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Biomedical subjects

J Fredrik Grimmer

Publications and source records attributed to J Fredrik Grimmer.

6 recordsLinked to original sources

Vestibular symptoms in children with enlarged vestibular aqueduct anomaly.

OBJECTIVE: The objective of this study is to describe the vestibular symptoms in pediatric patients with enlarged vestibular aqueduct (EVA) anomaly. METHODS: Retrospective chart review of pediatric and adult patients with EVA anomaly who were treated at the University of Utah Hospital or Primary Children's Medical Center, between 1995 and 2005. Radiographs were reviewed to confirm the diagnosis. Comparisons were made between adult and pediatric patients. RESULTS: Thirty-two patients were included in the study, 17 females and 15 males. Twenty-one patients were under the age of 18 and 11 patients were age 18 or older. On initial audiometric evaluation at a tertiary hospital, the pure tone average in the right ear was 75.0 dB and the pure tone average in the left ear was 80.4 dB. The incidence of vestibular symptoms in adult patients was 45.5% and in pediatric patients was 48.0%. Fourteen patients underwent cochlear implantation. Four patients (28.6%) who previously denied vestibular symptoms experienced post-operative vertigo after cochlear implantation. CONCLUSIONS: About half of the patients with EVA in our series experienced vestibular symptoms. Pediatric patients in our series experienced vertigo and vestibular symptoms with equal frequency when compared to adult patients. Some patients with EVA undergoing cochlear implantation experienced vestibular symptoms in the post-operative period.

Adolescent↗

Radiofrequency ablation of microcystic lymphatic malformation in the oral cavity.

OBJECTIVE: To determine the efficacy and safety of radiofrequency (RF) ablation of vesicles and the resulting symptomatic control of microcystic lymphatic malformation (LM) in the oral cavity. DESIGN: An institutional review board-approved retrospective study with follow-up telephone interview. SETTING: Tertiary pediatric medical center. Patients Eleven children (6 girls and 5 boys), aged 4 to 16 years, presenting between August 1, 2002, and December 1, 2004. Intervention Radiofrequency ablation of LM in the oral cavity. MAIN OUTCOME MEASURES: Symptoms related to LM, postoperative oral intake, and postoperative antibiotic requirements. RESULTS: Eleven patients presented with microcystic LM involving the lips, tongue, floor of the mouth, or buccal mucosa. Complaints included bleeding, infection, swelling, vesicle formation, and malocclusion. Patients underwent RF ablation (coblation) of oral cavity lesions. Seven (64%) of the 11 patients were able to tolerate oral intake in the recovery room. The need for antibiotics was reduced after RF ablation. All patients related diminished bleeding, pain, infection, or vesicle formation, with more than half reporting a significant improvement (6 patients) or complete resolution (1 patient). Five (62%) of 8 parents stated that the improvement after RF ablation was superior to that following previous procedures. CONCLUSIONS: Subtotal RF ablation of LM appears to be safe, with early postoperative oral intake and minimal postoperative pain. Further studies are needed to determine long-term control of LM.

Adolescent↗

Mucoepidermoid carcinoma of the parotid gland in children: A 10-year experience.

OBJECTIVE: To determine the presentation, pathologic features, treatment outcome, and prognosis of mucoepidermoid carcinoma of the parotid gland in children. DESIGN: Retrospective clinical and histopathologic study with institutional review board approval. SETTING: Tertiary pediatric medical center. PATIENTS: Seven children (4 girls and 3 boys) presented with mucoepidermoid carcinoma of the parotid gland between 1994 and 2004. MAIN OUTCOME MEASURES: Clinical presentation, pathologic features, treatment outcome, complications, local recurrence, distant metastasis, and overall survival. RESULTS: All patients presented with an asymptomatic parotid mass. Initial treatment in 7 patients included total parotidectomy (n = 3), superficial parotidectomy (n = 3), transoral enucleation (n = 1), and supraomohyoid neck dissection (n = 1). Four patients required additional surgical procedures because of a close and/or positive margin, including revision parotidectomy (n = 2), total parotidectomy (n = 1), superficial parotidectomy (n = 1), and supraomohyoid neck dissection (n = 1). One patient required postoperative radiation therapy. No evidence of local recurrence or distant metastasis was noted with a mean follow-up of 3.4 years. CONCLUSIONS: Mucoepidermoid carcinoma of the parotid gland is very rare in children. Clinical stage and histologic grade are the main prognostic factors. Complete excision (superficial or total parotidectomy) with preservation of facial nerve is the treatment of choice. Neck dissection should be considered when there is clinical evidence of regional metastasis, high TNM stage, high histologic grade, and involvement of regional nodes. Because of the possibility of long-term adverse effects in pediatric patients, radiotherapy should be used only in selected cases. Long-term follow-up is essential to rule out late recurrence.

Adolescent↗

Update on eustachian tube dysfunction and the patulous eustachian tube.

PURPOSE OF REVIEW: The purpose of this review is to summarize the recent knowledge on eustachian tube dysfunction and the patulous eustachian tube. RECENT FINDINGS: A clinically useful test for eustachian tube function is still lacking. Narrowing of the isthmus alone was demonstrated to be an insufficient cause of otitis media. Inflammatory mediators identified within the eustachian tube and middle ear cells were causally linked with otitis media with effusion. Increasing evidence was found that allergic disease and reflux may be two of the most important contributors of tubal inflammation causing otitis media with effusion. The adenoid size and proximity to the torus tubaris may also be important in considering which patients with persistent otitis media with effusion may benefit from adenoidectomy. Computed tomography scan has documented loss of soft tissue within the cartilaginous eustachian tube in patients with patulous eustachian tubes. An endoscopic approach to seal the tubal lumen has been found to be effective in relieving patulous symptoms. SUMMARY: These studies suggest that allergic rhinitis and gastroesophageal reflux should be investigated in patients with eustachian tube dysfunction. Adenoidectomy should also be considered in patients who have adenoids that obstruct the torus tubaris. Patients with a patulous eustachian tube may benefit from an endoscopic closure. Further research is needed to identify a clinically useful test for eustachian tube dysfunction.

Ear Diseases↗

Tracheal reconstruction using tissue-engineered cartilage.

OBJECTIVES: To determine whether rabbit cartilage can be tissue engineered using a polyglycolic acid (PGA) construct composed of PGA mesh, autologous chondrocytes, and alginate covalently linked with the cell adhesion sequence arginine-glycine-aspartic acid (RGD), and to investigate the feasibility of reconstructing tracheal defects using the PGA construct in conjunction with a bioabsorbable intratracheal stent. METHODS: Nineteen New Zealand White rabbits were used. Nine rabbits underwent subcutaneous implantation of 3 different PGA construct combinations: (1) PGA, autologous chondrocytes, and RGD-modified alginate; (2) PGA, autologous chondrocytes, and unmodified alginate; and (3) PGA and RGD-modified alginate. The remaining 10 animals underwent anterior tracheal reconstruction using fascia lata grafts and the complete PGA construct (PGA, autologous chondrocytes, and RGD-modified alginate). At the time of tracheal reconstruction, a poly-l-lactic acid intratracheal stent was placed in 5 of these latter animals. Rates of tracheal stenosis and mortality were compared with those of historical control animals. Histologic analysis was performed on the PGA constructs. RESULTS: In the subcutaneous implants, the PGA constructs made with chondrocytes (with and without RGD) demonstrated mature cartilage formation in 7 (78%) of the 9 animals. No cartilage was seen in PGA constructs made without chondrocytes. Two of the 10 animals that underwent tracheal reconstruction with the complete PGA construct survived to 20 weeks and demonstrated patent airways, 1 with a stent and 1 without a stent (80% overall mortality). Histologic analysis showed mature cartilage formation at the tracheal reconstruction site. Historical control animals that underwent reconstruction with fascia lata alone demonstrated the lowest overall mortality. CONCLUSIONS: Cartilage can be tissue engineered in rabbits using PGA mesh embedded with alginate-encapsulated autologous chondrocytes. It is also possible to reconstruct tracheal defects with this method of cartilage engineering, although the mortality rate in this study is high.

Alginates↗

Hmx2 and Hmx3 homeobox genes direct development of the murine inner ear and hypothalamus and can be functionally replaced by Drosophila Hmx.

The Hmx homeobox gene family appears to play a conserved role in CNS development in all animal species examined, and in higher vertebrates has an additional role in sensory organ development. Here, we show that murine Hmx2 and Hmx3 have both overlapping and distinct functions in the development of the inner ear's vestibular system, whereas their functions in the hypothalamic/pituitary axis of the CNS appear to be interchangeable. As in analogous knockin studies of Otx and En function, Drosophila Hmx can rescue conserved functions in the murine CNS. However, in contrast to Otx and En, Drosophila Hmx also rescues significant vertebrate-specific functions outside the CNS. Our work suggests that the evolution of the vertebrate inner ear may have involved (1) the redeployment of ancient Hmx activities to regulate the cell proliferation of structural components and (2) the acquisition of additional, vertebrate-specific Hmx activities to regulate the sensory epithelia.

Animals↗