Connexin 26 studies in patients with sensorineural hearing loss.

OBJECTIVE: To determine the spectrum of connexin 26 (Cx26) mutations and their phenotypes in children with sensorineural hearing loss (SNHL) or mixed hearing loss (MHL). DESIGN: Children with SNHL or MHL were prospectively tested for mutations in the entire coding region of the Cx26 gene. PATIENTS: Children with SNHL or MHL with no obvious etiology for the hearing loss. RESULTS: Between December 1, 1998, and July 1, 2000, 107 patients with SNHL or MHL from 99 families underwent Cx26 testing. Most patients were aged 1 week to 16 years (61 boys and 46 girls). Thirty (30%) of 99 probands had Cx26 mutations: biallelic mutations were detected in 18 (9 homozygous and 9 compound heterozygous) and single mutations were detected in 12. Twelve previously reported mutations (35delG, 167delT, E47X, L90P, M34T, G12V, V37I, R143W, V84L, V153I, V27I, and 310del14) and 3 novel mutations (E129K, T8M, and N206S) were found. Hearing loss in patients with biallelic Cx26 mutations ranged from unilateral high frequency to bilateral profound. Four children, 2 with biallelic mutations, had temporal bone abnormalities. CONCLUSIONS: Connexin 26 mutations are common in children with SNHL, and it is likely that the homozygous and compound heterozygous mutations cause the SNHL. However, pathogenicity is less certain when only a single Cx26 mutation is present. Patients with biallelic Cx26 mutations had a slightly higher incidence of milder hearing loss than in previous studies. Children with SNHL or MHL should be tested for Cx26 mutations early in their evaluation.

Mediastinitis associated with foreign body erosion of the esophagus in children.

OBJECTIVE: Timely and experienced intervention for esophageal foreign bodies generally allows for removal with minimal morbidity. However, esophageal foreign bodies present a risk for esophageal perforation and subsequent mediastinitis, especially if the diagnosis of the foreign body is delayed. Although much has been written about the management of esophageal foreign bodies and their complications, little has been mentioned in recent literature about the specific complication of mediastinitis. This review was performed to examine our experience with this uncommon complication of esophageal foreign bodies. METHODS: A retrospective review of the esophageal foreign body database at Children's Hospital of Wisconsin from 1987 to 1997 was performed to identify patients with esophageal foreign bodies and subsequent mediastinitis. RESULTS: Four patients with esophageal perforation with associated mediastinitis secondary to retained esophageal foreign bodies were identified. Three of the four patients were treated with conservative measures consisting of foreign body removal, intravenous antibiotics and discontinuing of oral nutrition. These patients all achieved resolution of their mediastinitis and esophageal perforation with subsequent return to normal diets and no significant morbidity. One patient, with vascular erosion, required aggressive, invasive therapy. CONCLUSION: From review of this limited number of patients, in the absence of major vascular erosion, conservative methods of treating children with foreign body esophageal perforation and subsequent mediastinitis appears to be effective.

Craniofacial, temporal bone, and audiologic abnormalities in the spectrum of hemifacial microsomia.

OBJECTIVES: To evaluate the clinical, audiologic, and temporal bone computed tomograpic findings in patients with hemifacial microsomia and to use the OMENS (each letter of the acronym indicates 1 of the following 5 dysmorphic manifestations: O, orbital asymmetry; M, mandibular hypoplasia; E, auricular deformity; N, nerve involvement; and S, soft tissue deficiency) grading system to assess possible correlations between the severity of dysmorphic features with the type of abnormalities in the temporal bone and with degree of hearing deficit. DESIGN: Retrospective study. SETTING: Tertiary care children's hospital. PATIENT: Forty patients with hemifacial microsomia. RESULT: Mandibular hypoplasia and auricular abnormalities were the most common clinical manifestations, present in 39 patients (97%) and 38 patients (95%), respectively. Conductive hearing loss was noted in 35 patients (86%) and sensorineural hearing loss in 4 patients (10%). Facial nerve weakness was present in 20 patients (50%). Twenty patients had unilateral aural atresia, 12 patients had unilateral aural stenosis, and 7 patients had bilateral anomalies. Moderate hypoplasia or atresia of the middle ear was noted in 36 patients (90%) and ossicles were malformed in 30 patients (75%). Hypoplasia of the oval window was the most common inner ear abnormality. CONCLUSIONS: Severity of craniofacial features (total OMENS score) significantly correlated with the degree of temporal bone abnormality, but no correlation was noted with the degree or type of hearing loss. We recommend the following: (1) use of the OMENS classification system for documentation and analysis of dysmorphic finding in hemifacial microsomia; (2) complete audiologic evaluation in all patients with hemifacial microsomia regardless of the type of craniofacial abnormalities; and (3) temporal bone computed tomography for further evaluation of hearing deficit.

The relationship between dental overbite and eustachian tube dysfunction.

OBJECTIVE: The purpose of this study was to investigate the association between deep dental overbite and eustachian tube dysfunction (ETD). DESIGN: Case-control study. SETTING: Tertiary care pediatric otolaryngology outpatient clinic at the Children's Hospital, Boston, Massachusetts. PATIENTS: 105 patients between the ages of 2 and 6 years. STUDY MEASUREMENTS: Dental overbite, overjet, and occlusal relationships were measured by an observer who was unaware of ETD status. ETD was defined as having ventilation tubes in place or having the recommendation for ventilation tube placement by an attending pediatric otolaryngologist. In addition, demographic information and medical and social histories were prospectively recorded. RESULTS: In a multivariate logistic regression model, children with deep bites were 2.8 times more likely to have ETD than those without deep bites (P = .03). Other independent risk factors for ETD identified in this model were family history of otitis media (OM) and age less than 3 years. CONCLUSIONS: Children with deep dental overbites are at a significantly increased risk for developing ETD.

Airway foreign bodies (FB): a 10-year review.

A retrospective chart review of children who had airway foreign body removed via direct laryngoscopy and bronchoscopy (DLB) from 1987-1997 was conducted in Children's Hospital, Boston. Patient characteristics noted included age, sex, and clinical presentation. Pre-operative radiographic findings, reason for delay in evaluation, DLB findings, length of procedure, reason for repeat DLB, and types of foreign body etc. were recorded. Serious complications from aspirated foreign bodies such as severe airway obstruction and death tend to occur in infants and younger children because of their small airway size. A history compatible with foreign body aspiration dictates diagnostic endoscopy with or without radiologic confirmation. Chest and airway radiographs supplemented by fluoroscopy can increase the ratio of correct and early diagnosis. Fluoroscopy should be universally accepted as an initial diagnostic technique in airway foreign body evaluation. Fluoroscopy is not a worthwhile investigation if a preceeding chest radiograph suggests the presence of a foreign body. Long-standing airway foreign bodies are associated with considerable morbidity, and early diagnosis remains the key to successful and uncomplicated management of foreign body aspiration. Education aimed at increasing diagnostic acumen of the physicians and heightening of public awareness are the most important steps needed to reduce the morbidity and mortality. Parents should be instructed to abstain from feeding nuts and seeds to young children and to keep small, potentially ingestible objects out of their reach.

Intraoperative recurrent laryngeal nerve monitoring during video-assisted throracoscopic surgery for patent ductus arteriosus.

OBJECTIVE: To develop a technique to identify and localize the recurrent laryngeal nerve (RLN) during video-assisted thoracoscopic surgery (VATS) for patent ductus arteriosus. DESIGN: Prospective clinical study. SETTING: Children's hospital. PARTICIPANTS: Sixty infants and children scheduled for elective closure of patent ductus arteriosus. INTERVENTIONS: With parental informed consent, 60 infants and children undergoing elective VATS for patent ductus arteriosus were studied. A thin, pencil-point, Teflon-coated, stimulating probe allowed direct stimulation (<2 mA, 100-msec pulse width) of the left RLN inside the thorax. A commercially available 4-channel neurologic monitor recorded compound evoked electromyograms (EMGs) from the left RLN and right RLN (as control) by needle electrodes placed percutaneously in the neck. Hoarseness, stridor, feeding difficulties, and voice changes were assessed postoperatively. MEASUREMENTS AND MAIN RESULTS: Left RLN EMGs were easily obtained in 59 of the 60 patients. The surgeon correctly identified the RLN visually once in the first 7 patients; this ability subsequently improved. EMG localization of the location or course of the RLN altered dissection, clip size, or clip position in 37 of 59 patients. CONCLUSION: Intraoperative EMG to identify location and route of the RLN was easy to perform, was effective in identifying RLN position, and appeared to facilitate dissection and clipping of the ductus.

A phylogenetically conserved NAD+-dependent protein deacetylase activity in the Sir2 protein family.

The yeast Sir2 protein, required for transcriptional silencing, has an NAD(+)-dependent histone deacetylase (HDA) activity. Yeast extracts contain a NAD(+)-dependent HDA activity that is eliminated in a yeast strain from which SIR2 and its four homologs have been deleted. This HDA activity is also displayed by purified yeast Sir2p and homologous Archaeal, eubacterial, and human proteins, and depends completely on NAD(+) in all species tested. The yeast NPT1 gene, encoding an important NAD(+) synthesis enzyme, is required for rDNA and telomeric silencing and contributes to silencing of the HM loci. Null mutants in this gene have significantly reduced intracellular NAD(+) concentrations and have phenotypes similar to sir2 null mutants. Surprisingly, yeast from which all five SIR2 homologs have been deleted have relatively normal bulk histone acetylation levels. The evolutionary conservation of this regulated activity suggests that the Sir2 protein family represents a set of effector proteins in an evolutionarily conserved signal transduction pathway that monitors cellular energy and redox states.

Necrotizing fasciitis of the pharynx following adenotonsillectomy.

Necrotizing fasciitis is a rare clinical entity in the head and neck region. We report a case of necrotizing fasciitis following adenotonsillectomy in a previously healthy 2-year-old girl. The child presented in a septic state with impending airway compromise. Computed tomography (CT) showed massive soft tissue widening with air in the retropharyngeal, parapharyngeal and retromandibular spaces. Intraoperative exploration showed necrosis of the posterior pharyngeal wall from the skull base to the cricoid, with extension into the parapharyngeal and retropharyngeal spaces. Cultures from the debrided tissues grew two aerobes and three anaerobes. Management involved airway support, surgical debridement, broad spectrum antibiotic coverage and nutritional support. The patient ultimately developed nasopharyngeal and oropharyngeal stenosis requiring tracheostomy and gastrostomy tube placement. This case report highlights an extremely rare complication of adenotonsillectomy.

Acupressure-acupuncture antiemetic prophylaxis in children undergoing tonsillectomy.

BACKGROUND: Acupuncture or acupressure at the Nei-Guan (P.6) point on the wrist produces antiemetic effects in awake but not anesthetized patients. The authors studied whether a combined approach using preoperative acupressure and intra- and postoperative acupuncture can prevent emesis following tonsillectomy in children. METHODS: Patients 2-12 yr of age were randomly assigned to study or placebo groups. Two Acubands with (study) and two without (placebo) spherical beads were applied bilaterally on the P.6 points; non-bead- and bead-containing Acubands, respectively, were applied on the sham points. All Acubands were applied before any drug administration. After anesthetic induction, acupuncture needles were substituted for the beads and remained in situ until the next day. All points were covered with opaque tape to prevent study group identification. A uniform anesthetic technique was used; postoperative pain was managed initially with morphine and later with acetaminophen and codeine. Emesis, defined as retching or vomiting, was assessed postoperatively. Ondansetron was administered only after two emetic episodes at least 2 min apart. Droperidol was added if emesis persisted. RESULTS: One hundred patients were enrolled in the study. There were no differences in age, weight, follow-up duration, or perioperative opioid administration between groups. Retching occurred in 26% of the study patients and in 28% of the placebo patients; 51 and 55%, respectively, vomited; and 60 and 59%, respectively, did either. There were no significant differences between the groups. Redness occurred in 8.5% of acupuncture sites. CONCLUSION: Perioperative acupressure and acupuncture did not diminish emesis in children following tonsillectomy.

Causes of pediatric sensorineural hearing loss: yesterday and today.

OBJECTIVE: To ascertain the present common causes of sensorineural hearing loss (SNHL) in children and compare them with those of previous reports. DESIGN: A retrospective review of the medical records for all children with a diagnosis of SNHL seen from January 1, 1993, through September 30, 1996, at our institution. SETTING: A tertiary care children's hospital. PATIENTS: Three hundred one children, aged 1 week through 18 years, who presented for evaluation of SNHL. RESULTS: Of the 301 children, 68.1% had a definite or probable cause of their SNHL identified; 18.9%, 1 or more possible causes; and 31.9%, no obvious cause. A family history of SNHL or prematurity and/or complicated perinatal course was found in 28.6% of patients. Named syndromes, multiple congenital anomalies, meningitis, or prenatal maternal factors, including maternal prenatal substance abuse, were present in another 38.5%. However, syndromes commonly reported to be associated with SNHL, such as Waardenburg syndrome, were seen in less than 1% of patients. The average age at diagnosis was 3.02 years for the bilateral moderate or worse SNHL; for unilateral SNHL, the average age was 3.97 years. The most useful diagnostic study was computed tomographic scanning. CONCLUSIONS: Sensorineural hearing loss is fairly common in children. Extensive workups, often without clear direction, should be reconsidered based on the children with SNHL who otolaryngologists are now seeing. Infant screening programs, although identifying many children earlier, will also provide the opportunity to fine-tune the evaluation (ie, cytomegalovirus titers and/or cultures at birth), increasing the diagnostic yield.

Treatment of chronic suppurative otitis media with topical ciprofloxacin.

To date, only ofloxacin has been approved by the US Food and Drug Administration for treatment of ears with a nonintact tympanic membrane. The purpose of this study was to determine the safety and efficacy of topical ciprofloxacin hydrochloride in the treatment of experimental chronic suppurative otitis media caused by Pseudomonas aeruginosa infection in cynomolgus monkeys. Forty adult cynomolgus monkeys were divided into 4 equal groups, and their ears were challenged with P aeruginosa, drained for 3 weeks, then treated twice daily for 4 weeks with 1 of 4 randomly assigned agents: 1) ciprofloxacin, 2) saline, 3) Cortisporin, or 4) vehicle. The animals were followed up with auditory brain stem response testing, culture, otoscopy, and histopathology. Both ciprofloxacin and Cortisporin treatment resulted in a significantly more rapid rate of clearance of P aeruginosa as compared to treatment with saline (100% versus 20%). Eradication was not associated with resolution of otorrhea after a 4-week period of treatment. There were no significant changes in auditory brain stem response wave latencies for any of the treatment groups. Histopathologic data revealed that there was no statistically significant difference in the amount of outer hair cell loss for the ciprofloxacin group as compared to the control ear and other treatment groups. We conclude, therefore, that topical ciprofloxacin is not ototoxic and is effective in sterilizing the otorrhea, but does not promote resolution of the drainage, in this animal model.

Invading the yeast nucleus: a nuclear localization signal at the C terminus of Ty1 integrase is required for transposition in vivo.

Retrotransposon Ty1 faces a formidable cell barrier during transposition--the yeast nuclear membrane which remains intact throughout the cell cycle. We investigated the mechanism by which transposition intermediates are transported from the cytoplasm (the presumed site of Ty1 DNA synthesis) to the nucleus, where they are integrated into the genome. Ty1 integrase has a nuclear localization signal (NLS) at its C terminus. Both full-length integrase and a C-terminal fragment localize to the nucleus. C-terminal deletion mutants in Ty1 integrase were used to map the putative NLS to the last 74 amino acid residues of integrase. Mutations in basic segments within this region decreased retrotransposition at least 50-fold in vivo. Furthermore, these mutant integrase proteins failed to localize to the nucleus. Production of virus-like particles, reverse transcriptase activity, and complete in vitro Ty1 integration resembled wild-type levels, consistent with failure of the mutant integrases to enter the nucleus.

Yeast N1e3p/Nup170p is required for normal stoichiometry of FG nucleoporins within the nuclear pore complex.

The FG nucleoporins are a conserved family of proteins, some of which bind to the nuclear localization sequence receptor, karyopherin. Distinct members of this family are found in each region of the nuclear pore complex (NPC), spanning from the cytoplasmically disposed filaments to the distal end of the nuclear basket. Movement of karyopherin from one FG nucleoporin to the next may be required for translocation of substrates across the NPC. So far, nothing is known about how the FG nucleoporins are localized within the NPC. To identify proteins that interact functionally with one member of this family, the Saccharomyces cerevisiae protein Nup1p, we previously identified 16 complementation groups containing mutants that are lethal in the absence of NUP1 These mutants were referred to as nle (Nup-lethal) mutants. Mutants in the nle3/nlel7 complementation group are lethal in combination with amino-terminal nup1 truncation mutants, which we have previously shown to be defective for localization to the NPC. Here we show that NLE3 (which is allelic to NUP170) encodes a protein with similarity to the mammalian nucleoporin Nup155. We show that Nle3p coprecipitates with glutathione S-transferase fusions containing the amino-terminal domain of Nup1p. Furthermore, a deletion of Nle3p leads to changes in the stoichiometry of several of the XFXFG nucleoporins, including the loss of Nup1p and Nup2p. These results suggest that Nle3p plays a role in localizing specific FG nucleoporins within the NPC. The broad spectrum of synthetic phenotypes observed with the nle3delta mutant provides support for this model. We also identify a redundant yeast homolog that can partially substitute for Nle3p and show that together these proteins are required for viability.

In vitro susceptibility of aural isolates of Pseudomonas aeruginosa to commonly used ototopical antibiotics.

The choice of antimicrobial agents used to treat Pseudomonas aeruginosa infections of the ear is quite empiric. Yet in spite of this, very little has been published examining susceptibility patterns of aural isolates of P. aeruginosa. Recently, increasing concern has emerged over the development of resistance to many of the commonly used ototopical preparations with activity against P. aeruginosa. This concern stems from the fact that these preparations have been in use for a long time, and P. aeruginosa is known to develop resistance fairly readily. We prospectively studied the susceptibilities of aural isolates of P. aeruginosa in 231 consecutive children who were seen in the outpatient Pediatric Otolaryngology Department at Children's Hospital of Pittsburgh during the years 1992 and 1993. The agents tested included neomycin, polymyxin B, colistin, and norfloxacin. We found that only 17.8% of the isolates were sensitive to neomycin, as opposed to > 95% for each of the other agents tested (polymyxin B, 99.6%; colistin, 97.4%; and norfloxacin, 98.3%). This difference proved to be statistically significant (p < 0.05). Given the concern of aminoglycoside-induced ototoxicity and the high rate of neomycin resistance, we believe that further investigation of other alternative ototopic agents with activity against P. aeruginosa is warranted.

Therapeutic implications in the treatment of aural Pseudomonas infections based on in vitro susceptibility patterns.

OBJECTIVE: To examine the in vitro susceptibility patterns of aural isolates of Pseudomonas aeruginosa and to identify changes over a 4-year period. DESIGN: Retrospective case series. SETTING: The outpatient department at Children's Hospital of Pittsburgh (Pa), a tertiary referral center. PATIENTS: Ambulatory children younger than 18 years from whose ears P aeruginosa was isolated. OUTCOME MEASURES: The in vitro susceptibility of aural isolates of P aeruginosa to ampicillin, cefotaxime, chloramphenicol, sulfisoxazole, ticarcillin, mezlocillin, gentamicin, tobramycin, cefazolin, tetracycline, piperacillin, nitrofurantoin, cephalexin hydrochloride, ceftriaxone, cefuroxime axetil, and sulfamethoxazole-trimethoprim. RESULTS AND CONCLUSIONS: No changes were found in the trends of the susceptibility patterns over the 4-year study period, with the exception of the semisynthetic penicillins, ticarcillin and mezlocillin. These two agents were found to be relatively ineffective against the strains of P aeruginosa isolated in 1989 (59% and 18% susceptibility, respectively). This finding is in contrast to their effectiveness over the remainder of the study period (96% and 90% susceptibility, respectively), which was excellent. These observations likely reflect a change in the breakpoints for the minimal inhibitory concentrations between these periods. The intravenous agent with the best susceptibility profile was piperacillin (96%). Of the aminoglycosides tested, 94% of the isolates were sensitive to tobramycin, as opposed to only 79% for gentamicin. This finding may have significance when one is empirically selecting ototopical therapy, since both tobramycin and gentamicin are available as topical preparations. Of the oral agents, the combination of sulfamethoxazole-trimethoprim was most effective (46%).

Head and neck manifestations of Beckwith-Wiedemann syndrome.

Beckwith-Wiedemann syndrome is a congenital disorder manifested by organomegaly, omphalocele, hypoglycemia, and macroglossia. We have found a significant number of these children to be at risk for upper airway obstruction during infancy or childhood. In this review of 13 children, 2 required tracheotomy during infancy for cor pulmonale caused by macroglossia. Seven of nine children older than 1 year required tonsillectomy and adenoidectomy to relieve upper airway obstruction. Although macroglossia can be a cause of airway obstruction in infants with Beckwith-Wiedemann syndrome, we have found that airway obstruction during childhood is related to tonsillar and adenoidal hypertrophy and not to macroglossia. Anterior tongue reduction is reserved for the correction of malocclusion, articulation errors, or cosmesis, whereas tonsillectomy and adenoidectomy may be curative of obstructive symptoms.

Correlation of beta-2 transferrin and middle ear abnormalities in congenital perilymphatic fistula.

Congenital perilymphatic fistula (PLF) as a diagnosis for progressive, fluctuating, or sudden sensorineural hearing loss with or without vertigo is still controversial. Beta-2 transferrin is a protein that is unique to cerebrospinal fluid, aqueous humor, and perilymph. A recent pilot study demonstrated that beta-2 transferrin may be an objective test to determine the existence of a congenital PLF. The authors prospectively evaluated and recommended surgery for 43 children with suspected PLF over the past 3 years. A prospective, blinded study was performed by having the attending otolaryngologist evaluate the middle ear at the time of surgery for a PLF and any middle ear abnormalities. Samples of fluid were collected from the oval and round windows and were tested for beta-2 transferrin. Of 16 patients undergoing tympanoplasty or tympanomastoidectomy who served as controls, none were positive for beta-2 transferrin. Of the 43 patients undergoing exploratory tympanoplasty for PLF, 20 (46.5%) were considered to be negative for PLF on microscopic visualization; 23 (53.5%) were found to be positive. Of the 20 patients thought to be negative for PLF, 18 (90%) tested negative for beta-2, but 2 of these patients were positive for beta-2, and both had a congenital middle ear abnormality. Of the 23 patients found to have a PLF at surgery, 6 (26.1%) tested positive for beta-2, and all of these 6 had middle ear abnormalities. Of the 17 patients negative for beta-2, 9 had normal anatomy; 6 had middle ear abnormalities, and 2 had erosive changes. The authors conclude that beta-2 transferrin, an objective test, confirms the existence of congenital PLF in children, which is associated with middle ear abnormalities.