PubMed Health⌕ Search

Biomedical subjects

R A Weatherly

Publications and source records attributed to R A Weatherly.

11 recordsLinked to original sources

Mucosal swabs detect HPV in laryngeal papillomatosis patients but not family members.

Seven patients, aged 2-7 years, with active recurrent respiratory papillomatosis (RRP) attending the University of Michigan Pediatric Otolaryngology Clinic were studied to determine if human papillomavirus (HPV) is harbored in sites of the upper aerodigestive tract other than in the laryngeal papilloma itself. We also determined if close family members had detectable virus in their oral cavities. Noninvasive swabs of buccal mucosa, posterior pharynx, nasal vestibule, and tonsillar pillar of patients, as well as buccal mucosa and posterior pharyngeal swabs of family members were studied. Swabs of the patients' papillomas served as the positive controls. HPV was detected using polymerase chain reaction (PCR) amplification and Southern hybridization techniques. Six of seven patients had detectable HPV in papilloma and endolaryngeal swabs. Four were HPV type 6, and two were HPV type 11. The patient whose swab was negative for HPV was found to be biopsy negative for papilloma 3 weeks after a single laser excision which was performed 6 months prior to the endolaryngeal swab. HPV types 16, 18 and 31 were not found in any of the patients. No swabs from other sites in patients or family members were HPV positive despite the presence of adequate DNA in the swabbed material for successful amplification of beta-actin sequences. The absence of HPV (other than in the papilloma itself) in the upper aerodigestive tract of patients and caregivers is consistent with the absence of reported cases of horizontal transmission to siblings or other family members. The findings are also consistent with the conventional view that juvenile respiratory HPV is transmitted vertically from vaginal condylomas in the mother.

Blotting, Southern↗

Use of internal bioabsorbable PLGA "finger-type" stents in a rabbit tracheal reconstruction model.

OBJECTIVES: To design and develop a biodegradable tracheal stent that can be used internally to stabilize and support surgically reconstructed airways. DESIGN: In vitro mechanical and degradative properties of 80:20 poly(D,L-lactide-co-glycolide) (PLGA) "finger-like" stents were determined. The stents were then tested in vivo in rabbits that underwent anterior patch tracheoplasties with fascia lata grafts. Comparisons were made between a control group and an internal stent group for stridor development, overall group mortality, reconstructed airway lumen size, and histological findings. SUBJECTS: Twenty-five New Zealand white rabbits. RESULTS: The average dry modulus for the internal stents was 6800 kPa. All of the internal stents cracked by 4 weeks in buffer solution. Significant mass loss was not noted in vitro until after 5 weeks in buffer solution. By 14 weeks, the stents were nearly 100% degraded. The attrition rate for the control group was 23% compared with 17% for the experimental group. The stridor rate for the control group was also higher at 38% compared with 17% for the stented group. The stented rabbits had a significantly smaller average stenosis (23%) across the entire reconstruction site than the control group (34%) (P<.05). CONCLUSION: Biodegradable PLGA stents degrade in a predictable fashion and have a statistically significant effect in augmenting anterior patch tracheoplasties with fascia lata grafts in rabbits.

Animals↗

Biodegradable external tracheal stents and their use in a rabbit tracheal reconstruction model.

OBJECTIVES/HYPOTHESIS: To design and develop an external biodegradable tracheal stent for use in airway reconstructive surgery. STUDY DESIGN: Experimental model. METHODS: Biodegradable external tracheal stents were fabricated from polyglycolic acid and poly(D,L-lactide-co-glycolide) (85:15). In vitro studies were performed to analyze the mechanical properties and degradative characteristics of these stents. Then the stents were tested in vivo in an anterior tracheal reconstruction model in New Zealand white rabbits. RESULTS: The average dry modulus for the external stents was 1,800 kilopascal (kPa). All of the external stents cracked by 4 weeks in buffer solution. Significant mass loss was not appreciated until after 10 weeks in solution, but by 20 weeks the stents were nearly 100% degraded. In the in vivo portion of the study, the attrition rate for the control group was 23.1% versus 50% for the external stent group. The stridor rate was approximately 38% for both groups Of the rabbits that survived the entire 3 months of the study, the stented group, when measured by a balloon catheter method, had more patent airways than the control group, with an average stenosis of 27.8% versus 47.2%, respectively (P < .05). However, more accurate postmortem cast measurements of the internal airways did not confirm this. CONCLUSIONS: The external biodegradable tracheal stent employed in this study degraded in a predictable fashion and may provide a new method to augment surgical reconstruction of the anterior tracheal wall.

Absorbable Implants↗

Pediatric myofibromatosis of the head and neck.

OBJECTIVES: To examine the clinical and pathological features of pediatric myofibroma of the head and neck and to discuss the challenges in diagnosis and treatment. DESIGN: A retrospective search of pathology department and clinical records to identify patients with myofibroma and a retrospective review of English-language medical publications. SETTING: Academic medical center. PATIENTS: Thirteen pediatric patients (aged from birth to 8 years old) diagnosed as having myofibroma of the head and neck. RESULTS: Nine of 13 patients were cured with conservative surgical excision. Four patients (31%) had recurrence, requiring multiple surgical procedures. One third showed spontaneous regression clinically or by histological examination. The clinical course did not parallel the histological appearance, as high cellularity and mitotic figures were commonplace among the specimens. A misdiagnosis of malignancy was not unusual in this series, as 3 patients had an initial diagnosis of fibrosarcoma, which on review was revised to myofibroma. CONCLUSIONS: Myofibromatosis is a distinct disorder among the great number of fibrous proliferations occurring in infants and children, with a particular predilection for the head and neck region. These lesions should be clearly distinguished from conventional adult-type fibromatoses (desmoid tumors), which are more aggressive. Most patients have solitary lesions that respond well to conservative surgical excision, whereas a few of these lesions behave more aggressively, requiring several surgical procedures for the management of recurrent or persistent tumor. Many of these lesions show spontaneous regression, suggesting that lesions not affecting vital functions, resulting in growth anomalies, or demonstrating rapid aggressive growth may be managed conservatively.

Biomarkers, Tumor↗

Apparently new syndrome of sensorineural hearing loss, retinal pigment epithelium lesions, and discolored teeth.

We report on a family with early-onset sensorineural hearing loss, abnormal retinal pigment epithelium granularity, accumulation of creamy-white lesions at the level of the retinal pigment epithelium particularly superior to the arcade, and selective discoloration (brown) of molars or canine deciduous teeth that follows an apparent autosomal recessive inheritance pattern. This appears to be a new syndrome that can be distinguished from the known otodental, oculo-acoustic and flecked retina syndromes by the occurrence of distinct dental and ocular abnormalities.

Child, Preschool↗

Tracheal schwannoma presenting as status asthmaticus in a sixteen-year-old boy: airway considerations and removal with the CO2 laser.

A 16-year-old with clinical features of atypical asthma is presented, with a description of the workup leading to the diagnosis of an intratracheal mass. The mass was visualized with a flexible fiberoptic bronchoscope, then surgically removed through a rigid bronchoscope using a CO2 laser. We believe this is the first report of resection using this technique. A discussion of tracheal neurilemmomas (schwannoma) is included. This case reinforces the age-old adage that "not all that wheezes is asthma."

Adolescent↗

Pharmacokinetics of kanamycin in the developing rat.

The developing rat is hypersensitive to aminoglycoside ototoxicity during the period of anatomical and functional development of the cochlea. Toxicity is expressed only after a few days of treatment when kanamycin is given during the most sensitive period for production of ototoxicity (postnatal days 11-20). In contrast, when the drug is administered after the 20th postnatal day, the same dose and duration of treatment do not produce an ototoxic effect. Only after prolonged treatment (e.g., > or = 20 days) is there an observed effect. We characterized the pharmacokinetics of kanamycin in the serum of 12- and 25-day-old rats and observed a greater than 2.5-fold increase in elimination half-life in the 12- versus 25-day-old rat. The longer duration half-life of kanamycin in younger rats may explain the hypersensitivity of immature mammals to aminoglycoside ototoxicity.

Analysis of Variance↗

Sensitive developmental periods for kanamycin ototoxic effects on distortion-product otoacoustic emissions.

The developing rat is hypersensitive to aminoglycoside toxicity, which is expressed early on as a destruction of outer hair cells (OHC). In the current study, distortion-product otoacoustic emissions (DPOAE), which specifically measure the micromechanical activity of OHCs, were used to assess functional effects of administering a regimen of kanamycin to three groups of neonatal rats representing discrete postnatal developmental periods. In this manner, pigmented rats were treated at postnatal days 1-10, 11-20, and 21-30. A series of input-output (I/O) functions obtained for the 2f1-f2 DPOAE during the post-treatment period indicated that detection thresholds were significantly elevated for the animals treated on postnatal days 1-10 and 11-20, with the greatest elevations observed at the higher test frequencies.

Analysis of Variance↗

cis-platinum ototoxicity in children.

Despite the recognized ototoxicity of cis-platinum, a clinical outline for the audiologic evaluation of patients receiving this drug has not been clearly defined. In a practical approach to this problem, the audiograms of 48 pediatric patients referred for monitoring during planned cis-platinum therapy were reviewed. Eleven patients tested with auditory brain-stem response (ABR) audiometry demonstrated several limitations of this modality. Fourteen children underwent initial ABR testing followed by at least two pure-tone audiograms. The remaining 23 patients had their hearing evaluated by pure-tone audiometry only. Various factors such as patient age, cis-platinum dosage, and cranial radiation exposure were analyzed for apparent effect. Younger patients tended to be more susceptible to audiologic changes with the administration of cis-platinum. The proportion of patients who demonstrated a hearing loss increased with successive dosing as did the severity of the hearing loss. Prior exposure to cranial radiation was strongly linked to the development of hearing loss following cis-platinum therapy. Guidelines are presented regarding the use of clinical audiometry in the screening of these pediatric oncology patients.

Adolescent↗

Experience with anterior cricoid split for difficult neonatal extubation.

The anterior cricoid split has been used as an alternative to tracheotomy in neonates who have been difficult to extubate. The procedure is described in detail. We review our experience with eight patients who underwent an anterior cricoid split, and we have correlated success with preoperative data in an attempt to establish criteria for patient selection.

Cricoid Cartilage↗