Biomedical subjects

P H Pownell

Publications and source records attributed to P H Pownell.

4 recordsLinked to original sources

PubMed1997

Diagnostic nasal endoscopy.

Endoscopy has gained wide popularity due to its protean applications and efficacy in many surgical specialties. Diagnosis and treatment of nasal diseases have advanced in the process. However, proper training in nasal endoscopy is critical. The nose is an intricate organ fundamentally and has such proximity to other vital structures that procedural miscues can cause serious complications. This paper traces the historical development of nasal endoscopy, explains its rationale, reviews anatomic and diagnostic issues, and describes the selection of equipment and correct application of technique, emphasizing the potential for advanced diagnostic skills.

Education, Medical↗

PubMed1994

The effect of cyclophosphamide on development of experimental cholesteatoma.

BACKGROUND: Recent work has shown that middle ear application of propylene glycol in chinchillas produces an inflammatory reaction resulting in cholesteatoma formation in 50% to 70% of animals. This study was done to determine if cyclophosphamide, an immune suppressor and anti-inflammatory agent, is capable of inhibiting cholesteatoma development in the animal model. METHODS: Ten adult chinchillas received systemic cyclophosphamide (20 mg/kg per day) for 14 days. On days 5, 8, and 11 of that period, the animals also received bilateral middle ear applications of 60% propylene glycol (0.2 mL per ear). Four weeks after the first propylene glycol application, the animals were killed for histologic evaluation. RESULTS: Eight of the 10 animals survived the full 4-week study period, providing 16 temporal bones for evaluation. It was found that cyclophosphamide reduced the leukocyte counts; however, middle ear inflammation appeared unaffected. Cholesteatoma occurred in eight (50%) of the 16 ears studied, and histologic findings were essentially identical to those previously seen in animals given propylene glycol alone. CONCLUSION: Under the conditions of this study, cyclophosphamide had no effect on cholesteatoma development in the animal model.

Administration, Topical↗

PubMed1992

Congenital abnormalities of the submandibular duct.

Five newborns presented with cystic lesions of the floor of mouth. Four of these patients proved to have congenitally imperforate submandibular salivary gland ducts and the other newborn proved to have a duplication anomaly of the submandibular gland duct and gland. The patients with imperforate Wharton's ducts underwent marsupialization with or without ductoplasty and have been without evidence of recurrence for up to three years. The duplication anomaly of the submandibular gland duct responded to simple excision. The diagnosis of congenital anomalies of the submandibular gland and duct can be made on physical examination. Magnetic resonance imaging can be helpful in differentiating congenital imperforate submandibular duct and duplication anomalies of the ductal system. Treatment of the former consists of duct marsupialization in the floor of mouth with or without ductoplasty. Treatment of the duplicated ductal system may best be treated with excision. A failure in diagnosis and treatment may result in ranula formation or sialoadenitis requiring more extensive therapy.

Cysts↗

PubMed1990

Rhabdomyoma of the cricopharyngeus in an infant.

Rhabdomyoma is a rare benign tumor characterized histologically by striated skeletal muscle. Rhabdomyomas can be classified into adult and fetal variants. The majority of adult variants arise in the head and neck region and are derived from the skeletal muscles of the pharyngeal (branchial) arches. The majority of cases of fetal variant rhabdomyomas have been described in the postauricular region of young children and the vulvovaginal region in middle-aged women. We present a case of a 15-month-old infant with a circumferential rhabdomyoma of the cricopharyngeus muscle requiring excision of the esophageal inlet and reconstruction with a free microvascular jejunal interposition graft. This case represents the youngest reported case of adult variant rhabdomyoma. The clinical, radiographic, and histologic findings of this unusual case and a review of reported cases of rhabdomyoma in the pediatric population will be presented.

Cricoid Cartilage↗