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Biomedical subjects

B F McCabe

Publications and source records attributed to B F McCabe.

At least 145 records · Page 8Linked to original sources
PubMedDate not supplied

Interferon and laryngeal papillomatosis. The Iowa experience.

Preliminary findings are presented from an ongoing clinical trial of 19 patients with moderate-to-severe respiratory papillomatosis. The patients were treated with partially purified human leukocyte (alpha) interferon; after treatment periods ranging from 6 weeks to 12 months, six had no residual disease, seven had minimal residual disease, four had moderate disease not requiring rescue laryngoscopies, and two had not responded to treatment. No patient had to be removed from the study because of drug toxicity. Although these appear to be among the best results in the literature to date, we do not know how long treatment will be required.

Adolescent↗
PubMedDate not supplied

Vascular loop as a cause of vertigo.

A vascular loop in the internal auditory canal pressing upon the vestibular nerve was found in a series of eight patients with episodic vertigo and severe motion intolerance. All patients had failed medical and surgical therapy for vestibular Meniere's disease, which this syndrome closely mimics. A vestibular nerve resection or section medial to the vascular loop produced relief of symptoms in all patients, but one patient required a second operation. We have no test or study to reliably diagnose this syndrome preoperatively. The history appears to be the best indicator to date.

Aged↗
PubMedDate not supplied

Labyrinthine fistula in chronic mastoiditis.

A series of 79 otic capsule fistulae occurring in 792 consecutive cases of chronic mastoiditis undergoing mastoidectomy was analyzed. The incidence (10%) is the same as in other large series, the primary difference being the location of the fistula. In all series cited, 90% of fistulae were in the lateral semicircular canal whereas in this series the comparable incidence was 75%. The 20 (25%) fistulae located in areas other than the lateral semicircular canal enabled us to document a method of "reading" the fistula test preoperatively to establish its precise location. Eye responses to the test and the fistula site were entirely consonant with the physiology of the vestibular system. The location of the fistula, in other words, can be reliably predicted by the eye movement. Clinicopathologic correlates are cited.

Chronic Disease↗
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Audiological results with two single channel cochlear implants.

We tested six patients with single channel cochlear implants on several tests from the Minimal Auditory Capabilities battery and the Iowa Cochlear Implant Tests. All patients were able to discriminate some everyday sounds and to identify the number of syllables in the words presented. Five patients were able to identify speaker sex reliably. Surprisingly, some patients had difficulty discriminating between a modulated noise and a voice or between a question and a statement or identifying the accented word in a sentence. On several audiovisual tests, an improvement was observed for the sound plus vision condition compared to the vision only condition. This was particularly true for sentence tests, but was not uniform across patients or across tests.

Adult↗
PubMedDate not supplied

Supraglottic jet ventilation for laser surgery of the larynx in children.

To investigate the efficacy and safety of supraglottic jet ventilation for laser surgery on the larynx, ten studies were performed in seven children scheduled for laser excision of juvenile laryngeal papillomata. The children were anesthetized using halothane, nitrous oxide, fentanyl 3 micrograms/kg, and a succinylcholine infusion. After the Leonard-Jako laryngoscope was in place, jet ventilation with 70% nitrous oxide in oxygen was begun through a 12-gauge Medicut intravenous cannula inserted in the right-hand light channel of the laryngoscope. Tracheal, inspired, and end-tidal oxygen, nitrous oxide, nitrogen, and carbon dioxide were determined by mass spectrometry simultaneously with arterial blood gases. Oxygen and carbon dioxide levels were always within normal limits, the end-tidal to arterial differences averaging 50 +/- 9 and 2 +/- 1 (SEM) mm Hg, respectively. Room air entrainment averaged 32 +/- 2%. The end-tidal nitrous oxide averaged 39 +/- 2%. The advantages of this technique are that it leaves the larynx completely free for the surgeon and it eliminates the possibility of endotracheal tube ignition. Supraglottic jet ventilation for this surgical procedure was determined to be effective and relatively safe.

Anesthesia, Inhalation↗
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Middle cranial fossa acoustic neuroma excision: results and complications.

The middle cranial fossa surgical approach has been used for the removal of acoustic neuromas in 43 patients at the University of Iowa since 1974. Hearing was maintained in 50% of patients with tumors 1.5 cm or less outside the porus acusticus. Postoperative hearing, facial nerve function, and complications were similar to reports using the suboccipital or retrosigmoid approach to preserve hearing for this size tumor. The character of the tumor appears to dictate the postoperative outcome rather than the surgical approach.

Adult↗
PubMedDate not supplied

Three-year experience of treating recurrent respiratory papilloma with interferon.

This paper presents the 3-year follow-up of the original 19 patients with recurrent respiratory papilloma treated with exogenous alpha human leukocyte interferon (alpha-IFN) at the University of Iowa. Two patients were dropped from the study because of poor patient compliance, and one was lost to follow-up. After approximately 1 year of alpha-IFN treatment, five patients were clear, and the rest continued to have disease: seven mild, two moderate, and two severe. A second course of alpha-IFN was administered to eight patients, all of whom had a decrease in the volume of the papilloma. The reduction in anatomic distribution was variable. During the observation period all patients either cleared (50%), improved (25%), or continued with severe disease (25%). In summary, the response of recurrent respiratory papilloma to alpha-IFN therapy is dramatic in some patients and slight in others.

Clinical Trials as Topic↗
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Side effects and toxicity of interferon in the treatment of recurrent respiratory papillomatosis.

Twenty-six patients with recurrent respiratory papillomatosis have received interferon administered according to one or more of five experimental protocols currently ongoing or completed at the University of Iowa. Short-term side effects following interferon administration were common and included fever, headache, chills, fatigue, myalgias, and nausea. Two patients experienced neurotoxicity manifested as somnolence, confusion, or petit mal type or grand mal type seizures. Preliminary data show evidence for some growth retardation in patients receiving long-term interferon therapy. Laboratory evidence of toxicity in the form of decreased WBC, RBC, and platelet counts occurred in five patients, and increased liver enzymes occurred in 16 patients. Neither cardiovascular nor renal toxicity was noted.

Acute Disease↗
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Complications of laser surgery for recurrent respiratory papillomatosis.

During an 8-year period, 66 patients with recurrent respiratory papillomatosis underwent 890 laser microlaryngoscopy procedures. A retrospective analysis of immediate and delayed complications occurring with laser microlaryngoscopy in the treatment of these patients revealed that complications secondary to anesthetic technique and laser methodology were remarkably low (0.3%). Delayed complications of tissue injury (36% of pediatric patients and 17% of adult patients) were more frequent and included anterior glottic webbing, interarytenoid scarring and arytenoid fixation, vocal fold fibrosis, and generalized endolaryngeal glottic stenosis. All patients were evaluated by direct visualization and recording at the time of the operative procedure, as well as by review of intraoperative photographs. A smaller group of patients underwent analysis of voice recordings and laryngeal stroboscopy. The frequency and severity of tissue injury was higher in the patients with more severe disease who underwent multiple operative procedures.

Adolescent↗
PubMedDate not supplied

The role of photoplethysmography in the prediction of the experimental flap survival.

A standard photoplethysmography, modified to differentiate between arterial and venous vasculature in skin tissue, has been used to measure arterial supply in 100 unipedicle skin flap in 25 pigs. A datum transform from a light intensity scale to a relative arterial blood density scale has been introduced and empirically labeled the vascular coefficient (VC). Statistical analysis of the VC data shows a significant difference between necrotic and surviving flap group mean data as early as 24 hours. Additional analysis in which a normal ogive was fitted to the sample VC data distributions suggests that statistically significant predictions of the probability of eventral flap necrosis can be made using VC measurements obtained immediately postoperatively. It is concluded that the modified photoplethysmograph, in conjunction with the VC data transform constitutes a usable measuring technique for skin flap viability prediction in the experimental animal.

Animals↗
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An alternative approach to the pterygopalatine fossa by removing the mandible and immediately replacing it.

A case is presented with a child with a desmoid tumor of the pterygopalatine fossa in which approximately a third of the mandible including the condyle was removed for exposure. The trimmed mandibular segment was then returned to position with a fascia cap over the condyle and intermaxillary fixation was instituted. The graft was followed by serial roentgenogram over five years. The graft took completely, grew with the patient, and resulted in normal dental occlusion and normal mandibular excursion.

Bone Neoplasms↗
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Epidermoid carcinoma of the floor of the mouth: surgical therapy vs combined therapy vs radiation therapy.

A retrospective analysis of 103 selected patients with floor-of-mouth epidermoid carcinoma compared the effectiveness of surgical therapy alone vs planned preoperative radiation combined therapy vs irradiation therapy. All three treatment methods appeared equally effective in irradicating stage I and II disease. Stage III floor-of-mouth epidermoid carcinoma was similarly controlled by either surgical therapy or combined therapy. Irradiation therapy alone was markedly inferior in treatment of stage III disease. Stage IV disease was poorly handled by any of the treatment methods. Histologic factors, tumor characteristics, tumor spread, nodal status, and staging did not appear in the majority of cases to significantly influence treatment selection or survival or both.

Adult↗
PubMedDate not supplied

Regeneration of the recurrent laryngeal nerve.

Ten dogs underwent exploration and section of the right recurrent laryngeal nerve. A segment was removed and both stumps were ligated. Reoperation at three months and again at 15 months revealed neural regeneration through the ligated site and reconstitution of the distal nerve in seven of the eight dogs surviving the 15-month period. This strong regenerative capability of the recurrent laryngeal nerve may explain recurrences of spastic dysphonia after nerve section. It is recommended that patients be advised of the possibility for return of the spasms. Investigators should always note whether the recurrent laryngeal nerve has regained stimulability in reporting results of experimental laryngeal paralysis and reinnervation.

Animals↗
PubMedDate not supplied

Meniere's disease at the University of Iowa: 1973 to 1980.

The goals of treatment in Meniere's disease are hearing preservation and control of vertigo. Controversy abounds with regard to the most expeditious and efficacious means of attaining these goals. Low-salt diet, diuretic therapy, endolymphatic-mastoid shunt, and middle cranial fossa vestibular neurectomy are all modes of treatment employed for Meniere's disease at the University of Iowa. This review of our experience from 1973 to 1980 summarizes the efficacy of each therapeutic option.

Endolymphatic Sac↗
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Neuronal habituation in the vestibular nuclei of the cat.

This is a study of the effects of repeated angular acceleration on the activity of vestibular nuclei units in anesthetized and in conscious cats. The experimental animals were subjected to trains of repeated and consecutive constant acceleration-deceleration ramps (4-8 degrees/sec2). In a few cases nystagmus was recorded along with extracellular unit activity. The effect of stimulus repetition on vestibular neuronal activity consisted of one of the following: 1. No change in response. 2. Progressive response decline. 3. An initial maintenance of a constant response level throughout the first part of the stimulus paradigm, followed by a progressive decline. 4. An initial gradual enhancement of response followed by a progressive decline. This classification is based on results of polynomial and non-linear broken-line regression analyses. Categories 3 and 4 were found predominantly in units recorded from conscious cats. The majority of neurons recorded from anesthetized cats that exhibited response changes upon stimulus repetition manifested a progressive response decline. The response decline in anesthetized cat units was usually on a faster time scale than in conscious cats. Correlations between unit response modification patterns and simultaneously recorded nystagmus were mostly of a moderate degree.

Acceleration↗