Regular Protocols Research Articles

Prescription opioid use: Patient characteristics and misuse in community pharmacy

ObjectivesOpioid pain medication misuse is a major concern for US public health. The purpose of this article is to: 1) describe the demographic and physical, behavioral, and mental health characteristics of patients who fill opioid medications in community pharmacy settings; and 2) describe the extent of opioid medication misuse behaviors among these patients. DesignWe recruited and screened a convenience sample of patients with the use of a tablet computer–based assessment protocol that examined behavioral, mental, and physical health. Descriptive and inferential statistics were calculated to describe respondents and their opioid medication misuse and health characteristics. SettingPatients were screened in 2 urban and 2 rural community pharmacies in southwestern Pennsylvania. ParticipantsSurvey participants were adult patients filling opioid pain medications who were not currently receiving treatment for a cancer diagnosis. InterventionNone. Main outcome measuresValidated screening measures included the Prescription Opioid Misuse Index, Alcohol Use Disorders Identification Test C, Short Form 12, Drug Abuse Screening Test 10, Primary Care Post-traumatic Stress Disorder (PTSD) screen, and the Patient Health Questionnaire 2. ResultsA total of 333 patients were screened (71.2% response rate). Nearly the entire population reported pain above and general health below national norms. Hydrocodone (19.2%) and morphine (20.8%) were found to be the medications with the highest rates of misuse—with hydrocodone having more than 4 times higher odds of misuse compared with other medications (adjusted odds ratio [AOR] 4.48, 95% confidence interval [CI] 1.1–17.4). Patients with positive screens for illicit drug use (AOR 8.07, 95% CI 2.7–24.0), PTSD (AOR 5.88, 95% CI 2.3–14.7), and depression (AOR 2.44, 95% CI 1.0–5.9) also had significantly higher odds for misuse compared with those with negative screening results. ConclusionThese findings provide important foundational data that suggest implementation of regular opioid misuse screening protocols within community pharmacies. Such screening activities could foster a culture of prevention and overall reduction for misuse among patients filling opioid medications in community pharmacies.

Are There Clinical or Pathological Parameters of Maxillary Oral Squamous Cell Carcinoma With an Influence on the Occurrence of Neck Node Metastasis? An Appraisal of 92 Patients

To determine the proportion of patients with cervical metastases caused by maxillary oral squamous cell carcinoma (OSCC) and to identify any clinical or pathologic parameters that might be associated with the occurrence of metastatic neck disease. A retrospective cohort study of all patients managed with primary surgical resection of maxillary OSCC at the authors' institution from 2006 through 2013 was performed. Cervical lymph node dissection and adjuvant therapy were performed as warranted by preoperative staging examinations or histopathologic evaluation or as recommended after multidisciplinary consultation, and regular follow-up protocols were followed. In this analysis, each maxillary OSCC was assigned to an anterior or aposterior anatomic group based on the location of the primary lesion, with the anatomic tumor location serving as the predictor variable and the occurrence of cervical lymph node metastases as the outcome variable. Descriptive and inferential statistics were calculated with a significance level set at a P value less than .05 and post hoc power analyses were performed. The study sample was composed of 92 patients (38 women, 54 men; average age, 60.9yr). Overall, 27 patients developed cervical metastases (29.3%). Neck disease was present in 15 patients (16.3%) at initial presentation. Delayed cervical metastases were diagnosed in 12 patients (13%) and manifested after an average period of 11.17months. The anatomic location of the OSCC within the maxillary structures (anterior vs posterior) and the histologic grade greatly influenced the occurrence of metastatic neck disease. No associations were found for the variables tumor size and resection status. In this series, cervical lymph node metastases were frequent and to some degree predictable based on anatomic location and tumor grade.

Automated Forensic Animal Family Identification by Nested PCR and Melt Curve Analysis on an Off-the-Shelf Thermocycler Augmented with a Centrifugal Microfluidic Disk Segment.

Nested PCR remains a labor-intensive and error-prone biomolecular analysis. Laboratory workflow automation by precise control of minute liquid volumes in centrifugal microfluidic Lab-on-a-Chip systems holds great potential for such applications. However, the majority of these systems require costly custom-made processing devices. Our idea is to augment a standard laboratory device, here a centrifugal real-time PCR thermocycler, with inbuilt liquid handling capabilities for automation. We have developed a microfluidic disk segment enabling an automated nested real-time PCR assay for identification of common European animal groups adapted to forensic standards. For the first time we utilize a novel combination of fluidic elements, including pre-storage of reagents, to automate the assay at constant rotational frequency of an off-the-shelf thermocycler. It provides a universal duplex pre-amplification of short fragments of the mitochondrial 12S rRNA and cytochrome b genes, animal-group-specific main-amplifications, and melting curve analysis for differentiation. The system was characterized with respect to assay sensitivity, specificity, risk of cross-contamination, and detection of minor components in mixtures. 92.2% of the performed tests were recognized as fluidically failure-free sample handling and used for evaluation. Altogether, augmentation of the standard real-time thermocycler with a self-contained centrifugal microfluidic disk segment resulted in an accelerated and automated analysis reducing hands-on time, and circumventing the risk of contamination associated with regular nested PCR protocols.

CT for evaluation of urolithiasis: image quality of ultralow-dose (Sub mSv) CT with knowledge-based iterative reconstruction and diagnostic performance of low-dose CT with statistical iterative reconstruction.

To compare radiation dose and image quality in regular, low, and ultralow-dose CT protocols, and to evaluate diagnostic performance of low-dose CT for urolithiasis. Sixty-five patients with suspected urolithiasis underwent three different scans under the regular, low, and ultralow-dose protocols. The regular dose scans were reconstructed using filtered back projection and the low-dose scans were reconstructed using a statistical iterative reconstruction. The ultralow-dose scans were reconstructed using both techniques in addition to a knowledge-based IR. Effective radiation doses were compared. Objective image noise was assessed by measuring standard deviation of HU and subjective image assessment was performed with a 3- or 5-point scale. Diagnostic performance of the low-dose image was evaluated, using the regular dose image as a standard reference and the interobserver agreement between two reviewers with different levels of experience was calculated. The effective radiation dose was significantly different in each protocol (p<0.001) and estimated dose reduction of the low-dose and ultralow-dose protocols was 76.4% and 89.8%, respectively. The knowledge-based iterative reconstruction algorithm showed poorer subjective image quality than the regular and low-dose protocols, but it also had the least objective image noise. Overall, the low-dose image set showed a greater than 84% concordance rate and 100% in ureter stones larger than 3mm. Interobserver agreement was substantial (kappa value=0.61). The knowledge-based IR can provide a better quality image while reducing radiation exposure under the same protocol. Furthermore, the diagnostic performance of the low-dose CT protocol is comparable to the regular dose scan.

Quality of life in patients with primary restless leg syndrome: community-based study.

Restless leg syndrome (RLS) is frequently associated with poor mental health and impaired quality of life (QoL), due to discomfort, pain, fatigue, inability to rest, sleep disturbances, and consequently, anxiety and depression. The aim of this study is to address this issue in a community-based cohort of patients with RLS. The present study is a sub-analysis of the community-based prevalence study. In this door-to-door survey, we identified according to four essential IRLSSG diagnostic criteria 107 people with RLS. Clinical characteristics of RLS, including QoL, were obtained from 94 subjects (88 %), who completed the Serbian translation of SF-36. The main finding of our study was that the severity of RLS, in particular frequency of symptoms, negatively influenced majority of the SF-36 domains. The severity of depressive and anxiety symptoms was negatively associated with all domains of SF-36. Age of participants significantly correlated with both physical and mental composite scores. In multivariate linear regression model, higher scores of Hamilton depression (p = 0.001) and anxiety (p = 0.003) Rating scales were the most significant negative contributors of the total SF-36 score in persons with RLS. Suggesting particular role of comorbid depression and anxiety, our results may have a practical implication in terms of different psychosocial treatment and support in addition to the regular therapeutic protocols in RLS patients.

Effects of chronic exercise on severity, quality of life and functionality in an elderly Parkinson's disease patient: case report.

Exercise produces potential influences on physical and mental capacity in patients with neuropsychiatric disorders, and can be made a viable form of therapy to treat Parkinson’s disease (PD). We report the chronic effects of a regular physical exercise protocol on cognitive and motor functions, functional capacity, and symptoms in an elderly PD patient without dementia. The patient participated of a program composed of proprioceptive, aerobic and flexibility exercises, during 1 hour, three days a week, for nine months. Patient used 600 mg of L-DOPA daily, and 1 hour prior to each exercise session. Assessment was conducted in three stages, 0-3, 3-6 and 6 to 9 months, using percentual variation to the scales Hoehn and Yahr, Mini-Mental State Examination (MMSE), Parkinson Activity Scale (PAS), Beck Depression Inventory (BDI), and Unified Parkinson's Disease Rating Scale (UPDRS-III). Reassessment showed clear changes in clinical parameters for Hoehn and Yahr (4 to 2.5), MMSE (14 to 22), PAS (13 to 29), BDI (9 to 7) and UPDRS-III (39 to 27) at the end of 9 months. According to our data, exercise seems to be effective in promoting the functional capacity and the maintenance of cognitive and motor functions of PD patients. Regular exercise protocols can be implemented as an adjunctive treatment for reducing the severity of PD.

Treatment outcomes of rapid desensitisation protocols for chemotherapeutic agents and monoclonal antibodies following hypersensitivity reactions

Hypersensitivity reactions (HSR) to chemotherapeutic agents and monoclonal antibodies are common and may limit further therapeutic options. Drug desensitisation aims to induce a temporary clinical unresponsiveness to drug antigens so the causative drugs of HSR can continue to be administered. Rapid desensitisation using standardised protocols has been conducted by the Department of Immunology at The Canberra Hospital for patients who developed HSR to chemotherapeutic agents and monoclonal antibodies. This retrospective audit reviewed the safety and efficacy of the desensitisation protocols used for patients across the Capital Region Cancer Service (CRCS). Patients across the CRCS who received rapid desensitisation were identified through a search of archived correspondence. Clinical files and pharmacy records were analysed to determine protocol safety and efficacy. From June 2006 to July 2013, 13 patients underwent rapid desensitisations to oxaliplatin, carboplatin, docetaxel or rituximab. A total of 25 desensitisations was conducted with 21 (84%) achieving full target dose without inducing recurrent HSR. As a result, nine patients were successfully desensitised and continued to receive treatment without any further HSR. Desensitisation was aborted in three patients because of recurrence of HSR, which was not of a greater severity than the initial HSR. After successful desensitisation, seven patients were able to resume the regular protocols without requiring additional supervision. Rapid desensitisation to various chemotherapeutic agents and monoclonal antibodies with standardised protocols used across CRCS is safe and effective; it provides a feasible treatment option enabling continuation of effective regimens in the setting of HSR.

Efficacy of Chitra granules (porous hydroxyapatite crystals) as an alloplastic bone graft

Introduction: Bone grafting is a gold standard technique in restoring the bone defects created due to the surgical removal of cysts and tumors as well as surgical corrections of skeletal deformities. The aim of the case series was to evaluate clinically, radiographically, and ultrastructurally the efficacy of Chitra granules, a porous hydroxyapatite synthetic bone graft, substituting as a restorative material in the maxillary bone defects. Materials and Methods: In this study, six patients were divided into two groups according to the size of the bone defect after the removal of periapical intraosseous lesions. Then, the defect was filled with Chitra granules mixed with sterile saline and the surgical site was closed as per regular surgical protocols. The surgical region was evaluated clinically and radiographically at regular intervals to assess healing and bone formation. Also, a bone biopsy was taken 3-6 months after implantation of bone graft for scanning electron microscopic study. Results: New bone formation with indistinct graft-surgical margin was evident in the postoperative radiographic evaluation after 6 months. Scanning electron microscopy revealed trabeculae of bone formation at the periphery and fibrous connective tissue growth in the pores of the granules along with ossification of fibrous connective tissue in and around the granules. Conclusion: In conclusion, with the encouraging results in the literature on the role of hydroxyapatite as an osseous filling material, Chitra granules as a biomaterial can be considered as a suitable alternative to autogenous grafts, allogenous grafts, and xenografts.

Disinfectant footbathing agents for the control of bovine digital dermatitis in dairy cattle

The use of biocidal agents in footbaths for dairy cows as an alternative to antibiotics is becoming standard practice in the UK. However, with numerous biocides available for use in footbaths and varying advice on the frequency with which footbaths should be used, practitioners may refer to the published literature for guidance. The evidence would suggest a variety of biocides are effective at improving bovine digital dermatitis (BDD) lesion score in cows with lesions. However, little published data is available on the protective effective of regular (such as daily) foot disinfection protocols for cows without BDD lesions despite the widespread anecdotal evidence for its efficacy. Formalin and copper sulphate are the most commonly used biocides, both of which should be used with significant precautions. Whichever biocide is used, practical considerations with regard to footbath design and care with making solutions to the correct concentration should be addressed.

Evaluation of the Scored Questionnaire to Identify Individuals with Chronic Kidney Disease in a Community-based Screening Program in Rural North Carolina

BackgroundJust over 10 percent of US adults over twenty years of age have chronic kidney disease (CKD). Early detection is essential to delay or halt CKD's progression, but screening and early detection of CKD in high risk populations is inconsistent, especially in rural and underserved communities.ObjectiveThe objective of this study was to evaluate the effectiveness of the Screening for Occult Renal Disease questionnaire as a simple, self-report tool to identify individuals with increased likelihood of prevalent CKD in a rural North Carolina setting.MethodsOver an eight month period, in the context of the Kidney Education Outreach Program (KEOP), sixteen CKD screenings were conducted in two underserved, rural NC communities. For this study, the SCORED questionnaire was administered prior to the execution of the regular KEOP screening protocol.ResultsFor 172 participants for whom both blood and urine specimens were collected, there were fifteen (8.7%) who demonstrated less than normal kidney function. The SCORED sensitivity and specificity were 100% and 42%, respectively. The positive predictive value was 14% and the negative predictive value was 100%. The positive likelihood ratio for low eGFR was 1.7 and conversely, the negative likelihood ratio for low eGFR was zero.ConclusionIn this study, the SCORED performed comparably to previous settings in established datasets and cohort studies, with high sensitivity and negative predictive values that allow for ruling out the presence of disease. SCORED appears to provides a practical alternative to the administration of regular CKD screening protocols that can be difficult to organize and administer in rural settings. The need for further evaluation of SCORED in underserved, high-risk communities is recommended.

Natural firing patterns reduce sensitivity of synaptic plasticity to spike-timing

Synaptic plasticity is sensitive to both the rate and the timing of preand postsynaptic spikes. In experimental protocols used to induce plasticity, the imposed spike trains are regular and the relative timing between every preand postsynaptic spike is fixed. This is at odds with natural firing patterns observed in the cortex of intact animals, where cells fire irregularly and the timing between preand post-synaptic spikes varies. To investigate synaptic changes elicited by in vivo-like irregularly firing neurons at different rates and realistic correlations between preand post-synaptic spikes, we use numerical simulations and mathematical analysis of synaptic plasticity models. We concentrate on a calcium-based model [1], and further consider a voltagebased model [2] and a spike-timing based model [3]. To allow for comparison, all models are fitted to plasticity results obtained in vitro [4]. We show that standard stimulation protocols overestimate the influence of spike-timing on synaptic plasticity. Using a simple modification of regular spike-pair protocols, we allow for neurons to fire irregularly. Such irregular spike-pairs reduce the amplitude of potentiation and depression obtained by varying the time difference between preand postsynaptic spikes. This protocol allows us to quantify the relative effects of firing rate and timing in natural firing patterns, and to predict changes induced by an arbitrary correlation function between preand post-synaptic spikes. We show that spike correlations change synaptic plasticity at low firing rates in all models; whereas their influence becomes negligible at high firing rates for the calcium-based model but remains significant for the other two models. Our findings yield predictions for novel experiments and help bridge the gap between existing results on synaptic plasticity and plasticity occurring under natural conditions.

Abstract 2518: Epidemiology of tobacco use among a sample of Hispanic/Latino men attending an STI clinic.

Abstract Background: Tobacco products are a major cause of death and disease worldwide. Although a substantial decrease in tobacco use has been documented in Puerto Rico (PR), tobacco-related disparities among vulnerable and underserved populations still needs to be addressed. It has been demonstrated that behavioral risk practices, such as unprotected sex, multiple sex partners, alcohol and drug use, are associated with tobacco use. Objective: To describe the epidemiological profile of tobacco use and correlates associated with lifetime and current tobacco consumption in a sample of Hispanic/Latino men attending a Sexually Transmitted Infection (STI) clinic in San Juan, PR. Methods: A cross-sectional study consisting of 206 men ≥ 16 years was conducted. Survey included demographic characteristics and behavioral assessment of high-risk practices such as tobacco, alcohol, and drug-related risks, as well as sexual practices and self-reported STIs. Frequency distributions and descriptive statistics were used to characterize the study sample. Bivariate analysis (chi-square test) was used to determine the relation between demographic, behavioral and clinical assessments with lifetime and current (last 12 months) tobacco use. Variables that achieved statistical significance in the bivariate analysis (p&amp;lt;0.05) were assessed in age-adjusted logistic regression models. Results: The mean age of the study participants was 38.0 ± 14.2 years. The vast majority (73.5%) of the participants reported having smoked tobacco, in which more than half of them (65.8%) were current smokers. The mean amount of cigarettes consumed in the last 12 months was 7.5 ± 9.2. Bivariate analyses showed that lifetime and current drug use was associated with lifetime and current tobacco use (p&amp;lt;0.05), and self-reported HIV status was marginally associated with current tobacco use (p=0.05). After age-adjusted logistic regression, lifetime drug users were up to 9 times more likely to have used tobacco in their lifetime as compared to non-drug users (OR=9.3; 95% CI=4.5-19.4). A significant association between current drug use and lifetime tobacco use was also observed in this sample (OR=16.7; 95% CI=4.8-57.9). On the other hand, men who reported ever used drugs, have more than a two-fold increase odds of current tobacco use as compared to non-drug users (OR=2.9; 95% CI=1.1-8.0). Conclusions: Lifetime and current smoking prevalence is high among this population of men attending this STI clinic, particularly among drug users. Due to the strong addictive component of nicotine, it is important to develop tobacco cessation interventions as an essential part of regular STI clinics protocols. Thus, tobacco cessation programs could be effective in STI clinic settings in order to promote cancer prevention and control, and other health related behaviors. Citation Format: Lizbeth M. Del Toro-Mejías, Elba C. Díaz-Toro, Hermes García, Kesyha Reyes, Kathleen Nieves-Más, Manuel E. Rivera, Vivian Colón-López. Epidemiology of tobacco use among a sample of Hispanic/Latino men attending an STI clinic. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2518. doi:10.1158/1538-7445.AM2013-2518

Assessment of health-related quality of life in patients with myasthenia gravis in Belgrade (Serbia)

The aim of this study was to assess factors that might influence the health-related quality of life (HRQoL) in patients with myasthenia gravis (MG). A cross-sectional study was performed including 230 consecutive patients with MG. Severity of the disease was estimated according to the MGFA classification and QMG score. HRQoL was assessed by the SF-36 questionnaire. Depressive and anxiety symptoms were assessed using the Hamilton rating scales for depression and anxiety, respectively. Social support was measured by the Multidimensional Scale of Perceived Social Support (MSPSS), and acceptance of the disease by the Acceptance of Illness Scale. The significant demographic predictors of worse HRQoL in MG patients were older age (p = 0.025) and lower education (p = 0.012). Among clinical features, significant independent contributing factors of worse HRQoL were more severe form of the disease according to MGFA (p = 0.001) and higher QMG score (p = 0.001). Finally, psychosocial predictors of worse quality of life were lower MSPSS score (p = 0.001), poor acceptance of the disease (p = 0.001), as well as higher levels of anxiety and depression (p = 0.001). Our study revealed that the HRQoL in patients with MG is similarly reduced in its psychological and physical aspects. These results may have a practical implication pointing out that different aspects of psychosocial support should be added to the regular therapeutic protocols.

Sudden generalized lung atelectasis during thoracotomy following thoracic lavage in 3 dogs

To describe sudden onset of generalized pulmonary atelectasis following thoracic lavage in 3 dogs. Thoracic lavage was performed following ligation of a patent ductus arteriosus in case 1, prior to closure of a large traumatic full thickness wound in the chest wall in case 2, and during investigation of an idiopathic spontaneous pneumothorax in case 3. In each case anesthesia and surgery were uneventful until thoracic lavage was performed, after which sudden generalized pulmonary atelectasis was observed. The atelectasis was visualized and was associated with oxyhemoglobin desaturation, decreased end-tidal carbon dioxide partial pressure (ETCO(2)), and a marked increase in the peak inspiratory pressure (PIP) required to achieve visible lung inflation. Occlusion of the endotracheal tube and cervical trachea was directly eliminated as the cause of atelectasis in cases 1 and 2, and indirectly eliminated in case 3. Improvement in pulmonary function occurred in all cases in response to increased PIP ± positive end expiratory pressure (PEEP). Generalized atelectasis should be considered a possible complication of thoracic lavage performed during thoracotomy. In the cases presented here, it is suspected that pre-existing reduction in lung volume (due to inadequate ventilation, surgical compression, absorption atelectasis) was exacerbated by the addition of the lavage fluid to the thoracic cavity. This pre-existing lung collapse is believed to have resulted in reduction of lung volume and that further reduction below the critical closing volume occurred following instillation of saline into the thorax resulting in the subsequent development of generalized atelectasis. The performance of regular arterial blood gas analyses and different ventilation protocols may have prevented the marked atelectasis that was observed in these cases.

Prognostic, clinical and demographic features in SCN1A mutation-positive Dravet syndrome

Dravet syndrome is a severe infantile onset epileptic encephalopathy associated with mutations in the sodium channel alpha 1 subunit gene SCN1A. To date no large studies have systematically examined the prognostic, clinical and demographic features of the disease. We prospectively collected data on a UK cohort of individuals with Dravet syndrome during a 5-year study period and analysed demographic information based on UK population and birth figures. From structured referral data we examined a range of clinical characteristics including epilepsy phenotype, seizure precipitants, electroencephalography data, imaging studies, mutation class and response to medication. Predictors of developmental outcome were determined by logistic regression. We identified 241 cases with SCN1A mutation-positive Dravet syndrome, 207 of which were UK-based. The incidence of mutation-positive Dravet syndrome is at least 1:40 900 UK births. Clinical features predicting a worse developmental outcome included status epilepticus (odds ratio = 3.1; confidence interval = 1.5-6.3; P = 0.003), interictal electroencephalography abnormalities in the first year of life (odds ratio = 5.7; confidence interval = 1.9-16.8; P = 0.002) and motor disorder (odds ratio = 3.3; confidence interval = 1.7-6.4; P < 0.001). No significant effect was seen for seizure precipitants, magnetic resonance imaging abnormalities or mutation class (truncating versus missense). Abnormal magnetic resonance imaging was documented in 11% of cases, principally with findings of non-specific brain atrophy or hippocampal changes. Sodium valproate, benzodiazepines and topiramate were reported as being the most helpful medications at the time of referral. Aggravation of seizures was reported for carbamazepine and lamotrigine. The identification of factors influencing prognosis both aids counselling and encourages early, syndrome-specific therapy. Prevention of status epilepticus with regular medication and emergency protocols is important and may influence developmental outcome.

High-pitch dual-source CT angiography of the whole aorta without ECG synchronisation: Initial experience

To investigate the feasibility, image quality and radiation dose for high-pitch dual-source CT angiography (CTA) of the whole aorta without ECG synchronisation. Each group of 40 patients underwent CTA either on a 16-slice (group 1) or dual-source CT device with conventional single-source (group 2) or high-pitch mode with a pitch of 3.0 (group 3). The presence of motion or stair-step artefacts of the thoracic aorta was independently assessed by two readers. Subjective and objective scoring of motion and artefacts were significantly reduced in the high-pitch examination protocol (p < 0.05). The imaging length was not significantly different, but the imaging time was significantly (p < 0.001) shorter in the high-pitch group (12.2 vs. 7.4 vs. 1.7 s for groups 1, 2 and 3). The ascending aorta and the coronary ostia were reliably evaluable in all patients of group 3 without motion artefacts as well. High-pitch dual-source CT angiography of the whole aorta is feasible in unselected patients. As a significant advantage over regular pitch protocols, motion-free imaging of the aorta is possible without ECG synchronisation. Thus, this CT mode bears potential to become a standard CT protocol before trans-catheter aortic valve implantation (TAVI).

A study on the prevention of sniffing nodes in mobile ad hoc networks

AbstractTraditionally, a sniffing attack is classified as a passive attack, as it follows all regular protocols without generating any forged messages, simply silently sniffing packets and retrieving valuable information. In mobile ad hoc networks (MANETs), some malicious applications can only work when the resided node is in sniffing mode, and performs the same routing protocol as other normal nodes. This paper proposes a modified Ad hoc On‐demand Distance Vector (AODV) routing protocol for the detection and isolation of sniffing nodes in MANETs, so as to prevent such sniffing‐based malicious applications. With the proposed protocol, sniffing nodes in MANETs can be found and isolated by their neighboring nodes, ensuring the failure of follow‐up attacks. In this study, the NS‐2 simulation tool was used to evaluate the designed routing protocol. The results showed that the proposed protocol could effectively detect and isolate sniffing nodes, and would not cause significant network overhead. Copyright © 2010 John Wiley &amp; Sons, Ltd.

1FC1.5 Interstitial radiosurgery for gelastic epilepsy due to hypothalamic hamartomas: tolerability and efficacy in childhood and adolescence

Study aim: Our objective was to examine the demography, clinical features and prognostic factors predicting developmental outcome in a United Kingdom cohort of children with Dravet Syndrome. Methods: In the study period, 12/2005 to 2/2010, we prospectively collected data on individuals with Dravet syndrome referred to the only UK centre offering genetic testing. We analysed demographic information based on UK population and birth data. From structured referral data we examined a range of clinical characteristics including epilepsy phenotype, seizure precipitants, EEG data, imaging studies, mutation class and response to medication. Predictors of developmental outcome were determined by logistic regression. Results: We identified 241 SCN1A mutation-positive Dravet syndrome cases of which 207 are UK-based. The incidence of Dravet Syndrome is at least one in every 40,900 UK births. Clinical features predicting a worse developmental outcome included status epilepticus (OR=3.1; CI=1.5−6.3; p = 0.003), interictal EEG abnormalities in the first year of life (OR=5.7; CI=1.9 16.8; p = 0.002) and motor disorder (OR=3.3; CI=1.7−6.4; p<0.001). No significant effect was seen for seizure precipitants, MRI abnormalities or mutation class (truncating vs. missense). Abnormal MRI imaging was documented in 11% of cases, principally with findings of non-specific brain atrophy or hippocampal changes. Valproate, benzodiazepines and topiramate were reported the most helpful medications at time of referral. Aggravation of seizures was reported for carbamazepine (60%) and lamotrigine (43%). Conclusions: Identification of factors influencing prognosis both aids counselling and encourages early, syndrome specific therapy. Prevention of status epilepticus with regular medication and emergency protocols is important and may influence developmental outcome.

Functional mathematical model of dual pathway AV nodal conduction

Dual atrioventricular (AV) nodal pathway physiology is described as two different wave fronts that propagate from the atria to the His bundle: one with a longer effective refractory period [fast pathway (FP)] and a second with a shorter effective refractory period [slow pathway (SP)]. By using His electrogram alternance, we have developed a mathematical model of AV conduction that incorporates dual AV nodal pathway physiology. Experiments were performed on five rabbit atrial-AV nodal preparations to develop and test the presented model. His electrogram alternances from the inferior margin of the His bundle were used to identify fast and slow wave front propagations. The ability to predict AV conduction time and the interaction between FP and SP wave fronts have been analyzed during regular and irregular atrial rhythms (e.g., atrial fibrillation). In addition, the role of dual AV nodal pathway wave fronts in the generation of Wenckebach periodicities has been illustrated. Finally, AV node ablative modifications have been evaluated. The model accurately reproduced interactions between FP and SP during regular and irregular atrial pacing protocols. In all experiments, specificity and sensitivity higher than 85% were obtained in the prediction of the pathway responsible for conduction. It has been shown that, during atrial fibrillation, the SP ablation significantly increased the mean HH interval (204 ± 39 vs. 274 ± 50 ms, P < 0.05), whereas FP ablation did not produce significant slowing of ventricular rate. The presented mathematical model can help in understanding some of the intriguing AV node mechanisms and should be considered as a step forward in the studies of AV nodal conduction.

SU‐FF‐J‐04: Improving Image Quality of Low Dose Cone Beam CT (CBCT) Imaging with Sparse Representation

Purpose: To present a methodology for reducing cone beam CT (CBCT) dose using low dose imaging protocols and sparse representation techniques to achieve similar image quality as regular or high dose imaging protocols. Method and Materials: The frequent usage of CBCT raises the concern of excessive non‐therapeutic dose delivered to patients, especially to pediatric patients. Sparse representation (SR) was applied to low dose CBCT imaging, achieved by using low mAs, to suppress image noise and streak artifacts. The denoising algorithm was applied to low dose clinical images based on the concept of sparse representation using the training dictionary, which was constructed from the regular dose clinical images to approximate the anatomical site of interest. Validation was carried out using two phantoms (a CATPHAN phantom and an anthropomorphic head &amp; neck phantom) and clinical prostate images. Comparisons with the modified edge preserving curvature anisotropic diffusion filter (MCDF) were carried out. Results: For CATPHAN phantom images, the SR algorithm outperformed the MCDF algorithm in terms of contrast to noise ratio (CNR). CNR was improved by an average of 32% for the SR algorithm. In contrast, MCDF only improved CNR by an average of 2.4%. Visual assessments of the anthropomorphic head &amp; neck phantom and patient images indicated the SR algorithm not only suppressed the image noise but also preserved fine details of anatomical structures and was significantly better than MCDF. Conclusion: SR can be used to reduce image noise and CBCT imaging artifacts present in low dose CBCT images. Dose reductions up to 88% were observed without loss of image quality based on visual assessment.