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Biomedical subjects

G J Matz

Publications and source records attributed to G J Matz.

At least 19 recordsLinked to original sources
PubMed1990

Facial nerve monitoring in otologic surgery: clinical indications and intraoperative technique.

While identification of the intratemporal portion of the facial nerve is mandatory in most otologic surgical procedures, inadvertent instrumentation, traction, or thermal injury may still result from inaccurate delineation, purposeful avoidance, or false protection of this critical structure. Improved functional preservation of the facial nerve has been achieved in acoustic neuroma surgery through the monitoring of evoked facial electromyographic activity. This technique may also be used during otologic procedures in which facial nerve manipulation is anticipated in the management of recurrent cholesteatoma, temporal bone trauma, congenital deformity, or purposeful access for cochlear implantation. Potential indications for using facial nerve monitoring in contemporary otologic surgery are detailed through illustrative case presentations, and necessary instrumentation and techniques are briefly reviewed. Intraoperative monitoring can assist the surgeon in isolating the facial nerve when chronic inflammation, traumatic injury, or anomalous development has resulted in distortion or absence of microanatomic landmarks.

Adult↗
PubMed1990

Clinical perspectives on ototoxic drugs.

Ototoxic drugs such as salicylates, the aminoglycoside antibiotics, loop diuretics, cisplatin, erythromycin, and vancomycin are widely used in clinical practice. The most commonly used are aspirin and the aminoglycoside antibiotics. This chapter briefly discusses the pharmacology of the commonly prescribed ototoxic drugs and the doses that may result in ototoxicity. An outline for the monitoring of ototoxic drugs is presented. The role of topical ear drops as a possible cause of ototoxicity is reviewed.

Aminoglycosides↗
PubMed1990

The incisor absent rat: an animal model for the study of otosclerosis.

The incisor absent (ia) rat is introduced as an animal model for the study of otosclerosis. Previous animal models have failed to accurately reflect the dynamic nature of this disease. Auditory brainstem response testing suggested a conductive hearing loss in the incisor absent rat as compared to age-matched normal controls. The hearing loss, which was manifested during puberty, was progressive in nature up to 18 weeks of age. Microscopic dissection of the middle ear revealed bony abnormalities of the ossicles and oval window in the incisor absent rat. Scanning electron microscopy of the ossicles demonstrated bony lesions at the incudostapedial joint and stapes footplate. Histologic examination demonstrated thickened spongiotic bone involving the otic capsule and ossicles. The incisor absent rat model possesses an inheritable defect of the otic capsule and ossicles that results in a progressive conductive hearing loss. The genetically transmitted lesion appears histologically similar to otospongiosis. The bony pathology in the incisor absent rat is caused by defective osteoclasts and transplantation of bone marrow cells from normal rats to the incisor absent rats corrects the cellular abnormality. The incisor absent rat may represent the best animal model to date for the study of otosclerosis, its cause, and clinical treatment.

Animals↗
PubMed1989

Indirect videolaryngoscopy versus direct endoscopy for larynx and pharynx cancer staging. Toward elimination of preliminary direct laryngoscopy.

Thirty-nine patients with cancer of the larynx and pharynx (33 untreated and six previously treated patients) underwent tumor mapping by both direct laryngoscopy (DL) and indirect videolaryngoscopy (IVL). The examiner in each case was unaware of the findings of the other evaluation method. After definitive treatment had been carried out so that pathologic and operative information was also available, comparisons of the accuracies of the two methods of staging were made. In 32 cases, IVL provided information equal to or better than that provided by DL, and a tissue sample also could be obtained during IVL. On the basis of these findings, we conclude that aggressive, office-based IVL can guide initial treatment planning (partial or total laryngectomy versus irradiation) and patient counseling. A confirmatory DL can be performed without surprises at the time of definitive surgery, rather than as a separate procedure - a cost-effective modification of standard practice.

Biopsy↗
PubMed1986

Comparative study of ototoxicity and nephrotoxicity in patients randomly assigned to treatment with amikacin or gentamicin.

Fifty-four patients treated with gentamicin and 52 patients treated with amikacin were evaluated for nephrotoxicity and ototoxicity in a prospective, randomized, blinded comparative trail. According to our definition of nephrotoxicity (an increase in serum creatinine levels to at least 50 percent and 0.5 mg/dl above the baseline value), nephrotoxicity occurred in eight (15 percent) of the patients who were treated with gentamicin and none of the patients who were treated with amikacin (p = 0.006). Using several other definitions of nephrotoxicity, the differences in incidence between the treatment arms were not significant. Nephrotoxicity appeared to be associated with impaired baseline renal function, greater age, and the presence of bacteremia. Ototoxicity occurred in six (11 percent) of the 54 gentamicin-treated patients; auditory toxicity occurred in three patients, and toxic changes were observed in three of the 33 patients who could also be evaluated for vestibular toxicity. Similarly, ototoxicity was observed in seven (13 percent) of the 52 amikacin-treated patients; auditory toxicity occurred in four patients, and of the 34 patients who could also be evaluated for vestibular toxicity, three exhibited vestibular toxicity without auditory toxicity are one experienced vestibular effects in addition to those affecting the cochlea. We observed a modest association of ototoxicity with nephrotoxicity and with an elevated mean trough aminoglycoside serum level. The results of this study indicate that amikacin may be less nephrotoxic than gentamicin in humans; however, the broad applicability of this finding to other patient populations is uncertain.

Adolescent↗
PubMed1983

Cis-platinum.

Explore the source record for details and available documents.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1981

Aminoglycoside-induced cochlear pathology in man.

Temporal bones from five patients with hearing loss as a result of aminoglycoside treatment were examined by the method of microdissection and surface preparations, followed by celloidin embedding and serial sectioning of the modiolus. Three patients had received the newer antibiotics, gentamicin, tobramycin, and amikacin; the other two neomycin. In the cochleas from two patients of the first group there was only a small loss of hair cells, restricted to the lower end of the basal turn. The third, who had been treated with several antibiotics over a longer period of time, showed more extensive but strikingly asymmetrical patterns of degeneration in the two ears. This patient, as well as the fourth, who had received neomycin during peritoneal lavage, had numerous patchy areas of complete disappearance of Corti's organ in the basal turn, with incipient degeneration of the distal ends of the nerve fibers in adjacent portions of the osseous spiral lamina. The fifth patient, who had become deaf after prolonged treatment with neomycin by mouth, showed a complete loss of cochlear hair cells. Nerve fibers were present only in the middle and upper turns, where supporting cells remained. Midmodiolar sections showed a proportionately much greater loss of the distal than of the proximal processes of the cells of the spiral ganglion. These findings underscore once again the special hazard for the inner ear that is associated with the clinical use of neomycin, regardless of the route of administration.

Adult↗
PubMed1980

Aminoglycoside ototoxicity.

Aminoglycoside antibiotics are frequently employed in the treatment of serious infections caused by aerobic gram negative bacilli. The use of these potent antibacterial agents is limited by the risks of ototoxicity and nephrotoxicity. Aminoglycosides are excreted by glomerular filtration at a rate proportional to the serum concentration. Impaired renal excretion reduces the rate of clearance from the serum. Utilizing information about aminoglycoside pharmacokinetics, the susceptibility of infecting pathogens to aminoglycosides, and risk factors for ototoxicity, physicians can attempt to optimize the administratioin of an aminoglycoside to maximize the therapeutic efficacy and to minimize the risk of ototoxicity. Periodic assessments of renal function and of aminoglycoside levels in the serum are essential to guide therapy. The otolaryngologist and audiologist must be able to provide information about ototoxicity to medical colleagues using these drugs. They should also be prepared to evaluate and follow patients who develop sensorineural inner ear dysfunction during or after a course of therapy with an aminoglycoside antibiotic.

Adult↗
PubMed1980

Bacterial meningitis and sensorineural hearing loss: a prospective investigation.

The objectives of the present investigation are as follows: to prospectively assess the incidence of sensorineural hearing loss (SHL) associated with bacterial meningitis; to evaluate the onset and degree of SHL; and to describe the audiometric pattern. Forty-seven patients were studied otologically and audiologically. The incidence of SHL was 11%. Late onset of SHL was not observed, however, one patient demonstrated a probable progressive hearing loss. Both bilateral and unilateral hearing loss were noted. The degree of hearing loss varied from mild to profound, with no consistent audiometric pattern. Intensive follow-up on one hearing-impaired patient included temporal bone polytomograms. Obliterative labyrinthitis is detailed. Antibiotic treatment and laboratory data are evaluated. Suggestions are provided for the post-meningitic course.

Anti-Bacterial Agents↗
PubMed1979

Sequential combination chemotherapy for advanced squamous cell carcinoma of the head and neck.

Thirty-four patients with advanced squamous cell carcinoma of the head and neck have been treated with sequential combination chemotherapy consisting of Cytoxan, methotrexate, oncovin, bleomycin and adriamycin, followed by Leucovorin (COMBAL). All patients had undergone extensive prior radiation and/or surgery. All the patients had recurrent cancer. Toxicity included two deaths from drug induced pancytophenia and one from sepsis. Treatment was well tolerated and could be given in the outpatient clinic. No bleomycin pulmonary or adriamycin cardiac toxicity was seen. Results include 4 patients who achieved complete remission, objective improvement in measurable lesions in 6 others, stabilization of disease for 1 to 3 mo. in 5, and progression of disease in 13. Survival has ranged from 1 to 19+ months with a median of 10.7 mo. for patients that were evaluated. We conclude that COMBAL produces objective evidence of improvement in approximately 45% of patients with far advanced, previously treated squamous cell carcinoma of the head and neck.

Adolescent↗
PubMed1977

Comparative clinical studies of ototoxicity and nephrotoxicity of amikacin and gentamicin.

A comparative study of the oto- and nephrotoxicity of amikacin and gentamicin was carried out prospectively. Twenty-six gentamicin-treated patients and 27 amikacin-treated patients were monitored for changes in auditory and renal function during and after therapy. Thirteen of those treated with gentamicin and 20 of those treated with amikacin underwent vestibular caloric testing which could be evaluated for evidence of toxicity. In four (15.4%) of the gentamicin-treated patients, nephrotoxicity developed; no such toxicity was seen in the amikacin-treated patients. This difference may have been due to a fortuitously higher incidence of pretreatment renal impairment in the gentamicin-treated group. In two gentamicin-treated patients (7.7%), ototoxicity developed (one auditory, one vestibular), and in two amikacin-treated patients (7.4%), auditory toxicity developed. Statistical analysis of oto- and nephrotoxicity and their risk factors was not attempted because of the small numbers of patients who could be evaluated. Additional patients are being studied.

Adult↗
PubMed1976

The ototoxic effects of ethacrynic acid in man and animals.

A review of the literature was carried out to summarize the ototoxic effects of ethacrynic acid on man and animal. The effects of this drug on the electrolytes of the endolymphatic and perilymphatic systems, on the cochlear potentials and the auditory cortical-evoked responses, were reviewed. Histological animal studies determined by light and electron microscopy were described. Potentiation of this drug with previous aminoglycoside therapy was discussed. In this paper, a human case report with temporal bone findings was present in addition to the histopathological effects of this drug which were shown in a series of animals receiving this drug over a period of time. Edematous and cellular changes in the stria vascularis, especially with animals receiving large doses of the drug, were described. No permanent alterations in the cochlear potentials resulted from the long-term therapy with ethacrynic acid.

Animals↗