Ractopamine and Other Growth-Promoting Compounds in Beef Cattle Operations: Fate and Transport in Feedlot Pens and Adjacent Environments.

The current study represents a comprehensive investigation of the occurrence and fates of trenbolone acetate (TBA) and metabolites 17α-trenbolone (17α-TBOH), 17ß-TBOH, and trendione (TBO); melengesterol acetate (MGA); and the less commonly studied ß-andrenergic agonist ractopamine (RAC) in two 8 month cattle feeding trials and simulated rainfall runoff experiments. Cattle were administered TBA, MGA, or RAC, and their residues were measured in fresh feces, pen floor material, and simulated rainfall runoff from pen floor surfaces and manure-amended pasture. Concentrations of RAC ranged from 3600 ng g-1, dry weight (dw), in pen floor to 58 000 ng g-1 in fresh feces and were, on average, observed at 3-4 orders of magnitude greater than those of TBA and MGA. RAC persisted in pen floors (manure t1/2 = 18-49 days), and contamination of adjacent sites was observed, likely via transport of windblown particulates. Concentrations in runoff water from pen floors extrapolated to larger-scale commercial feedlots revealed that a single rainfall event could result in mobilization of gram quantities of RAC. This is the first report of RAC occurrence and fate in cattle feedlot environments, and will help understand the risks posed by this chemical and inform appropriate manure-management practices.

Necrotizing sialometaplasia.

Necrotizing sialometaplasia of salivary gland tissue is a benign, self-limiting disease usually confined to the minor salivary glands. To date only 49 cases have been reported. The clinical and histologic appearance may simulate squamous cell carcinoma, and unnecessary mutilating surgery may be performed if an erroneous diagnosis is made. The otolaryngologist must recognize this disease entity since it heals spontaneously and requires no treatment. Necrotizing sialometaplasia has no known premalignant potential.

Myofascial pain-dysfunction syndrome: the role of nonmasticatory muscles in 91 patients.

Ninety-one new patients with myofascial pain-dysfunction (MPD) syndrome were studied prospectively. The patients experienced aural fullness, tinnitus, vertigo, odynophagia, and headache in addition to the cardinal symptoms of otalgia, muscle tenderness, temporomandibular joint (TMJ) click, and trismus. Some nonmasticatory muscles were found to be tender as frequently as the masticatory muscles. It is proposed that MPD syndrome as seen clinically involves more than just the masticatory musculature and is a composite of several head and neck myofascial pain syndromes including tensor tympani syndrome, muscle tension headache, cervical syndrome, and hyoid syndrome.

Congenital middle ear cholesteatoma: two unusual cases and a review of the literature.

Forty-three patients with congenital middle ear cholesteatoma have been described since the first case in 1953. In these patients ten cholesteatomas were confined to the anterior mesotympanum in young children who had no ossicular damage. Involvement of the posterior mesotympanum (8 ears), meso and epitympanum (21 ears), and antrum and middle ear (7 ears) was associated with an 81% incidence of ossicular erosion in addition to other abnormalities. Anterior mesotympanic cholesteatomas were readily identified by the appearance of a white mass behind a translucent drum. The other congenital cholesteatomas had a more varied appearance with a mass and a whitish appearance each noted in about half. In almost half there was a bulging of the TM. Two new cases are reported: a 4-year-old with an extensive epi and mesotympanic cholesteatoma initially misdiagnosed as non-suppurative otitis media and a 23-year-old with the third reported case of bilateral congenital cholesteatoma.

Normal opaque cerebellopontine cisternogram.

An attempt has been made through this study to establish a tumor suspect pool of 100 patients, each one highly suspect because of a single or usually several strong clinical indicators of a retrocochlear lesion. In turn each patient has been proven tumor negative by virtue of a normal opaque cerebellopontine cisternogram. This has given us a unique opportunity to critically reassess the clinical indications of VIIIth nerve tumor from a reverse or negative viewpoint. All data from these patients has been carefully analyzed in relation to indication for opaque cisternography, clinical symptomatology, vestibular function, final etiologic diagnosis, and the associated special auditory tests, tomograph of the internal auditory canal, the associated vestibular aqueduct findings. This paper parallels our earlier study of 121 surgically proven schwannomas providing a total tumor suspect pool of 221 patients with a comparable tumor positive-tumor negative distribution.