105 EVALUATION OF A NEW PHYSIOTHERAPY-LED VESTIBULAR SERVICE EMBEDDED IN THE FALLS AND SYNCOPE UNIT

Background

Clinical presentations in the falls and syncope unit (FASU) are diverse and require a range of skillsets. Vestibular disorders amount to a significant proportion of presentations. In our FASU, we embedded a 0.5 FTE specialist physiotherapist with expertise in vestibular disorders to work alongside medical and nursing staff. We conducted a service evaluation of the activity of this new service.

Methods

Retrospective Service Evaluation Approval was granted by our Research & Innovation Office. Pseudonymised data was collected corresponding to all new FASU physiotherapy service attendances between August 2021 and May 2022. Descriptive statistics were complemented by a binary logistic regression model to establish independent predictors of more than one physiotherapy session being required over the period.

Results

There were 104 episodes recorded by the new service, corresponding to 101 unique patients. Mean age was 67.7 (SD 19.0, range 17-93), and 73.1% were women. 67% were treated and discharged in 1 session. On average, patients had had a mean of 2 falls prior to the consultation (range 0-25). 28.8% were using a walking aid, and 54.8% self-reported fear of falling. 25% of the referrals to the service were due to suspected vestibular disorders, 62% of which were directly treated by the physiotherapy service. The logistic regression model adjusting by age, sex, use of walking aid, number of falls, and fear of falling showed that only referral for vestibular disorder was an independent predictor of patients needing more than 1 physiotherapy treatment (OR 3.91, 95% CI 1.32-11.58, P=0.014).

Conclusion

Vestibular disorders are common in FASU, and a majority can be treated by a specialist physiotherapy service. Repeated vestibular maneuvers are often needed in such patients. A responsive, embedded physiotherapy service in FASU can directly address this need and further evaluation will focus on the impact of this service on avoidance of ED attendances.

110 DEVELOPMENT AND DELIVERY OF A MULTI-DISCIPLINARY HYBRID EDUCATION PROGRAM IN SYNCOPE AND RELATED DISORDERS DURING THE COVID-19 PANDEMIC

Background

Syncope and related disorders is an important area for training of all health professionals. During the COVID-19 pandemic, we adapted the delivery of our annual face-to-face certified program to a 9-month hybrid program. Here, we describe the development, delivery, and evaluation of such new program.

Methods

A pre-existing curriculum was modified to incorporate online content, online lecture delivery and interactive group learning, in addition to individual practical placements in a syncope management unit, in line with government and hospital infection control guidance at the time. Monthly content included video consultant case presentations, ECG analysis and interpretation, and instructional videos of diagnostic testing and relevant technologies. A comprehensive online week-long lecture program was developed.

Results

The lecture week included 30 clinical lectures, 10 clinical case presentations and 10 ‘how to’ practical videos for testing/monitoring procedures. Further learning over zoom incorporated learner case presentations in a small group format. At the completion of the course the leaners attended a final online half day of lectures and completed the multi choice question examination.

Conclusion

“Thank you so much for putting together such a fantastic week of training.” “The quality and expertise of the speakers was outstanding.” “I have taken a huge amount away to incorporate into my practice and local unit.”

The above learner feedback is consistent with our aim to deliver a high-quality specialist program for those interested in advancing the management of syncope and related disorders. Over time, this specialist training will aid the development of regional syncope management units across Ireland. The benefits of a hybrid learning model include multiple options to cater for all categories of learners, thus suggesting it is the cornerstone of future learning modalities.

281 PREVALENCE OF STOPPFALL FALLS-RISK-INCREASING DRUGS (FRIDS) IN PATIENTS PRESENTING TO HOSPITAL WITH A FALL

Background

Falls cause presentation and admission to hospital. Falls-Risk-Increasing-Drugs (FRIDs) are a modifiable risk factor. STOPPFalls criteria was developed, using an expert Delphi panel, to achieve consensus on a comprehensive list of FRIDs. The aim of this study was to identify the prevalence of STOPPFall PRIDs in patients presenting to hospital with falls and identify whether review by a specialist Falls and Syncope Service (FASS) reduces FRIDs.

Methods

This was a retrospective observational study. Patients ≥65 years reviewed by the hospital FASS in the emergency department (over 6-months) and in house (over 2-months), were included. Medication appropriateness at admission and discharge were assessed using STOPPFall criteria. Ethical approval was received from the local research and innovation office (ref7013).

Results

Of 156 patients, 87(55.8%) were ≥65 years; 46% female, mean age 78.1(SD7.5) years. The mean number of conditions was 4(SD4.4); the mean number of regular medications was 6.9(SD4.5). Reasons for referral to FASS included falls (34.5%), dizziness/near fall (35.6%), and transient loss of consciousness (29.9%). For 21.8% there was an associated injury; 11.5% a fracture. Thirty-seven (42.5%) had experienced at least one fall in the previous 12-months.

Sixty-four (73.6%) were on ≥1 STOPPFall FRID. The most common STOPPFall FRID prescribed to older adults were diuretics (24.1%), anti-depressants (20.7%) and benzodiazepines/benzodiazepine-related drugs (13.8%). At least 1 STOPPFall FRID was stopped in 31.3%. The most commonly deprescribed STOPPFall FRIDs were diuretics (20%), alpha blockers (6%) and benzodiazepines/benzodiazepine-related drugs (4.7%). Adults <65years (n=69) were more likely to be prescribed a STOPPFall FRID at admission than older adults (≥65years); 88.4% vs 73.6%, p=0.021.

Conclusion

STOPPFall FRIDs are prevalent in fallers of all ages. Even one review by a specialist FASS leads to medication optimization. The effectiveness of STOPPFalls criteria in the prevention of falls should be evaluated further in intervention studies.

204 FRAILTY BUT NOT AGE IS ASSOCIATED WITH IMPAIRED ORTHOSTATIC CEREBRAL OXYGENATION

Background

The effects of age and frailty on cerebrovascular function are poorly understood. Here we investigate the hypotheses that aging, and frailty are accompanied by impaired regulation of cerebral oxygenation during standing in a patient population of older adults.

Methods

We recruited patients from a national Falls and Syncope service. All patients underwent an active stand test (5–10 min lying, 3 min standing) with continuous monitoring of blood pressure (BP) and heart rate. Tissue saturation index (TSI) was concurrently measured using near-infrared spectroscopy and its recovery measured at 30s after standing. Frailty was assessed as a comorbidity count using a 27-item questionnaire. Robust linear regression was used to investigate the association between TSI, age and frailty in a multivariate model with covariate adjustment, including the concurrent BP values. A p-value <0.05 was considered significant.

Results

304 patients (median(IQR): 71(14) years, 57% females) were recruited. Age was not associated with cerebral oxygenation after standing (β: −0.001 (−0.017 0.015), p = 0.899), even after stratification by sex (males: β: −0.010 (−0.045 0.024), p = 0.558, females: β: 0.000 (−0.017 0.018), p = 0.967). Frailty, was associated with a lower TSI at 30s after standing (β: −0.153 (−0.248–0.058), p = 0.002). After sex stratification, no associations with frailty were observed in males (β: −0.052 (−0.226 0.123), p = 0.557), while frailer females demonstrated a lower TSI at 30 seconds after standing (β: −0.179 (−0.294–0.063), p = 0.003) despite BP correction.

Conclusion

Our results suggest alternative mechanisms of cerebral oxygenation regulation independent of blood pressure (and presumably cerebral autoregulation) are involved in frailty related impairments of brain haemodynamics which are also independent of ageing. Such impairments represent novel biomarkers of frailty and represent potentially novel modifiable risk factors (independent of BP management) of hypoperfusion related disorders in clinical ageing.

Recent CO2 levels promote increased production of the toxin parthenin in an invasive Parthenium hysterophorus biotype

Recent carbon dioxide (CO₂) concentrations promoted higher parthenin concentrations in an invasive Parthenium hysterophorus biotype. Mean concentrations of parthenin, an allelopathic and defensive sesquiterpene lactone, were 49% higher at recent (~400 ppm) than at mid-twentieth-century (~300 ppm) CO₂ concentrations, but did not vary in a non-invasive biotype, suggesting that recent increases in atmospheric CO₂ may have already altered the chemistry of this destructive weed, potentially contributing to its invasive success.

Cerebral perfusion responses to active standing are attenuated in patients with vasovagal syncope

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Irish Research Council (IRC): Government of Ireland Postgraduate Scholarship Programme 2018, Dublin, Ireland Fundació Universitària Agustí Pedro i Pons, Universitat de Barcelona, Barcelona, Spain

Background

Syncope is a transient loss of consciousness due to cerebral hypoperfusion. While traditionally peripheral haemodynamics are monitored during clinical assessment of syncope, relatively little is known about cerebrovascular haemodynamics during orthostasis in patients with syncope.

Purpose

Here we investigated whether young patients with syncope present an altered cerebral perfusion when compared to healthy controls. Given potential hyper-reactivity of the autonomic nervous system previously reported in these patients, we hypothesise that an overly active cerebral autoregulation will be present in patients with syncope.

Methods

Consecutive patients were prospectively recruited from a National Falls and Syncope Unit, and a convenience sample of young healthy community dwelling adults was recruited from a local university (16-30 years). Participants performed a 3 minute active stand test with continuous measurement of beat-to-beat peripheral haemodynamics (blood pressure (BP), heart rate (HR)) and changes in concentration of oxygenated Δ[O2Hb] and deoxygenated Δ[HHb] haemoglobin were derived from a near-infrared spectroscopy (NIRS) monitor. Baseline, steady state and other time domain features were derived for Δ[O2Hb] (nadir, overshoot, overshoot-to-nadir, overshoot-to-nadir recovery rate) and Δ[HHb] (peak, trough, peak-to-trough, peak-to-trough recovery rate) and multiple linear regression was used to compare differences between the two groups correcting for covariates (p < 0.05 significant).

Results

Patients (n = 40) were younger (20(5.5) vs 23(1) years, p = 0.003) than controls (n = 17) and were well matched in gender, weight, height, BMI and resting haemodynamics. Patients had a smaller Δ[O2Hb] overshoot-to-nadir difference (β: -0.749, CI:(-1.593 0.094), p = 0.08), a slower Δ[O2Hb] recovery rate (β: -0.186, CI:(-0.388 0.016), p = 0.071), and smaller Δ[HHb] peak-to-trough difference (β: -0.530, CI:( -0.921 0.138), p = 0.018) and slower Δ[HHb] recovery rate (β: -0.151, CI: (0.244 0.057), p = 0.008).

Conclusion

Patients with syncope had signs of an attenuated cerebral oxygenation response to an AS when compared to controls. We hypothesise that this is due to hyper-reactive cerebral autoregulation mechanism, which might be related to a hyper-sensitive autonomic system. Furthering our understanding of vasovagal syncope physiology can help inform future interventions and treatments. This study shows the clinical value of measuring cerebral perfusion using NIRS, an easy to use and readily applicable tool, in the assessment of syncope. Abstract Figure. Cerebral oxygenation upon standing

Do patients with syncope have a hyper-reactive autonomic nervous system?

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Irish Research Council (IRC): Government of Ireland Postgraduate Scholarship Programme 2018, Dublin, Ireland Fundació Universitària Agustí Pedro i Pons, Universitat de Barcelona, Barcelona, Spain.

Background

The origin of syncope, a transient loss of consciousness due to cerebral hypoperfusion, remains unclear. Recent studies suggest that a hypersensitive autonomic nervous system might be involved in the pathophysiology of vasovagal syncope (VVS).

Purpose

Here we test the hypothesis that patients with VVS have a hyper-reactive autonomic nervous system by investigating the peripheral haemodynamic responses during a standing (AS) test in a group of young VVS patients vs a control group.

Methods

A prospective sample of consecutive patients from a National Falls and Syncope Unit was recruited, and a convenience sample of young healthy community dwelling adults was recruited from a local university (16-30 years). Participants performed a 3 minute AS with continuous measurement of beat-to-beat blood pressure (BP), heart rate (HR), and cerebral oxygenation measured with near infrared spectroscopy. Baseline, steady-state and other time domain features were obtained for systolic BP (SBP) (i.e. nadir, overshoot, overshoot-to-nadir, overshoot-to-nadir recovery rate) and for HR (i.e. peak, trough, peak-to-trough, peak-to-trough recovery rate). Multiple linear regression was used to compare these features between patients and controls while correcting for covariates (p < 0.05 significant).

Results

Forty patients and 17 controls were included, the former group being younger ((20(5.5) vs 23(1) years, p = 0.003). During steady-state standing SBP was higher as compared to controls (β: 6.853, CI: (0.713 12.993), p = 0.029). Patient data trended toward lower steady-state HR (β: -5.262, CI:(-11.201 0.677), p = 0.081), together with a larger peak-to-trough difference (β: 7.212, CI:(1.329 -15.754), p = 0.096).

Conclusion

These results tend to support the hypothesis and previous literature suggesting the presence of autonomic hyper-reactivity in patients with syncope, presenting as an exaggerated peripheral circulatory response to standing. Understanding the pathophysiology of VVS can help us improve its assessment and develop better treatment pathways for these patients. Abstract Figure.

Impact of a specialist service in the Emergency Department on admission, length of stay and readmission of patients presenting with falls, syncope and dizziness

BACKGROUND

Up to half of patients presenting with falls, syncope or dizziness are admitted to hospital. Many are discharged without a clear diagnosis for their index episode, however, and therefore a relatively high risk of readmission.

AIM

To examine the impact of ED-FASS (Emergency Department Falls and Syncope Service) a dedicated specialist service embedded within an ED, seeing patients of all ages with falls, syncope and dizziness.

DESIGN

Pre- and post-cohort study.

METHODS

Admission rates, length of stay (LOS) and readmission at 3 months were examined for all patients presenting with a fall, syncope or dizziness from April to July 2018 (pre-ED-FASS) inclusive and compared to April to July 2019 inclusive (post-ED-FASS).

RESULTS

There was a significantly lower admission rate for patients presenting in 2019 compared to 2018 [27% (453/1676) vs. 34% (548/1620); X2 = 18.0; P < 0.001], with a 20% reduction in admissions. The mean LOS for patients admitted in 2018 was 20.7 [95% confidence interval (CI) 17.4-24.0] days compared to 18.2 (95% CI 14.6-21.9) days in 2019 (t = 0.98; P = 0.3294). This accounts for 11 344 bed days in the 2018 study period, and 8299 bed days used after ED-FASS. There was also a significant reduction in readmission rates within 3 months of index presentation, from 21% (109/1620) to 16% (68/1676) (X2 = 4.68; P = 0.030).

CONCLUSION

This study highlights the significant potential benefits of embedding dedicated multidisciplinary services at the hospital front door in terms of early specialist assessment and directing appropriate patients to effective ambulatory care pathways.

1064 Sleep Patterns Among Urban Haitian Earthquake Survivors Who Experienced the Trauma of Nonpartner Sexual Violence: A Latent Class Analysis Approach

Introduction

Sleep health is crucial to recovery from trauma. Haiti’s Cité Soleil residents (approximately 350,000) live in extreme poverty and regularly experience or witness life-threatening events, including gang and non-partner sexual violence (NPSV). Differences in levels of sleep disturbance among men and women in resource-limited settings who survive disasters as well as NPSV are understudied. In a larger study in which we investigated trauma symptoms among 2010 Haiti earthquake survivors via the Trauma-symptom checklist -40 (N=526; 290 males, 236 females), we also assessed self-reported frequency of sleep disturbance symptoms using the measure’s sleep disturbance subscale, comparing the latter by NPSV victim status and by gender.

Methods

SAS enabled 3-Class Latent Class Analysis (LCA): Class 1 (“No symptoms”), Class 2 (“Some symptoms”), Class 3 (“All Symptoms)”.

Results

Distribution of class membership differed by gender (χ2 = 23.9, df = 2, p &lt; .0001). Proportions of respondents assigned to the three classes differed between genders (Females: Class 1, 29.2%; Class 2, 35.5%; Class 3, 35.3%); Males: Class 1, 25.7%; Class 2, 54.4%; Class 3, 19.9%). NPSV status influenced levels of sleep disturbance symptoms, and membership distribution differed across classes by gender (χ2 = 23.9, df = 2, p &lt; .0001). Class 2 membership was greater for men (65.9%), but class 3 membership was greater for women (59.3%). Women who experienced NPSV were statistically more likely members of sleep disturbance symptom classes (Class 2 or Class 3) than Class 1 (χ2= 14.9, df = 2, p = 0.0006). No difference was found in Class membership for men reporting NPSV (χ2= 1.6, df = 2, p = 0.45).

Conclusion

Investigating the sleep health of Cité Soleil residents adds to the body of literature on sleep health, sleep equity and gendered vulnerability. Findings suggest women in post-disaster settings, especially in LMICs, are at even greater risk for a variety of adverse health outcomes and for suboptimal sleep, even when local men have similar traumatogenic experiences, such as NPSV. Girls and women in post-disaster LMIC settings need trauma-informed sleep health promotion and NPSV-prevention.

Support

N/A

Reduced axonal motor protein expression in non-lesional grey matter in multiple sclerosis

Background:

Multiple sclerosis (MS) is a neurological disease characterised by central nervous system inflammation, demyelination, axonal degeneration and neuronal injury. Preventing neuronal and axon damage is of paramount importance in attempts to prevent disease progression. Intact axonal transport mechanisms are crucial to axonal integrity and evidence suggests these mechanisms are disrupted in MS. Anterograde axonal transport is mediated to a large extent through the kinesin superfamily proteins. Recently, certain kinesin superfamily proteins (KIF5A, KIF1B and KIF21B) were implicated in MS pathology.

Objectives:

To investigate the expression of KIF5A, KIF21B and KIF1B in MS and control post-mortem grey matter.

Methods:

Using both quantitative real-time polymerase chain reaction (PCR) and Immunodot-blots assays, we analysed the expression of kinesin superfamily proteins in 27 MS cases and 13 control cases not linked to neurological disease.

Results:

We have shown significant reductions in KIF5A, KIF21B and KIF1B messenger ribonucleic acid (mRNA) expression and also KIF5A protein expression in MS grey matter, as compared to control grey matter.

Conclusion:

We have shown significant reductions in mRNA and protein levels of axonal motor proteins in the grey matter of MS cases, which may have important implications for the pathogenesis of neuronal/axonal injury in the disease.

Factors that influence awareness and treatment of atrial fibrillation in older adults

AIM

The aims of this study were to investigate the prevalence of atrial fibrillation (AF), treatment rates of AF and the factors underlying awareness and treatment, in a large nationally representative study.

METHODS

A population sample of people aged 50+, living in the Republic of Ireland, were recruited as part of The Irish longitudinal study on ageing. Ten-minute electrocardiogram recordings were obtained (n = 4890), and analysed to detect AF. Self-reported arrhythmias, subjective and objective health measures (cardiovascular diseases, CHA2DS2-VASc variables and blood pressure) and medications were also recorded. Logistic regressions were used to determine associations with outcomes of presence of AF, lack of awareness and untreated AF.

RESULTS

Overall prevalence of AF was 3% (95% CI: 2.4-3.7%), with a marked age gradient and sex difference [4.8% (men) vs. 1.4% (women); P < 0.0001]. In total, 67.8% were at high risk of stroke (CHA2DS2-VASc ≥ 2), of whom 59.3% were inadequately treated. A high proportion of 38.1% were unaware of having AF. CHA2DS2-VASc nor HAS-BLED score influenced awareness or treatment. Lack of awareness was associated with lower education (P = 0.01), lower cognition (P = 0.04), rural location (OR = 3.67; P = 0.02) and number of general practitioner visits (P = 0.01), whereas untreated AF was influenced by frailty status (P = 0.04).

CONCLUSION

With projected doubling of numbers of persons over 80 in the next 30 years in the British Isles, detection and management of AF is pressing. Two-thirds of adults at high risk of stroke were inadequately treated. More regular screening for AF, application of criteria for stroke and bleeding risk and awareness of factors influencing diagnosis and treatment is recommended.

Soil Nutrients, Bacteria Populations, and Veterinary Pharmaceuticals across a Backgrounding Beef Feedlot

Beef cattle backgrounding operations that grow out weaned calves for feedlot finishing contain several environmentally significant constituents. A better understanding of these constituents and their environmental distribution will aid in the development of effective management guidelines for sustainable beef production. This research investigated soil nutrients, bacterial, and veterinary pharmaceutical concentrations across a small backgrounding beef feedlot on a karst landscape. Results indicated that all contaminants were highly concentrated in the feeder area (FD) and were lower in the other feedlot areas. The FD soils had a pH of 8.2, 59 mg kg soil organic matter (SOM), 2002 mg kg soil test phosphorus (STP), 99.7 mg kg NH-N, and 18.3 mg kg NO-N. The other locations were acidic (5.9-6.9 pH) and contained 39 mg kg SOM, 273 mg kg STP, 21.5 mg kg NH-N, and 2.0 NO-N mg kg. Bacteria populations in the FD averaged 2.7 × 10 total cells, 3.9 × 10 spp., 2.9 × 10 spp, and 4.5 × 10 cells per gram of soil. spp. and spp. concentrations were 1 to 4 orders of magnitude lower at the other locations. showed lower dynamic range and was generally uniformly distributed across the landscape. Antibiotic and parasiticide concentrations in the FD were 86.9 ng g monensin, 25.0 ng g lasalocid, and 10.3 ng g doramectin. Their concentrations were 6- to 27-fold lower in the other feedlot locations. Contaminant management plans for this small feedlot will therefore focus on the feeder and nearby grazing areas where soil nutrients, bacteria populations, and veterinary pharmaceuticals were most concentrated.

Resource utilisation for syncope presenting to an acute hospital Emergency Department

BACKGROUND

Syncope is a common clinical problem accounting for up to 6% of hospital admissions. Little is known about resource utilisation for patients admitted for syncope management in Ireland.

AIM

To determine the utilisation of resources for patients admitted for syncope management.

METHODS

Single centre observational case series of consecutive adult patients presenting to an acute hospital Emergency Department with syncope over a 5-month period.

RESULTS

Two-hundred and fourteen of 18,898 patients (1.1%) had a syncopal episode, 110 (51.4%) of whom were admitted. Mean length of stay was 6.9 days. Sixty-four of these admissions were deemed unnecessary by retrospective review when compared to ESC guidelines. Eighty-five (77.3%) admitted patients had cardiac investigations and 56 (51%) had brain imaging performed.

CONCLUSIONS

Syncope places a large demand on overstretched hospital resources. Most cases can be managed safely as an outpatient and to facilitate this, hospitals should develop outpatient Syncope Management Units.

Prevalence of viral erythrocytic necrosis in Pacific herring and epizootics in Skagit Bay, Puget Sound, Washington

Epizootics of viral erythrocytic necrosis (VEN) occurred among juvenile Pacific herring Clupea pallasii in Skagit Bay, Puget Sound, Washington, during 2005-2007 and were characterized by high prevalences and intensities of cytoplasmic inclusion bodies within circulating erythrocytes. The prevalence of VEN peaked at 67% during the first epizootic in October 2005 and waned to 0% by August 2006. A second VEN epizootic occurred throughout the summer of 2007; this was characterized by disease initiation and perpetuation in the age-1, 2006 year-class, followed by involvement of the age-0, 2007 year-class shortly after the latter's metamorphosis to the juvenile stage. The disease was detected in other populations of juvenile Pacific herring throughout Puget Sound and Prince William Sound, Alaska, where the prevalences and intensities typically did not correspond to those observed in Skagit Bay. The persistence and recurrence of VEN epizootics indicate that the disease is probably common among juvenile Pacific herring throughout the eastern North Pacific Ocean, and although population-level impacts probably occur they are typically covert and not easily detected.

Is executive impairment associated with schizophrenic syndromes? A meta-analysis

BACKGROUND

A key neuropsychological proposal in schizophrenia is that negative and disorganization symptoms are associated with different patterns of impairment on executive tasks.

METHOD

Studies reporting correlations between positive, negative or disorganization symptoms and any type of executive test were meta-analysed. The influence of moderating factors was also examined, including age, treatment and stage of illness and whether symptoms were relapsing or persistent. The magnitudes of the correlations were compared with those for general intellectual impairment.

RESULTS

Pooled correlations between executive impairment and both negative symptoms and disorganization were significant in the small-to-moderate range. That for positive symptoms ('reality distortion'), however, was close to zero. The pattern of correlations among different executive tests differed significantly for negative symptoms and disorganization. Patients with stable clinical pictures showed significantly higher correlations with executive impairment than those with relapsing and remitting illnesses. Both negative symptoms and disorganization also correlated significantly with general intellectual function as indexed by current IQ.

CONCLUSIONS

Meta-analysis supports the view that negative symptoms and disorganization are associated with partially dissociable patterns of executive impairment. However, co-existent general intellectual impairment has been an important confounding factor in the studies to date.

Secretion of flaviviral non-structural protein NS1: from diagnosis to pathogenesis

Flaviviruses are major arthropod-borne human pathogens responsible for life-threatening encephalitis, hepatitis and haemorrhagic fevers. These enveloped, single-stranded, positive-sense RNA viruses encode a polyprotein precursor of about 3400 amino acids, processed into three structural and seven non-structural proteins. The non-structural glycoprotein NS1 is essential for flavivirus viability. During host-cell infection in vitro, NS1 is found associated with intracellular organelles as a requisite for its role in viral replication, or is transported to the cell surface where it may trigger specific signalling pathways. In addition, a secreted form of the protein is released from flavivirus-infected mammalian cells. We have previously shown that the NS1 protein circulates during the acute phase of the disease in the plasma of patients infected with dengue virus type 1 and have extended our retrospective studies to dengue type 2 and type 3 cohorts, confirming the value of the NS1 antigen as an alternative diagnostic marker. Interestingly, detection of the NS1 protein in yellow fever virus and West Nile virus infections suggests that NS1 secretion is a hallmark of human flavivirus infections. The objectives of our current studies are to define the biological properties of the secreted form of the NS1 protein, to evaluate its possible contribution to viral pathogenesis, and to validate this protein as a candidate target for passive immunoprophylaxis against flaviviruses.

Lung cancer among silica-exposed workers: the quest for truth between chance and necessity

BACKGROUND

In 1997, IARC upgraded crystalline silica to a Group 1 human carcinogen. However, the IARC report itself acknowledged variations in risk depending on inherent characteristics of the crystalline silica or external factors affecting its biological activity or distribution of its polymorphs.

METHODS

We reviewed silica physical and physico-chemical properties and how such properties may affect its interaction with the target cells. Studies of silica, silicosis and lung cancer published from 1997 onwards are then reviewed in the search of any new advances in knowledge about silica carcinogenicity. Finally, other possible confounding factors contributing to inconsistent findings on silica, silicosis, and lung cancer are reviewed.

RESULTS

Host factors, physico-chemical characteristics of the surface of silica particles, exposure circumstances, and the mineral ore composition experimentally affect the ability of silica particles of inducing release of reactive oxygen species (ROS) and TNF-alpha by alveolar macrophages, possibly accounting for the great variation in lung cancer risk among dust exposed workers across the individual studies. Most recent epidemiological studies do not consider such complex pattern of modifying factors, and they keep replicating inconsistent findings. The hypothesis of a silicosis-mediated pathway, although more consistent from an epidemiological perspectives, and reassuring in terms of the effectiveness of current standards in preventing lung cancer risk among silica exposed workers, does not seem to explain elevated risks at low silica exposure levels.

CONCLUSION

Future studies of lung cancer risk among workers exposed to silica-containing dust should consider measurement of ROS and TNF-alpha release by workplace dust samples as intermediate end-points predicting lung cancer risk better than silica concentration, allowing to more effectively address preventive action.

Use of fluconazole as a surrogate marker to predict susceptibility and resistance to voriconazole among 13,338 clinical isolates of Candida spp. Tested by clinical and laboratory standards institute-recommended broth microdilution methods

Clinical laboratories frequently face the problem of delayed availability of commercially prepared approved reagents for performing susceptibility testing of new antimicrobials. Although this problem is encountered more often with antibacterial agents, it is also an issue with antifungal agents. A current example is voriconazole, a new triazole antifungal with an expanded spectrum and potency against Candida spp., Aspergillus spp., and other opportunistic fungal pathogens. The present study addresses the use of fluconazole as a surrogate marker to predict the susceptibility of Candida spp. to voriconazole. Reference broth microdilution MIC results for 13,338 strains of Candida spp. isolated from more than 200 medical centers worldwide were used. Voriconazole MICs and interpretive categories (susceptible, < or =1 microg/ml; susceptible dose dependent, 2 microg/ml; resistant, > or =4 microg/ml) were compared with those of fluconazole by regression statistics and error rate bounding analyses. For all 13,338 isolates, the absolute categorical agreement was 91.6% (false susceptible or very major error [VME], 0.0%). Since voriconazole is 16- to 32-fold more potent than fluconazole, the performance of fluconazole as a surrogate marker for voriconazole susceptibility was improved by designating those isolates with fluconazole MICs of < or =32 microg/ml as being susceptible to voriconazole, resulting in a categorical agreement of 97% with 0.1% VME. Clinical laboratories performing antifungal susceptibility testing of fluconazole against Candida spp. can reliably use these results as surrogate markers until commercial FDA-approved voriconazole susceptibility tests become available.

Activity of Hydroxamic Acids from Secale cereale Against the Plant-Parasitic Nematodes Meloidogyne incognita and Xiphinema americanum

ABSTRACT Cyclic hydroxamic acids are secondary metabolites found in the family Poaceae and have been implicated in the allelopathy of rye (Secale cereale). The toxicity of these compounds against plant-parasitic nematodes is unknown. DIBOA (2,4-dihydroxy-(2H)-1,4-benzoxazin-3(4H)-one), DIMBOA (2,4-hydroxy-7-methoxy-(2H)-1,4-benzoxazin-3(4H)-one), and their degradation products BOA (benzoxazolin-2(3H)-one) and MBOA (6-methoxy-benzoxazolin-2(3H)-one) were screened in vitro against Meloidogyne incognita second-stage juveniles (J2) and eggs and mixed-stages of Xiphinema americanum. Xiphinema americanum was more sensitive to DIBOA and DIMBOA than M. incognita J2, with a maximum apparent mortality of 96 and 92% compared to 73 and 72% at 90 mug/ml. Eggs of M. incognita were less sensitive to the hydroxamic acids than J2; only DIBOA resulted in a 50% reduction in egg hatch, with a lethal concentration (LC(50)) of 74 mug/ml compared to 21 mug/ml for J2. When M. incognita J2 were exposed to DIBOA for 48 h and the compound was removed and replaced with water, the LC(50) value increased from 21.0 to 40.7 mug/ml. MBOA was not toxic to X. americanum or M. incognita eggs, but was toxic to M. incognita J2, with LC(50) values of 44 and 20 mug/ml before and after the compound was removed and replaced with water. BOA was the least toxic hydroxamic acid tested; it did not reduce M. incognita egg hatch after 1 week of exposure or increase X. americanum mortality after 24 h of exposure. While in vitro studies provide a valuable starting point in determining the toxicity of the chemical component of rye, the relevance of the data to soil remains to be determined.

Global trends in the antifungal susceptibility of Cryptococcus neoformans (1990 to 2004)

The antifungal susceptibilities of 1,811 clinical isolates of Cryptococcus neoformans obtained from 100 laboratories in 5 geographic regions worldwide between 1990 and 2004 were determined. The MICs of amphotericin B, flucytosine, fluconazole, voriconazole, posaconazole, and ravuconazole were determined by the National Committee for Clinical Laboratory Standards broth microdilution method. Isolates were submitted to a central reference laboratory (University of Iowa) from study centers in Africa (5 centers, 395 isolates), Europe (14 centers, 102 isolates), Latin America (14 centers, 82 isolates), the Pacific region (7 centers, 50 isolates), and North America (60 centers, 1,182 isolates). Resistance to amphotericin B, flucytosine, and fluconazole was < or = 1% overall. Susceptibility to flucytosine (MIC, < or = 4 microg/ml) ranged from 35% in North America to 68% in Latin America. Similarly, only 75% of isolates from North America were susceptible to fluconazole (MIC, < or = 8 microg/ml) compared to 94 to 100% in the other regions. Isolates remained highly susceptible to amphotericin B (99% susceptibility at a MIC of < or = 1 microg/ml) over the entire 15-year period. Susceptibility to flucytosine (MIC, < or = 4 microg/ml) increased from 34% in 1990 to 1994 to 66% in 2000 to 2004. Susceptibility to fluconazole (MIC, < or = 8 microg/ml) increased from 72% in 1990 to 1994 to 96% in 2000 to 2004. Voriconazole, posaconazole, and ravuconazole all were very active (99% of isolates susceptible at MIC of < or = 1 microg/ml) against this geographically diverse collection of isolates. We conclude that in vitro resistance to antifungal agents used in the treatment of cryptococcosis remains uncommon among isolates of C. neoformans from five broad geographic regions and has not increased over a 15-year period.

Cross-resistance between fluconazole and ravuconazole and the use of fluconazole as a surrogate marker to predict susceptibility and resistance to ravuconazole among 12,796 clinical isolates of Candida spp

Cross-resistance within a class of antimicrobial agents is a problem that is often encountered with antibacterial agents, and it is also an issue with antifungal agents. A current example is ravuconazole, a new triazole antifungal with an expanded spectrum and potency against Candida spp., Aspergillus spp., and other opportunistic fungal pathogens. The present study addresses the issue of cross-resistance between fluconazole and ravuconazole and the use of fluconazole as a surrogate marker to predict the susceptibility of Candida spp. to ravuconazole. Reference broth microdilution MIC results for 12,796 strains of Candida spp. isolated from more than 200 medical centers worldwide were used. Ravuconazole MICs and tentative interpretive categories (susceptible, </=1 microg/ml; resistant, >/=2 microg/ml) were compared with those of fluconazole by using regression statistics and error rate bounding analyses. For all 12,796 isolates, the absolute categorical agreement rate was 92.5% (rate of false-susceptible results, or very major errors [VME], 0.1%). Ravuconazole was active (MIC, </=1 microg/ml) against 99.9% of the fluconazole-susceptible isolates, 96% of the fluconazole-susceptible dose-dependent isolates, and 49% of the fluconazole-resistant isolates, including 99% of the Candida krusei isolates. Since ravuconazole is 16- to 32-fold more potent than fluconazole, the performance of fluconazole as a surrogate marker for ravuconazole susceptibility was improved by designating those isolates with fluconazole MICs of </=32 microg/ml susceptible to ravuconazole, resulting in a categorical agreement rate of 98.3%, with a VME rate of 0.3% (99 and 0.4%, respectively, when C. krusei was omitted). Cross-resistance between fluconazole and ravuconazole applies most directly to fluconazole-resistant Candida glabrata and is variable among other species of Candida. Fluconazole may serve as a surrogate marker to predict the susceptibility of Candida spp. to ravuconazole.

Further standardization of broth microdilution methodology for in vitro susceptibility testing of caspofungin against Candida species by use of an international collection of more than 3,000 clinical isolates

The influence of test variables on in vitro susceptibility testing of caspofungin was examined with 694 isolates of Candida albicans including seven laboratory-derived glucan synthesis mutants. The conditions providing the greatest separation between the mutant strains and the clinical isolates were RPMI medium, MIC end point criterion of partial inhibition, and incubation for 24 h. These testing conditions were then applied to 3,322 isolates of Candida spp. (3,314 clinical isolates and eight glucan synthesis mutants). Among the 11 isolates for which caspofungin MICs were >/=2 microg/ml, eight were accounted for by the glucan synthesis mutants. The MICs for >99% of isolates were </=1 microg/ml, and thus these isolates were differentiated from strains with reduced in vitro and in vivo susceptibilities to caspofungin.

Public health monitoring of developmental disabilities with a focus on the autism spectrum disorders

Developmental disabilities (DDs) are conditions characterized by physical, cognitive, psychological, sensory, adaptive, and/or communication impairments manifested during development. Approximately 17% of individuals in the United States 18 years and younger have a DD, and for most children the cause of their condition is unknown. Of particular interest are the autism spectrum disorders (ASDs), characterized by unusual social, communication, and behavioral development. Previously autism was thought to be a rare condition, but the number of children receiving services for an ASD has increased dramatically in the last decade. Concerns about increases in DDs, particularly ASDs, their causes, and the high costs of intervention have highlighted the need for systematic public health monitoring. Service provider data, such as annual reporting of special education services or of state DD programs, do not provide a complete estimate of the rates for DDs, including ASDs. Unlike genetic metabolic disorders or congenital hearing loss (HL) for which newborn screening programs can provide accurate prevalence rates, there are currently no genetic or biologic markers for the ASDs to enable consistent and early identification of affected children. Centers for Disease Control and Prevention's (CDC) Metropolitan Atlanta Developmental Disabilities Surveillance Program (MADDSP) is a model for population monitoring of ASDs/DDs that has been implemented in other states. This article discusses the role of ASD/DD tracking in public health, as well as the challenges of ASD/DD tracking, including case definition and identification, associated conditions, linkages, and data access.

In vitro activities of voriconazole, posaconazole, and fluconazole against 4,169 clinical isolates of Candida spp. and Cryptococcus neoformans collected during 2001 and 2002 in the ARTEMIS global antifungal surveillance program

We examined the in vitro activities of voriconazole, posaconazole, and fluconazole against 3,932 isolates of Candida spp. and 237 isolates of Cryptococcus neoformans obtained from over 100 medical centers worldwide during 2001 and 2002. The MICs of the antifungal drugs were determined by broth microdilution tests performed according to the National Committee for Clinical Laboratory Standards (NCCLS) methods using RPMI 1640 as the test medium. Voriconazole and posaconazole were very active against Candida spp. (97-98% susceptible at MICs < or =1 microg/ml) and C. neoformans (98-100% susceptible at MICs < or =1 microg/mL). C. albicans (MIC90, 0.015-0.03 microg/ml) was the most susceptible species of Candida to both agents and C. glabrata (MIC90, 1-2 microg/mL) was the least susceptible. Both voriconazole and posaconazole were more active than fluconazole against all Candida spp. and C. neoformans. These results provide further evidence for the increased spectrum and potency of the new triazoles against a large and geographically diverse collection of opportunistic fungal pathogens.

Evaluation of the NCCLS M44-P Disk Diffusion Method for Determining Susceptibilities of 276 Clinical Isolates of Cryptococcus neoformans to Fluconazole

We evaluated the NCCLS M44-P fluconazole disk diffusion method in comparison with the NCCLS M27-A2 broth microdilution method for determining the susceptibility of 276 isolates of Cryptococcus neoformans . Disk diffusion testing was performed using Mueller-Hinton agar supplemented with 2% glucose and 0.5 μg of methylene blue/ml. Among the 276 isolates, 259 (93.8%) were susceptible, 16 (5.8%) were susceptible—dose dependent, and 1 (0.4%) was resistant to fluconazole as determined by the NCCLS broth microdilution method. The overall categorical agreement between the two methods was 86%, with 0% very major errors, 2% major errors, and 12% minor errors. The disk diffusion method using Mueller-Hinton agar supplemented with glucose and methylene blue appears to be a useful approach for determining the fluconazole susceptibility of C. neoformans.