Faculty Bibliography

Epidermolysis bullosa (EB) is a group of rare inherited disorders in which minor trauma causes blister formation in the skin and mucosa, including the esophagus. Morbidity varies with the type of disease and ranges from occasional trivial skin blisters to death in infancy. Laryngeal involvement presenting as hoarseness and respiratory distress has been reported in nine patients, five of whom had junctional EB. We present the sixth case of junctional EB with laryngeal involvement, and offer guidelines for otolaryngologists and anesthesiologists caring for these fragile patients

We have obtained the complete coding sequence of neurocan, a chondroitin sulfate proteoglycan of rat brain which is developmentally regulated with respect to its molecular size, concentration, carbohydrate composition, sulfation, and immunocytochemical localization. Two degenerate oligonucleotides, based on amino acid sequence data from the proteoglycan isolated from adult brain by immunoaffinity chromatography with the 1D1 monoclonal antibody, were used as sense and antisense primers in the polymerase chain reaction with a brain cDNA library as template to generate an unambiguous cDNA probe. A second probe for the N-terminal portion of the early postnatal form of the proteoglycan was obtained by reverse transcription/polymerase chain reaction. The composite sequence of overlapping cDNA clones is 5.2-kilobases (kb) long, including 1.3 kb of 3'-untranslated sequence and 76 base pairs of 5'-untranslated sequence. An open reading frame of 1257 amino acids encodes a protein with a molecular mass of 136 kDa containing 10 peptide sequences present in the adult and/or early postnatal brain proteoglycans. The deduced amino acid sequence revealed a 22-amino acid signal peptide followed by an immunoglobulin domain, tandem repeats characteristic of the hyaluronic acid-binding region of aggregating proteoglycans, and an RGDS sequence. The C-terminal portion (amino acids 951-1215) has approximately 60% identity to regions in the C termini of the fibroblast and cartilage proteoglycans, versican and aggrecan, including two epidermal growth factor-like domains, a lectin-like domain, and a complement regulatory protein-like sequence. The central 595-amino acid portion of neurocan has no homology with other reported protein sequences. The proteoglycan contains six potential N-glycosylation sites and 25 potential threonine O-glycosylation sites. In the adult form of the proteoglycan (which represents the C-terminal half of neurocan) a single 32-kDa chondroitin 4-sulfate chain is linked at serin-944, whereas three additional potential chondroitin sulfate attachment sites (only two of which are utilized) are present in the larger proteoglycan species. A probe corresponding to a region of neurocan having no homology with versican or aggrecan hybridized with a single band at approximately 7.5 kb on Northern blots of mRNA from both 4-day and adult rat brain (but not with muscle, kidney, liver, or lung mRNA), indicating that the 1D1 proteoglycan of adult brain, containing a 68-kDa core protein, is generated by a developmentally regulated in vivo proteolytic processing of the 136-kDa species which is predominant in early postnatal brain.(ABSTRACT TRUNCATED AT 400 WORDS)

Speech production parameters of three postlingually deafened adults who use cochlear implants were measured: after 24 h of auditory deprivation (which was achieved by turning the subject's speech processor off); after turning the speech processor back on; and after turning the speech processor off again. The measured parameters included vowel acoustics [F1, F2, F0, sound-pressure level (SPL), duration and H1-H2, the amplitude difference between the first two spectral harmonics, a correlate of breathiness] while reading word lists, and average airflow during the reading of passages. Changes in speech processor state (on-to-off or vice versa) were accompanied by numerous changes in speech production parameters. Many changes were in the direction of normalcy, and most were consistent with long-term speech production changes in the same subjects following activation of the processors of their cochlear implants [Perkell et al., J. Acoust. Soc. Am. 91, 2961-2978 (1992)]. Changes in mean airflow were always accompanied by H1-H2 (breathiness) changes in the same direction, probably due to underlying changes in laryngeal posture. Some parameters (different combinations of SPL, F0, H1-H2 and formants for different subjects) showed very rapid changes when turning the speech processor on or off. Parameter changes were faster and more pronounced, however, when the speech processor was turned on than when it was turned off. The picture that emerges from the present study is consistent with a dual role for auditory feedback in speech production: long-term calibration of articulatory parameters as well as feedback mechanisms with relatively short time constants

A retrospective study of pediatric patients with obstructive sleep apnea who underwent adenotonsillectomy between 1987 and 1990 was undertaken to determine the frequency of postoperative respiratory compromise and to determine if risk factors for its development could be identified. Sixty-nine patients less than 18 years old had polysomnographically documented obstructive sleep apnea and were observed postoperatively in the pediatric intensive care unit. Of these, 16 (23%) had severe respiratory compromise, defined as intermittent or continuous oxygen saturation of 70% or less, and/or hypercapnia, requiring intervention. Compared with patients without respiratory compromise, these patients were younger (3.4 +/- 4 vs 6.1 +/- 4 years) and had more obstructive events per hour of sleep on the polysomnogram (49 +/- 41 vs 19 +/- 30). They were more likely to weight less than the fifth percentile for age (odds ratio [OR], 5.1; 95% confidence interval [CI], 1.4 to 18.7), to have an abnormal electrocardiogram and/or echocardiogram (OR, 4.5; 95% CI, 1.3 to 15.1), and to have a craniofacial abnormality (OR, 6.2; 95% CI, 1.5 to 26). Multiple logistic regression analysis revealed the most significant risk factors were age below 3 years and an obstructive event index greater than 10. Children with obstructive sleep apnea are at risk for respiratory compromise following adenotonsillectomy; young age and severe sleep-related upper airway obstruction significantly increase this risk. We recommend in-hospital postoperative monitoring for children undergoing adenotonsillectomy for obstructive sleep apnea

Congenital nasal pyriform aperture stenosis has recently been described as a cause of nasal airway obstruction in the newborn. As some investigators have observed, the nasal pyriform aperture is narrowed owing to bony overgrowth of the nasal process of the maxilla. This overgrowth is confirmed by computed tomography. In six previously reported cases, follow-up as long as 16 months revealed normal facial growth. We describe six patients with congenital nasal pyriform aperture stenosis. On eruption of deciduous dentition, four of the six patients were found to have a single prominent central maxillary incisor, ie, 'megaincisor.' Computed tomographic scans have confirmed this dental anomaly as well as maxillary bony overgrowth. A single maxillary incisor has been described as an autosomal dominant microform of holoprosencephaly, a developmental field defect. We propose that in some patients congenital nasal pyriform aperture stenosis may represent more than an isolated congenital abnormality of the airway and may, in fact, be a midfacial dysostosis with associated endocrine and central nervous system abnormalities

Studies of aural and other body tissues suggest that otosclerosis represents the local manifestation of a general disorder of connective tissue. In particular, collagen abnormalities have been described. We have undertaken a pilot study of the in vivo messenger RNA (mRNA) transcription for procollagenase (precursor of collagenase), as well as for stromelysin and tissue inhibitor of metalloprotease (TIMP), an activator and a specific inhibitor of tissue collagenase activity, respectively. Human skin from individuals with surgically confirmed otosclerosis was compared to skin from their family members (clinically positive and clinically negative) and from unrelated normal controls. Preliminary data indicate that on average there are significantly lower levels of mRNA production for stromelysin among individuals with otosclerosis as compared to all others tested. Similar trends were demonstrated for TIMP and procollagenase, although these did not achieve statistical significance. In addition to suggesting a pathogenetic mechanism for the development of the disease, these data could serve as the basis of possible confirmatory tests for early diagnosis of otosclerosis and as a method for evaluating the genotype of offspring of affected individuals prior to their age of clinical manifestation. This could translate into the application of prophylactic treatment regimens in the future. The proposed abnormalities also suggest candidate genes for otosclerosis.

The intrasulcular incision provides excellent transpalatine exposure of the nasopharynx with a viable palatal flap. There is less chance for naso-oral fistula formation since the resulting suture line is always over underlying bone. This safely allows extensive removal of the hard palate. Additionally, the continuous sling suture allows excellent flap reapproximation using the teeth as anchors for the replaced palatal flap. Patients tolerate oral feedings within 24 hours of their operations and require minimal postoperative analgesics. The extended intrasulcular incision offers many advantages over other methods for transpalatine exposures to the nasopharynx

Measurements of interfacial (double layer) capacitance, C(DL), and charge transfer resistance, R(CT), have been made as a function of temperature at fluid electrolyte interfaces with electrodes made from two different Tl-based high-temperature superconductor materials. Measurements spanning the 112-119 K superconducting transition temperatures, T(c), of the HTSC electrodes reveal a smooth decrease in C(DL) with decreasing temperatures, except that an abrupt, ca. 1 deg wide change in the shape of the C(DL) Vs temperature curve occurs at the T(c) of the electrode. These are the first data which show that the onset of superconductivity can be reflected in a chemical phenomenon at a molecular fluid/HTSC interface. Of the several contributors to interfacial capacitance, it is hypothesized that alteration in charge carrier distribution or polarizability over the outermost electrode lattice layer as electron pairs start to appear at T(c) is the most likely origin of the T(c)-correlated capacitance feature. Alterations in the charge transfer resistance for electrochemical solvent reduction appear over the same temperature interval as the capacitance feature, but not as consistently.

Multiple forms of surgical treatment exist for Zenker's diverticulum. Appropriate treatment needs to be tailored based on the needs of the patient and the resources and skills of the surgeon. We have reviewed the available surgical options and presented a series of 10 patients treated with a new technique, the KTP/532 laser diverticulotomy. The diverticulotomy is particularly well-suited to the debilitated patient who cannot tolerate a prolonged operation or a prolonged postoperative recovery. The results of the technique are comparable with those of other forms of diverticulotomy, and it is concluded that the KTP/532 laser is a simple, safe, and effective form of surgical treatment with exciting potential for future use