In vitro regulation of expression of cartilage-derived morphogenetic proteins by growth hormone and insulinlike growth factor 1 in the bovine cricoid chondrocyte.

OBJECTIVES: To delineate the endogenous growth factors that regulate cricoid cartilage growth at the molecular level. Specifically, to attempt to establish the presence of cartilage-derived morphogenetic proteins (CDMPs), cartilage-specific members of the bone morphogenetic protein family, in newborn bovine cricoid chondrocytes and to assess the expression of these endogenous growth factors with the addition of exogenous growth hormone or insulinlike growth factor 1 in an in vitro chondrocyte culture model. METHODS AND DESIGN: Basic science molecular biologic research methods, including high-density monolayer and explant chondrocyte cultures with extraction of messenger RNA and quantitation via Northern blot hybridization via radiolabeled complementary DNA probes. SETTING: Intramural basic science research laboratory. RESULTS: Both CDMP-1 and CDMP-2 were found in newborn cricoid chondrocytes. Addition of exogenous growth hormone did not appear to influence the expression of CDMP-1 or CDMP-2. Addition of exogenous insulinlike growth factor 1 appeared to down-regulate the expression of CDMP-1 but had no effect on the expression of CDMP-2. No major differences in CDMP level of expression were noted between high-density monolayer cultures vs explant cultures. No tissue specificity differences were noted in regulation of CDMPs between cricoid and articular chondrocytes. CONCLUSIONS: Our preliminary studies indicate the presence of endogenous morphogenetic proteins in newborn bovine cricoid chondrocytes. These novel polypeptide hormones (CDMP-1 and CDMP-2) have not been previously reported in laryngeal cartilage chondrocytes. Change in level of transcription of these morphogenetic proteins under various in vitro conditions suggests that these proteins are subject to regulation and/or play a regulatory role in cricoid chondrocyte growth and differentiation. Further experimentation is needed to confirm these findings.

A stepwise approach to the diagnosis and treatment of hereditary hearing loss.

What To Do Do suspect a genetic cause in all cases of hearing loss. Do develop a working knowledge of common types of HHI that you may draw on to aid in diagnosis. Do think of HHI when the audiogram reveals a hearing loss with a "cookie bite" configuration. Do refer the infant to a geneticist in cases where you suspect a syndromic HHI, a nonsyndromic HHI, and in cases of "cryptogenic" hearing loss where an underlying HHI may be present. Often, the associated symptoms are subtle and best detected by a professional who deals with these issues on a daily basis. Do get the infant or family plugged into an audiologist or otolaryngologist and speech pathologist who will preferably work as a team to maximize aural rehabilitation and ensure serial follow-up. It is never too early to fit a child with hearing aids. Do refer to the HHIRR center at Boys Town. Do refer to the correct "deaf" organization or "blind-deaf" organization. Do think about working up other siblings or family members. Do keep in mind that some members of the "deaf society" may regard deafness as an alternative lifestyle and may not be amenable to their child's referral for additional workup and aural rehabilitation. What Not To Do Do not assume the child is deaf and nothing can be done. Do not wait until the child is older to refer to an otolaryngologist, speech therapist, and audiologist. Do not order a sonogram. Do not order a temporal bone CT scan on newborns. Do not forget about other siblings who may have a similar pathology. Do not forget that some forms of HHI can present beyond infancy. The pediatrician is the front line and can play a major role in the diagnosis, workup, and treatment of HHI. Armed with the proper degree of suspicion, careful elicitation of family history, meticulous physical examination, evaluation of the audiogram, and adequate fund of knowledge of common types of genetic deafness, the pediatrician can make a timely diagnosis and appropriate referrals. This avoids delay in detection of significant hearing impairment and the associated lack of essential skills in speech, language, and social interaction. No child is too young to have some type of hearing assessment. Early detection and intervention are best done with a multidisciplinary team approach with a neonatologist or pediatrician, audiologist, speech therapist, and otolaryngologist. In the future, blood tests using genetic probes may be available to screen for many types of HHI.

Sodium ipodate (oragrafin) in the preoperative preparation of Graves' hyperthyroidism.

Fourteen Graves' hyperthyroid patients who had been prepared for surgery with sodium ipodate (SI) 500 mg orally twice daily for 3 days were retrospectively studied. SI was administered in combination with propylthiouracil (10 cases) and beta blockers (all cases), which had been previously initiated. Free serum thyroxine (T4) and total triiodothyronine (T3) concentrations were measured before and after SI therapy on the morning of surgery. SI treatment significantly reduced total T3 concentration from 445.9 to 193.4 ng/dL (P < 0.0001) and free T4 concentration from 3.874 to 2.800 ng/dL (P = 0.0003). Preoperatively, only one patient had persistent tachycardia, and intraoperatively this same patient required beta blockers. Blood loss was unremarkable or reduced (average blood loss, 121 mL). On clinical examination glands were firm with normal or somewhat decreased vascularity. On histologic study all glands demonstrated changes consistent with treated Graves' disease. Preoperative treatment with SI appears to be a safe and efficacious method of preparing hyperthyroid patients for surgery.

Penetrating injury to the oral cavity: a case report and review of the literature.

Penetrating injury to the oral cavity, although rare, may cause serious morbidity and mortality in the pediatric population. Impalement injuries are known to cause delayed vascular injury to the internal carotid artery, leading to significant neurologic sequelae. We present an unusual case of impalement injury and make recommendations regarding the successful evaluation and management of such injuries.

Airway obstruction in the Pierre Robin sequence.

Airway obstruction and feeding difficulties vary among patients with Pierre Robin sequence (PRS). Treatment is challenging and the appropriate management may not be readily identified, leading to delay in securing the airway. A retrospective review of 90 children with PRS was done to identify subgroups at a higher risk of developing severe airway obstruction using oxygen and apnea monitoring, sleep studies, and response to treatment. Patients with isolated PRS (group I, 27 patients) and Stickler syndrome (group II, 32 patients) do not suffer from debilitating airway and feeding difficulties when compared to those with unique syndromes (group III, 16 patients) and recognized named syndromes (group IV, 15 patients). Feeding difficulties were universal with the severity proportional to airway obstruction. Aggressive intervention should be considered early in group III and IV patients.

Enlarged vestibular aqueduct and sensorineural hearing loss in childhood.

OBJECTIVE: To determine if all children with enlarged vestibular aqueducts (EVAs) have development of uniform progressive sensorineural hearing loss (SNHL). To determine whether the size of the EVA correlates with severity, frequencies involved, and stability of SNHL. To determine if the audiologic pattern of SNHL correlates with likelihood of progression of SNHL. DESIGN: Retrospective study. SETTING: Children's National Medical Center, Washington, DC, a tertiary care center with a large otologic practice. PATIENTS: Fifteen children (26 ears) with EVA on computed tomographic scan. METHODS: History, physical examination, computed tomographic scans, and serial audiograms were reviewed. Factors analyzed included age at diagnosis, audiometric configuration (high tone, midtone, low tone, flat), degree of hearing loss at presentation, length of follow-up, and presence of associated inner ear anomalies. RESULTS: Nine ears had progressive SNHL, 16 ears had stable SNHL, and 1 ear had profound SNHL. The predominant audiologic configuration was flat. The audiogram configuration does not correlate with progression of SNHL. The size of the vestibular aqueduct does not correlate with the level, type, or progression of SNHL. CONCLUSION: Our study failed to uncover factors that might be predictive of progression of hearing loss. We conclude that until a better understanding of the natural history and pathophysiologic condition of EVAs is achieved, there is no surgical or other intervention that can be demonstrated as being efficacious.