Search PubMed⌕ Search

Biomedical subjects

Craig A Buchman

Publications and source records attributed to Craig A Buchman.

27 records · Page 2Linked to original sources
PubMed2003

Dose-response relationship of topically applied mitomycin C for the prevention of laser myringotomy closure.

OBJECTIVE: We sought to determine a dose-response curve for topical mitomycin C when used to prolong the patency of laser-assisted myringotomies. STUDY DESIGN AND SETTING: Bilateral myringotomies were performed using the argon laser in 40 guinea pigs with normal ears. Pledgets with (0.05, 0.2, 0.4, or 2.0 mg/mL) mitomycin C were applied topically. Monitoring consisted of weekly or biweekly otomicroscopy. RESULTS: As in previous studies, all saline-treated myringotomies closed by day 7. By day 14, all myringotomies (100%) in the 0.05 mg/mL group were closed. By contrast, all myringotomies (100%) remained patent in the 0.2 and 0.4 mg/mL treatment groups, and 56% of the myringotomies remained patent in the 2.0 mg/mL group at day 14. By day 56, all myringotomies were closed in the 2.0 mg/mL group, 5 (50%) myringotomies were patent in the 0.4 mg/mL group, and 1 (11%) myringotomy was patent in the 0.2 mg/mL group. The study was terminated on day 84 (12 weeks). At that time, only the 0.4 mg/mL group had patent myringotomies (n = 3; 30%). The highest dose (2.0 mg/mL) of mitomycin was significantly associated with otorrhea. Otorrhea also appeared to be associated with earlier myringotomy closure. CONCLUSION: There is a dose-response curve for topical mitomycin C when used for prolonging myringotomy patency in doses up to 0.4 mg/mL. Higher doses do not appear to prolong patency and are associated with greater otorrhea, suggesting middle ear toxicity.

Administration, Topical↗
PubMed2003

Influenza A virus infection of human Schwann cells in vitro.

OBJECTIVES: Sudden sensorineural hearing loss, vestibular neuronitis, vocal fold paralysis and Bell's palsy have been associated with a viral etiology, due to the infection of nerve cells. The goal of this research was to ascertain whether Schwann cells can support infection with human influenza A virus and thereby represent a plausible alternative site for virus-host interaction. Viral infection of Schwann cells may lead to secretion of inflammatory mediators, leukocyte recruitment, demyelination and nerve damage. MATERIAL AND METHODS: Cultured human Schwann cells were exposed to human influenza A virus. Infection was assayed at various times post-inoculation (0, 24, 48 and 72 h) using light microscopy, immunocytochemistry and influenza A virus-specific reverse transcriptase polymerase chain reaction (RT-PCR). A group of unexposed cells served as controls. RESULTS: Following exposure to the virus, vacuolization, cellular expansion and detachment from the dish were seen as early as 24 h post-inoculation. The exposed cells demonstrated positive immunocytochemical staining for influenza A virus antigen at 24, 48 and 72 h. Using RT-PCR, a sharp rise in influenza A virus-specific mRNA was detected. CONCLUSIONS: Human Schwann cells can be infected with human influenza A virus. Further studies will assess the inflammatory response in this model.

Cell Transformation, Viral↗
PubMed2002

Revision ossicular reconstruction with the titanium Kurz prosthesis.

OBJECTIVE/HYPOTHESIS: One European multicenter study has reported favorable outcomes after ossicular reconstruction with the titanium Kurz prosthesis. At the time of this study, however, no study has analyzed its outcomes when used for reconstruction after prior failure with another implant (revision reconstruction). The study reports our experience with the titanium Kurz prosthesis for revision ossicular reconstruction. STUDY DESIGN: A retrospective review was made of all revision ossicular reconstructions at our institution from October 1998 to September 2001. METHODS: Seventeen cases were reviewed. Patients were divided into two groups: patients who underwent revision ossicular reconstruction with the Kurz prosthesis and patients who underwent revision ossicular reconstruction with another prosthesis (the "other" group). Audiograms were reviewed and air-bone gaps were calculated for each patient. RESULTS: The average postoperative air-bone gap after Kurz revision was 15.6 dB, a statistically significant improvement over the average postoperative air-bone gap from the "other" revision group (P =.022). CONCLUSION: The titanium Kurz prosthesis has been an effective implant at our institution for revision ossicular reconstruction. Future research should focus on a prospective, randomized trial comparing the Kurz prosthesis with other prostheses currently in use.

Adolescent↗
PubMed2002

Sensory auricular branch of the facial nerve.

GOAL: To better describe the anatomy of the sensory auricular branch of the facial nerve. BACKGROUND: Clinical experience and the medical literature suggest that the facial nerve supplies sensory fibers to the external auditory canal and pinna. The anatomic distribution of these fibers remains poorly defined. METHODS: Ten cadaveric temporal bone dissections with photographic documentation, two clinical cases, and histologic examination of a candidate nerve fiber were collected. RESULTS: The anatomic distribution and histologic confirmation of a facial nerve branch coursing through the posterior wall of the external auditory canal is described. Mean (+/-SD) measurements along the mastoid segment of the facial nerve from the short process of the incus and chorda tympani nerve origin to the auricular branch origin were 11.6 +/- 1.4 mm (range 9-13 mm) and 3.9 +/- 3.0 mm (range 0-8 mm), respectively. Sacrifice of this nerve in a patient resulted in posterior external auditory canal and inferior conchal bowl hypesthesia. CONCLUSION: The anatomy of a facial nerve branch coursing through the external auditory canal is presented. The anatomic and functional findings of this study suggest that this nerve represents an auricular sensory branch. Understanding these anatomic details may help in identifying the main trunk of the facial nerve in surgery, preventing postoperative external auditory canal hypesthesia, as well as understanding the significance of Ramsay-Hunt Syndrome and Hitselberger's Sign.

Adult↗
PubMedDate not supplied

Nasal and otologic effects of experimental respiratory syncytial virus infection in adults.

PURPOSE: Upper respiratory tract viral infections continue to cause substantial patient morbidity and complications including sinusitis, otitis media, and pneumonia. This study was conducted to more clearly define the extent and frequency of nasal and otologic effects of respiratory syncytial virus infection in healthy adult volunteers. MATERIALS AND METHODS: Thirty-two healthy, susceptible adult volunteers were cloistered for a 9-day period. During this time, subjects underwent nasal inoculation with respiratory syncytial virus. Monitoring included daily self-assessment of general health, as well as nasal and otologic symptoms. Objective measurements of nasal and otologic function included expelled nasal secretion weight, saccharin-dye mucociliary clearance, sonotubometry, tympanometry, and physical examination. A nasal lavage was done each morning, and fluids were submitted for viral detection. Twenty-one days after viral inoculation, all subjects had convalescent blood samples drawn for assay of virus-specific antibody titres. RESULTS: Eighteen subjects (56%) became infected with the challenge as determined by either viral shedding (47%) or antigen detection (41%) from the nose or a 4-fold rise in virus-specific antibody titer (34%). Infected subjects more frequently reported adverse nasal (congestion, rhinorrhea) and general symptoms (fever, malaise, illness). By day 6, only 46% of infected subjects had normal middle ear pressure (> -100 mm H2O). Nasal secretion also increased substantially after infection. No patterned changes in mucociliary clearance or sonotubometry occurred, and no subjects developed otitis media. CONCLUSIONS: Nasal inoculation of healthy, susceptible adult volunteers with respiratory syncytial virus results in detectable infection in only about half of the subjects challenged. Infected subjects experience substantial symptoms and signs of a viral upper respiratory tract illness. As in our previous studies using rhinovirus and influenza A virus, respiratory syncytial virus disrupted the maintenance of normal middle ear pressures. These findings provide further support for the relationship between viral upper respiratory tract infections and otitis media.

Adolescent↗
PubMedDate not supplied

Management of labyrinthine fistulae in chronic ear surgery.

The appropriate management of labyrinthine fistulae has been debated in the literature for years. After several recent cases of labyrinthine fistulae at our institution, a review of the published data regarding hearing outcome with fistula management was undertaken. Results of this critical review were presented at departmental grand rounds. The grand rounds presentation, data and discussion are presented to better illuminate the topic of labyrinthine fistula management.

Adult↗
PubMedDate not supplied

X-linked stapes gusher: CT findings in one patient.

A 31-year-old male patient presented with progressive mixed hearing loss since birth. A stapedectomy was attempted and was unsuccessful because of perilymph gushing. CT of the temporal bones showed bulbous dilatation of the fundi of the internal auditory canals and absence of the bone plates separating them from the base of the cochleas. This unusual abnormality was found after the attempted stapedectomy and explains the clinical findings. The findings in male patients are fairly typical X-linked congenital deafness.

Adult↗