Citations

Bilateral nerve cable graft repairs were made in the sciatic nerves of Wistar rats. One group of repairs was treated locally with triamcinolone acetonide (0.5 mg), one group was exposed to the systemic effects of the drug, and one group was left untreated. Nerve regeneration was measured by nerve‐stimulated muscle twitch strength, as well as several electrophysiologic parameters of the compound action potential conducted through the graft. Results suggest that nerve regeneration through an autogenous graft is significantly improved by local treatment with triamcinolone acetonide. Further studies are indicated to determine appropriate dosage necessary to maximize the beneficial local effects.

From 1966 through 1983, 408 patients underwent primary removal of an acoustic neuroma at the Mayo Clinic. Of these, 21 had preoperative pure tone hearing levels of 25 dB hearing loss or better at 500, 1000, and 2000 Hz, which for this study was defined as normal pure tone hearing. Fourteen patients (67%) had dysequilibrium and 13 (62%) had subjective hearing impairment. Nystagmus was the most common physical finding. Five patients (23%) had completely symmetric pure tone hearing levels through all frequencies tested. The mean speech discrimination score was 90%. Mean tumor size was 2.4 cm. Brain stem evoked response audiometry was the most helpful of the special tests in the evaluation of these patients with normal pure tone hearing levels. Our results suggest that 5% of patients with acoustic neuromas have normal pure tone hearing levels. A careful history, a thorough physical examination, and an appropriate selection of tests will identify these patients.

We propose an animal model from which it is possible to follow nerve‐muscle unit recovery after a nerve graft easily, consistently, and relatively inexpensively. The model is also compatible with subsequent histologic or histochemical analysis. We document the recovery of a group of animals after nerve grafting to demonstrate the flexibility of the model.

Hematoporphyrin derivative (HpD), a mixture of compounds chemically prepared from naturally occurring crude hematoporphyrin, is preferentially concentrated in neoplastic cells and produces red fluorescence when irradiated with blue‐violet light. In addition, HpD exhibits other photodynamic properties, which, in the presence of oxygen and visible light, result in cytotoxicity. Preliminary reports indicate that early, superficial carcinomas of the upper aerodigestive tract and tracheobronchial tree can be localized and treated successfully with HpD phototherapy (HpD‐PT), in which a fiberoptic bundle transmits laser light to the tumors. To assess this modality's potential for treating solid tumors, the cytotoxic effect of HpD‐PT was measured in a murine tumor model. We specifically assessed the effect of cooling on the pure photodynamic action of HpD‐PT. Adult female mice with typical mammary tumors received interstitial phototherapy 24 hours after HpD was given intraperitoneally. Light from an argon‐dye laser was delivered through an optical fiber, along with simultaneous cooling from a cryosurgical probe, for 15 minutes. After being cooled with a cryosurgical probe, tumors were excised 48 hours after treatment and the necrotic area was measured. The results indicate that cooling enhances the tumoricidal action of HpD‐PT.

Fifty patients who underwent nasal septal reconstruction for anterior septal deformities were examined preoperatively and postoperatively with anterior mask rhinomanography. A high degree of correlation was found between the reduction in nasal resistance after operation and the patients' subjective assessment of improvement. Those patients who improved subjectively had a mean decrease in nasal resistance of 1.2 cm H2O/L/sec, whereas those patients who indicated no improvement had a mean increase in nasal resistance of 0.2 cm H2O/L/sec.

Posterior mask rhinomanometry was used to measure nasal resistance during exercise and hypercapnia in 10 healthy adult volunteers. Exercise was produced by peddling a stationary bicycle at three loads. Hypercapnia was produced by breathing O2 mixtures containing 5%, 6%, and 8% CO2. The results showed that (1) nasal resistance decreases linearly as expired CO2 levels and exercise levels increase, (2) minute ventilation increases linearly as expired CO2 levels and exercise levels increase, and (3) nasal resistance varies inversely with minute ventilation during both hypercapnia and exercise. The constant relationship between nasal resistance and minute ventilation during hypercapnia and exercise suggests that nasal resistance is regulated by the respiratory center to match the level of respiratory demand.

To define the relationship between central control of upper airway muscles and respiratory muscle function, the electromyographic responses of the dilator nares muscles to stimulation of chemoreceptors and pulmonary receptors were studied in six anesthetized dogs. Only at maximal levels of hypoxia was the inspiratory activity of the dilator nares significantly increased. Hypercapnic stimulation increased the inspiratory activity with each incremental increase in CO2. Pulmonary stretch receptor stimulation produced by lung inflation inhibited dilator nares activity. Pulmonary irritant receptor stimulation by intravenously administered histamine increased dilator nares activity, as did pulmonary J receptor stimulation by the intravenous administration of capsaicin.

Nasal secretory activity was measured in seven dogs in response to topical stimulation by histamine and methacholine. The methacholine response was blocked by atropine but not by chlorpheniramine. The histamine response was blocked by chlorpheniramine but not by atropine. These results suggest that there are two independent mechanisms of nasal secretion in the dog.

From 1978 to 1981, 151 patients with nasopharyngeal carcinoma (NPC) were enrolled in a prospective, collaborative study of North American patients, most of them white. Thirty‐seven had World Health Organization (WHO) type 1 tumors, and 114 had WHO types 2 and 3 tumors. The anti‐Epstein‐Barr virus (EBV) profile of elevated antibody titers directed against viral capsid antigen and early antigen was seen in 85% of the patients with WHO types 2 and 3 tumors but in only 16% of the patients with WHO type 1 tumors. Geometric mean titers tended to be higher in higher stages of the disease in several staging systems. Low antibody‐dependent cellular cytotoxicity at diagnosis appears to reflect a poorer prognosis, and the determination of antibody titers by this assay may prove to be useful for identifying persons in whom recurrent disease is likely to develop after conventional therapy. Anti‐EBV titers can aid in diagnosis and treatment planning in patients with NPC, particularly those with occult primary NPC.