Systematic Review of CT Angiography in Guiding Management in Pediatric Oropharyngeal Trauma

OBJECTIVES

Pediatric oropharyngeal trauma is common. Although most cases resolve uneventfully, there have been reports of internal carotid artery injury leading to devastating neurovascular sequelae. There is significant controversy regarding the utility of CT angiography (CTA) in children with seemingly minor oropharyngeal trauma. The goal of this study was to appraise changes in diagnosis and treatment based on CTA results.

METHODS

A comprehensive search of PubMed, Embase, CINAHL, Scopus, the Cochrane Ear, Nose and Throat Disorders Group Trials Register, and the ClinicalTrials.gov database was performed following PRISMA guidelines.

RESULTS

The search yielded 5,078 unique abstracts, of which 8 articles were included. A total of 662 patients were included, with 293 having any CT head/neck imaging, and 255 with CTA. Eleven injuries/abnormalities of the carotid were found on CTAs, comprising edema around the carotid (n = 8), potential intimal tear (n = 1), carotid spasm (n = 1), and carotid compression (n = 1). The pooled proportion of imaging findings on CTA that could lead to changes in clinical management was 0.00 (95% CI 0.00-0.43). Angiography was obtained in 10 patients, in 6 cases due to abnormal CTA. Angiography identified 1 patient with vessel spasm and two patients with carotid intima disruption without thrombus. No patient underwent vascular repair or suffered cerebrovascular injury.

CONCLUSION

Imaging with CTA yielded radiological abnormalities in a few instances. These results do not support the routine use of CTA in screening pediatric oropharyngeal trauma when balanced against the risk of radiation, as it rarely resulted in management changes and was not shown to improve outcomes.

LEVEL OF EVIDENCE

N/A Laryngoscope, 133:457-466, 2023.

Quality Versus Quantity: Using Scholarly Activity to Assess Otolaryngology Residency Candidates

Selecting qualified candidates each year for residency positions has become more difficult in recent years, due to the sharp increase in Otolaryngology applicants. Although there are objective measures that can be used to directly compare medical students during the initial screening process, most information in the application is highly subjective and/or variable across institutions. Many programs count the total posters/presentations and publications to gauge scholarship. This measure of quantity may lead to negative bias toward those who have no home program, limited time outside of academics, and/or inadequate resources to engage in volunteer research. Evaluating the quality of research may be superior to quantity. A first-author publication is a viable proxy that demonstrates applicants have developed skills that set them apart from their peers. They likely possess non-clinical, translatable skills including internal motivation, self-regulation, curation of information, and task completion that map closely with qualities that make for excellent residents.

Brain charts for the human lifespan

Over the past few decades, neuroimaging has become a ubiquitous tool in basic research and clinical studies of the human brain. However, no reference standards currently exist to quantify individual differences in neuroimaging metrics over time, in contrast to growth charts for anthropometric traits such as height and weight1. Here we assemble an interactive open resource to benchmark brain morphology derived from any current or future sample of MRI data ( http://www.brainchart.io/ ). With the goal of basing these reference charts on the largest and most inclusive dataset available, acknowledging limitations due to known biases of MRI studies relative to the diversity of the global population, we aggregated 123,984 MRI scans, across more than 100 primary studies, from 101,457 human participants between 115 days post-conception to 100 years of age. MRI metrics were quantified by centile scores, relative to non-linear trajectories2 of brain structural changes, and rates of change, over the lifespan. Brain charts identified previously unreported neurodevelopmental milestones3, showed high stability of individuals across longitudinal assessments, and demonstrated robustness to technical and methodological differences between primary studies. Centile scores showed increased heritability compared with non-centiled MRI phenotypes, and provided a standardized measure of atypical brain structure that revealed patterns of neuroanatomical variation across neurological and psychiatric disorders. In summary, brain charts are an essential step towards robust quantification of individual variation benchmarked to normative trajectories in multiple, commonly used neuroimaging phenotypes.

Changes in Ventricular and Cortical Volumes following Shunt Placement in Patients with Idiopathic Normal Pressure Hydrocephalus

BACKGROUND AND PURPOSE

While changes in ventricular and extraventricular CSF spaces have been studied following shunt placement in patients with idiopathic normal pressure hydrocephalus, regional changes in cortical volumes have not. These changes are important to better inform disease pathophysiology and evaluation for copathology. The purpose of this work is to investigate changes in ventricular and cortical volumes in patients with idiopathic normal pressure hydrocephalus following ventriculoperitoneal shunt placement.

MATERIALS AND METHODS

This is a retrospective cohort study of patients with idiopathic normal pressure hydrocephalus who underwent 3D T1-weighted MR imaging before and after ventriculoperitoneal shunt placement. Images were analyzed using tensor-based morphometry with symmetric normalization to determine the percentage change in ventricular and regional cortical volumes. Ventricular volume changes were assessed using the Wilcoxon signed rank test, and cortical volume changes, using a linear mixed-effects model (P < .05).

RESULTS

The study included 22 patients (5 women/17 men; mean age, 73 [SD, 6] years). Ventricular volume decreased after shunt placement with a mean change of -15.4% (P < .001). Measured cortical volume across all participants and cortical ROIs showed a mean percentage increase of 1.4% (P < .001). ROIs near the vertex showed the greatest percentage increase in volume after shunt placement, with smaller decreases in volume in the medial temporal lobes.

CONCLUSIONS

Overall, cortical volumes mildly increased after shunt placement in patients with idiopathic normal pressure hydrocephalus with the greatest increases in regions near the vertex, indicating postshunt decompression of the cortex and sulci. Ventricular volumes showed an expected decrease after shunt placement.

Dual blockade of EGFR and CDK4/6 delays head and neck squamous cell carcinoma progression by inducing metabolic rewiring

Despite preclinical success, monotherapies targeting EGFR or cyclin D1-CDK4/6 in Head and Neck squamous cell carcinoma (HNSCC) have shown a limited clinical outcome. Here, we aimed to determine the combined effect of palbociclib (CDK4/6) and afatinib (panEGFR) inhibitors as an effective strategy to target HNSCC. Using TCGA-HNSCC co-expression analysis, we found that patients with high EGFR and cyclin D1 expression showed enrichment of gene clusters associated with cell-growth, glycolysis, and epithelial to mesenchymal transition processes. Phosphorylated S6 (p-S6), a downstream effector of EGFR and cyclin D1-CDK4/6 signalling, showed a progressive increase from normal oral tissues to leukoplakia and frank malignancy, and associated with poor outcome of the patients. This increased p-S6 expression was drastically reduced after combination treatment with afatinib and palbociclib in the cell lines and mouse models, suggesting its utiliy as a prognostic marker in HNSCC. Combination treatment also reduced the cell growth and induced cell senescence via increasing reactive oxygen species with concurrent ablation of glycolytic and tricarboxylic acid cycle intermediates. Finally, our findings in sub-cutaneous and genetically engineered mouse model (K14-CreERtam;LSL-KrasG12D/+;Trp53R172H/+) studies showed a significant reduction in the tumor growth and delayed tumor progression after combination treatment. This study collectively demonstrates that dual targeting may be a critical therapeutic strategy in blocking tumor progression via inducing metabolic alteration and warrants clinical evaluation.

Differential mutation spectrum and immune landscape in African Americans versus Whites: A possible determinant to health disparity in head and neck cancer

African Americans (AA) with Head and Neck Squamous Cell Carcinoma (HNSCC) have a worse disease prognosis than White patients despite adjusting for socio-economic factors, suggesting the potential biological contribution. Therefore, we investigated the genomic and immunological components that drive the differential tumor biology among race. We utilized the cancer genome atlas and cancer digital archive of HNSCC patients (1992-2013) for our study. We found that AA patients with HNSCC had a higher frequency of mutation compared to Whites in the key driver genes-P53, FAT1, CASP8 and HRAS. AA tumors also exhibited lower intratumoral infiltration of effector immune cells (CD8+, γδT, resting memory CD4+ and activated memory CD4+ T cells) with shorter survival than Whites. Unsupervised hierarchical clustering of differentially expressed genes demonstrated distinct gene clusters between AA and White patients with unique signaling pathway enrichments. Connectivity map analysis identified drugs (Neratinib and Selumetinib) that target aberrant PI3K/RAS/MEK signaling and may reduce racial disparity in therapy response.

Abstract A31: Deregulation of NOTCH 1/NR4A2 signaling axis in head and neck cancer pathogenesis

Background: Notch1 and its intracellular cytoplasmic domain (NICD) are dysregulated in many solid tumors, including head and neck squamous cell carcinoma (HNSCC), and associated with disease initiation and progression. NICD-mediated upregulation of nuclear receptor related 1 (NURR1/NR4A2) is linked to differentiation/development, homeostasis, and cellular metabolism. However, the role and molecular mechanism(s) of Notch1/NICD- NR4A2 axis in HNSCC pathogenesis are still unknown and need to be investigated.

Methods: The clinicopathologic importance of Notch1 and NR4A2 was investigated using HNSCC patient samples and publicly available databases. NR4A2 was stably knocked out (KO) and Notch1 signaling was blocked using small-molecule inhibitor (PF3084014) in HNSCC cell lines and analyzed for tumorigenic and metastatic potential. We also examined the whole-genome NR4A2 target genes using ChIP sequencing.

Results: Both Notch1 and NR4A2 were highly overexpressed in HNSCC patients. Inhibition of Notch1 signaling or NR4A2 KO significantly decreased the clonogenicity and migratory potential of HNSCC cells. Our ChIP analysis revealed that NR4A2 regulates genes involved in metabolism, hypoxia, cell cycle progression, integrin and Wnt signaling. Interestingly, we observed that NR4A2 regulates stem cell markers including Sox2, Nanog, and CD44 and their expression was drastically reduced upon Notch 1 inhibition.

Conclusion: Targeting Notch1-NR4A2 signaling axis may be crucial for inhibition of cancer stem cell-mediated HNSCC pathogenesis.

Citation Format: Sanjib Chaudhary, Ramesh Pothuraju, Zafar Sayed, Dwight T. Jones, Surinder K. Batra, Muzafar A. Macha. Deregulation of NOTCH 1/NR4A2 signaling axis in head and neck cancer pathogenesis [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; 2019 Apr 29-30; Austin, TX. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_2):Abstract nr A31.

Immunometabolic Alterations by HPV Infection: New Dimensions to Head and Neck Cancer Disparity

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer, with high morbidity and mortality. Racial disparity in HNSCC is observed between African Americans (AAs) and whites, effecting both overall and 5-year survival, with worse prognosis for AAs. In addition to socio-economic status and demographic factors, many epidemiological studies have also identified factors including coexisting human papillomavirus (HPV) infection, primary tumor location, and a variety of somatic mutations that contribute to the prognostic incongruities in HNSCC patients among AAs and whites. Recent research also suggests HPV-induced dysregulation of tumor metabolism and immune microenvironment as the major regulators of HNSCC patient prognosis. Outcomes of several preclinical and clinical studies on targeted therapeutics warrant the need to elucidate the inherent mechanistic and population-based disparities underlying patient responses. This review systematically reports the underlying reasons for inconsistency in disease prognosis and therapy responses among HNSCC patients from different racial populations. The focus of this review is twofold: aside from discussing the causes of racial disparity, we also seek to identify the consequences of such disparity in terms of HPV infection and its associated mutational, metabolic, and immune landscapes. Considering the clinical impact of differential patient outcomes among AA and white populations, understanding the underlying cause of this disparity may pave the way for novel precision therapy for HNSCC.

Emerging therapeutic potential of graviola and its constituents in cancers

Cancer remains a leading cause of death in the USA and around the world. Although the current synthetic inhibitors used in targeted therapies have improved patient prognosis, toxicity and development of resistance to these agents remain a challenge. Plant-derived natural products and their derivatives have historically been used to treat various diseases, including cancer. Several leading chemotherapeutic agents are directly or indirectly based on botanical natural products. Beyond these important drugs, however, a number of crude herbal or botanical preparations have also shown promising utility for cancer and other disorders. One such natural resource is derived from certain plants of the family Annonaceae, which are widely distributed in tropical and subtropical regions. Among the best known of these is Annona muricata, also known as soursop, graviola or guanabana. Extracts from the fruit, bark, seeds, roots and leaves of graviola, along with several other Annonaceous species, have been extensively investigated for anticancer, anti-inflammatory and antioxidant properties. Phytochemical studies have identified the acetogenins, a class of bioactive polyketide-derived constituents, from the extracts of Annonaceous species, and dozens of these compounds are present in different parts of graviola. This review summarizes current literature on the therapeutic potential and molecular mechanism of these constituents from A.muricata against cancer and many non-malignant diseases. Based on available data, there is good evidence that these long-used plants could have both chemopreventive and therapeutic potential. Appropriate attention to safety studies will be important to assess their effectiveness on various diseases caused or promoted by inflammation.

Afatinib radiosensitizes head and neck squamous cell carcinoma cells by targeting cancer stem cells

The dismal prognosis of locally advanced and metastatic squamous cell carcinoma of the head and neck (HNSCC) is primarily due to the development of resistance to chemoradiation therapy (CRT). Deregulation of Epidermal Growth Factor Receptor (EGFR) signaling is involved in HNSCC pathogenesis by regulating cell survival, cancer stem cells (CSCs), and resistance to CRT. Here we investigated the radiosensitizing activity of the pan-EGFR inhibitor afatinib in HNSCC in vitro and in vivo. Our results showed strong antiproliferative effects of afatinib in HNSCC SCC1 and SCC10B cells, compared to immortalized normal oral epithelial cells MOE1a and MOE1b. Comparative analysis revealed stronger antitumor effects with afatinib than observed with erlotinib. Furthermore, afatinib enhanced in vitro radiosensitivity of SCC1 and SCC10B cells by inducing mesenchymal to epithelial transition, G1 cell cycle arrest, and the attenuating ionizing radiation (IR)-induced activation of DNA double strand break repair (DSB) ATM/ATR/CHK2/BRCA1 pathway. Our studies also revealed the effect of afatinib on tumor sphere- and colony-forming capabilities of cancer stem cells (CSCs), and decreased IR-induced CSC population in SCC1 and SCC10B cells. Furthermore, we observed that a combination of afatinib with IR significantly reduced SCC1 xenograft tumors (median weight of 168.25 ± 20.85 mg; p = 0.05) compared to afatinib (280.07 ± 20.54 mg) or IR alone (324.91 ± 28.08 mg). Immunohistochemical analysis of SCC1 tumor xenografts demonstrated downregulation of the expression of IR-induced pEGFR1, ALDH1 and upregulation of phosphorylated γH2AX by afatinib. Overall, afatinib reduces tumorigenicity and radiosensitizes HNSCC cells. It holds promise for future clinical development as a novel radiosensitizer by improving CSC eradication.

Genomic profiling of Acute lymphoblastic leukemia in ataxia telangiectasia patients reveals tight link between ATM mutations and chromothripsis

Recent developments in sequencing technologies led to the discovery of a novel form of genomic instability, termed chromothripsis. This catastrophic genomic event, involved in tumorigenesis, is characterized by tens to hundreds of simultaneously acquired locally clustered rearrangements on one chromosome. We hypothesized that leukemias developing in individuals with Ataxia Telangiectasia, who are born with two mutated copies of the ATM gene, an essential guardian of genome stability, would show a higher prevalence of chromothripsis due to the associated defect in DNA double-strand break repair. Using whole-genome sequencing, fluorescence in situ hybridization and RNA sequencing, we characterized the genomic landscape of Acute Lymphoblastic Leukemia (ALL) arising in patients with Ataxia Telangiectasia. We detected a high frequency of chromothriptic events in these tumors, specifically on acrocentric chromosomes, as compared with tumors from individuals with other types of DNA repair syndromes (27 cases total, 10 with Ataxia Telangiectasia). Our data suggest that the genomic landscape of Ataxia Telangiectasia ALL is clearly distinct from that of sporadic ALL. Mechanistically, short telomeres and compromised DNA damage response in cells of Ataxia Telangiectasia patients may be linked with frequent chromothripsis. Furthermore, we show that ATM loss is associated with increased chromothripsis prevalence in additional tumor entities.

Passive Smoke Exposure as a Risk Factor for Airway Complications during Outpatient Pediatric Procedures

OBJECTIVE: Determine if passive smoke exposure (PSE) increases airway complications during outpatient mask anesthesia procedures in children.

METHODS: A prospective cohort of children who underwent surgical procedures under mask anesthesia was studied with the American Thoracic Society children's questionnaire on environmental and respiratory factors. Double-blinded outcomes with respect to adverse airway events were recorded both intraoperatively and in the recovery room for patients with and without passive smoke exposure. Multivariate comparisons assessing the likelihood of these airway complications were conducted between the PSE and nonexposed groups.

RESULTS: Of 405 children, 168 (41.5%) had PSE. The incidence of airway complications during anesthesia or postanesthetic recovery was higher for all outcome measures for PSE children (all P ≤ 0.005), except for recovery room breath holding ( P = 0.086). Intraoperative laryngospasm and airway obstruction were 4.9 and 2.8 times more likely with PSE, respectively.

CONCLUSIONS: PSE significantly increases the risk of anesthesia-related airway complications during outpatient pediatric procedures.

EBM rating: A-1b

Prognosis for Spontaneous Resolution of OSA in Children

BACKGROUND

Adenotonsillectomy (AT) is commonly performed for childhood OSA syndrome (OSAS), but little is known about prognosis without treatment.

METHODS

The Childhood Adenotonsillectomy Trial (CHAT) randomized 50% of eligible children with OSAS to a control arm (watchful waiting), with 7-month follow-up symptom inventories, physical examinations, and polysomnography. Polysomnographic and symptomatic resolution were defined respectively by an apnea/hypopnea index (AHI) <2 and obstructive apnea index (OAI) <1 and by an OSAS symptom score (Pediatric Sleep Questionnaire [PSQ]) < 0.33 with ≥ 25% improvement from baseline.

RESULTS

After 194 children aged 5 to 9 years underwent 7 months of watchful waiting, 82 (42%) no longer met polysomnographic criteria for OSAS. Baseline predictors of resolution included lower AHI, better oxygen saturation, smaller waist circumference or percentile, higher-positioned soft palate, smaller neck circumference, and non-black race (each P < .05). Among these, the independent predictors were lower AHI and waist circumference percentile < 90%. Among 167 children with baseline PSQ scores ≥ 0.33, only 25 (15%) experienced symptomatic resolution. Baseline predictors were low PSQ and PSQ snoring subscale scores; absence of habitual snoring, loud snoring, observed apneas, or a household smoker; higher quality of life; fewer attention-deficit/hyperactivity disorder symptoms; and female sex. Only lower PSQ and snoring scores were independent predictors.

CONCLUSIONS

Many candidates for AT no longer have OSAS on polysomnography after 7 months of watchful waiting, whereas meaningful improvement in symptoms is not common. In practice, a baseline low AHI and normal waist circumference, or low PSQ and snoring score, may help identify an opportunity to avoid AT.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT00560859; URL: www.clinicaltrials.gov.

A taxonomic index, with names of descriptive authorities of termite genera and species: an accompaniment to Biology of Termites: A Modern Synthesis (Bignell DE, Roisin Y, Lo N, Editors. 2011. Springer, Dordrecht. 576 pp.)

Biology of Termites: A Modern Synthesis (Bignell DE, Roisin Y, Lo N, (Editors), Springer, Dordrecht, 576pp, ISBN 978-90-481-3976-7, e-ISBN 978-90-481-3977-4, DOI 10.1007/978-90-481-3977-4) was published in 2011. With the agreement of the publishers, we give a taxonomic index of the book comprising 494 termite entries, 103 entries of other multicellular animal species mentioned as associates or predators of termites, with 9 fungal, 60 protist, and 64 prokaryote identities, which are listed as termite symbionts (sensu stricto). In addition, we add descriptive authorities for living (and some fossil) termite genera and species. Higher taxonomic groupings for termites are indicated by 25 code numbers. Microorganisms (prokaryotes, protists, and fungi) are listed separately, using broad modern taxonomic affiliations from the contemporary literature of bacteriology, protozoology, and mycology.

A taxonomic index, with names of descriptive authorities of termite genera and species: an accompaniment to Biology of Termites: A Modern Synthesis (Bignell DE, Roisin Y, Lo N, Editors. 2011. Springer, Dordrecht. 576 pp.)

Biology of Termites: A Modern Synthesis (Bignell DE, Roisin Y, Lo N, (Editors), Springer, Dordrecht, 576pp, ISBN 978-90-481-3976-7, e-ISBN 978-90-481-3977-4, DOI 10.1007/978-90-481-3977-4) was published in 2011. With the agreement of the publishers, we give a taxonomic index of the book comprising 494 termite entries, 103 entries of other multicellular animal species mentioned as associates or predators of termites, with 9 fungal, 60 protist, and 64 prokaryote identities, which are listed as termite symbionts (sensu stricto). In addition, we add descriptive authorities for living (and some fossil) termite genera and species. Higher taxonomic groupings for termites are indicated by 25 code numbers. Microorganisms (prokaryotes, protists, and fungi) are listed separately, using broad modern taxonomic affiliations from the contemporary literature of bacteriology, protozoology, and mycology.

Effect of Alcohol Consumption on Balance as Measured by Posturography

Objectives:

Evaluate the effect of increasing blood alcohol concentration (BAC) on the vestibular system as measured by abnormal body sway on posturography. Determine if there is a consistent level of BAC during which sway becomes adversely affected, as suggested by legal state limits of BAC for driving.

Methods:

Prospective study of 30 healthy adults randomized to alcohol versus no alcohol who consumed one beverage hourly followed by BAC measurement by BACtrack Select S80 Breathalyzer and posturography on both firm/soft surfaces with eyes open/closed. Primary outcome was dose-response rate of BAC on mean body sway. Nonlinear growth models were used to control for covariates.

Results:

The experimental (alcohol) group had 20 adults, and the control (no alcohol) group had 10 adults. BAC levels measured by breathalyzer ranged from 0 to 0.12. Overall analysis showed no statistically significant difference between male and female performance ( P > 0.05). Increased alcohol consumption was associated with increased abnormal body sway ( P < 0.05); however, the exact level of BAC inducing abnormal sway was variable from individual to individual. An ANOVA model demonstrated a trend toward a learning curve with repeat posturography for the control group.

Conclusions:

This study demonstrated increasing vestibular dysfunction from increasing alcohol ingestion as measured with abnormal body sway by posturography. While all participants eventually showed increased sway with increased BAC, the point at which abnormal sway became evident was highly variable between individuals. Therefore, using strict state legal BAC limits do not always correlate with balance impairment.

Bacteriology of the paranasal sinuses in pediatric cystic fibrosis patients

OBJECTIVES

To review the characteristic microbiology of the paranasal sinuses in patients with cystic fibrosis who undergo endoscopic sinus surgery. To examine the subtypes of organisms cultured from the maxillary sinuses and determine their sensitivity to antibiotic therapy.

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary care children's hospital.

METHODS

Sinus cultures were obtained from 51 patients with cystic fibrosis during endoscopic sinus procedures between 2000 and 2004 at a tertiary care children's hospital. A retrospective chart review was undertaken to obtain culture and sensitivity data of the sinus contents.

RESULTS

The most common bacteria isolated was Staphylococcus aureus (71%), followed by Pseudomonas aeruginosa (PSA) (27%), Haemophilus influenzae (21%), Staphylococcus non-aureus (16%) and Streptococcus viridans (12%). Streptococcus pneumoniae and Moraxella catarrhalis were rarely isolated (2% and 0% respectively). Twenty-nine percent of the patients with cultures positive for PSA were of the mucoid variant. Only one patient had culture positive Escherichia coli. Antibiotic resistance among the more common organisms cultured from the sinus samples is also listed.

CONCLUSION

Staph. aureus is the most common isolate in the sinuses of this pediatric CF population followed by P. aeruginosa and H. influenzae. Although many isolates are pansensitive, some isolates are panresistant.

Age-related changes in the default mode network are more advanced in Alzheimer disease

OBJECTIVE

To investigate age-related default mode network (DMN) connectivity in a large cognitively normal elderly cohort and in patients with Alzheimer disease (AD) compared with age-, gender-, and education-matched controls.

METHODS

We analyzed task-free-fMRI data with both independent component analysis and seed-based analysis to identify anterior and posterior DMNs. We investigated age-related changes in connectivity in a sample of 341 cognitively normal subjects. We then compared 28 patients with AD with 56 cognitively normal noncarriers of the APOE ε4 allele matched for age, education, and gender.

RESULTS

The anterior DMN shows age-associated increases and decreases in fontal lobe connectivity, whereas the posterior DMN shows mainly age-associated declines in connectivity throughout. Relative to matched cognitively normal controls, subjects with AD display an accelerated pattern of the age-associated changes described above, except that the declines in frontal lobe connectivity did not reach statistical significance. These changes survive atrophy correction and are correlated with cognitive performance.

CONCLUSIONS

The results of this study indicate that the DMN abnormalities observed in patients with AD represent an accelerated aging pattern of connectivity compared with matched controls.

Altered functional connectivity in asymptomatic MAPT subjects: a comparison to bvFTD

OBJECTIVE

To determine whether functional connectivity is altered in subjects with mutations in the microtubule associated protein tau (MAPT) gene who were asymptomatic but were destined to develop dementia, and to compare these findings to those in subjects with behavioral variant frontotemporal dementia (bvFTD).

METHODS

In this case-control study, we identified 8 asymptomatic subjects with mutations in MAPT and 8 controls who screened negative for mutations in MAPT. Twenty-one subjects with a clinical diagnosis of bvFTD were also identified and matched to 21 controls. All subjects had resting-state fMRI. In-phase functional connectivity was assessed between a precuneus seed in the default mode network (DMN) and a fronto-insular cortex seed in the salience network, and the rest of the brain. Atlas-based parcellation was used to assess functional connectivity and gray matter volume across specific regions of interest.

RESULTS

The asymptomatic MAPT subjects and subjects with bvFTD showed altered functional connectivity in the DMN, with reduced in-phase connectivity in lateral temporal lobes and medial prefrontal cortex, compared to controls. Increased in-phase connectivity was also observed in both groups in the medial parietal lobe. Only the bvFTD group showed altered functional connectivity in the salience network, with reduced connectivity in the fronto-insular cortex and anterior cingulate. Gray matter loss was observed across temporal, frontal, and parietal regions in bvFTD, but not in the asymptomatic MAPT subjects.

CONCLUSIONS

Functional connectivity in the DMN is altered in MAPT subjects before the occurrence of both atrophy and clinical symptoms, suggesting that changes in functional connectivity are early features of the disease.

Open Air Laboratories (OPAL): a community-driven research programme

OPAL is an English national programme that takes scientists into the community to investigate environmental issues. Biological monitoring plays a pivotal role covering topics of: i) soil and earthworms; ii) air, lichens and tar spot on sycamore; iii) water and aquatic invertebrates; iv) biodiversity and hedgerows; v) climate, clouds and thermal comfort. Each survey has been developed by an inter-disciplinary team and tested by voluntary, statutory and community sectors. Data are submitted via the web and instantly mapped. Preliminary results are presented, together with a discussion on data quality and uncertainty. Communities also investigate local pollution issues, ranging from nitrogen deposition on heathlands to traffic emissions on roadside vegetation. Over 200,000 people have participated so far, including over 1000 schools and 1000 voluntary groups. Benefits include a substantial, growing database on biodiversity and habitat condition, much from previously unsampled sites particularly in urban areas, and a more engaged public.

Minimally invasive endoscopic management of subglottic stenosis in children: success and failure

OBJECTIVE

To assess the efficacy and safety of endoscopic management of subglottic stenosis both as a primary and as an adjunctive treatment in the pediatric population.

METHODS

Retrospective review of pediatric patients with subglottic stenosis undergoing endoscopic airway procedures at a tertiary care pediatric medical center. Outcomes were assessed by systematic review to determine the success and failure of the endoscopic approach.

RESULTS

Forty patients (22 male, 18 female) underwent endoscopic interventions for a diagnosis of subglottic airway stenosis between 2003 and 2006. Age ranged from 22 days old to 20 years old. Recorded degree of subglottic stenosis ranged from 10% to 99%. Fifty-three percent (21/40) had a history of prematurity, and 40% (16/40) had secondary airway diagnoses. Twenty-four patients underwent an endoscopic intervention initially (including laser or dilation, with or without topical mitomycin treatment), including four patients who underwent tracheostomy prior to the first endoscopic intervention. Sixteen underwent laryngotracheoplasty initially, including ten patients who underwent tracheostomy prior to the laryngotracheoplasty. Endoscopic treatment resulted in resolution of symptoms, and/or decannulation, and no further need for an open procedure in 58% of patients. Of the 24 patients undergoing endoscopic interventions initially, 14 patients underwent two or more endoscopic interventions, and 10 patients subsequently required tracheostomy or laryngotracheoplasty. When endoscopic procedures were used as an adjunct to laryngotracheoplasty, 60% (12/20) had resolution of symptoms, underwent decannulation, and did not require tracheostomy or revision laryngotracheoplasty.

CONCLUSIONS

The endoscopic approach can be successful in the management of properly selected patients with subglottic stenosis, either as the initial treatment modality or as an adjunctive treatment in cases of re-stenosis after open airway surgery. The likelihood of success with a minimally invasive procedure as the primary treatment decreases with worsening initial grade of subglottic stenosis.

Comparison of Postoperative Pain in Pediatric Patients Undergoing Coblation Tonsillectomy versus Cautery Tonsillectomy

Objective. To compare postoperative pain scores between monopolar electrocautery and coblation subcapsular tonsillectomy.

Study Design. Prospective double-blind randomized study.

Setting. Tertiary care children’s hospital.

Subjects and Methods. Between December 2004 and April 2008, 61 children, ages 4 to 20 years (mean age, 10 years; SD, 4 years), were randomized to have one tonsil removed by electrocautery and the other tonsil removed by coblation. Subjects used the FACES scale to rate pain on each side immediately postoperatively, 2 days postoperatively, and 2 weeks postoperatively. Postoperative hemorrhage was also tracked.

Results. Coblation tonsillectomy resulted in statistically less pain than electrocautery immediately after surgery, but this difference was not clinically significant.

Conclusions. Pediatric pain is similar following monopolar electrocautery or coblation subcapsular tonsillectomy.

Autolytic Activity and Butanol Tolerance of Clostridium acetobutylicum

The effects of acetone and butanol on the growth of vegetative cells and the stability of swollen-phase bright-stationary-phase cells (clostridial forms) of Clostridium acetobutylicum P262 and an autolytic deficient mutant (lyt-1) were investigated. There was little difference in the sensitivity of strain P262 and the lyt-1 mutant vegetative cells and clostridial forms to acetone. The stability of the different morphological stages was unaffected by acetone concentrations far in excess of those encountered in factory fermentations. Butanol concentrations between 7 and 16 g/liter, which are within the range obtained in industrial fermentations, increased the degeneration of strain P262 clostridial forms but had no effect on the stability of lyt-1 clostridial forms which never underwent autolysis. Vegetative cells of the lyt-1 mutant were able to grow in higher concentrations of butanol than strain P262 vegetative cells. It was concluded that there is a relationship between butanol tolerance and autolytic activity.

Characterization, Biosynthesis, and Regulation of Granulose in Clostridium acetobutylicum

Synthesis of granulose was investigated in 15 solvent-producing Clostridium strains. Only one of the strains did not produce granulose. The structure of granulose in Clostridium acetobutylicum P262 consisted of a high-molecular-weight polyglucan containing only (1-->4) linked d-glucopyranose units. Biosynthesis of granulose in C. acetobutylicum P262 was dependent on ADPglucose pyrophosphorylase, and granulose synthase and mutants defective in granulose accumulation lacked either one or both enzyme activities. Granulose-positive revertants exhibited both enzyme activities. ADPglucose pyrophosphorylase and granulose synthase were not subject to allosteric control by metabolites. Granulose accumulation and the biosynthetic enzyme activities were initiated immediately before the pH breakpoint and were detected in cells only at the end of the exponential growth phase. Granulose accumulation did not occur under conditions of nitrogen limitation, excess carbon, or excess energy.

Autolytic Activity and an Autolysis-Deficient Mutant of Clostridium acetobutylicum

The optimum conditions for autolysis and autoplast formation in Clostridium acetobutylicum P262 have been defined. Autolysis was optimal at pH 6.3 in 0.04 M sodium phosphate buffer, and the bacterium produced latent and active forms of an autolytic enzyme. The ability of cells to autolyze decreased sharply when cultures entered the stationary phase. Autoplasts were induced by 0.25 to 0.5 M sucrose and were stable in media containing sucrose, CaCl(2), and MgCl(2). A pleiotropic autolysis-deficient mutant (lyt-1) was isolated. The mutant produced less autolysin than did the parent P262 strain, and it had an altered cell wall which was more resistant to both its own and P262 autolysins. The mutant formed long chains of cells, and lysozyme was required for the production of autoplasts. Growth of the P262 strain or the lyt-1 mutant was inhibited by the same concentrations of penicillin, ampicillin, and vancomycin. The lyt-1 mutant strain treated with the minimum growth-inhibitory concentration of penicillin autolyzed upon the addition of wild-type autolysin to the autolysis buffer at the same rate as did the untreated P262 strain. Chloramphenicol did not protect the penicillin-treated lyt-1 cells against autolysis enhanced by exogenous wild-type autolysin.

Purification and Characterization of an Autolysin from Clostridium acetobutylicum

A proteinaceous substance with antibiotic-like activity, resembling that of a bacteriocin, was isolated from an industrial-scale acetone-butanol fermentation of Clostridium acetobutylicum. The substance, purified by acetone precipitation, diethylaminoethyl cellulose chromatography, and polyacrylamide gel electrophoresis, was characterized as a glycoprotein with a molecular weight of 28,000. The glycoprotein was partially inactivated by certain protease enzymes. It had no effect on deoxyribonucleic acid, ribonucleic acid, or protein synthesis, and it did not result in the loss of intracellular adenosine triphosphate. The glycoprotein lysed sodium dodecyl sulfate-treated cells and cell wall preparations, and therefore it is referred to as an autolysin. The autolysin gene appeared to be chromosomal since plasmid deoxyribonucleic acid was not detected in the C. acetobutylicum strain.

Protein annotation and modelling servers at University College London

The UCL Bioinformatics Group web portal offers several high quality protein structure prediction and function annotation algorithms including PSIPRED, pGenTHREADER, pDomTHREADER, MEMSAT, MetSite, DISOPRED2, DomPred and FFPred for the prediction of secondary structure, protein fold, protein structural domain, transmembrane helix topology, metal binding sites, regions of protein disorder, protein domain boundaries and protein function, respectively. We also now offer a fully automated 3D modelling pipeline: BioSerf, which performed well in CASP8 and uses a fragment-assembly approach which placed it in the top five servers in the de novo modelling category. The servers are available via the group web site at http://bioinf.cs.ucl.ac.uk/.

Sensorineural hearing loss in patients with cystic fibrosis

OBJECTIVE

To determine the prevalence of sensorineural hearing loss (SNHL) in cystic fibrosis (CF) patients and its relationship to antibiotic use.

STUDY DESIGN

Case series with chart review.

SETTING

Tertiary care pediatric hospital.

SUBJECTS AND METHODS

We reviewed the medical records of CF patients seen in our children's hospital between March 1994 and December 2007. Data collected included patient demographics, audiograms, tympanograms, genotype, and use of potentially ototoxic antibiotics.

RESULTS

Seven of 50 (14%) patients had SNHL. Three percent of patients who received <or=10 courses of intravenous aminoglycosides had SNHL versus 43 percent of those who received >10 courses (P<0.01). No patients who received five or fewer courses of nasal irrigation with aminoglycosides had SNHL versus 23 percent of those who received more than five courses (P<0.05). Nine percent of patients who received five or fewer courses of macrolides had SNHL versus 60 percent of those who received more than five courses (P=0.079).

CONCLUSION

CF patients receiving aminoglycosides are at high risk for developing SNHL.

The sequence-structure relationship and protein function prediction

An incomplete understanding of protein sequence/structure/function relationships causes many difficulties for prediction methods. The highly complex nature of these relationships is a consequence of the interplay between physics and evolution that has been studied using a wide array of experimental and theoretical techniques. We review recent findings relating to conservation of sequence, structure and function and discuss their use in developing improved prediction methods.

Use of a preoperative bleeding questionnaire in pediatric patients who undergo adenotonsillectomy

Objective

To determine the efficacy of a preoperative bleeding questionnaire (POBQ) and coagulation screening in predicting hemorrhage associated with adenotonsillectomy.

Study Design

Retrospective study.

Subjects and Methods

Between January 1998 and December 2003, 7730 tonsillectomy and adenotonsillectomy patients were administered the POBQ preoperatively. Further coagulation screening was based on POBQ responses.

Results

A total of 232 (3.0%) of 7730 had postoperative bleeding; 184 (3.2%) of 5782 patients who had negative questionnaires bled postoperatively compared with 48 (2.5%) of 1948 patients with positive questionnaires ( P = 0.126). Of 1948 patients with positive questionnaires, 141 (7.2%) had abnormal preoperative coagulation screens and 9 (6.4%) of 141 bled; of the 1807 (92.8%) with negative coagulation screens, 39 (2.2%) bled ( P = 0.005).

Conclusion

The POBQ is an effective tool for identifying patients who are at potential risk for post-tonsillectomy bleeding. Patients with both a positive POBQ and coagulation screen had a statistically higher likelihood of postoperative bleeding than other patients. The POBQ allowed the identification of individuals with bleeding disorders to be treated before surgery, likely decreasing the risk of bleeding in these patients.

Pseudomonas aeruginosa transmission is infrequent in New Zealand cystic fibrosis clinics

Pseudomonas aeruginosa is an important pathogen in cystic fibrosis (CF). Although most patients harbour unique P. aeruginosa isolates, some clinics report patients sharing common strains. The overall importance of person-to-person transmission in P. aeruginosa acquisition and whether routine patient segregation is necessary remains uncertain. The present authors therefore investigated the extent of P. aeruginosa transmission in New Zealand CF clinics. New Zealand's seven major CF centres were assessed, combining epidemiological data with computer-assisted SalI DNA fingerprinting of 496 isolates from 102 patients. One cluster of related isolates was significantly more prevalent in the largest clinic than expected by chance. The seven patients with isolates belonging to this cluster had more contact with each other than the remaining patients attending this centre. No other convincing evidence of transmission was found in any of the other smaller clinics. Three P. aeruginosa strains believed to be transmissible between patients in Australian and British CF clinics are present in New Zealand, but there was no definite evidence they had spread. Pseudomonas aeruginosa transmission is currently infrequent in New Zealand cystic fibrosis clinics. This situation could change rapidly and ongoing surveillance is required. The current results confirm that computer-assisted SalI DNA fingerprinting is ideally suited for such surveillance.

FFPred: an integrated feature-based function prediction server for vertebrate proteomes

One of the challenges of the post-genomic era is to provide accurate function annotations for large volumes of data resulting from genome sequencing projects. Most function prediction servers utilize methods that transfer existing database annotations between orthologous sequences. In contrast, there are few methods that are independent of homology and can annotate distant and orphan protein sequences. The FFPred server adopts a machine-learning approach to perform function prediction in protein feature space using feature characteristics predicted from amino acid sequence. The features are scanned against a library of support vector machines representing over 300 Gene Ontology (GO) classes and probabilistic confidence scores returned for each annotation term. The GO term library has been modelled on human protein annotations; however, benchmark performance testing showed robust performance across higher eukaryotes. FFPred offers important advantages over traditional function prediction servers in its ability to annotate distant homologues and orphan protein sequences, and achieves greater coverage and classification accuracy than other feature-based prediction servers. A user may upload an amino acid and receive annotation predictions via email. Feature information is provided as easy to interpret graphics displayed on the sequence of interest, allowing for back-interpretation of the associations between features and function classes.

Bronchoscopy findings in children and young adults with tracheostomy due to congenital anomalies and neurological impairment

The aim of this study was to examine bronchoscopy findings for children and young adults with long-term tracheostomies due to congenital anomalies and neurological impairment and identify characteristics associated with abnormal bronchoscopic findings. We conducted a retrospective study of 128 bronchoscopy cases (81 children) at a pediatric rehabilitation center. Thirty-eight cases (30%) had normal findings and 14 children (17% of all children) were decannulated following bronchoscopy. Ninety cases (70% of cases) had abnormal findings (e.g. granulomas, airway inflammation, fixed obstruction). An acute indication for bronchoscopy was the strongest predictor of an abnormal finding, while age (younger) and diagnosis (multiple congenital anomalies (MCA)) also were associated with abnormalities. For a subsample of children undergoing bronchoscopy for routine surveillance (n= 90), underlying diagnosis (MCA) was the strongest predictor of an abnormal finding, while younger age contributed slightly. These findings add to the limited literature describing bronchoscopic findings in children and youth with tracheostomies due to congenital anomalies or neurological impairment. These findings may be useful for rehabilitation clinicians in determining care needs for children with long-term tracheostomy.

Effectiveness of postoperative follow-up telephone interviews for patients who underwent adenotonsillectomy: a retrospective study

OBJECTIVE

To evaluate the effectiveness of follow-up telephone interviews and questionnaires after tonsillectomy and adenoidectomy.

DESIGN

Cohort study and retrospective review of the outcomes of patients whose follow-ups were conducted by telephone interview. Patients were contacted 2 to 4 weeks after surgery; responses were recorded on a standardized postoperative questionnaire.

SETTING

Tertiary pediatric hospital.

PATIENTS

A total of 2554 consecutive patients who had undergone tonsillectomy, adenoidectomy, or both procedures and completed a follow-up telephone interview during the period of January 8, 2000, to September 23, 2004.

MAIN OUTCOME MEASURES

Time to return to normal diet and activities, postoperative complications, pain management, postoperative visits, and caregiver's evaluation of the follow-up telephone survey.

RESULTS

A total of 2554 patient outcomes were reviewed. The mean patient age was 5.9 years. Follow-up contact occurred a mean of 24.1 days after surgery. Of the surgical procedures performed, there were 1957 adenotonsillectomies, 235 adenoidectomies, and 362 tonsillectomies. At the time of follow-up, 2.7% of the patients had undergone an additional surgical procedure to treat postoperative bleeding, 96.9% had resumed eating a normal diet, and 96.2% had resumed normal activities. Bleeding from the nose or mouth was reported to have occurred at some point during the recovery period in 12.8%. On a pain scale of 1 to 10, a mean pain peak of 6.7 was reported. For most patients, pain was highest on the second day after surgery. The percentage of patients who had temporary voice change was 62.7%, and 15.4% had a follow-up clinic visit. Regarding caregivers, 99.5% reported being given instructions for postoperative care, and 98.8% reported that they felt well prepared to care for their child at home. There were no adverse events reported from surgical intervention.

CONCLUSIONS

Compared with our previous experience with scheduled postsurgical clinic follow-ups, telephone interviews and standardized postoperative questionnaires pose no additional risk to patients. Considerable cost reduction and patient convenience were realized with a reduction of patient visits.

Benchmarking template selection and model quality assessment for high-resolution comparative modeling

Comparative modeling is presently the most accurate method of protein structure prediction. Previous experiments have shown the selection of the correct template to be of paramount importance to the quality of the final model. We have derived a set of 732 targets for which a choice of ten or more templates exist with 30-80% sequence identity and used this set to compare a number of possible methods for template selection: BLAST, PSI-BLAST, profile-profile alignment, HHpred HMM-HMM comparison, global sequence alignment, and the use of a model quality assessment program (MQAP). In addition, we have investigated the question of whether any structurally defined subset of the sequence could be used to predict template quality better than overall sequence similarity. We find that template selection by BLAST is sufficient in 75% of cases but that there are examples in which improvement (global RMSD 0.5 A or more) could be made. No significant improvement is found for any of the more sophisticated sequence-based methods of template selection at high sequence identities. A subset of 118 targets extending to the lowest levels of sequence similarity was examined and the HHpred and MQAP methods were found to improve ranking when available templates had 35-40% maximum sequence identity. Structurally defined subsets in general are found to be less discriminative than overall sequence similarity, with the coil residue subset performing equivalently to sequence similarity. Finally, we demonstrate that if models are built and model quality is assessed in combination with the sequence-template sequence similarity that a extra 7% of "best" models can be found.

Pediatric Endoscopic Dacryocystorhinostomy Failures: Who and Why?

OBJECTIVE

The objectives of this study are to report outcomes of pediatric patients with nasolacrimal duct obstruction (NLDO) who underwent primary endoscopic dacryocystorhinostomy (DCR) and discuss causes of failure.

STUDY DESIGN

The authors conducted a retrospective case series.

METHODS

Charts of all patients less than 16 years of age who underwent primary endoscopic DCR from 1997 to 2004 were reviewed. Patients were grouped based on the presence or absence of facial anomalies or syndromes and whether the NLDO was congenital or acquired. Success was defined as complete resolution of symptoms, improvement included anatomic patency or partial symptoms, and failure as no improvement or demonstration of patency.

RESULTS

Thirty-four patients (43 ducts) aged 11 months to 14 years were identified. There were 17 males and 17 females. Follow up ranged from 2 to 54 months (average, 21 months). Twenty-four patients (29 ducts) had congenital NLDO, seven patients (11 ducts) had congenital syndromes associated with craniofacial abnormalities, and three patients (three ducts) had acquired NLDO. In patients with congenital NLDO without craniofacial abnormalities or syndromes, 22 of 29 eyes (76%) were cured with another three (10%) showing improvement. Only one of 11 (9%) eyes of patients with congenital craniofacial abnormality or syndrome experienced complete resolution and only four of 11 (36%) eyes showed improvement. Of the patients with acquired NLDO, two of three (67%) of the eyes were cured and one (33%) improved.

CONCLUSIONS

Endoscopic DCR is safe and effective for most children, although patients with craniofacial abnormalities or syndromes are extremely difficult to cure.

Prediction of novel and analogous folds using fragment assembly and fold recognition

A number of new and newly improved methods for predicting protein structure developed by the Jones-University College London group were used to make predictions for the CASP6 experiment. Structures were predicted with a combination of fold recognition methods (mGenTHREADER, nFOLD, and THREADER) and a substantially enhanced version of FRAGFOLD, our fragment assembly method. Attempts at automatic domain parsing were made using DomPred and DomSSEA, which are based on a secondary structure parsing algorithm and additionally for DomPred, a simple local sequence alignment scoring function. Disorder prediction was carried out using a new SVM-based version of DISOPRED. Attempts were also made at domain docking and "microdomain" folding in order to build complete chain models for some targets.

The sesquiterpene lactone parthenolide induces selective apoptosis of B-chronic lymphocytic leukemia cells in vitro

We have studied the in vitro actions of the sesquiterpene lactone parthenolide (PTL) on cells isolated from patients with chronic lymphocytic leukemia (CLL). Dye reduction viability assays showed that the median LD(50) for PTL was 6.2 muM (n=78). Fifteen of these isolates were relatively resistant to the conventional agent chlorambucil but retained sensitivity to PTL. Brief exposures to PTL (1-3 h) were sufficient to induce caspase activation and commitment to cell death. Chronic lymphocytic leukemia cells were more sensitive towards PTL than were normal T lymphocytes or CD34(+) haematopoietic progenitor cells. The mechanism of cell killing was via PTL-induced generation of reactive oxygen species, resulting in turn in a proapoptotic Bax conformational change, release of mitochondrial cytochrome c and caspase activation. Parthenolide also decreased nuclear levels of the antiapoptotic transcription factor nuclear factor-kappa B and diminished phosphorylation of its negative regulator IkappaB. Killing of CLL cells by PTL was apparently independent of p53 induction. This is the first report showing the relative selectivity of PTL towards CLL cells. The data here warrant further investigation of this class of natural product as potential therapeutic agents for CLL.

Pediatric deaths due to otolaryngologic causes: a population-based study in Massachusetts, 1990-2002

OBJECTIVE

To identify the most common otolaryngologic causes of mortality in the 0 to 19 age group in the state of Massachusetts and to estimate the pediatric otolaryngologic mortality rate based on population data.

STUDY DESIGN

Population-based retrospective cohort study.

METHODS

The Massachusetts State Registry of Vital Records and Statistics electronic database was searched for all otolaryngology related causes of death from 1990 to 2002 for children aged 0 to 19. The individual death certificates were then reviewed, and a database of otolaryngology related pediatric deaths was created.

RESULTS

A total of 59 otolaryngology related deaths were identified in the pediatric population from 1990 to 2002. Eighty-one percent of deaths occurred because of airway compromise caused by infection, anatomic obstruction, or congenital anomaly. The remaining 19% of deaths occurred because of aspiration, nonairway infections, and malignant neoplasms. Ninety-five percent of deaths in the children under age 10 were caused by airway compromise. Six of seven deaths (86%) in the age 15 to 19 group occurred because of malignant neoplasms. The overall mortality rate caused by otolaryngologic causes was estimated to be 0.28 per 100,000 population.

CONCLUSIONS

The overall mortality rate for otolaryngology related deaths is low in the pediatric population. The vast majority of deaths are caused by airway compromise, primarily because of laryngotracheobronchitis or other upper airway obstruction. In older children (ages 15-19), malignant head and neck neoplasms are the leading cause of otolaryngology related deaths.

Factors associated with sensorineural hearing loss among survivors of extracorporeal membrane oxygenation therapy

OBJECTIVES

To endeavor to explain why some graduates of extracorporeal membrane oxygenation (ECMO) therapy develop sensorineural hearing loss (SNHL) whereas others do not, to study the variability seen in the degree of SNHL, to attempt to explain why some graduates with SNHL experience progressive worsening whereas others do not, and to describe the time course of the onset of SNHL on the basis of identified risk factors.

DESIGN

A retrospective chart review with proportional-hazards regression analysis to identify specific risk factors for SNHL from a list of patient and treatment variables.

SETTING

Children's Hospital Boston, a pediatric tertiary-care facility and ECMO center.

PATIENTS

Neonatal ECMO graduates born in 1986-1994 who survived to discharge and underwent audiologic evaluations (n = 111) and a random sample of ECMO graduates who survived to discharge and did not undergo audiologic evaluations (n = 30).

OUTCOME MEASURES

Audiologic data, including the presence or absence of SNHL, the severity of SNHL at the most recent evaluation, the stability or progressive worsening of hearing (with the first evaluation compared with the most recent evaluation), and the occurrence of delayed-onset SNHL.

RESULTS

Twenty-nine (26%) of 111 ECMO graduates who underwent audiologic testing had SNHL at the last evaluation. Of these 29 subjects with SNHL, 21 (72%) had progressive SNHL, of whom 14 (48%) had delayed-onset SNHL. The age of identification of SNHL ranged from 4 months to 8 years 11 months. Factors identified with proportional-hazards regression analyses as being associated significantly with the time to onset of SNHL were a primary diagnosis of congenital diaphragmatic hernia (hazard ratio: 2.60), length of ECMO therapy (hazard ratio: 7.18), and number of days children received aminoglycoside antibiotics (hazard ratio: 5.56). Kaplan-Meier "time-to-event" curves were constructed to illustrate the time course of onset of SNHL, as affected by each of the variables identified as significant risk factors.

CONCLUSIONS

These findings illustrate the need for early, routine, audiologic evaluations throughout childhood for all ECMO graduates. Children at even greater risk for developing SNHL because of a history of congenital diaphragmatic hernia, prolonged ECMO therapy, and/or a lengthy course of aminoglycoside antibiotic therapy should be monitored even more closely throughout childhood, depending on the child's individual risk indicators, as suggested here. On the basis of these risk indicators, efforts can be made to minimize the risk of hearing loss while a child is being treated with ECMO. In addition, these risk indicators can assist with counseling families of ECMO graduates regarding the child's specific risk of developing SNHL and how it can be managed should it occur.