Xylazine Use Among People Who Inject Drugs, Philadelphia 2022

OBJECTIVES

Xylazine is commonly mixed with illicit opioids in Philadelphia, and potential associations with wound issues, infectious diseases, and overdoses are of public health concern. We used data from the National HIV Behavioral Surveillance Survey among persons who inject drugs (PWIDs) in Philadelphia to better identify individuals at risk and inform patients and clinicians about xylazine risk factors.

METHODS

We compared characteristics of participants who reported using xylazine to those who reported not using xylazine in the past 12 months. Among those who reported xylazine use, we compared characteristics between people who prefer and did not prefer to use xylazine.

RESULTS

In this sample of PWIDs, most prefer not to use xylazine, yet use is common. Compared with PWIDs not using xylazine, PWIDs who use xylazine were more likely to have recent homelessness, polysubstance use, overdose history, and hepatitis C virus infection ( P < 0.05 for all comparisons). Compared with concordant xylazine use, discordant xylazine use was associated with lower preference for fentanyl, heroin as the primary injection drug, and lower use of syringe service programs ( P < 0.05 for all comparisons).

CONCLUSIONS

Public health entities should prioritize studying the use and health effects of xylazine in their jurisdictions and consider supporting point-of-care and drug-checking surveillance in addition to raising awareness of xylazine in the drug supply.

Lifetime body mass index and grip strength at age 46 years: the 1970 British Cohort Study

BACKGROUND

Ongoing rises in obesity prevalence have prompted growing concerns about potential increases in the burden of age-related musculoskeletal conditions including sarcopenia and sarcopenic obesity. This is of particular concern for future generations of older adults who have lived more of their lives in an obesogenic environment than current generations of older adults. We aimed to study longitudinal associations between body mass index (BMI) and grip strength in midlife using data from a large population-based sample, the 1970 British Cohort Study (BCS70).

METHODS

BCS70 participants with valid measures of maximum grip strength at age 46 years were included in analyses [3671 males (49%) and 3876 females (51%)]. Using sex-specific linear regression models, we examined associations of (i) BMI at ages 10, 16, 30, and 46 years; (ii) body fat percentage (BF%) and waist-hip ratio at age 46 years; (iii) BMI gains between 10-16, 16-30, and 30-46; and (iv) age at onset of obesity, with grip strength.

RESULTS

At age 46 years, mean (standard deviation) grip strength was 48.10 kg (8.98) in males and 29.61 kg (5.81) in females. Higher BMI at all ages was associated with stronger grip, and the scale of associations was greater in males than females from age 16 onwards (P_{sex interactions}  < 0.01). For example, in fully adjusted models, a 1 standard deviation increase in BMI at age 16 was associated with mean differences in grip strength at age 46 years of 1.41 kg (95% confidence interval: 1.07, 1.75) in males and 0.72 kg (0.53, 0.91) in females. Higher BF% at age 46 was also associated with stronger grip in both sexes. Greater gains in BMI between ages 10 and 16 were associated with stronger grip in both sexes, but subsequent gains in BMI were only associated with stronger grip in males. Associations of greater length of exposure to obesity and stronger grip were also more consistent among males than females. For example, in fully adjusted models, mean grip strength at age 46 years of males and females who had been obese since age 10 or 16 years was 4.39 kg (1.85, 6.93) and 1.25 kg (-0.18, 2.69) higher than males and females who had never been obese, respectively.

CONCLUSIONS

Higher BMI from childhood onwards is associated with stronger grip at age 46 years. This suggests that, at this age, anabolic effects of fat on muscle are outweighing the catabolic effects thought to lead to the manifestation of sarcopenic obesity later in life, especially among men. Midlife may be an optimal time to intervene to prevent sarcopenic obesity.

Rationale and study design of the MINERVA study: Multicentre Investigation of Novel Electrocardiogram Risk markers in Ventricular Arrhythmia prediction-UK multicentre collaboration

INTRODUCTION

The purpose of this study is to assess the ability of two new ECG markers (Regional Repolarisation Instability Index (R2I2) and Peak Electrical Restitution Slope) to predict sudden cardiac death (SCD) or ventricular arrhythmia (VA) events in patients with ischaemic cardiomyopathy undergoing implantation of an implantable cardioverter defibrillator for primary prevention indication.

METHODS AND ANALYSIS

Multicentre Investigation of Novel Electrocardiogram Risk markers in Ventricular Arrhythmia prediction is a prospective, open label, single blinded, multicentre observational study to establish the efficacy of two ECG biomarkers in predicting VA risk. 440 participants with ischaemic cardiomyopathy undergoing routine first time implantable cardioverter-defibrillator (ICD) implantation for primary prevention indication are currently being recruited. An electrophysiological (EP) study is performed using a non-invasive programmed electrical stimulation protocol via the implanted device. All participants will undergo the EP study hence no randomisation is required. Participants will be followed up over a minimum of 18 months and up to 3 years. The first patient was recruited in August 2016 and the study will be completed at the final participant follow-up visit. The primary endpoint is ventricular fibrillation or sustained ventricular tachycardia >200 beats/min as recorded by the ICD. The secondary endpoint is SCD. Analysis of the ECG data obtained during the EP study will be performed by the core lab where blinding of patient health status and endpoints will be maintained.

ETHICS AND DISSEMINATION

Ethical approval has been granted by Research Ethics Committees Northern Ireland (reference no. 16/NI/0069). The results will inform the design of a definitive Randomised Controlled Trial (RCT). Dissemination will include peer reviewed journal articles reporting the qualitative and quantitative results, as well as presentations at conferences and lay summaries.

TRIAL REGISTRATION NUMBER

NCT03022487.

Remote app-based management of atrial fibrillation during the COVID-19: The centre characteristics and experiences of the European TeleCheck-AF project

Funding Acknowledgements

Type of funding sources: None.

OnBehalf

TeleCheck-AF Investigators

Aims

Herein we describe the characteristics, inclusion rates and experiences from participating centres in the European TeleCheck-AF project. TeleCheck-AF is a multicentre international project initiated to maintain care delivery for patients with atrial fibrillation (AF) during COVID-19 through teleconsultations supported by an on-demand photoplethysmography-based heart rate and rhythm monitoring app (FibriCheck®). 

Methods

Two surveys exploring centre characteristics (n = 25) and centre experiences (n = 23) were completed.

Results

Most centres were academic (64%) and specialized public cardiology/district hospitals (36%). Majority of centres had AF outpatient clinics (64%) and only 36% had AF ablation clinics. The time required to start patient inclusion and total number of included patients in the project was comparable for centres experienced (56%) or inexperienced in mHealth use. Within 28 weeks, 1930 AF patients were recruited, mainly for remote AF control (31% of patients) and AF ablation follow-up (42%). Average inclusion rate was highest during the lockdown restrictions and reached a steady state at a lower level after easing the restrictions (188 vs 52 weekly recruited patients). Majority (>80%) of the centres reported no problems during the implementation of the TeleCheck-AF approach. Centres agreed that the on-boarding process of their center in the TeleCheck-AF project was simple and access to the patients measurements via stand-alone cloud infrastructure was trouble-free and possible from the first day on. They also agreed that remote heart rate and rhythm assessment by the FibriCheck® app around teleconsulatation supported their medical decision making; that their patients responded positively to use FibriCheck® for seven days; and that they felt comfortable to interpret PPG recordings. 

Conclusions

Despite different health care settings and mHealth experiences, the TeleCheck-AF approach could be set up within an extremely short time and easily used in different European centres during COVID-19.

The Effects of Displacing Sedentary Behavior With Two Distinct Patterns of Light Activity on Health Outcomes in Older Adults (Implications for COVID-19 Quarantine)

Rationale: The COVID-19 pandemic is limiting outdoor and community-based activities, especially for older adults owing to the requirement for self-isolation, potentially increasing prolonged sedentary behavior (SB). Given a poor tolerance for intense exercise, SB displacement with light intensity physical activity (LIPA) is a promising health enhancing alternative. Therefore, the aims of this study were to investigate the effects of two different types of SB displacement on health outcomes in older adults and any differential impact of associated LIPA pattern.

Method: 28 older women (age: 73 ± 5 years, height: 1.60 ± 0.07 m, weight: 67 ± 10 kg, and BMI: 26.1 ± 3.6 kg/m²) underwent overnight fasted dual energy x-ray absorptiometry (DEXA) imaging, blood sampling, and functional assessments before being randomly allocated to one of two groups: (1) single continuous bout of 45–50 min LIPA daily (n = 14); or (2) SB fragmentation (SBF; ~48 min LIPA daily, 2 min LIPA for every 30 min of SB; n = 14). Compliance was systematically monitored using tri-axial accelerometery. All measures were taken at weeks 0 and 8.

Results: Physical behavior significantly altered (decreased SB/increased LIPA; p < 0.05) and to a similar extent in both groups. We observed a significant reduction in serum triglycerides [p = 0.045, effect size (ɳ_p²) = 0.15; SBF: −0.26 ± 0.77 mmol/L, LIPA: −0.26 ± 0.51 mmol/L], improved 30 s sit-to-stand (STS) count (p = 0.002, ɳ_p² = 0.32, 2 ± 3 STS) and speed (p = 0.009, ɳ_p² = 0.35, −10 ± 33%), as well as increased average handgrip strength (p = 0.001, ɳ_p² = 0.45, 6 ± 12%), and gait speed (p = 0.005, ɳ_p² = 0.27, 0.09 ± 0.16 m/s) in both groups. Interestingly, SBF caused a greater increase in peak handgrip strength (8 ± 14%), compared to LIPA (2 ± 10%; p = 0.04, ɳ_p² = 0.38).

Conclusion: SB displacement induced significant improvements in fasting triglycerides, gait speed, as-well as STS endurance/speed in older women. Frequent vs. continuous SB displacement also caused greater increases in handgrip strength. While both SB displacement protocols display promise as efficacious home-based interventions for self-isolating older adults, our results would suggest a physical functioning advantage of the SBF protocol for certain outcomes.

Minimizing sedentary behavior (without increasing medium-to-vigorous exercise) associated functional improvement in older women is somewhat dependent on a measurable increase in muscle size

The optimal pattern of sedentarism displacement and mechanisms underlying its health effects are poorly understood. Therefore, the aim of this study was to quantify muscle-tendon adaptation in response to two different sedentarism displacement interventions and relate any adaptations to functional outcomes. Thirty-four older women (73±5yrs) underwent skeletal muscle-tendon size and functional assessments. Participants were randomly allocated to: Sedentary behavior fragmentation (SBF), Light intensity physical activity (LIPA), or Control groups. Measures were taken at weeks 0 and 8. Gait speed significantly increased (p=0.003), in both experimental groups (SBF: 0.06 ± 0.08m/s, 6±10%, LIPA: 0.06 ± 0.07m/s, 6±6%), but not control (-0.02 ± 0.12m/s, -2±9%). Accordingly, the relative change in Vastus Lateralis muscle volume, accounted for 30% (p=0.027), and 45% (p=0.0006) of the explained variance in the relative change in gait speed, for SBF and LIPA respectively. Gastrocnemius Medialis fascicle length changes were positively associated with gait speed changes, following LIPA exclusively (R²= 0.50, p=0.009). This is the first study to show SBF and LIPA are adequate loading in older women, with related muscle adaptation and clinically relevant gait speed improvements. Such adaptations appear similar irrespective of whether sedentarism displacement is prescribed in a single bout (LIPA) or in frequent micro-bouts (SBF).

Displacing Sedentary Behaviour with Light Intensity Physical Activity Spontaneously Alters Habitual Macronutrient Intake and Enhances Dietary Quality in Older Females

Displacing Sedentary Behaviour (SB) with light intensity physical activity (LIPA) is increasingly viewed as a viable means of health enhancement. It is, however, unclear whether any behavioural compensations accompany such an intervention. Therefore, the aim of this study was to identify any dietary changes that accompany SB displacement. We hypothesised that SB displacement would improve dietary quality. Thirty-five elderly females (73 ± 5 years) were randomly allocated to one of three groups: (1) sedentary behaviour fragmentation (SBF) (n = 14), (2) continuous LIPA (n = 14), or (3) control (n = 7). Habitual diet (four-day food diary) and physical behaviour (accelerometery) were assessed at weeks 0 and 8. Out of 45 nutrients examined, only glucose exhibited a group × time interaction (p = 0.03), mediated by an exclusive reduction following SBF (-31%). SBF was also the sole experimental group to increase nutrients promoting bone health (SBF: 17%, LIPA: -34%. control: 21%), whereas both experimental groups consumed more nutrients promoting anabolism (SBF: 13%, LIPA: 4%, control: -34%) (z-scores). New ambulators (n = 8) also consumed more nutrients promoting bone health (16%)/anabolism (2%) (z-scores), including significantly increased Zinc intake (p = 0.05, 29%). Displacing SB with LIPA improves dietary quality in older females. Furthermore, SB fragmentation appears advantageous for various dietary outcomes.

Effect of mouthguard design on retention and potential issues arising with usability in sport

BACKGROUND/AIMS

Mouthguard retention could potentially increase an athlete's motivation to wear the device, due to potential improvements in physical comfort. The aim of this study was to examine the retentive properties of selected customised mouthguard designs, during normal conditions (dry) and within the presence of artificial saliva (wet). Additionally, the correlation between thickness and retention was investigated.

MATERIAL AND METHODS

Six different custom mouthguard designs (MG1-MG6) reported in previous studies, were pressure-formed with 2 and 4 mm blanks accordingly. Thickness was measured 10 times at seven anatomical points and the mean (±SD) was recorded. A novel rig was fabricated to connect the mouthguards to a Hounsfield H10KS Tensometer, which was used to fully displace each device from the model at a constant rate of 50 mm/min. The test was repeated under both dry and wet conditions.

RESULTS

Retention forces recorded at the anterior region demonstrated higher measurements under wet conditions than dry (P < 0.001). The total retention of the mouthguards was influenced by alterations in their design. Trend analysis indicated that 64% of MG retention could be explained by their thickness under dry conditions and 55% when wet.

CONCLUSIONS

Design and thickness of mouthguards are key factors in retention. Mouthguard fabrication techniques should be considered in order to minimize dislodgment of the devices as well as potentially increasing the wearability of mouthguards during sport.

A Type 1 Diabetes Genetic Risk Score Predicts Progression of Islet Autoimmunity and Development of Type 1 Diabetes in Individuals at Risk

OBJECTIVE

We tested the ability of a type 1 diabetes (T1D) genetic risk score (GRS) to predict progression of islet autoimmunity and T1D in at-risk individuals.

RESEARCH DESIGN AND METHODS

We studied the 1,244 TrialNet Pathway to Prevention study participants (T1D patients' relatives without diabetes and with one or more positive autoantibodies) who were genotyped with Illumina ImmunoChip (median [range] age at initial autoantibody determination 11.1 years [1.2-51.8], 48% male, 80.5% non-Hispanic white, median follow-up 5.4 years). Of 291 participants with a single positive autoantibody at screening, 157 converted to multiple autoantibody positivity and 55 developed diabetes. Of 953 participants with multiple positive autoantibodies at screening, 419 developed diabetes. We calculated the T1D GRS from 30 T1D-associated single nucleotide polymorphisms. We used multivariable Cox regression models, time-dependent receiver operating characteristic curves, and area under the curve (AUC) measures to evaluate prognostic utility of T1D GRS, age, sex, Diabetes Prevention Trial-Type 1 (DPT-1) Risk Score, positive autoantibody number or type, HLA DR3/DR4-DQ8 status, and race/ethnicity. We used recursive partitioning analyses to identify cut points in continuous variables.

RESULTS

Higher T1D GRS significantly increased the rate of progression to T1D adjusting for DPT-1 Risk Score, age, number of positive autoantibodies, sex, and ethnicity (hazard ratio [HR] 1.29 for a 0.05 increase, 95% CI 1.06-1.6; P = 0.011). Progression to T1D was best predicted by a combined model with GRS, number of positive autoantibodies, DPT-1 Risk Score, and age (7-year time-integrated AUC = 0.79, 5-year AUC = 0.73). Higher GRS was significantly associated with increased progression rate from single to multiple positive autoantibodies after adjusting for age, autoantibody type, ethnicity, and sex (HR 2.27 for GRS >0.295, 95% CI 1.47-3.51; P = 0.0002).

CONCLUSIONS

The T1D GRS independently predicts progression to T1D and improves prediction along T1D stages in autoantibody-positive relatives.

Pharmacologic interventions for fatigue in cancer and transplantation: a meta-analysis

Background

Our objective was to determine whether, compared with control interventions, pharmacologic interventions reduce the severity of fatigue in patients with cancer or recipients of hematopoietic stem-cell transplantation (hsct).

Methods

For a systematic review, we searched medline, embase, the Cochrane Central Register of Controlled Trials, cinahl, and Psychinfo for randomized trials of systemic pharmacologic interventions for the management of fatigue in patients with cancer or recipients of hsct. Two authors independently identified studies and abstracted data. Methodologic quality was assessed using the Cochrane Risk of Bias tool. The primary outcome was fatigue severity measured using various fatigue scales. Data were synthesized using random-effects models.

Results

In the 117 included trials (19,819 patients), the pharmacologic agents used were erythropoietins (n = 31), stimulants (n = 19), l-carnitine (n = 6), corticosteroids (n = 5), antidepressants (n = 5), appetite stimulants (n = 3), and other agents (n = 48). Fatigue was significantly reduced with erythropoietin [standardized mean difference (smd): -0.52; 95% confidence interval (ci): -0.89 to -0.14] and with methylphenidate (smd: -0.36; 95% ci: -0.56 to -0.15); modafinil (or armodafinil) and corticosteroids were not effective.

Conclusions

Erythropoietin and methylphenidate significantly reduced fatigue severity in patients with cancer and in recipients of hsct. Concerns about the safety of those agents might limit their usefulness. Future research should identify effective interventions for fatigue that have minimal adverse effects.

Antibody mimetic receptor proteins for label-free biosensors

Small synthetic antibody mimetic receptor proteins which offer high stability, specificity and affinity are presented as capture molecules in solid-state electro-chemical biosensors.

Validation of the Children's International Mucositis Evaluation Scale (ChIMES) in paediatric cancer and SCT

BACKGROUND

Objectives were to describe the reliability and validity of a new paediatric-specific mucositis scale, the Children's International Mucositis Evaluation Scale (ChIMES).

METHODS

In a multi-centre prospective study, children aged 0 to ≤18 years were eligible if they were receiving any of the following: myeloablative stem cell transplantation (SCT), ≥60 mg m(-2) course(-1) doxorubicin or ≥12 g m(-2) methotrexate. Multiple measures of mucositis were included along with ChIMES. Respondents were parent proxy report for children aged <12 years, and child self-report for children aged 12-18 years and 8 to <12 years. Mucositis diaries were completed at baseline and on Days 7-17 following chemotherapy/conditioning. On Day 14, the respondent reported presence of mucositis and change since the previous day.

RESULTS

The 185 respondents included parents (N=98), children aged 12-18 years (N=66) and children aged 8 to <12 years (N=21). Test-retest reliability was excellent for ChIMES Total Score and ChIMES Percentage Score with r>0.8 for all respondent types. Criteria for construct validation were met across all measures. ChIMES also demonstrated responsiveness with significant differences between baseline and Day 14.

CONCLUSION

ChIMES is a paediatric-specific measure of mucositis with favourable psychometric properties. It exhibits reliability, construct validity and responsiveness. ChIMES should be incorporated into clinical trials of mucositis prevention and treatment in paediatric cancer and SCT.

HIF1A P582S gene association with endurance training responses in young women

Sequence variations in the gene encoding the hypoxia-inducible factor-1alpha, HIF1A, have been associated with physiologic function and could be associated with exercise responses. In the HIF1A P582S gene polymorphism (C1772T; rs 11549465 C/T), a single nucleotide transition from C → T alters the codon sequence from the usual amino acid; proline (C-allele), to serine (T-allele). This polymorphism was examined for association with endurance training responses in 58 untrained young women who completed a 6-week laboratory-based endurance training programme. Participant groups were defined as CC homozygotes versus carriers of a T-allele (CC vs. CT genotypes). Adaptations were examined at the systemic-level, by measuring [Formula: see text] and the molecular-level by measuring enzymes determined from vastus lateralis (n = 20): 3-hydroacyl-CoA-dehydrogenase (HAD), which regulates mitochondrial fatty acid oxidation; cytochrome C oxidase (COX-1), a marker of mitochondrial density; and phosphofructokinase (PFK), a marker of glycolytic capacity. CT genotypes showed 45% higher training-induced gains in [Formula: see text] compared with CC genotypes (P < 0.05). At the molecular level, CT increased the ratios PFK/HAD and PFK/COX-1 (47 and 3%, respectively), while in the CC genotypes these ratios were decreased (-26 and -54%, respectively). In conclusion, the T-allele of HIF1A P582S was associated with greater gains in [Formula: see text] following endurance training in young women. In a sub-group we also provide preliminary evidence of differential muscle metabolic adaptations between genotypes.

Presence Of Left Atrial Appendage Thrombus In Patients Presenting For Left Atrial Ablation Of Atrial Fibrillation Despite Pre-Operative Anticoagulation

Background: One of the recognised complications of left atrial ablation for atrial fibrillation (AF) is stroke. Left atrial (LA) thrombus, which may be dislodged by catheter manipulation, is an absolute contraindication to ablation. It is unclear whether imaging of the left atrial appendage (LAA) by transesophageal echo (TEE) is mandatory to exclude LA clot prior to ablation, particularly in "low-risk" patients with paroxysmal AF and normal left ventricular (LV) function. Methods and Results: We carried out a retrospective analysis of pre-ablation TEE in patients presenting for ablation of AF. Images from 244 ablation procedures carried out in 148 patients were examined, including 106 patients with paroxysmal AF and normal LV function. Despite at least 4 weeks of pre-operative therapeutic anticoagulation with Warfarin (INR>2.0), LAA thrombus was identified in 4 patients (2.7% (0.1-5.3%)). These included 2 patients with paroxysmal AF and normal LV function, although both had a high arrhythmia burden. The thrombi regressed with intensification of anticoagulation. Conclusions: Pre-operative imaging of the LAA remains advisable to exclude thrombus prior to ablation for AF even in patients with paroxysmal AF and normal LV function, especially if there is a high AF burden.

The clinical utility of search coil horizontal vestibulo-ocular reflex testing

CONCLUSION

Testing of the horizontal vestibulo-ocular reflex (VOR) with head rotations (including head impulses) using the magnetic scleral search coil technique (SCT HHI) provides valuable additional diagnostic information in patients with persistent dizziness, oscillopsia or imbalance. It identifies high and low frequency/acceleration vestibular abnormalities that are frequently missed using other methods.

OBJECTIVES

To evaluate the diagnostic utility of SCT measurement of the horizontal VOR in the multidisciplinary neurotology clinic of a tertiary referral centre.

PATIENTS AND METHODS

The records of 127 consecutive patients referred for persistent dizziness, oscillopsia, imbalance, or with clinical findings suggestive of high frequency/acceleration vestibular dysfunction were reviewed. All had been tested with clinical head impulses, bithermal calorics and vestibular-evoked myogenic potentials. VOR gain (peak eye velocity/peak head velocity) had been measured both in response to sinusoidal oscillations in a rotating chair (0.1-11 Hz) and to manually delivered horizontal head rotations (peak head velocities 50-500 degrees/s) using SCT.

RESULTS

Agreement between the different test modalities of horizontal semicircular canal function was moderate. Relative to SCT HHI, clinical HHI showed the highest sensitivity and the lowest specificity (both 70%). SCT HHI appeared to have the greatest diagnostic yield, when compared with calorics and SCT ROT (23% of all abnormalities shown were detected only by SCT HHI) and also allowed detection of significant asymmetries in patients with bilateral vestibular dysfunction.

The high-frequency/acceleration head heave test in detecting otolith diseases

OBJECTIVE

To investigate whether transient, high-acceleration interaural head heaves (translational vestibulo-ocular reflex [tVOR]) could aid in the diagnosis of otolith diseases.

STUDY DESIGN

Prospective cohort study.

SETTING

Tertiary referral center.

PATIENTS

Thirteen patients with symptoms suggestive of otolith diseases and 10 age-matched controls.

INTERVENTIONS

Patients underwent a clinical otoneurologic examination and standard laboratory audiovestibular evaluation, including audiometry, electronystagmography with bithermal caloric, Halmagyi-Curthoys head thrust test with search coils, and vestibular-evoked myogenic potential. All subjects underwent subjective visual vertical (SVV) and tVOR testings.

MAIN OUTCOME MEASURES

Sensitivity (ratio of peak eye to peak head velocities) and velocity gain (ratio of actual to ideal peak eye velocities).

RESULTS

Five of 13 patients showed no abnormality in any tests. Of the remaining 8, 3 (38%) had reduced tVOR responses, whereas 1 (13%) had abnormal SVV. Sensitivity and velocity gains were symmetrically reduced in 2 patients, who had symptoms for 8 and 24 months. A third patient, symptomatic for 7 weeks, had asymmetric reduction of tVOR responses and a deviated SVV.

CONCLUSION

Both head heave and SVV tests detect acute, asymmetric otolith diseases. Subjective visual vertical test relies on imbalance of utricular tone and may not detect bilateral symmetric diseases or partial diseases with central compensation. Our preliminary data in a small group of patients show that measuring the tVOR in a higher and more physiologic range of frequencies may serve as useful adjunct to detect acute and chronic otolith dysfunction and seems to be superior to the SVV in detecting bilateral symmetric or asymmetric otolith diseases.

The High-Frequency/Acceleration Head Heave Test in Detecting Otolith Diseases

OBJECTIVE:: To investigate whether transient, high-acceleration interaural head heaves (translational vestibulo-ocular reflex [tVOR]) could aid in the diagnosis of otolith diseases. STUDY DESIGN:: Prospective cohort study. SETTING:: Tertiary referral center. PATIENTS:: Thirteen patients with symptoms suggestive of otolith diseases and 10 age-matched controls. INTERVENTIONS:: Patients underwent a clinical otoneurologic examination and standard laboratory audiovestibular evaluation, including audiometry, electronystagmography with bithermal caloric, Halmagyi-Curthoys head thrust test with search coils, and vestibular-evoked myogenic potential. All subjects underwent subjective visual vertical (SVV) and tVOR testings. MAIN OUTCOME MEASURES:: Sensitivity (ratio of peak eye to peak head velocities) and velocity gain (ratio of actual to ideal peak eye velocities). RESULTS:: Five of 13 patients showed no abnormality in any tests. Of the remaining 8, 3 (38%) had reduced tVOR responses, whereas 1 (13%) had abnormal SVV. Sensitivity and velocity gains were symmetrically reduced in 2 patients, who had symptoms for 8 and 24 months. A third patient, symptomatic for 7 weeks, had asymmetric reduction of tVOR responses and a deviated SVV. CONCLUSION:: Both head heave and SVV tests detect acute, asymmetric otolith diseases. Subjective visual vertical test relies on imbalance of utricular tone and may not detect bilateral symmetric diseases or partial diseases with central compensation. Our preliminary data in a small group of patients show that measuring the tVOR in a higher and more physiologic range of frequencies may serve as useful adjunct to detect acute and chronic otolith dysfunction and seems to be superior to the SVV in detecting bilateral symmetric or asymmetric otolith diseases.

Endothelial dysfunction in a murine model of thyroid hormone resistance

BACKGROUND

The development of a knockin mouse model of resistance to thyroid hormone (RTH) has led to a greater understanding of both the molecular and clinical behaviour of this syndrome. We have investigated the vascular response in RTH using a specific (TRbeta PV) knockin mouse model targeting the PV mutation to the thyroid hormone receptor beta gene locus.

MATERIALS AND METHODS

Ring segments of the thoracic aorta were used to assess the response of homozygous, heterozygous and wild-type controls to contractile agents, potassium chloride and phenylephrine. Each genotype after maximal contraction was exposed to increasing concentrations of relaxing agents, acetylcholine (ACh) and sodium nitroprusside (SNP).

RESULTS

The response of these aortic ring segments to ACh and SNP demonstrates that endothelium-dependent relaxation to ACh was significantly impaired in both heterozygous and homozygous mice compared to controls (69.8 +/- 2.0%, 59.7 +/- 1.4% and 75.0 +/- 1.7%, respectively; P < 0.001). However, endothelium independent responses to SNP showed no difference between genotypes (114.4 +/- 3.2%, 116.8 +/- 2.6% and 106.9 +/- 4.9%; P = NS).

CONCLUSION

These data suggest that endothelial function is impaired in the RTH mouse aorta. The respective roles of elevated thyroid stimulating hormone (TSH), elevated thyroid hormone concentrations and the mutated thyroid hormone beta receptor require further elucidation.

Dewatered alum sludge: a potential adsorbent for phosphorus removal

Alum sludge refers to the by-product from the processing of drinking water in water treatment works. In this study, groups of batch experiments were designed to identify the characteristics of dewatered alum sludge for phosphorus adsorption. Air-dried alum sludge (moisture content 10.2%), which was collected from a water treatment works in Dublin, was subjected to artificial P-rich wastewater adsorption tests using KH2PO4 as a model P source. Adsorption behaviours were investigated as a function of amount and particle size of alum sludge, pH of solution and adsorption time. The results have shown that pH plays a major role not only in the adsorption process but also in the adsorption capacity. With regard to adsorption capacity, this study reveals the Langmuir adsorption isotherm being the best fit with experimental data (R2 = 0.98-0.99). The maximum adsorption capacities range from 0.7 to 3.5 mg-P/g when the pH of the synthetic P solution was varied from 9.0 to 4.3, accordingly. The outcome of this study indicated that alum sludge is suitable for use as an adsorbent for removal of phosphate from wastewater.

Symptomatic high frequency/acceleration vestibular loss: consideration of a new clinical syndrome of vestibular dysfunction

CONCLUSION

Symptomatic high frequency/acceleration vestibular loss is a distinct clinical entity that can be missed on conventional ENG with caloric testing. Under certain circumstances, symptomatic patients with a high frequency/acceleration vestibular loss should undergo an MSSC study for confirmation, if required.

OBJECTIVE

To document that normal electronystagmography (ENG) with conventional bithermal caloric testing is inadequate for diagnosing clinically significant high frequency/acceleration vestibular loss.

MATERIAL AND METHODS

Patients with clinical symptoms and signs of persistent peripheral vestibular dysfunction despite normal conventional bithermal caloric testing on ENG underwent high frequency/acceleration horizontal magnetic scleral search coil (MSSC) eye movement studies. The clinical findings and results from audiometric tests, conventional ENG with bithermal caloric tests and MSSC tests were reviewed.

RESULTS

Eleven patients were identified as having an abnormal MSSC study, indicating a high frequency/acceleration vestibular loss consistent with their clinical history despite normal or equivocal bithermal caloric responses on conventional ENG. Although valuable, ENG caloric testing evaluates lateral semicircular canal function and should be considered a non-physiological test primarily of low frequency vestibular function. High frequency/acceleration head thrust testing clinically detected a "high frequency/acceleration vestibular loss" in 8/11(72.7%) cases.

Gingivitis and toothbrushes: potential roles in viridans streptococcal bacteraemia

We report a case of Streptococcus oralis bacteraemia in a paediatric neutropenic patient with acute myeloid leukaemia whose predominant form of oral compromise was severe gingivitis, rather than mucositis. By phenotypic and genotypic analyses, the strain of S. oralis from blood culture was indistinguishable from an isolate from his mouth, suggesting that gingivitis may have provided a portal of entry for viridans streptococci into the bloodstream. To improve the patient's oral and dental hygiene and reduce gingivitis, conventional disposable foam toothettes were substituted with a new soft toothbrush for use as part of the oral care protocol. As there are no guidelines regarding the frequency of replacement of toothbrushes used by immunocompromised patients, the brush was swabbed regularly and culture performed to detect microbial colonization. Viridans streptococci were cultured from the toothbrush after 2 weeks of use. Phenotypic, followed by genotypic analyses, demonstrated that a strain of S. oralis from the toothbrush was indistinguishable from the strain previously isolated from blood culture and mouth. Soft toothbrushes may be useful tools for maintaining oral hygiene in immunocompromised individuals. However the results of this study indicate that regular replacement is warranted, as the toothbrush itself may become colonized with the organisms responsible for bacteraemia.

Adherence to highly active antiretroviral therapy in the real world: experience of twelve English HIV units

In order to describe how human immunodeficiency virus (HIV) clinics in and around London are trying to optimize their patients' adherence to highly active antiretroviral therapy (HAART), we performed a survey of practice and policy in the clinics using a postal questionnaire. Clinics were also asked to review up to 10 randomly selected case notes of patients receiving HAART and complete a questionnaire on each about how adherence was encouraged and assessed. Twelve clinics took part in the project and surveyed the notes of 89 patients. The results show that several clinics define adequate adherence as taking more than 95% of prescribed doses although there was no uniform definition across the participating units. Adherence was encouraged through simplifying HAART regimens, providing dose-dispensing boxes and alarms, arranging early follow-up for patients starting treatment, and offering continuing support through specific health care workers. Adequate discussion and provision of written information was seen as an important aid to adherence but the case note survey showed evidence of deficiencies in this area in approximately 40% of patients. Assessed levels of adherence were less than 95% in 27% of patients. The main reasons for suboptimal adherence were found to be lack of motivation to take treatment by the patients, high pill burden, and drug side effects although there were several other contributing factors. This study shows that the HIV units take HAART adherence seriously but there are several deficiencies in putting policy into practice.

The treatment of retinoblastoma: a case study

Research in the treatment of retinoblastoma and multidrug resistance has led to new treatment protocols for children. This case study introduces information regarding a clinical trial for the treatment of intraocular retinoblastoma. It also highlights important nursing issues in the care of these children and their families.

Management of Chlamydia trachomatis genital tract infection in Genitourinary Medicine clinics in the United Kingdom's North Thames Region 1999

Assessment of clinical management of Chlamydia trachomatis genital tract infection was made, with particular regard to the UK National Guideline. Questionnaires for self-completion, mailed to lead clinicians in 31 Genitourinary Medicine (GUM) clinics in the North Thames Region between May and June 1999, focused on policies and practice. Audit of actual management of up to 10 most recent cases (5 male and 5 female) attending each clinic within the past 2 years was also undertaken. Twenty-two units (71% response) completed the survey questionnaire and 23 units (74% response) audited a total of 229 cases (males=108, females=118, sex not stated=3). Findings indicate that GUM clinics are managing these infections largely as recommended in the national guideline. Nucleic acid amplification techniques will supersede established diagnostic tests for GUM clinics in North Thames, increasing costs for the service, but also sensitivity of detection.