What Can Proton Beam Therapy Achieve for Patients with Pectus Excavatum Requiring Left Breast, Axilla and Internal Mammary Nodal Radiotherapy?

AIMS

Exposure of the heart to radiation increases the risk of ischaemic heart disease, proportionate to the mean heart dose (MHD). Radiotherapy techniques including proton beam therapy (PBT) can reduce MHD. The aims of this study were to quantify the MHD reduction achievable by PBT compared with volumetric modulated arc therapy in breath hold (VMAT-BH) in patients with pectus excavatum (PEx), to identify an anatomical metric from a computed tomography scan that might indicate which patients will achieve the greatest MHD reductions from PBT.

MATERIALS AND METHODS

Sixteen patients with PEx (Haller Index ≥2.7) were identified from radiotherapy planning computed tomography images. Left breast/chest wall, axilla (I-IV) and internal mammary node (IMN) volumes were delineated. VMAT and PBT plans were prepared, all satisfying target coverage constraints. Signed-rank comparisons of techniques were undertaken for the mean dose to the heart, ipsilateral lung and contralateral breast. Spearman's rho correlations were calculated for anatomical metrics against MHD reduction achieved by PBT.

RESULTS

The mean MHD for VMAT-BH plans was 4.1 Gy compared with 0.7 Gy for PBT plans. PBT reduced MHD by an average of 3.4 Gy (range 2.8-4.4 Gy) compared with VMAT-BH (P < 0.001). PBT significantly reduced the mean dose to the ipsilateral lung (4.7 Gy, P < 0.001) and contralateral breast (2.7 Gy, P < 0.001). The distance (mm) at the most inferomedial extent of IMN volume (IMN to heart distance) negatively correlated with MHD reduction achieved by PBT (Spearman's rho -0.88 (95% confidence interval -0.96 to -0.67, P < 0.001)).

CONCLUSION

For patients with PEx requiring left-sided breast and IMN radiotherapy, a clinically significant MHD reduction is achievable using PBT, compared with the optimal photon technique (VMAT-BH). This is a patient group in whom PBT could have the greatest benefit.

Interleukin-6 and outcomes in patients recently hospitalized with heart failure and preserved ejection fraction

Introduction

Inflammation may play a role in the pathophysiology of heart failure with preserved ejection fraction (HFpEF). Interleukin-6 (IL-6) is an important inflammatory mediator but information about its prognostic relevance in HFpEF is lacking.

Purpose

To examine the association between IL-6 and outcomes in patients with HFpEF.

Methods

We assessed the relationship between IL-6 tertile (T1–3) and all cause death, cardiovascular (CV) death and first HF hospitalisation (HFH) in 340 patients admitted to hospital with HFpEF. The association between log IL-6 and outcomes was examined in a Cox regression model adjusted for MAGGIC risk score and log B-type natriuretic peptide (BNP).

Results

Range of IL-6 (pg/ml) was: T1 (0.71–4.27), T2 (4.28–7.91) and T3 (7.94–236.32). Patients with higher IL-6 were older (73.9 versus 70.3 years), more commonly male (58.4% versus 39.5%) and had higher serum creatinine (117.6 versus 106.5 μmol/l), C-reactive protein ([CRP] 17.4 versus 4.4mg/l), troponin I (6.2 versus 5.0μg/l) and BNP (331.0 versus 254.5pg/ml). Rates of CV death and all-cause mortality, but not HFH, remained significantly higher in T3 versus T1 after adjustment. When modelled as a continuous variable, one log unit increase in IL-6 was associated with higher risk of CV death (HR 1.34 [1.05–1.70]), p=0.02) and all cause death (HR 1.41 [1.13–1.75], p=0.002).

Conclusion

In patients recently hospitalised with decompensated HFpEF, IL-6 is an independent predictor of CV death and all-cause mortality after adjusting for the MAGGIC risk score and BNP. The potential utility of IL-6 as a therapeutic target in HFpEF warrants investigation.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Scottish Executive Chief Scientist Office [project grant entitled, “Microvolt T-Wave Alternans in Chronic Heart Failure: A Study of Prevalence and Incremental Prognostic Value” (Ref CZH/4/439)]

Reducing the Risk of Death From Pneumocystis jirovecii Pneumonia After Radical Radiation Therapy to the Lung

AIMS

Lung cancer is the leading cause of cancer death. Radiotherapy given in the curative setting is associated with a 3% risk of death from Pneumocystis jirovecii pneumonia (PJP). Prolonged courses of high-dose steroids also increase the risk of PJP. International guidelines recommend the use of chemoprophylaxis with trimethoprim-sulfamethoxazole for patients at high risk. We assessed the effect of an intervention designed to reduce the impact of PJP.

MATERIALS AND METHODS

Prophylaxis guidelines were introduced in 2016. Case records of patients treated with radical radiotherapy were examined for the periods 2014 to 2015 (pre-intervention) and 2017 to 2018 (post-intervention). In total, 247 patients were treated pre-intervention and 334 post-intervention.

RESULTS

Freedom from PJP death at 1 year was 96% before intervention and 99% after (hazard ratio 0.3, 95% confidence interval 0.1-0.9, P = 0.029). Although the rate of use of chemoprophylaxis according to the guideline rose from 1% to 13% (P = 0.003), the use of high-dose steroids also fell from 35% to 16% (P < 0.00001).

CONCLUSIONS

Reducing radiotherapy-associated infections is an important component of radical treatment in lung cancer. Highlighting chemoprophylaxis guidelines reduced the death rate from PJP, with an associated more judicious use of steroids. Advocating prophylaxis in patients with lymphocyte count <0.6 × 109/l is the next intervention to be studied.

Per-oral image guided gastrojejunostomy insertion for levodopa-carbidopa intestinal gel in Parkinson's disease is safe and may be advantageous

BACKGROUND

Procedural aspects and complications of gastrojejunostomy insertion are important considerations in the use of levodopa-carbidopa intestinal gel therapy (LCIG) and may limit uptake. We describe our experience of using per-oral image guided gastrojejunostomy (PIG-J) which avoids the need for endoscopy and routine sedation in percutaneous endoscopic gastrojejunostomy (PEG-J) and allows more secure tube placement than radiologically inserted gastrojejunostomy techniques.

METHODS

We describe a case series of 32 patients undergoing PIG-J insertion for LCIG therapy in a single centre. Under local anaesthetic, a fluoroscopy-guided gastric puncture allows access for the guidewire which is then used to pull through the gastrostomy tube allowing for secure fixation, followed by placement of the gastrojejunal extension.

RESULTS

Between December 2015 to April 2020, 32/34 patients referred for PIG-J underwent this procedure successfully, 2 cases unsuccessful due to technical considerations. One patient developed delirium following successful implantation. Ten patients (31%) required a replacement tube due to blockage or displacement within the first 12 months of placement, including 2 patients who needed more than one replacement. Minor complications occurred in 10 other patients (31%), including infection (9 patients); a small haematoma not requiring intervention who later developed an infection (1 patient); and peri-stomal acid leakage (1 patient).

CONCLUSION

In summary, PIG-J insertion is safe with a similar complication rate to traditional PEG-J, well tolerated and effective for use in LCIG administration. This may widen access to LCIG for PD patients who may not be suitable or unable to tolerate PEG-J.

Clinical Outcome of "Asleep" Deep Brain Stimulation for Parkinson Disease Using Robot-Assisted Delivery and Anatomic Targeting of the Subthalamic Nucleus: A Series of 152 Patients

BACKGROUND

Recent advances in methods used for deep brain stimulation (DBS) include subthalamic nucleus electrode implantation in the "asleep" patient without the traditional use of microelectrode recordings or intraoperative test stimulation.

OBJECTIVE

To examine the clinical outcome of patients who have undergone "asleep" DBS for the treatment of Parkinson disease using robot-assisted electrode delivery.

METHODS

This is a retrospective review of clinical outcomes of 152 consecutive patients. Their outcomes at 1 yr postimplantation are reported; these include Unified Parkinson's Disease Rating Scale (UPDRS) assessment, Tinetti Mobility Test, Parkinson's Disease Questionnaire (PDQ)-39 quality of life assessment, Mattis Dementia Rating Scale, Beck Depression Inventory, and Beck Anxiety. We also report on a new parietal trajectory for electrode implantation.

RESULTS

A total of 152 patients underwent assessment at 1 yr. UPDRS III improved from 39 to 20.5 (47%, P < .001). The total UPDRS score improved from 67.6 to 36.4 (46%, P < .001). UPDRS II scores improved from 18.9 to 10.5 (44%, P < .001) and UPDRS IV scores improved from 7.1 to 3.6 (49%, P < .001). There was a significant reduction in levodopa equivalent daily dose after surgery (mean: 35%, P < .001). PDQ-39 summary index improved by a mean of 7.1 points. There was no significant difference found in clinical outcomes between the frontal and parietal approaches.

CONCLUSION

"Asleep" robot-assisted DBS of the subthalamic nucleus demonstrates comparable outcomes with traditional techniques in the treatment of Parkinson disease.

Extended Treatment with Glial Cell Line-Derived Neurotrophic Factor in Parkinson's Disease

Background:

Intraputamenal glial cell line-derived neurotrophic factor (GDNF), administered every 4 weeks to patients with moderately advanced Parkinson’s disease, did not show significant clinical improvements against placebo at 40 weeks, although it significantly increased [¹⁸F]DOPA uptake throughout the entire putamen.

Objective:

This open-label extension study explored the effects of continued (prior GDNF patients) or new (prior placebo patients) exposure to GDNF for another 40 weeks.

Methods:

Using the infusion protocol of the parent study, all patients received GDNF without disclosing prior treatment allocations (GDNF or placebo). The primary outcome was the percentage change from baseline to Week 80 in the OFF state Unified Parkinson’s Disease Rating Scale (UPDRS) motor score.

Results:

All 41 parent study participants were enrolled. The primary outcome decreased by 26.7±20.7% in patients on GDNF for 80 weeks (GDNF/GDNF; N = 21) and 27.6±23.6% in patients on placebo for 40 weeks followed by GDNF for 40 weeks (placebo/GDNF, N = 20; least squares mean difference: 0.4%, 95% CI: –13.9, 14.6, p = 0.96). Secondary endpoints did not show significant differences between the groups at Week 80 either. Prespecified comparisons between GDNF/GDNF at Week 80 and placebo/GDNF at Week 40 showed significant differences for mean OFF state UPDRS motor (–9.6±6.7 vs. –3.8±4.2 points, p = 0.0108) and activities of daily living score (–6.9±5.5 vs. –1.0±3.7 points, p = 0.0003). No treatment-emergent safety concerns were identified.

Conclusions:

The aggregate study results, from the parent and open-label extension suggest that future testing with GDNF will likely require an 80- rather than a 40-week randomized treatment period and/or a higher dose.

Randomized trial of intermittent intraputamenal glial cell line-derived neurotrophic factor in Parkinson's disease

We investigated the effects of glial cell line-derived neurotrophic factor (GDNF) in Parkinson’s disease, using intermittent intraputamenal convection-enhanced delivery via a skull-mounted transcutaneous port as a novel administration paradigm to potentially afford putamen-wide therapeutic delivery. This was a single-centre, randomized, double-blind, placebo-controlled trial. Patients were 35–75 years old, had motor symptoms for 5 or more years, and presented with moderate disease severity in the OFF state [Hoehn and Yahr stage 2–3 and Unified Parkinson’s Disease Rating Scale motor score (part III) (UPDRS-III) between 25 and 45] and motor fluctuations. Drug delivery devices were implanted and putamenal volume coverage was required to exceed a predefined threshold at a test infusion prior to randomization. Six pilot stage patients (randomization 2:1) and 35 primary stage patients (randomization 1:1) received bilateral intraputamenal infusions of GDNF (120 µg per putamen) or placebo every 4 weeks for 40 weeks. Efficacy analyses were based on the intention-to-treat principle and included all patients randomized. The primary outcome was the percentage change from baseline to Week 40 in the OFF state (UPDRS-III). The primary analysis was limited to primary stage patients, while further analyses included all patients from both study stages. The mean OFF state UPDRS motor score decreased by 17.3 ± 17.6% in the active group and 11.8 ± 15.8% in the placebo group (least squares mean difference: −4.9%, 95% CI: −16.9, 7.1, P = 0.41). Secondary endpoints did not show significant differences between the groups either. A post hoc analysis found nine (43%) patients in the active group but no placebo patients with a large clinically important motor improvement (≥10 points) in the OFF state (P = 0.0008). ¹⁸F-DOPA PET imaging demonstrated a significantly increased uptake throughout the putamen only in the active group, ranging from 25% (left anterior putamen; P = 0.0009) to 100% (both posterior putamina; P < 0.0001). GDNF appeared to be well tolerated and safe, and no drug-related serious adverse events were reported. The study did not meet its primary endpoint. ¹⁸F-DOPA imaging, however, suggested that intermittent convection-enhanced delivery of GDNF produced a putamen-wide tissue engagement effect, overcoming prior delivery limitations. Potential reasons for not proving clinical benefit at 40 weeks are discussed.

Deep brain stimulation: practical insights and common queries

The number of patients with deep brain stimulation (DBS) devices implanted is increasing. Although practices vary between centres, patients are typically given training and information from their DBS nurse or clinician, as well as a comprehensive device manual and contact details for their device manufacturer. However, for the lifetime of a patient with a DBS system, most of their secondary care often occurs in a centre without a co-located DBS service. The local neurologist is often asked pragmatic questions regarding the do's and don'ts for patients with DBS systems. While a DBS centre or device manufacturer can provide advice, we thought that it will be helpful to outline the overall management of DBS for movement disorders and the approach to commonly raised questions. We describe briefly the clinical application of DBS and discuss common scenarios where there are possible compatibility issues around the device.

Effects of acute and chronic sunitinib treatment on cardiac function and calcium/calmodulin-dependent protein kinase II

BACKGROUND AND PURPOSE

Calcium/calmodulin-dependent protein kinase IIδ (CaMKIIδ) is an important regulator of cardiac contractile function and dysfunction and may be an unwanted secondary target for anti-cancer drugs such as sunitinib and imatinib that have been reported to alter cardiac performance. This study aimed to determine whether anti-cancer kinase inhibitors may affect CaMKII activity and expression when administered in vivo.

EXPERIMENTAL APPROACH

Cardiovascular haemodynamics in response to acute and chronic sunitinib treatment, and chronic imatinib treatment, were assessed in guinea pigs and the effects compared with those of the known positive and negative inotropes, isoprenaline and verapamil. Parallel studies from the same animals assessed CaMKIIδ expression and CaMKII activity following drug treatments.

KEY RESULTS

Acute administration of sunitinib decreased left ventricular (LV) dP/dtmax. Acute administration of isoprenaline increased LVdP/dtmax dose-dependently, while LVdP/dtmax was decreased by verapamil. CaMKII activity was decreased by acute administration of sunitinib and was increased by acute administration of isoprenaline, and decreased by acute administration of verapamil. CaMKIIδ expression following all acute treatments remained unchanged. Chronic imatinib and sunitinib treatments did not alter fractional shortening; however, both CaMKIIδ expression and CaMKII activity were significantly increased. Chronic administration of isoprenaline and verapamil decreased LV fractional shortening with parallel increases in CaMKIIδ expression and CaMKII activity.

CONCLUSIONS AND IMPLICATIONS

Chronic sunitinib and imatinib treatment increased CaMKIIδ expression and CaMKII activity. As these compounds are associated with cardiac dysfunction, increased CaMKII expression could be an early indication of cellular cardiotoxicity marking potential progression of cardiac contractile dysfunction.

First case of Chlorella wound infection in a human in Australia

A 30-year-old man developed an infected knee wound 2 days after jumping his bicycle into a freshwater dam. He required repeated debridement and tissue grew bright green colonies typical of the alga Chlorella plus Aeromonas hydrophila. This, and one previously reported case, responded to surgical debridement and careful wound management.

Substandard and falsified anti-tuberculosis drugs: a preliminary field analysis

SETTING

Pharmacies in 19 cities in Angola, Brazil, China, Democratic Republic of Congo, Egypt, Ethiopia, Ghana, India (n = 3), Kenya, Nigeria, Russia, Rwanda, Thailand, Turkey, Uganda, United Republic of Tanzania and Zambia.

OBJECTIVE

To assess the quality of the two main first-line anti-tuberculosis medicines, isoniazid and rifampicin, procured from private-sector pharmacies, to determine if substandard and falsified medicines are available and if they potentially contribute to drug resistance in cities in low- and middle-income countries.

DESIGN

Local nationals procured 713 treatment packs from a selection of pharmacies in 19 cities. These samples were tested for quality using 1) thin-layer chromatography to analyze levels of active pharmaceutical ingredient (API), and 2) disintegration testing.

RESULTS

Of 713 samples tested, 9.1% failed basic quality testing for requisite levels of API or disintegration. The failure rate was 16.6% in Africa, 10.1% in India, and 3.9% in other middle-income countries.

CONCLUSIONS

Substandard and falsified drugs are readily available in the private marketplace and probably contribute to anti-tuberculosis drug resistance in low- and middle-income countries. This issue warrants further investigation through large-scale studies of drug quality in all markets.

Clinical outcomes from bilateral versus unilateral stimulation of the pedunculopontine nucleus with and without concomitant caudal zona incerta region stimulation in Parkinson's disease

INTRODUCTION

The Pedunculopontine nucleus is a novel target for deep brain stimulation and this may improve postural instability and gait dysfunction in Parkinson's disease. If unilateral Pedunculopontine nucleus stimulation is as efficacious as bilateral stimulation this would lead to less surgical risk.

METHODS

5 Parkinson's disease patients with bilateral caudal Zona Incerta region and Pedunculopontine nucleus electrodes were assessed using the motor component of the Unified Parkinson's Disease Rating Scale. Patients were assessed in the on-medication state to determine the optimal combination of stimulation setting for axial symptom control.

RESULTS

The on-medication composite axial-subscore only showed a statistically significant improvement when bilateral Pedunculopontine nucleus and caudal Zona Incerta region stimulation was used.

CONCLUSIONS

In the on-medication state bilateral Pedunculopontine nucleus and caudal Zona Incerta region stimulation is required in order to produce a significant change in the motor Unified Parkinson's Disease Rating Scale axial-subscore from baseline.

Combined pedunculopontine-subthalamic stimulation in Parkinson disease

OBJECTIVE

To assess the effect of deep brain stimulation (DBS) in the pedunculopontine nucleus (PPN) and caudal zona incerta (cZi)-both separately and in combination-on motor symptoms and regional cerebral blood flow (rCBF) in patients with Parkinson disease (PD).

METHODS

Four patients with bilateral cZi and PPN DBS electrodes were rated with the Unified Parkinson's Disease Rating Scale motor subscale (UPDRS-III) when taking and withdrawn from medication. A block of 16 [(15)O]-H(2)O PET resting measurements of rCBF were performed in 4 different states with patients withdrawn from medication: 1) no stimulation, 2) cZi stimulation alone, 3) PPN stimulation alone, 4) combined PPN/cZi stimulation.

RESULTS

When patients were medicated, combined PPN/cZi stimulation produced a statistically significant improvement in UPDRS-III score compared to cZi stimulation alone. In the "off" medication state, the clinical effect of combined stimulation was not significantly different from that induced by cZi stimulation alone. Concomitant PPN/cZi stimulation had a cumulative effect on levels of rCBF, effectively combining subcortical and cortical changes induced by stimulation of either target in isolation.

CONCLUSIONS

These findings suggest that concomitant low frequency stimulation of PPN and cZi regions induces additive brain activation changes and provides improved control of PD symptoms when medicated.

CLASSIFICATION OF EVIDENCE

This study provides Class IV evidence that concomitant low frequency stimulation of PPN and cZI improves motor symptoms in patients with PD on dopamine replacement. It provides Class III evidence that concomitant low frequency stimulation of PPN and cZi induces additive rCBF changes in motor areas of brain.

Parental attributions of controllability as a moderator of the relationship between developmental disability and behaviour problems

BACKGROUND

Children with developmental disabilities present behaviour problems to a greater extent than do typically developing children. Psychosocial models of child development suggest that parental attributions of child and adult controllability could moderate this relationship between child disability status and behaviour.

METHODS

The influence of parental attributions of adult and child controllability on the relationship between problem behaviours and disability was explored in mothers of children with developmental disabilities (DD) (N = 20) with a mean age of 9 years 3 months (SD 24.6 months), and in mothers of typically developing (TD) children (N = 26) with a mean age of 9 years 4 months (standard deviation 23.7 months). The DD group comprised 11 children with autistic spectrum disorders or other communication impairments, three children with Down Syndrome, one with cerebral palsy, one with attentional problems, and four with specific or complex developmental problems. Child behaviour was measured by the Child Behaviour Checklist. Parental attributions were measured using a modified version of the Parent Attribution Test and mothers were divided into higher and lower controllability groups on the basis of their responses on this test.

RESULTS

Multivariate analysis of variance found significant group × adult controllability interaction effects for 'aggressive behaviour', 'rule-breaking behaviour', as well as borderline significant effects for 'social problems' and 'other problems'. Simple effects analysis suggested that when mothers had lower attributions of adult controllability, there were indeed significantly more problem behaviours in the DD group, but when mothers had attributions of higher adult controllability there was no longer any significant difference in problematic behaviour between the two groups.

CONCLUSIONS

Parental attributions of controllability may moderate the well-established effect of disability on problem behaviour. Implications for parent intervention programmes are discussed.

Outcomes from stimulation of the caudal zona incerta and pedunculopontine nucleus in patients with Parkinson's disease

INTRODUCTION

Axial symptoms including postural instability, falls and failure of gait initiation are some of the most disabling motor symptoms of Parkinson's disease (PD). We performed bilateral deep brain stimulation (DBS) of the pedunculopontine nucleus (PPN) in combination with the caudal zona incerta (cZi) in order to determine their efficacy in alleviating these symptoms.

METHODS

Seven patients with predominant axial symptoms in both the 'on' and 'off' medication states underwent bilateral cZi and PPN DBS. Motor outcomes were assessed using the motor component of the Unified Parkinson's Disease Rating Scale (UPDRS 3) and a composite axial subscore was derived from items 27, 28, 29 and 30 (arising from chair, posture, gait and postural stability). Quality of life was measured using the PDQ39. Comparisons were made between scores obtained at baseline and those at a mean follow-up of 12 months.

RESULTS

In both the off and on medication states, a statistically significant improvement in the UPDRS part 3 score was achieved by stimulation of the PPN, cZi and both in combination. In the off medication state, our composite axial subscore of the UPDRS part 3 improved with stimulation of the PPN, cZi and both in combination. The composite axial subscore, in the 'on' medication state, however, only showed a statistically significant improvement when a combination of cZi and PPN stimulation was used.

CONCLUSIONS

This study provides evidence that a combination of PPN and cZi stimulation can achieve a significant improvement in the hitherto untreatable 'on' medication axial symptoms of PD.

Young people's views of mental health education in secondary schools: a Scottish study

BACKGROUND

This exploratory study used mixed methods to investigate young people's preferences in the delivery of mental health education and to investigate possible age and gender differences.

METHOD

Information was gathered about the delivery of mental health education in three secondary schools. Nine pupil focus groups were carried out to identify key themes which were then further developed and administered through questionnaires to a larger sample of 773 pupils.

RESULTS

Gender and age differences were found in young people's preferences about who should deliver mental health education, and what, when, where and how this should be delivered.

CONCLUSION

Mental health education should reflect the needs of young people. Age and gender preferences should be considered when designing these programmes.

Preliminary studies on the effect of moderate physical activity on blood levels of glutathione

Molecular epidemiological approaches are being used to study how physical activity may protect against cancer. Prior epidemiological data suggest that physical activity protects against lung cancer; however, interpretation of these data is complicated by potential confounding by smoking. Glutathione (GSH) detoxifies cigarette smoke carcinogens and the paper tests whether physical activity levels are associated with blood GSH levels. Study subjects were enrolled in a chemoprevention trial testing whether antioxidant micronutrient supplementation reduces genetic damage from cigarette smoking. Physical activity data were collected by questionnaire from 178 subjects at 12 months of follow-up in the trial. Total GSH (tGSH), which is the sum of free and protein-bound GSH and glutathione disulfide levels, was measured using the 5,5'-dithiobis-(2-nitrobenzenoic acid) colormetric assay with red blood cell samples collected at the 12-month time point. In multivariate linear regression analyses that controlled for gender and cigarettes smoked per day, tGSH was positively associated with hours per week of moderate intensity activity (beta=0.005, p=0.02). Hours per week of vigorous intensity activity were unassociated with tGSH and the effect of moderate activity remained after control for vigorous activity. The results are consistent with prior research showing differential effects of moderate and vigorous activity and suggest a mechanism through which physical activity may influence lung cancer risk.

A case-control study of community-associated Clostridium difficile infection

OBJECTIVES

The aim of this study was to determine the incidence of and risk factors for community-associated Clostridium difficile infection (CDI).

METHODS

Prospective surveillance of community-derived faecal samples for C. difficile cytotoxin, followed by a questionnaire-based case-control study in two distinct patient cohorts (one semi-rural and the other urban).

RESULTS

The proportion of randomly selected faecal samples positive for C. difficile cytotoxin was 2.1% in both patient cohorts (median ages 73 and 45 years for the urban and semi-rural cohorts, respectively). Exposure to antibiotics in the previous 4 weeks, particularly multiple agents (P < 0.001), aminopenicillins (P < 0.05) and oral cephalosporins (P < 0.05), was significantly more frequent among cases than controls. Hospitalization in the preceding 6 months was significantly associated with CDI (45% versus 23%; P = 0.022). However, almost half the cases had not received antibiotic therapy in the month before C. difficile detection, and approximately one-third neither had exposure to antibiotics nor recent hospitalization. Contact with infants aged < or =2 years was significantly associated with CDI (14% versus 2%; P = 0.02). Prior exposure to gastrointestinal-acting drugs (proton pump inhibitor, H2 antagonist or non-steroidal anti-inflammatory) was not significantly more common in CDI cases. C. difficile PCR ribotype 001 caused 60% and 13% of urban and semi-rural community-associated CDI cases, respectively.

CONCLUSIONS

Reliance on antibiotic history and age (> or =65 years) will contribute to missed diagnoses of community-associated CDI. Potential risk factors for community-associated CDI should be explored further to explain the large proportion of cases not linked to recent antibiotic therapy or hospitalization.

Candidate gene analysis of 21q22: support for S100B as a susceptibility gene for bipolar affective disorder with psychosis

A genome-wide scan in 60 bipolar affective disorder (BPAD) affected sib-pairs (ASPs) identified linkage on chromosome 21 at 21q22 (D21S1446, NPL = 1.42, P = 0.08), a BPAD susceptibility locus supported by multiple studies. Although this linkage only approaches significance, the peak marker is located 12 Kb upstream of S100B, a neurotrophic factor implicated in the pathology of psychiatric disorders, including BPAD and schizophrenia. We hypothesized that the linkage signal at 21q22 may result from pathogenic disease variants within S100B and performed an association analysis of this gene in a collection of 125 BPAD type I trios. S100B single nucleotide polymorphisms (SNPs) rs2839350 (P = 0.022) and rs3788266 (P = 0.031) were significantly associated with BPAD. Since variants within S100B have also been associated with schizophrenia susceptibility, we reanalyzed the data in trios with a history of psychosis, a phenotype in common between the two disorders. SNPs rs2339350 (P = 0.016) and rs3788266 (P = 0.009) were more significantly associated in the psychotic subset. Increased significance was also obtained at the haplotype level. Interestingly, SNP rs3788266 is located within a consensus-binding site for Six-family transcription factors suggesting that this variant may directly affect S100B gene expression. Fine-mapping analyses of 21q22 have previously identified transient receptor potential gene melastatin 2 (TRPM2), which is 2 Mb upstream of S100B, as a possible BPAD susceptibility gene at 21q22. We also performed a family-based association analysis of TRPM2 which did not reveal any evidence for association of this gene with BPAD. Overall, our findings suggest that variants within the S100B gene predispose to a psychotic subtype of BPAD, possibly via alteration of gene expression.

The association between benzo[a]pyrene-DNA adducts and body mass index, calorie intake and physical activity

Prior work suggests that body size and fat content may influence carcinogen-DNA adduct levels measured in white blood cells. Here we consider energy balance more broadly by assessing the impact of body mass index (BMI), physical activity and calorie intake on the presence of benzo[a]pyrene-DNA (BP-DNA) adducts in white blood cell DNA. Our cross-sectional study employed subjects from a separately conducted intervention trial. Physical activity and food intake data were collected at 12 and 15 months of follow-up, respectively. BP-DNA adducts were measured by high-performance liquid chromatography (HPLC) in white blood cell samples collected at 12 months of follow-up. Complete data on all variables were available from 143 subjects. Logistic regression showed that BMI was inversely associated with the presence of detectable adducts (OR = 0.90, p = 0.02), and that hours of moderate-intensity physical activity were positively associated with the presence of detectable adducts (OR = 1.04, p = 0.04). These results provide further evidence that body fat content influences carcinogen-DNA adduct levels, probably by altering the distribution of the lipophilic parent compound.

Stenotrophomonas maltophilia contamination of nebulizers used to deliver aerosolized therapy to inpatients with cystic fibrosis

There is circumstantial evidence that nebulizer equipment may be a source of Stenotrophomonas maltophilia for patients with cystic fibrosis. Eighty-nine inpatient nebulizers were examined for evidence of S. maltophilia contamination of which nine (10%) yielded 14 strains of the bacterium. Environmental samples were obtained from 73 different sites on the ward, of which 17 (23%) yielded a further 21 strains. Positive sites included taps, sink drains, and potable water. Genotyping using ERIC-PCR and pulsed-field gel electrophoresis revealed that two pairs of patients' nebulizers were contaminated with closely related strains. None of the S. maltophilia isolates obtained from the ward environment shared genotypes with those obtained from the nebulizers. The frequency of isolation of S. maltophilia from potable water sources on the ward suggests that contamination may result from using it to clean reusable nebulizer equipment, particularly if this is followed by inadequate drying. Although the actual source of S. maltophilia contamination of hospital-use nebulizer equipment in this study remained elusive, these results have important infection control implications.

Transmission of colistin-resistant Pseudomonas aeruginosa between patients attending a pediatric cystic fibrosis center

We report on an outbreak of colistin-resistant Pseudomonas aeruginosa (CRPA) that occurred in a United Kingdom pediatric cystic fibrosis (CF) unit and involved six children over a period of 5 years. All CRPA-positive children had received aerosolized colistin therapy before first isolation of resistant organisms (mean duration, 3.1 years). Four of the 6 had also received courses of intravenous colistin in the year before the first isolation of CRPA. No impact of CRPA acquisition on respiratory function, clinical condition, or radiological parameters could be demonstrated. Four of the 6 children carried isolates of CRPA indistinguishable on genotyping. Two of these 4 children were sisters. The other 2 were on the same ward together at time of first isolation, and subsequently shared overlapping admissions with one of the sisters. While there is no conclusive evidence for the route of transmission, the frequency of overlapping in-patient admissions between 3 of these patients is suggestive of patient-to-patient transfer in the nosocomial setting.CF clinicians should be aware that colistin resistance can occur in P. aeruginosa, and some of these strains are capable of spread within CF units.

Susceptibility of Burkholderia cepacia and other pathogens of importance in cystic fibrosis to u.v. light

To investigate the potential usefulness of u.v. germicidal irradiation (UVGI) in preventing the spread of Burkholderia cepacia, an important pathogen in cystic fibrosis (CF), the in-vitro susceptibility of B. cepacia to UVGI was determined. Five strains were exposed to UVGI from a 7.2-W source. Burkholderia cepacia was less susceptible to UVGI than other important CF-related pathogens, namely Staphylococcus aureus and Pseudomonas aeruginosa, but was more susceptible than Stenotrophomonas maltophilia. No strain of B. cepacia survived longer than an 8 s exposure to UVGI, with doses required to achieve 1 log reduction in bacterial numbers ranging from 28.3 to 57.5 J m(-2).

Survival of Stenotrophomonas maltophilia following exposure to concentrations of tobramycin used in aerosolized therapy for cystic fibrosis patients

The use of aerosolized tobramycin is an important component in the management of patients with cystic fibrosis, particularly those with chronic Pseudomonas aeruginosa infection. Clinicians have been concerned that long-term therapy with aerosolized tobramycin may increase the risk of colonization with multi-resistant bacteria, including Stenotrophomonas maltophilia. The ability of five strains (three clinical, two environmental) of S. maltophilia to survive exposure to 16000 microg/mL tobramycin, a concentration commonly found inside the atomization chamber of nebulizers used to deliver aerosolized therapy, was studied. Under a variety of different growth conditions, all five strains were able to survive exposure to 16000 microg/mL of tobramycin. Post-exposure recovery was enhanced at 20 degrees C and 30 degrees C in comparison with 37 degrees C under all test conditions. The importance of these findings in relation to the epidemiology of S. maltophilia in patients with cystic fibrosis is discussed.

Peer review: an approach to performance evaluation in a professional practice model

Role expectations of staff nurses are changing, and nurses must become empowered and actively involved in facilitating that change, rather than having their role changed for them. The shared governance framework provides an efficient way to meet current changes and increased responsibilities. Peer review is an integral component of this framework. A professional practice model with peer review increases the accountability of its members by encouraging improved work achievement and reinforcing high standards of practice. Promoting communication and sharing of each individual's practice enhances a sense of teamwork and encourages creativity and an increased sense of ownership regarding nursing practice among all model members.