Relations between cochlear histopathology and hearing loss in experimental cochlear implantation.

This study reviews the cochlear histology from four hearing preservation cochlear implantation experiments conducted on 73 guinea pigs from our institution, and relates histopathological findings to residual hearing. All guinea pigs had normal hearing prior to surgery and underwent cochlear implantation via a cochleostomy with a silastic-platinum dummy electrode. Pure tone auditory brainstem response (ABR) thresholds from 2 to 32 kHz were recorded prior to surgery, and at one and four weeks postoperatively. The cochleae were then fixed in paraformaldehyde, decalcified, paraffin embedded, and mid-modiolar sections were prepared. The treatment groups were as follows: 1) Systemic dexamethasone, 0.2 mg/kg administered 1 h before implantation, 2) Local dexamethasone, 2% applied topically to the round window for 30 min prior to cochlear implantation, 3) Local n-acetyl cysteine, 200 µg applied topically to the round window for 30 min prior to implantation, 4) inoculation to keyhole-limpet hemocyanin (KLH) prior to implantation, and 5) untreated controls. There was a significant correlation between the extent of the tissue reaction in the cochlea and the presence of foreign body giant cells (FBGCs), new bone formation and injury to the osseous spiral lamina (OSL). The extent of the tissue response, as a percentage of the area of the scala tympani, limited the best hearing that was observed four weeks after cochlear implantation. Poorer hearing at four weeks correlated with a more extensive tissue response, lower outer hair cell (OHC) counts and OSL injury in the basal turn. Progressive hearing loss was also correlated with the extent of tissue response. Hearing at 2 kHz, which corresponds to the region of the second cochlear turn, did not correspond with loco-regional inner hair cell (IHC), OHC or SGC counts. We conclude that cochlear injury is associated with poorer hearing early after implantation. The tissue response is related to indices of cochlear inflammation and injury. An extensive tissue response limits hearing at four weeks, and correlates with progressive hearing loss. These latter effects may be due to inflammation, but would also be consistent with interference of cochlear mechanics.

The evolving role of pharmacy benefits management firms in a managed care environment.

The next five to seven years will see a major shake-up in the pharmacy benefits management industry. A highly competitive race is underway between independent, retail pharmacy chain-sponsored and pharmaceutical manufacturer-controlled PBMs to see who will develop and monitor prescription drug efficacy protocols that reduce the total costs associated with an episode of illness.

Use and non-use of medication by sufferers of selected symptoms of depression.

The overuse of drugs as a means of alleviating stress and anxiety is thought to be characteristic of modern American society. This article addresses the problem by asking the question: given the number of people suffering from certain common symptoms, what percentage will seek relief through the use of medication? Multiple standardization is used to assess the effects of race, sex, age, marital status, and SES on the proportions of people reporting each symptom and the proportions of those who took medications, both before and after standardization for subgroup differences. More than 40 percent of the nearly 4000 adults surveyed reported some problems of sleeplessness and enervation, but when only those who reported persistent problems are examined, very few resorted to medications. The authors conclude that the U.S. is not a "pill-popping" society as depicted by the popular press.

Localization of parathyroid adenomas by cervical esophagram.

By using a standardized method of cervical esophagraphy, parathyroid adenomas were successfully localized preoperatively in 19 of 20 consecutive patients with hyperparathyrodism. Two of the 19 patients had a second adenoma which was not demonstrated. The esophagrams were performed in the frontal projection with a 105-mm camera by utilizing rapid sequential filming. Film exposure was synchronized so that roentgenograms were obtained with the esophagus maximally distended. A persistent indentation of the esophagus present on multiple films was compatible with parathyroid enlargement. Our results suggest that cervical esophagrams are useful in the preoperative localization of parathyroid adenomas.