Faculty Bibliography

Wheezing and childhood asthma are not synonymous but rather comprise a heterogeneous group of conditions that have different outcomes over the course of childhood. Most infants who wheeze have a transient condition associated with diminished airway function at birth and have no increased risk of asthma later in life. However, children with persistent wheezing throughout childhood and frequent exacerbations represent the main challenge today. Studying the natural history of asthma is important for the understanding and accurate prediction of the clinical course of different phenotypes. To date, a great improvement has been achieved in reducing the frequency of asthma symptoms. However, neither decreased environmental exposure nor controller treatment, as recommended by the recent National Asthma Education And Prevention Program, can halt the progression of asthma in childhood or the development of persistent wheezing phenotype. This review focuses on the recent studies that led to the current understanding of asthma phenotypes in childhood and the recommended treatments.

Chronic obstructive pulmonary disease (COPD) is characterized by small airways, alveolar and systemic inflammation and remodeling causing airflow limitation and parenchymal destruction. Mechanisms of oxidative stress include exposure to cigarette smoke and environmental stimuli that activate proinflammatory responses, stimulate alveolar neutrophils and macrophages and lead to apoptosis of endothelial and epithelial cells. COPD may have origins in fetal and neonatal factors that affect intrauterine growth of lungs and airways, lead to low birth weight and impair the development of immune response. Maternal smoking may diminish interferon response secondary to micronutrient deficiency, particularly of Vitamin A, and support persistence of Respiratory Syncytial Virus (RSV), normally a childhood pathogen, into adult life. Muscle wasting and cachexia are systemic features of COPD. Cachexia is associated with systemic inflammation and worsened by Vitamin D deficiency. Nutritional depletion is related to poor survival and is a rational target for therapeutic intervention in advanced and critically ill patients. Preliminary studies and suggest that supplementation with omega-3 polyunsaturated fatty acids and micronutrient repletion with Vitamin A, Vitamin D3, and zinc may have beneficial effects in COPD.

OBJECTIVE: Newborn hearing screening has been widely adopted and made an achievement to some degree. Current screening protocols rely solely on detecting existing auditory disorders at the time of screening and are unable to identify individuals susceptible to auditory disorders in later life. Even if the hearing loss newborn is referred, most cases could not be diagnosed until 6-12 months old with no etiology being elucidated. This study reports the first effort to combine traditional hearing screening with genetic screening to improve the efficacy of newborn hearing screening. METHODS: This study was undertaken in 12 regional hospitals located in 11 provinces of China. 14,913 newborn babies received hearing concurrent genetic screening. The hearing screening was performed with OAE or AABR. Blood sample was collected with a universal newborn genetic screening card. And three common gene, mtDNA 12S rRNA, GJB2 and SLC26A4 were screened with standard protocol. RESULTS: Among all the 14,913 newborns, 86.1% (12,837/14,913) individuals passed the first-step hearing screening, 7.8% (1168/14,913) babies passed only one side, and the other 6.1% (908/14,913) were bilaterally referred. Gene screening found 306 individuals had one or two mutant alleles, the carrier rate is 2.05% (306/14,913) among the entire newborn population. The risk for hearing loss was 100% (7/7) for those newborns carrying causative GJB2 or SLC26A4 mutations (homozygotes or compound heterozygotes), 14.4% (23/160) for GJB2 heterozygote carriers, 12.3% (15/122) for SLC26A2 heterozygous carriers, and the total prevalence of referral hearing screening was approximately 14.7% (45/306). However, 85.3% (261/306) newborns passed hearing screening among these carriers including 18 newborns with 12S rRNA mt.1555A>G pathogenic mutation, who would suffer from sudden hearing loss once applying aminoglycoside drugs. CONCLUSION: The cohort studies provided the essential population parameters for developing effective programs for hearing care of newborns in China. Hearing concurrent gene screening in newborns may confirm the abnormal results from hearing screening tests, help to find the etiologic of the hearing loss, and better recognize infants at risk for late-onset hearing loss occurring prior to speech and language development. In conclusion, a survey on 14,913 Chinese newborns proved that concurrent genetic screening could improve newborn hearing screening for hearing defects.

During most of recorded history, the application of knowledge to the care of individual patients was founded on the experience of individual medical practitioners; when published, it basically took the form of case reports. Not until the middle of the 20th Century did randomized controlled trials (RCTs) come to be the gold standard. By the beginning of the 21st Century, however, the limitations of RCTs and their syntheses, the meta-analyses, have come to be recognized, and their applicability to the individual patient questioned and, indeed, challenged. The intense increase in our knowledge base and in accompanying technology has made possible the personalization of medicine beyond the possibilities of earlier periods. The approach of personalized medicine requires evaluation of four parameters: the individual patient's intrinsic susceptibility, intrinsic morbidity, extrinsic susceptibility, and extrinsic morbidity. The characteristics of the disease agent--how much (duration) and how virulent--also must be factored in. These individualized data define the appropriate intervention: high susceptibility and/or morbidity or low susceptibility and/or morbidity and the aggregate of the intrinsic and extrinsic risk factors are cofactored in medical decision making.

Certain spectrum characteristics have been identified as important for register equalization around the male passaggio, an effect ascribed to formant tuning although descriptions of formant tuning diverge. Eight professional singers sang scales including their passaggio range on different vowels, applying two formant tuning strategies as found in (1) classical and (2) non-classical singing. Formant frequencies were measured using inverse filtering. Results revealed differences between the two strategies. For the classical formant tuning, systematic changes of formant frequencies with pitch were observed. For the highest note sung on /a/, F1 was below the second partial and F2 in the vicinity of the third. Similar spectrum characteristics were achieved by different F1 and F2 values between singers.

OBJECTIVE: Assess the postoperative use of dexmedetomidine (Precedex) in pediatric patients following airway reconstruction. STUDY DESIGN: Historical cohort study. SETTING: Tertiary medical center. SUBJECTS AND METHODS: A retrospective review of 24 children undergoing laryngotracheal reconstruction (LTR) or laryngeal cleft repair (LCR) was conducted. Twelve children were treated with standard sedation protocols where dexmedetomidine was administered in lieu of propofol (Diprivan); 12 age-, gender-, and procedure-matched controls were selected. Subjects were divided into groups based on duration of postoperative intubation for cross-comparison; group 1 was intubated <24 hours, group 2 was intubated 2 to 6 days, and group 3 was intubated 7 days or longer. Baseline heart rate and blood pressure measurements were compared to hourly measurements for the first 6 hours following initiation of dexmedetomidine or mechanical ventilation in the control group. Number of supportive respiratory interventions, adverse events, self-extubations, premature termination of dexmedetomidine, amount of muscle relaxants, agents to treat withdrawal, and length of stay were evaluated. RESULTS: Ten patients undergoing LTR and 2 patients undergoing LCR receiving dexmedetomidine were compared to 10 LTR and 2 LCR control patients. Overall, dexmedetomidine was well tolerated and without significant adverse effects, particularly in cases of short-term intubation or as a bridge to extubation. CONCLUSION: In cases requiring short-term intubation following airway reconstruction, dexmedetomidine may offer a safe alternative to propofol by providing readily reversible sedation during the periextubation period. Further studies are needed to determine the safety, efficacy, dosing, and potential complications of longer term dexmedetomidine administration in pediatric airway reconstruction.

BACKGROUND: We report a case of Rosai-Dorfman disease (RDD) presenting as an oropharyngeal mass, and we provide a detailed discussion of this rare clinical entity. METHODS: An initial biopsy, described as being consistent with lymphoma, was reviewed at a second outside institution and was thought to be reactive lymphoid hyperplasia. The patient then presented to our institution for a second opinion. Direct laryngoscopy revealed a firm 1- to 2-cm lesion involving the left soft palate and superior tonsillar pillar. RESULTS: The diagnosis of RDD was confirmed with immunohistochemical staining on both cytology and histology. The patient elected conservative management and has remained asymptomatic for over 15 months. CONCLUSION: The diagnosis of RDD may be challenging in cases presenting initially with extranodal disease. Close follow-up and repeat biopsies may be necessary. Identification of Rosai-Dorfman cells with emperipolesis and confirmation with appropriate immunohistochemical staining on both cytology and histology is diagnostic of RDD. Conservative treatment is appropriate in select cases.