3D time-of-flight (3D-TOF) MR angiography (MRA). Additional diagnostic difficulties may arise from T1 contamination artifact of an associated blood clot. Our aim was to assess whether contrast-enhanced MRA could improve the evaluation of giant aneurysms and to compare two different types of contrast-enhanced MRA.

METHODS

We studied 11 aneurysms in 10 patients (age range, 31-77 years) with giant aneurysms of the anterior (n = 9) and posterior (n = 2) cerebral circulation by comparing 3D-TOF, first-pass dynamic contrast-enhanced MRA, and steady-state contrast-enhanced 3D-TOF sequences. Additional comparison with digital subtraction angiography (DSA) was performed in eight aneurysms.

RESULTS

In nine of 11 aneurysms, 3D-TOF did not adequately show the lumen and exiting vessels. Contrast-enhanced 3D-TOF and dynamic contrast-enhanced MRA showed the aneurysm sac and exiting vessels in all of these cases. Dynamic contrast-enhanced MRA showed a better intravascular contrast than did contrast-enhanced 3D-TOF, which led to better delineation of the aneurysms. T1 contamination artifact from intra- or extraluminal blood clot was evident on the 3D-TOF images in four cases. The artifact was less marked on the contrast-enhanced 3D-TOF image and was completely eliminated on the dynamic contrast-enhanced MRA image by subtraction of precontrast images. The diagnostic information provided by dynamic contrast-enhanced MRA was comparable to that provided by DSA.

CONCLUSION

Precontrast 3D-TOF is inadequate for the assessment of giant cerebral aneurysms. Both contrast-enhanced 3D-TOF and dynamic contrast-enhanced MRA reliably show the aneurysm sac and connected vessels. Dynamic MRA provides a superior contrast between flow and background and eliminates T1 contamination artifact. It should therefore be considered as the MRA sequence of choice.

Prognosis for people with back pain under a No-fault 24-hour-cover compensation scheme

STUDY DESIGN

A retrospective descriptive casenote review of consecutive back pain claimants assessing claim outcome at 12 months from onset.

OBJECTIVE

To assess prognosis for back pain claimants in a no-fault 24-hour-cover accident compensation system.

BACKGROUND

New Zealand has a unique accident compensation system that may provide incentives for health professionals to classify people with backache as having a back injury and incentives for back pain claimants to continue claims longer than would be the case in other compensation systems.

METHODS

One hundred consecutive back pain claimants were identified from a single office of New Zealand's sole accident compensation insurer (Accident Rehabilitation and Compensation Insurance Corporation; ACC), who were still receiving compensation payments 4 weeks after the initial date of the claim. The study end point was case closure in the subsequent 12 months. Case closure rate was analyzed in relation to several potential prognostic variables.

RESULTS

Of the 100 cases identified in which the claimant was receiving compensation 4 weeks from the initial date of the claim, 43 cases were not closed by 6 months, and 30 cases were not closed at 12 months. The variable most strongly associated with case nonclosure was whether the claimant was receiving earnings-related compensation (equal to 80% of previous income), with 41% of this group still receiving compensation at 12 months versus 16% of the group not receiving earnings-related compensation (chi2 = 8.55, P = 0.003). These results compare unfavorably with those from previous published studies from The Netherlands and Jersey in the United Kingdom.

CONCLUSION

New Zealand's unique accident compensation environment may discourage return to work for people with back pain. New Zealand legislators should assess the impact of the ACC scheme on people with back pain, particularly in light of the recent recommendations of the International Association for the Study of Pain Task Force on Back Pain in the Workplace, that compensation cover for workers with back pain be limited to 6 weeks.

MRA versus digital subtraction angiography in acute subarachnoid haemorrhage: a blinded multireader study of prospectively recruited patients

We performed a blinded multireader study comparing MR angiography (MRA) with digital subtraction angiography (DSA) in 34 prospectively recruited patients who presented with acute subarachnoid haemorrhage (SAH). Two observers independently reviewed the MRA and DSA studies some months after clinical presentation. Presence of an aneurysm was rated on a 4-point confidence scale. Cases in which the initial interpretation of the observers varied were jointly reviewed to reach a consensus opinion. DSA was deliberately chosen not to represent the reference standard and the clinical course and surgical findings were used to explain significant differences between the consensus readings of MRA and DSA. Diagnostic confidence and interobserver agreement were, overall, higher on DSA than on MRA studies (kappa DSA = 0.64 versus kappa MRA = 0.52 with 95% CI for delta = kappa DSA-kappa MRA [-0.06, 0.31]). With both methods, discrepancies between observers were due to aneurysms overlooked rather than false-positive readings by one observer. Diagnostic accuracy therefore improved when the readings of the two observers were combined, particularly for MRA. Intermethod agreement was only fair and similar for both readers (kappa reader 1 = 0.37 versus kappa reader 2 = 0.32 with 95% CI for delta = kappa reader 1-kappa reader 2 [-0.02, 0.11]). Both interobserver and intermethod agreements improved when the data were analysed on a per-study (positive or negative study) rather than on a per-aneurysm basis. Differences in the consensus reading were due to five aneurysms (four single and one multiple) detected only with MRA and five (two single and three multiple) detected only with DSA. MRA and DSA should be regarded as complementary in the investigation of patients with acute SAH. DSA can no longer be regarded as the reference standard.

Inpatient treatment of rheumatoid arthritis with synacthen depot: a double blind placebo controlled trial with 6 month followup

OBJECTIVE

To assess the additional benefit of synacthen depot over standard inpatient care for patients hospitalized with active rheumatoid arthritis (RA).

METHODS

All patients admitted to our unit with active RA without exclusion criteria were invited to participate and randomized to subcutaneous synacthen depot 0.5 mg on alternate days for 2 injections or 2 injections of saline. Patients, staff, and assessors of response were blinded to the intervention. Assessment [OMERACT set, American College of Rheumatology (ACR) global improvement, dose of intraarticular (IA) or intramuscular (IM) methylprednisolone] was performed at admission to hospital, at discharge, and at 3 and 6 months. Oral prednisone use constituted a protocol violation.

RESULTS

Of 137 patients with RA admitted over the period of recruitment, 36 (26%) were enrolled; 31 completed followup. There were no between-group differences in the change from admission of any individual disease activity measure at any time point. However, using a rigorous global response measure (ACR 50%), a difference was detected in favor of synacthen depot at discharge (52.6% of the intervention group improved vs. 17.6% of controls; p = 0.029, number-needed-to-treat 2.86). Patients treated with synacthen depot showed a trend toward more IA or IM corticosteroid between discharge and 3 months (mean dose 56 vs. 31 mg; p = 0.19) and a trend toward more patients requiring a change in slow acting antirheumatic drug after discharge (4 vs. 1; p = 0.27).

CONCLUSION

There is some additional benefit of synacthen depot in the hospital treatment of RA, but the effect is lost by 3 months, with a suggestion of rebound worsening in these patients. We postulate that oversuppression of corticotrophin releasing hormone by exogenous adrenocorticotrophic hormone in patients who already have a hypothalamic deficit may contribute to the rebound worsening of disease activity seen in these patients.

Posterior communicating artery aneurysm presenting with haemorrhage into an arachnoid cyst

A patient is reported on with a subarachnoid haemorrhage (SAH) from an aneurysm of the posterior communicating artery, who initially presented with a sentinel bleed into an arachnoid cyst and normal magnetic resonance angiography (MRA) of the intracranial vasculature which led to a delay in diagnosis. Although this is a very rare presentation of a relatively common condition, it is important to recognise the importance of intracystic haemorrhage in such circumstances as well as the limitations of MRA, as a delay in diagnosis may have serious clinical consequences.

A retrospective review of yttrium-90 synovectomy in the treatment of knee arthritis

We reviewed the case notes and X-rays of all patients with knee arthritis treated with yttrium-90 for the first time at a single institution from November 1981 to November 1995. Outcomes were assessed as 'improved' or 'not improved' by review of the case notes at 3, 6 and 12 months, and by the absence of further intra-articular (IA) steroid injections. Of the 121 knees treated, 87 had adequate follow-up information to allow an assessment of outcomes. Overall, 46% (95% CI 36-57) were improved at 12 months and 37% (95% CI 27-47) had no further IA injections (mean follow-up of 3.5 yr). Knees with osteoarthritis (OA) fared significantly worse with 10% (95% CI 0-29) vs 51% (95% CI 39-63) improved at 12 months (P < 0.05). Knees younger than 30 appeared to do better with 78% (95% CI 51-100) vs 28% (95% CI 17-45) having no further IA injections (P < 0.02). Knees with normal X-rays (Kellgren grade 0-1) did significantly better than those with more severe radiographic abnormalities (Kellgren grade 3-4), with 56% (95% CI 40-73) vs 24% (95% CI 8-40) improved (P < 0.01). Radiosynovectomy with yttrium-90 for knee arthritis appears to be of less value for patients with OA or with secondary OA changes on X-ray, and may be of more value for younger patients and those with spondyloarthropathies.

"Dural tail" adjacent to a giant posterior cerebral artery aneurysm: case report and review of the literature

The "dural tail" sign on gadolinium (Gd-DTPA)-enhanced MRI has been described in association with meningiomas. Various series with histopathological correlation have shown that in some cases there is tumour invasion into the dura mater, but in the majority of cases it represents a hypervascular, non-neoplastic reaction. While this sign was originally thought to be specific for meningioma, subsequent case reports have described the presence of a dural tail in other intra- and extra-axial lesions. We present a patient with a giant aneurysm arising from the P2 segment of the right posterior cerebral artery, adjacent to the tentorium, with a prominent dural tail on Gd-DTPA-enhanced MRI. In this location, differentiation of an aneurysm from a meningioma was critical.

MRI in children receiving total parenteral nutrition

Cranial MRI was obtained in 13 of a group of 57 children receiving long-term parenteral nutrition, who were being investigated for hypermanganasaemia. Increased signal intensity on T1-weighted images has been reported in adult patients on long-term parenteral nutrition and with encephalopathy following chronic manganese exposure in are welding. It has been postulated that these changes are due to deposition of the paramagnetic trace element manganese. In excess manganese is hepato- and neurotoxic and we present the correlation of whole blood manganese levels with imaging findings. The age range of our patients was 6 months to 10 years, and the duration of therapy 3 months to 10 years. In 7 children we found characteristic increased signal intensity on T1-weighted images, with no abnormality on T2-weighted images. All patients had elevated whole blood manganese levels, suggesting that the basis for this abnormality is indeed deposition of manganese within the tissues.

Manganese toxicity in children receiving long-term parenteral nutrition

BACKGROUND

In patients receiving long-term parenteral nutrition (PN), cholestatic disease and nervous system disorders have been associated with high blood concentrations of manganese. In such patients, the normal homoeostatic mechanisms of the liver and gut are bypassed and the requirement for this trace element is not known; nor has it been certain whether hypermanganesaemia causes the cholestasis or vice versa. We explored the direction of effect by serial tests of liver function after withdrawal of manganese supplements from children receiving long-term PN. We also examined the relation between blood manganese concentrations and brain lesions, as indicated by clinical examination and magnetic resonance imaging (MRI).

METHODS

From a combined group of 57 children receiving PN we identified 11 with the combination of hypermanganesaemia and cholestasis; one also had a movement disorder. Manganese supplements were reduced in the first three and withdrawn in the remainder. MRI was done in two of these children. We also looked at manganese concentrations and MRI scans in six children who had received PN for more than 2 years without developing liver disease.

FINDINGS

In the hypermanganesaemia/cholestasis group, four of the 11 patients died. In the seven survivors baseline whole-blood manganese was 615-1840 nmol/L, and after 4 months it had declined by a median of 643 nmol/L (p < 0.01). Over the same interval total bilirubin declined by a median of 70 mumol/L (p < 0.05). Two of these children had movement disorders, one of whom survived to have an MRI scan; this showed, with T1 weighted images, bilateral symmetrically increased signal intensity in the globus pallidus and subthalamic nuclei. Such changes were also seen in five other children--one from the hypermanganesaemia/cholestasis group and four of six in the long-term PN group without liver disease (in all of whom blood manganese was above normal).

INTERPRETATION

The cholestasis complicating PN is multifactorial, but these results add to the evidence that manganese contributes. In view of the additional hazard of basal ganglia damage from high manganese levels in children receiving long-term PN, we recommend a low dose regimen of not more than 0.018 mumol/kg per 24 h together with regular examination of the nervous system.

Intraosseous vertebral haemangioblastoma: MRI

A 30-year-old man with low back pain and gradual onset of cord compression was found to have a highly vascular extradural tumour in the lower thoracic region. Involvement of the right pedicle and a large part of the body of T9 suggested a vertebral haemangioma, but histology revealed haemangioblastoma. One case of an intraosseous haemangioblastoma has been described previously; we present the features of another case shown by MRI and discuss the differentiation between haemangioma and haemangioblastoma.

Intrapetrous carotid artery aneurysm presenting as epistaxis and otalgia

Aneurysm of the intrapetrous carotid artery is an extremely rare and potentially serious occurrence that presents diagnostic and therapeutic difficulties. Such aneurysms may follow trauma, atherosclerosis, mastoid surgery or most commonly can represent a developmental abnormality. We present the case of an 18-year-old female with a short history of recurrent left-sided otalgia and epistaxis who underwent successful endovascular balloon entrapment of a left intrapetrous carotid aneurysm.

Intrauterine pregnancy and aortic valve replacement

Cardiopulmonary bypass (CPB) does not appear to cause excessive maternal risk, but the potential for fetal complications is of great concern. In general, operative intervention should be delayed until at least the second trimester. When this is not possible, ethical issues arise and a clash of maternal autonomy versus "fetal rights" ensues. This conflict is further complicated by maternal status changes that may accompany valvular disease or develop after CPB. The case described herein summarizes and discusses these conflicts.

A cost containment program targeting home infusion drug therapy

A program was instituted to determine if retrospective, concurrent, and prospective analysis of home infusion therapy cases by a multidisciplinary team comprising clinicians and financial analysts would lead to cost reductions and cost-effective behavioral changes by providers. Actual invoices and prospective price quotes for infusion therapy were reviewed and compared to a database of "usual and customary" prices. The results were presented to providers with the intent of obtaining a reduction in prices for the services rendered or about to be rendered. As a result, $3,265,248 in short-term cost reductions were achieved, and $15,146,789 in long-term cost reductions are projected. Analysis resulted in average cost reductions of $2,247 and $10,424 respectively. Very significant cost reductions can be achieved through the use of a multidisciplinary team and a comprehensive pricing database for home infusion therapy.

Value of single-photon emission-computed tomography in acute stroke therapeutic trials

BACKGROUND AND PURPOSE

New therapeutic interventions for acute ischemic stroke are aimed at improving cerebral blood flow in the first 3 to 6 hours after symptom onset. Single-photon emission-computed tomography (SPECT) performed in the setting of clinical therapeutic trials may give us a better understanding of the physiological response to new forms of treatment and could impact acute management decisions.

METHODS

We prospectively studied 15 patients with hemispheric ischemic stroke with SPECT within 6 hours of symptom onset and again at 24 hours. The ischemic defect was assessed in a semiquantitative manner that used computer-generated regions of interest (SPECT graded scale). This measure was correlated with clinical presentation (National Institutes of Health [NIH] Stroke Scale), initial clinical course (change in NIH Stroke Scale), long-term outcome (Barthel Index at 3 months), and complications of cerebral hemorrhage and edema.

RESULTS

The severity of the SPECT graded scale on the admission scan correlated with the severity of neurological deficit (admission NIH Stroke Scale) (P < .05) and was positively associated with poor long-term outcome as measured with the Barthel Index (P < .001) and the complications of cerebral hemorrhage and massive cerebral edema (P < .005). In fact, there was a threshold value for the SPECT graded scale above which all patients suffered poor long-term outcome and the complications of cerebral hemorrhage and edema.

CONCLUSIONS

The measurement of an ischemic defect using SPECT is a valid assessment of hemispheric stroke severity in the hyperacute setting and may be useful for selecting or stratifying patients in clinical therapeutic trials.

Measuring gastric contents during general anaesthesia: evaluation of blind gastric aspiration

Various medications have been reported to decrease gastric content volume and thus risk for pulmonary aspiration. The majority of studies have used blind gastric tube aspiration of stomach contents as the method of measuring the volume of gastric contents. This study evaluated the accuracy of this method by first measuring gastric content volume using blind gastric aspiration and then aspirating residual content in the stomach, using a visually guided flexible fiberoptic gastroscope. Ten obese patients undergoing elective surgery were studied. Gastric contents were collected using a multi-orificed gastric tube and blind aspiration. Immediately after this was completed, residual gastric volume was collected using a visually guided gastroscope. The sum of these two aspirate volumes (true total gastric volume) was statistically compared with the blind aspirate volume. The blind aspirate volume underestimated true total gastric volume by an average of 14.7 ml and was significantly different from true total gastric volume (p less than 0.05). Blind gastric aspiration was thus demonstrated only to approximate true gastric volume. Its use to measure precisely gastric volume cannot, therefore, be recommended.

Radiotherapy treatment planning using lymphoscintigraphy

A method for the three dimensional location of lymph nodes with respect to the skin surface is described. The technique is based on the reconstruction of surface shape using isocentric radiographs taken with metal chains draped on the patient. Registration of the radiographic study to the lymphoscintigraphic study is accomplished automatically by matching the location of four radiopaque and radioisotope markers. This method allows nodes to be located in a beam's eye view with any set up of an isocentric radiotherapy machine. An accurate determination of the depth of lymph nodes is obtained, which is of value in electron beam therapy.

Adjuvant radiotherapy following radical prostatectomy: results and complications

Between 1954 and 1978, 148 patients underwent radical perineal prostatectomy for adenocarcinoma clinically confined to the prostate gland. This report is based on 45 of these patients with microscopic extension of disease beyond the gland and a minimum 5-year followup. Of the patients 22 received adjuvant external beam radiation therapy and 23 did not. The groups were comparable with regard to significant prognostic variables. Patient selection was by surgeon preference. Local recurrences were seen in 1 of 22 patients (5 per cent) receiving adjuvant radiotherapy and 7 of 23 (30 per cent) undergoing an operation alone (p less than 0.05). Of 8 patients with local recurrence 7 died of the disease. Delayed radiotherapy of a local recurrence generally was not effective in controlling the disease. Of the 11 patients who died of prostatic cancer with a mean followup of 9.2 years 3 received adjuvant radiotherapy and 8 did not. Severe but nonfatal long-term complications were seen in 14 per cent of the irradiated patients and 6 per cent of those treated with an operation alone. Most of the complications occurred in the earlier years of the study in patients who received 60cobalt radiotherapy. When clinical stage B cancer of the prostate is found to be pathological stage C following radical perineal prostatectomy, adjuvant radiotherapy can decrease the incidence of subsequent local recurrence. The potential risk of adjuvant radiation therapy should be weighed and its use considered, particularly in patients whose tumor extends to the surgical margins or who have seminal vesicle invasion.

Industrial exposure to organophosphorus compounds. Studies of a group of workers with a decrease in esterase-staining monocytes

When an automated counting instrument using an esterase stain was employed, decreased monocyte counts were observed in a group of process workers exposed to organophosphate esters. Their monocyte counts were not found to be depressed with manual counting or with an automated counter using another staining method. The apparent depression was transient. In these workers and a comparison group, theoretical adverse consequences of decreased monocyte esterase and also possible changes in other esterases were explored. No anergy was seen with mumps or staphylococcal phage lysate hypersensitivity skin tests. Histology of the mumps reaction was similar in both groups. The depressed monocyte counts were significantly associated with a mild reduction in erythrocyte cell acetylcholinesterase, but no reduction was seen in plasma pseudocholinesterase or lymphocyte neurotoxic esterase.

Neurotoxic and antihypertensive effects of phenytoin in turkeys

Broad-Breasted White male turkeys were fed a control diet until 4 weeks of age, at which time they were randomized into a control group and two treatment groups which received 0.06% (38.7 mg/kg) and 0.09% (58.2 mg/kg) phenytoin, respectively, until termination of the experiment at 12 weeks of age. Plasma concentrations of phenytoin on the two dosages were 8.0 +/- 0.8 and 15.7 +/- 1.7 micrograms/ml. Systemic arterial blood pressure in the control turkeys was 214 +/- 5/171 +/- mm Hg and was reduced in a dose-related fashion to 185 +/- 8/143 +/- 11 and 156 +/- 5/125 +/- 4 mm Hg in the two treatment groups; likewise, the rate of systolic ejection (dp/dt maximum) was less in the phenytoin-treated turkeys. Heart rate also dropped significantly with drug administration but the difference between the two treatment groups was not significant. Evidence of neurotoxicity developed in 25% of the turkeys on the lower drug schedule; these birds had mean plasma phenytoin levels of 12.8 micrograms/ml as contrasted to the concentration of 8.0 micrograms/ml for the entire group. On 0.09% phenytoin 50% of the birds had abnormal signs and a mean phenytoin concentration of 20.5 micrograms/ml, whereas the mean drug level for the entire group on this drug level was 15.7 micrograms/ml. Early signs of neurotoxicity developed within 2 to 3 days of initiation of phenytoin and consisted of extensor rigidity of the neck and hyperactivity; at the higher drug concentrations, back pedaling and somersaulting appeared. General health and weight gain were not affected. No qualitative or quantitative changes were found in the Purkinje cells in the cerebellum of the affected turkeys.

Cartilaginous metaplasia of the thoracic aorta of control turkeys and exacerbation by beta-aminopropionitrile

Seventeen of sixty distal extremities of the thoracic aortas of 12-week-old control male turkeys and 37 of 40 distal extremities of the aortas of turkeys fed 0.07% beta-aminopropionitrile (BAPN) from 4 to 12 weeks of age contained areas of cartilaginous metaplasia when examined by light microscopy. The cartilaginous areas were generally elongated and located in the subendothelium of control turkeys, but a roundish area of cartilage was occasionally evident in the deep media. The magnitude of chondroplasia was enhanced by feeding BAPN; the extensive lesion usually extended from the subendothelium to deep in the media. Regardless of treatment, chondrocytes were pleomorphic, contained vacuoles, and had cytoplasmic processes. The cells were separated by pools of proteoglycans and connective tissue. The ultrastructure of chondrocytes in the aortas of both treatment groups was typical of this cell type. They had undulations or projections of the cell membranes. The cisternae of endoplasmic reticulum were dilated and contained electron-translucent material which was similar to extracellular proteoglycans. Golgi apparatus, free ribosomes, mitochondria, glycogen granules, filaments, and a centriole also were present in the cytoplasm. The extracellular matrix, which included collagenous and elastic fibers and also delicate fibrils and interconnecting matrix granules, separated adjacent chondrocytes by spaces of varying size.