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Biomedical subjects

M M Paparella

Publications and source records attributed to M M Paparella.

At least 145 records · Page 8Linked to original sources
PubMed1980

Permeability of the middle ear to staphylococcal pyrogenic exotoxin in otitis media.

Middle ear permeability after instillation of staphylococcal pyrogenic exotoxin was studied in each of 12 cats, 6 of them with otitis media induced by obstructing their eustachian tubes. This is the first report that there is passage of toxin to the perilymph, cerebrospinal fluid and blood not only in diseased ears, but also in normal controls, 25 min and 12 h after exposure of the middle ear cavity and round window membrane to toxin. The data suggest a pathophysiological explanation for the association of otitis media and sensorineural hearing loss and/or endolymphatic hydrops; potentially both entities can be caused by exotoxins. It also documents the extraordinary capabilities of movement of staphylococcal exotoxin.

Animals↗
PubMed1980

Ototoxicity of propylene glycol in experimental animals.

The ototoxicity of antibiotics given either systemically or topically has been recently recognized. However, the ototoxicity of topically applied alcohols and other solvents used as vehicles for drugs has not been well recognized. One of the most common solvents, propylene glycol, was chosen for this study, and this agent in various concentrations was instilled into the middle ear of guinea pigs and chinchillas for various periods of time. Its effect on the function of the cochlea was studied as well as the histopathologic changes in the temporal bones. Deterioration of the cochlear microphonics and the endocochlear direct current potential was found. A 10 per cent solution applied for six days caused a reduction in the cochlear microphonics. Fifty per cent or stronger solution always caused a reduction in the cochlear microphonics. The deterioration in the cochlear microphonics persisted one month. Dose related changes in the endocochlear potential were noted. Morphologic changes were severe and included granulation tissue in the middle ear and destruction and ossification of the auditory bulla and bony cochlea. Propylene glycol should not be used in the ear that has a perforation of the tympanic membrane.

Animals↗
PubMed1980

Silent otitis media.

There is a traditional view that chronic otitis media and chronic mastoiditis must exist in the presence of a tympanic membrane perforation. Based on a human histopathological study of 123 temporal bones with chronic otitis media out of 333 temporal bones with all forms of otitis media pathology, only 24 patients (36 ears) had symptoms of otological disease recorded on their charts and only 19.5% of these had an associated tympanic membrane perforation. Unsuspected findings of chronic otitis media (active or inactive) are occasionally confirmed at exploratory tympanotomy. Such quiet chronic pathological findings in the middle ear have occurred in association with endolymphatic hydrops and cochlear end organ lesions suggesting the possibility that silent chronic otitis media may help explain sensorineural hearing loss, vertigo, and tinnitus for certain patients. We put forth the hypothesis that clinically undetectable silent otitis media in neonates and infants might help explain why certain children are otitis media prone. Our otopathology laboratory includes 111 ears harvested from neonates and infants (average age 8 months). Histological analysis revealed normal findings in some, whereas significant numbers of others show all forms of otitis media, including purulent otitis media, chronic otitis media, serous otitis media, and mucoid otitis media, with occasional overlap of types. Clinical implications will be discussed with emphasis on silent otitis media and its relationship to the pathogenesis of otitis media and silent chronic otitis media and its possible role in causing insidious labyrinthine changes. A significant outcome of this study was the marked degree of unresolved mesenchyme in the clinically manifest otitis media group or silent otitis media group as compared to a control group. This association and role of mesenchyme is discussed relative to the pathogenesis of infantile otitis media.

Child, Preschool↗
PubMed1980

Otitis media with perforation of the tympanic membrane: a longitudinal experimental study.

Despite the high incidence and prevalence of otitis media, its pathogenesis is not thoroughly understood. In an effort to provide a better understanding of this disease, experimental animal models have been developed which corroborate the changes observed in humans. In this study a new factor was added: tympanic membrane perforation 1 week after Eustachian tube obstruction. Twelve cats were divided in 4 even groups, and sacrificed at 1 and 2 weeks, 1 and 3 months after perforation, and their temporal bones were studied. Findings revealed an early massive reaction of the mucoperiosteum with granulation and polypoidal tissue formation which filled a considerable portion of the middle ear cavity. Polypoidal changes involved the stapediovestibular joint, possibly explaining the cases of stapes fixation found at tympanomastoidectomy procedures for chronic otitis media. Cholesterol granulomas with the classic characteristics as described in humans were observed in all animals at 3 month periods. These were preceded by clefts in the effusions, at 1 month, containing red blood cells. These clefts were considered as probable precursors of cholesterol granuloma formation. The association of endolymphatic hydrops, round window membrane changes, and otitis media without purulent labyrinthitis was observed; however, it was felt that the paucity of animals precluded any definite conclusions.

Animals↗
PubMed1980

Oval and round window changes in otitis media. Potential pathways between middle and inner ear.

A longitudinal sequential study of oval and round window changes in otitis media in an experimental animal (cat) using Eustachian tube obstruction was done. Thirty-two animals were used. In this first sequential study of the oval and round windows in otitis media, the continuum of round window membrane changes from 1 day to 6 months after obstruction revealed changes to be gradual and similar to those of the mucoperiostium. These changes are suitable for changes in permeability and suggest that this membrane is a very likely pathway from the middle to the inner ear. Bony fistulas were not observed and the oval window remained essentially unchanged in time, thus they were not considered routes into the inner ear. Other possible routes are discussed.

Animals↗
PubMed1979

Infiltration of the tensor tympani and stapedius muscles in otitis media. An experimental study in the cat.

A longitudinal sequential study of otitis media was done in an experimental animal (cat) using eustachian tube obstruction. Fifty animals were used. Cellular infiltration of the tensor tympani and stapedius muscles was studied in a continuum from day 1 to 6 months after inducing otitis media. We observed that there is infiltration of the connective tissue of both muscles in otitis media, and that the cellular changes follow the same pattern as that seen in the mucoperiostium and the round window of the middle ear, although to a lesser degree. In this first report of sequential changes in middle ear muscles in otitis media, clinical implications of these findings are discussed.

Animals↗
PubMed1979

Endolymphatic hydrops and otitis media.

Clinical observation of patients with fluctuant sensorineural hearing loss following or occurring with chronic otitis media led to the hypothesis that endolymphatic hydrops can result from chronic otitis media. Illustrative case reports are described. This hypothesis resulted in a temporal bone study of 560 cases in which 109 temporal bones demonstrated the presence of hydrops and 194 evidenced otitis media. Seventy-five cases demonstrated both otitis media and hydrops, of which 20 cases were selected for more detailed histopathological study. An interesting finding was the presence of apical hydrops in every case of the latter group. Statistical interpretation of this data helped rule out a coincidental or chance occurrence. A discussion of this clinical relationship included the significance of subclinical (silent) otitis media as a possible cause of endolymphatic hydrops.

Adult↗
PubMed1979

Air caloric testing in otitis media. (preliminary studies).

On certain occasions it becomes important to evaluate vestibular function in a patient with otitis media. The potential application of the air caloric test in evaluating such patients was examined. Patients with unilateral otitis media before and after surgery were studied to answer certain clinical questions. More questions were raised than answers provided. The preliminary conclusions from this study are: 1. Patients with tympanostomy tubes or small perforation of one ear may show a caloric response in the perforated ear equal to that of the intact ear. 2. Patients with a large tympanic membrane perforation on one side may show hyperactive caloric responses on the perforated side. 3. Patients with a moist ear may show inverted horizontal nystagmus to warm air caloric testing. This applies to patients with a large perforation or mastoidectomy cavity. 4. Patients with a dry open mastoid or fenestration cavity are likely to show a hyperactive caloric response on the side of previous surgery, accompanied by vegetative symptoms. This size of the cavity appears to be less important than the presence of the cavity per se. 5. Patients may be safely tested in the early postoperative period.

Air↗
PubMed1978

Lactate dehydrogenase as a measure of inflammation in experimental otitis media.

A reliable animal model for acute otitis media due to Streptococcus pneumoniae was used to study the accumulation of lactate dehydrogenase (LDH) in middle ear effusion during acute pneumococcal otitis media and after penicillin treatment. The findings indicate that LDH levels rise in the middle ear effusion during the early phase of acute infection and decrease as the infection resolves over time. Penicillin treatment affects the natural course of infection by resolving most visible signs of inflammation and by sterilizing the middle ear. However, once middle ear infection was established, penicillin treatment did not reduce the elevated levels of effusion LDH, suggesting that inflammation persists after sterilization of infected middle ears.

Animals↗
PubMed1978

Mastoiditis and brain hernia (mastoiditis cerebri).

Ten patients with brain hernia occurring as an insidious complication of chronic mastoiditis coincidentally discovered at the time of surgery are described. Four had previous surgery, six did not. A history of trauma was othwise absent. Cerebrospinal fluid otorrhea did not occur. Our method of management is described. Pathology and pathogenesis are discussed. Three patients had pedunculated brain hernias, while seven had diffuse (fungoid) herniation. Granulation tissue appeared as an important part of the disease process. These may represent abortive attempts at brain abscess formation since the widespread use of antibiotics. Pacchionian bodies may also play a role in the pathogenesis.

Adult↗
PubMed1978

Ménière's disease in children.

Approximately 3% of all patients with Meniere's disease are in the pediatric age group. These children require extensive evaluation. A history of physical or acoustic trauma should be sought and an allergic work-up should be obtained. A search for metabolic disturbances and identification of inflammatory disorders is also necessary. If a treatable etiology is identified, specific therapy should be directed toward its control. If, after careful evaluation, the etiology remains obscure, non-specific therapy should be instituted in an effort to alleviate the symptomatology of Meniere's disease. Surgical decompression of the endolymphatic sac and drainage into the mastoid cavity results in relieving the symptoms, particularly vertigo, and appears to be efficacious in patients who have failed diligent attempts at medical therapy.

Age Factors↗