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Biomedical subjects

T V McCaffrey

Publications and source records attributed to T V McCaffrey.

At least 37 records · Page 2Linked to original sources
PubMed1996

Acoustic measurement of subglottic stenosis.

A device that determines cross-sectional area (CSA) of the airway by acoustic reflections (Hood, Inc) was used to measure subglottic area. Airway models were made from Plexiglas rings with known internal dimensions similar to clinically encountered stenoses of various lengths and diameters. Acoustic measurements of airway area were made and compared to actual CSA. There is a strong correlation between CSA measured acoustically and the actual area of simulated stenoses. However, when the CSA of the stenosis was < 0.64 cm2, the signal was impaired, resulting in overestimation of the stenotic CSA. In simulated stenoses with a CSA of < 0.38 cm2, acoustic measurement of the CSA beyond the stenotic segment was unreliable. Determination of the origin of stenosis was accurate with this method. The CSA of cadaver airways was also measured acoustically. The CSA 2.0 cm below the glottis of normal airways in males ranged from 1.28 to 2.74 cm2 and in females 0.87 to 1.43 cm2, with means of 2.16 and 1.09 cm2. It appears that acoustic measurement of CSA of subglottic stenosis is a feasible clinical technique that yields dimensions of the airway in situations in which direct measurements are impossible. It was suggested that this technique be used for assessment of subglottic stenosis and evaluation of the efficacy of treatment of subglottic stenosis.

Culture Techniques↗
PubMed1996

The roles of muscarinic receptor subtypes in modulation of nasal ciliary action.

Muscarinic receptors are believed to play an important role in modulation of ciliary action in respiratory system. We studied the in vitro effect of methacholine, a beta-methyl ester of acetylcholine, on the ciliary beat frequency (CBF). Adenoid explants were cultured in Minimum Essential Medium Eagle (MEM). CBF was determined using microphotometry. Methacholine (10(-6) M) increased CBF a maximum of 10.34 +/- 0.42% (p < 0.001). The non-selective muscarinic antagonist atropine (10(-6) M) significantly inhibited the ciliostimulatory effects of methacholine (p < 0.001). To characterize the muscarinic receptor subtypes in nasal mucosa, the selective M1-, M2- and M3-muscarinic antagonists pirenzepine dihydrochloride (PZ), gallamine triethiodide (gallamine), and 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP) were used prior to addition of methacholine, PZ and 4-DAMP, at concentrations of 10(-6) to 10(-8) M, significantly inhibited the ciliostimulatory effects of methacholine (p < 0.0001). There was no significant inhibition of methacholine-induced ciliostimulation by gallamine (p > 0.3). Our study showed that ciliostimulation by methacholine in human upper airway mucosa involves M1- and M3- muscarinic receptor subtypes, but not the M2-receptor subtype. The identification of the muscarinic receptor subtypes and intracellular signalling mechanisms involved in CBF modulation will permit the selection appropriate of pharmacological agents for treating the cholinergic symptoms of rhinitis.

Atropine↗
PubMed1995

Management of the recurrent laryngeal nerve in suspected and proven thyroid cancer.

Vocal cord paralysis occurs with and without infiltration of the recurrent laryngeal nerve. Patients with no paralysis may have recurrent laryngeal nerve infiltration. We studied 262 patients with invasive thyroid carcinoma and an additional 480 patients that we operated on, and we offer an approach to the management of the recurrent laryngeal nerve during surgery for suspected or proven thyroid cancer. Because complete excision of papillary carcinoma with resection of the recurrent laryngeal nerve did not improve survival over incomplete excision, we recommend incomplete excision of papillary carcinoma infiltrating a functioning recurrent laryngeal nerve with postoperative I-131 and thyroid-stimulating hormone suppression. We observed (1) lymphoma and Reidel's thyroiditis causing paralysis with infiltration of the recurrent laryngeal nerve with recovery of function, (2) benign and malignant nodules causing paralysis without infiltration of the recurrent laryngeal nerve with recovery of function, and (3) infiltration of the recurrent laryngeal nerve without paralysis in lymphoma, Graves' disease, and thyroiditis. In surgery for a suspicious nodule with paralysis, identify the recurrent laryngeal nerve, resect it if it is infiltrated by carcinoma, and preserve it if not infiltrated or if infiltrated by any pathology besides carcinoma.

Adolescent↗
PubMed1995

Open slope quotient: a new glottographic parameter.

This study introduces a new objective measurement of the vibratory pattern termed the open slope quotient (OSQ). This parameter is based on the maximum slope of the photoglottographic waveform during glottal opening. Using an excised canine larynx model, the electroglottographic and photoglottographic waveforms, sound intensity, and subglottic pressure were recorded as vocal fold tension; glottic width and airflow rate were systematically varied. Multiple regression analysis of the data from nine larynges revealed OSQ to be inversely related to glottic width (p < 0.001) and vocal fold tension (p < 0.001) and directly related to glottic resistance (p < 0.001) and subglottic pressure (p < 0.001). The OSQ was better correlated with glottic width, subglottic pressure, and glottic resistance than speed quotient. OSQ is related to the velocity of vocal fold opening and laryngeal resistance. OSQ may also be related to vocal fold stiffness.

Animals↗
PubMed1995

Signal transduction mechanisms in substance P-mediated ciliostimulation.

Substance P is a neuropeptide released by afferent neurons in the respiratory tract during inflammatory reactions. It produces effects on blood vessels, bronchial smooth muscle, nasal glands, and respiratory cilia. We studied the in vitro effect of substance P on the ciliary beat frequency of human adenoid explants and its mechanism of action. Substance P was added to cultured adenoid at concentrations of 10(-10), 10(-8), 10(-6), and 10(-4) mol/L. Ciliary beat frequency was determined with phase-contrast microscopy and microphotometry. Substance P increased ciliary beat frequency a maximum of 11.9% +/- 3.8% (p < 0.01). Diclofenac (10(-6) mol/L) significantly blocked the ciliostimulatory effects of SP (p < 0.022), indicating that prostaglandin synthesis is an intermediate step in the action of substance P on ciliary beat frequency. The L-arginine analogs, NG-nitro-L-arginine methyl ester and NG-monomethyl-L-arginine, inhibit nitric oxide synthesis from L-arginine. L-Arginine analogs (10(-4) to 10(-2) mol/L) inhibited the effect of substance P (p < 0.02 at the higher concentration). This inhibition was reversed by adding L-arginine, demonstrating that nitric oxide production is a required step in substance P-induced ciliostimulation. Substance P stimulates ciliary activity in human nasal mucosa as a result of secondary production and release of endogenous prostaglandins and nitric oxide. It is likely that inflammatory disease processes that stimulate release of substance P and subsequent prostaglandin and nitric oxide production modify mucociliary transport. Pharmacologic modification of substance P and its second messengers may eventually permit regulation of this important defense mechanism and control of neurogenic inflammation.

Adenoids↗
PubMed1995

The effect of botulinum toxin type A injection on compound muscle action potential in an in vivo rat model.

Serial measurements were performed on the compound muscle action potential (CMAP) amplitude and the force generated by the rat lower hind limb flexors to investigate the time course of intramuscular injections of botulinum toxin type A (BOTOX). Thirty animals were used in this in vivo rat model. CMAP amplitude and muscle force were measured at predetermined intervals for 28 weeks. Compound muscle action potential amplitude and force declined markedly the first 5 to 7 days after injection of BOTOX but recovered in a near linear manner. The response magnitude and recovery rate were dose-dependent. Recovery of CMAP amplitude preceded recovery of muscle force. No clear evidence of a systemic effect on the untreated leg or a concentration effect was found. CMAP amplitude may be useful in determining optimal timing of repeat injections in treating neuromuscular disorders.

Action Potentials↗
PubMed1994

Familial paragangliomas of the head and neck.

OBJECTIVE: It has been known for some time that paragangliomas of the head and neck may be familial. Recent evidence suggests genomic imprinting is an important factor in the clinical development of these tumors. In genomic imprinting the imprintable gene is transmitted in a mendelian manner, but expression of the gene is determined by the sex of the transmitting parent. In the case of paragangliomas, the gene does not result in the development of tumors when maternally inherited. The purpose of this study was to determine if this hypothesis correctly predicted the inheritance pattern of familial paraganglioma in a large series of patients. SETTING: A retrospective review of case records of the Mayo Clinic, Rochester, Minn, a tertiary referral center, was performed for the years 1950 to 1992 to identify patients with familial paragangliomas of the head and neck. PATIENTS: A total of 38 patients with familial paragangliomas of the head and neck were identified in nine kindreds. RESULTS: Carotid body tumors were the most common paragangliomas of the head and neck (34 cases). Glomus jugulare or glomus vagale occurred in eight cases. In 16 (42%) of the patients there were multiple tumors. Surgical complications, primarily cranial nerve palsies, were more frequent for tumors larger than 5 cm in diameter. CONCLUSIONS: An autosomal dominant inheritance pattern could be shown for paragangliomas of the head and neck that was consistent with genomic imprinting. It is recommended that all individuals in kindreds with paragangliomas be screened after the age of 16 years to detect early asymptomatic tumors.

Adolescent↗
PubMed1994

Lymphoma involving the esophagus.

Fewer than 1% of all lymphomas involve the esophagus; however, lymphoma of the esophagus represents an important cause of dysphagia. This study reviewed all cases of biopsy-proven lymphoma involving the esophagus presenting at our institution between 1945 and 1992. Twenty-seven cases were identified. Three were primary esophageal lymphomas. Eleven percent of the cases presented Hodgkin's disease. Eighty-nine percent were non-Hodgkin's lymphoma. Eighty-nine percent of the patients experienced dysphagia. Eleven lymphomas (41%) were located at the gastroesophageal junction, while the other 17 were in the esophagus proper. Seven of these cases occurred at relapse. Three had mediastinal adenopathy with secondary esophageal involvement. Morbidity included tracheoesophageal fistula in 22%, and surgical repair was performed in half of these cases. Vocal cord paralysis occurred in 22%, with minimal sequelae. Esophageal stricture was present in 30%, usually necessitating dilation. The presentation, diagnosis, and management of this problem are multidisciplinary.

Adult↗
PubMed1994

Advanced giant cell granuloma: a twenty-year study.

Giant cell granuloma is a benign lesion that generally involves the mandible and maxilla. It may be locally aggressive and result in extensive tissue destruction in advanced cases. A retrospective analysis of giant cell granuloma during the interval 1970 to 1990 revealed 18 cases of advanced disease, as defined by bone destruction and a greatest dimension of 2.0 cm or more. Epidemiologic factors, physical findings, imaging studies, pathologic specimens, treatment modalities, and outcome were reviewed for each case. Eight lesions were treated by local excision and curettage, and 10 were treated by partial mandibulectomy. Five mandibular defects were reconstructed with iliac bone grafts and one with a free flap. Only one patient with maxillary giant cell granuloma who underwent curettage had regrowth of what is suspected to have been residual disease. Individualized treatment, tailoring the extent of resection to the extent of disease, provided excellent results.

Adolescent↗
PubMed1994

Surgical treatment of extracranial internal carotid artery dissecting aneurysms.

Aneurysms of the extracranial internal carotid artery (ICA) are uncommon. A significant proportion of such aneurysms are now recognized to be caused by arterial dissection. In some patients, surgical treatment may become necessary. The surgical treatment of 22 patients with spontaneous or traumatic dissecting aneurysms arising from the extracranial ICAs is reviewed. The mean age of the 7 women and 15 men was 39 years. The aneurysm arose from the proximal third of the extracranial ICA in 1 patient, from the middle third in 1 patient, and from the distal third in 20 patients. Five patients underwent cervical carotid ligation; in 13 patients, the aneurysms were resected, and the ICAs were reconstructed, and 4 patients underwent cervical-to-intracranial ICA bypasses. There were 2 postoperative strokes (9%). Facial and lower cranial nerve palsies were commonly seen after high cervical exposure, but these cranial nerve palsies were transient. There were no long-term neurological sequelae during a mean follow-up of 6.2 years. In our relatively limited experience, extracranial ICA dissecting aneurysms can be treated with acceptable morbidity using a variety of techniques. However, the indications for surgical intervention in these aneurysms remain limited.

Adult↗
PubMed1994

Factors affecting survival of patients with tumors of the anterior skull base.

Fifty-four patients with primary neoplasms of the anterior skull base were treated by craniofacial resection with curative intent. The most common tumor was esthesioneuroblastoma (24), followed by squamous cell carcinoma (10). The overall 2-year and 5-year survivals were 75% and 49%, respectively. High-grade tumors, grades 3 and 4, had a poorer prognosis. Tumor size, dural involvement, sphenoid sinus involvement, age, and sex had no significant influence on survival when examined by multivariate survival analysis. Sixteen complications were noted in the postoperative period. Cerebrospinal fluid leakage occurred in 2 patients and loss of frontal bone occurred in 4. There were no operative or perioperative deaths. Craniofacial resection permits surgical resection of the majority of anterior skull base tumors with acceptable morbidity.

Adolescent↗
PubMed1993

The effect of tissue expansion on the random flap viability and wound tensile strength of previously irradiated rabbit skin.

Tissue expansion facilitates coverage of cutaneous defects both through the generation of additional skin surface area and by increasing random flap length/width viability factors. The opportunity to apply tissue expansion techniques to head and neck defects within previously irradiated skin fields continues to increase. To study the effect of tissue expansion on the cutaneous perfusion and wound-healing capacity of irradiation-damaged skin, rabbit scalps were subjected to 5 weeks of fractionated radiation followed at 4 months by prolonged tissue expansion. Standardized random flaps were then created and reset within the expanded skin and analyzed in parallel with nonirradiated and nonexpanded control animals. Flap viability as expressed by area and mean maximum length was determined at 10 days postwounding followed by determination of wound-breaking strength. Irradiated tissues demonstrated a significantly reduced flap viability that was significantly increased by expansion. However, tissue expansion-related increases in flap length exceeded those expressed as percent of total area surviving for irradiated animals. Tissue expansion resulted in significant increases in wound tensile strength only in nonirradiated animals. These findings suggest that, compared with controls, several of the benefits of tissue expansion are less appreciable in radiation-damaged skin.

Analysis of Variance↗
PubMed1993

Functional endoscopic sinus surgery: an overview.

"Functional endoscopic sinus surgery" is a minimally invasive technique for treating chronic and acute sinusitis. It is based on the concept that most diseases of the paranasal sinuses are due to obstruction of the anterior ethmoid cells in the region of the middle meatus. With use of surgical treatment of the ethmoid sinus and endoscopic instrumentation, chronic and acute sinus disease can be managed; associated morbidity is minimal. Thus, the need for radical resection of the ethmoid sinus and the Caldwell-Luc operation has decreased. Herein the origins and anatomic basis of endoscopic sinus surgery are described, and some current applications in the management of diseases of the paranasal sinuses are reviewed.

Endoscopy↗
PubMed1993

Surgery for head and neck cancer.

During the past year, several areas of head and neck surgery have had notable refinements and advancements. In the area of early laryngeal cancer, the complementary roles of radiation therapy and surgery have been discussed, as well as refinements in endoscopic laser techniques. Issues of the incidence of nodal metastasis and the role of in-continuity versus discontinuous neck dissection in oral and pharyngeal carcinoma have been considered. Rehabilitation techniques following treatment of oral cancer using free microvascular sensate flap reconstructions have been presented. The role of free jejunal interposition and gastric pull-up for reconstruction in hypopharyngeal cancer have been discussed, as well as their compatibility with postoperative radiotherapy. Finally, the concepts for treatment of neck nodal metastases have been discussed in relation to the roles of radiotherapy, radical neck dissection, and modified neck dissection.

Head and Neck Neoplasms↗
PubMed1993

Evaluation of cefixime in the treatment of bacterial maxillary sinusitis.

The efficacy and safety of cefixime, the first oral third-generation cephalosporin, were evaluated in a multicenter clinical trial involving 118 adult patients with acute sinusitis or acute exacerbations of chronic sinusitis. Patients received a single daily dose of 400 mg of cefixime for a mean duration of 10 days; 106 patients completed a course of therapy. Clinical cure and improvement were achieved in 90% of these patients (61% cured and 29% improved). Among the patients evaluated again 2 weeks after therapy, 91% had a sustained clinical cure or improvement. Sinus exudate specimens were obtained from all patients by transantral puncture before therapy. Pathogens were isolated from 76 patients (66%), the most common pathogens being Haemophilus influenzae, alpha-hemolytic streptococci, and Streptococcus pneumoniae. Eighty-six percent of pathogens were presumed eradicated. Three patients discontinued therapy because of side effects. The most frequently reported adverse effects were gastrointestinal, with 20% of patients reporting diarrhea. Cefixime was effective in the treatment of bacterial sinus infections in adults and was well tolerated.

Acute Disease↗
PubMed1993

Transcutaneous Teflon injection for vocal cord paralysis.

In 1989, I reported a series of 19 cases of unilateral vocal cord paralysis treated by transcutaneous Teflon injection. At that time it was shown that unilateral vocal cord paralysis could be effectively treated in the office in the unanesthetized patient using a transcutaneous route of injection. Since that time, an additional 43 patients have been treated using a similar technique. The initial impression of safety and efficacy has been confirmed in this subsequent series. Several refinements in this technique have simplified its use and improved its reliability. No airway complications have been observed to date and no patients have required hospital admission. Transcutaneous Teflon injection can be considered a useful method for treatment of vocal cord paralysis in selected patients.

Adult↗
PubMed1993

Management of laryngotracheal stenosis on the basis of site and severity.

Seventy-five cases of laryngotracheal stenosis treated between 1981 and 1991 were reviewed to determine the effectiveness of surgical treatment on the basis of site and severity of stenosis. Decannulation and absence of exertional dyspnea were the criteria of successful management. The treatment methods used were endoscopic laser incision and dilatation, expansion laryngotracheoplasty, and segmental resection. Endoscopic procedures were effective in treating thin (< 1 cm) stenoses in the subglottis and trachea. Laryngotracheoplasty was most effective in treating thick stenoses of the glottis and subglottis. Tracheal stenoses were most effectively treated by segmental resections. The probability for decannulation decreased with longer narrower stenoses and with increasing clinical stage.

Adolescent↗