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Biomedical subjects

S D Gray

Publications and source records attributed to S D Gray.

At least 37 records · Page 2Linked to original sources
PubMed1999

Severe pharyngeal stenosis treated with inferiorly based sternocleidomastoid myocutaneous flap.

Severe pharyngeal stenosis is a debilitating condition associated with apnea and dysphagia. Treatment options include local flaps and free mucosal grafts. We present 2 cases of severe stenosis. apparently from adenotonsillectomy, that failed more conservative repairs. Both were treated successfully with a sternocleidomastoid myocutaneous flap rotated in through a lateral pharyngotomy. No further treatment has been required. Technical considerations and operative planning are discussed.

Adenoidectomy↗
PubMed1998

Age- and gender-related elastin distribution changes in human vocal folds.

The composition of the lamina propria in human vocal folds has been shown to affect vocal performance. Elastin plays a significant role in the biomechanical effects of the lamina propria. We obtained 19 larynges from the state medical examiner from subjects whose cause of death was unrelated to the trachea and laryngeal regions. The sample contained male and female subjects in the infant, adult, and geriatric age groups. We stained the vocal folds for elastin with Verhoeff's elastic tissue stain and studied them with use of an image analysis system configured for light microscopy. Distributions of elastin were measured from superficial to deep within the lamina propria (from epithelium to vocal muscle). These elastin distributions were then compared with the use of statistical software. The data showed that there was an increase in elastin content from the infant through geriatric stages. No gender-related differences were found. Infant folds had about 23% of the elastin found in adults, and geriatric subjects had about 879% of the elastin found in adults. Both of these results were statistically significant (p < 0.05). The distributions were consistent with previous observations that the lamina propria is a layered structure with most of the elastin present in the intermediate layer. This layer was larger in geriatric subjects than in adult and pediatric subjects. We observed that the fiber diameter appeared to be larger in geriatric subjects (this observation is currently being verified with electron microscopy) whereas smaller, spiraled fibers appeared in pediatric subjects.

Actin Cytoskeleton↗
PubMed1998

Does botulinum toxin alter laryngeal secretions and mucociliary transport?

Localized botulinum toxin injection disrupts cholinergic transmission and has potential to cause focal dysautonomia. Mucociliary transport and laryngeal secretions are thought to be mediated in part by autonomic, cholinergic transmission. We questioned whether patients who receive Botox injection for adductor spasmodic dysphonia (ADSD) report postinjection symptoms possibly related to altered mucociliary clearance or laryngeal secretions. Medical histories, audiotaped interviews, and symptom ratings were retrospectively examined for 29 patients with ADSD who were followed after one or more Botox injections. Patients had received bilateral, percutaneous Botox injections of 2.5 units using an EMG-guided approach. One or more weeks after injection, four patients reported either burning, tickling, or irritation of the larynx/throat, excessive thick secretions, or dryness. Symptoms recurred with subsequent injections in two patients and were not associated with swallowing difficulty. These symptoms are consistent with, but not diagnostic of, the known effects of botulinum toxin on cholinergic, autonomic transmission.

Adult↗
PubMed1998

Analysis of cellular location and concentration in vocal fold lamina propria.

Studies have shown that the lamina propria plays an important role in voice production. Recent studies have analyzed the presence of different proteins and quantified their extent in the lamina propria, but no similar study has yet been done on cellular makeup. The distribution of three different cell types in the lamina propria of 22 human vocal folds was studied. These types are fibroblasts, macrophages, and myofibroblasts. The roles of these cells in the extracellular matrix are described. Their distribution was quantified with use of an image-analysis system. We arbitrarily divided the lamina propria into five sections (each representing 20% of the lamina propria) and compared cell numbers among these sections. Gender comparisons were also made. From these studies it is evident that the cellular distribution in the lamina propria is not uniform. Fibroblasts were more abundant in the deepest 20% of the lamina propria (p < 0.008), myofibroblasts were more abundant in the most superficial 20% (p < 0.016), and in the 36% of our samples that contained macrophages in the lamina propria, there was a significantly higher number of macrophages in the first 20% of the lamina propria (p < 0.003). The only significant gender difference was that women had twice as many macrophages in the most superficial 20% of the lamina propria as men (p < 0.05). The higher myofibroblast activity in the first 20% could indicate that the superficial layer is a region of constant repair. The increased number of macrophages in the superficial layer likely indicates an inflammatory response to inhalants (because of the role of macrophages in the inflammatory response and the fact that only 36% of the patients showed any macrophage activity at all).

Actins↗
PubMed1997

Acute knee trauma: how many plain film views are necessary for the initial examination?

OBJECTIVE: To determine whether anteroposterior (AP) and lateral views of the knee are equivalent to four views in acute fracture detection. DESIGN: Three musculoskeletal radiologists retrospectively interpreted the plain film knee examinations of each patient, establishing ground truth for the presence or absence of a fracture. Cases were presented to four masked senior radiology residents twice--once as a two-view study and again as a four-view study--with 4 weeks separating the two reading sessions to minimize recall bias. Sensitivity, specificity, and diagnostic performance were calculated. PATIENTS: Ninety-two patients presenting to the emergency department with acute knee trauma were evaluated with at least a four-view plain film examination. RESULTS AND CONCLUSIONS: Mean sensitivity for fracture detection using four views (85%) was significantly higher than that using two views (79%). Mean specificity and receiver operating characteristic curve areas were not significantly different using two or four views. Four views are more sensitive than AP and lateral views alone in detection of acute knee fracture.

Acute Disease↗
PubMed1997

Imaging of the knee. Current status.

This article reviews the variety of imaging modalities that are currently being used to evaluate the knee. Nuclear scintigraphy is discussed with emphasis on prosthesis abnormalities. Sonography is discussed with regard to the evaluation of popliteal masses. The uses of computed tomography, especially in the evaluation of the tibial plateau fracture, are discussed, and the role of fluoroscopy, computed tomography, and sonography in image-guided needle procedures are reviewed. Emphasis is placed on the role of MR imaging in knee imaging, with attention to internal derangements, bursal and capsular pathology, and other assorted intra- and extra-articular disorders. The focus of this article is to review the wealth of information that may be obtained by using these imaging modalities.

Arthrography↗
PubMed1997

The intermediate layer: a morphologic study of the elastin and hyaluronic acid constituents of normal human vocal folds.

The lamina propria of vocal folds are important in voice production. We evaluated the morphologic features of elastin and hyaluronic acid, two important constituents of the lamina propria. Thirty normal human vocal folds were obtained from patients dying of traumatic causes without vocal fold injury. These tissues were immediately prepared for histologic and ultrastructural examination by standard methods. For specific study of the ultrastructure of the layers of the lamina propria, six vocal folds were divided horizontally through the midplane of the lamina propria. We found that the elastin composition of the vocal folds is variable, the largest amount being seen in the midportion on elastin-van Gieson (EVG) staining and ultrastructural evaluation. The superficial layer of the lamina propria contains fewer large elastin fibers. In this region, we found that elastin was predominantly composed of elaunin and oxytalan, which stain poorly with EVG. Using computer-assisted image analysis, we quantified the differences in elastin composition between the layers. The amount of elastin varied between men and women, and these differences could not be accurately measured by the methods employed. Hyaluronic acid was abundant especially in the midportion of the lamina propria and was significantly more abundant in men than women on quantification. The significance of these observations in normal vocal folds is discussed.

Adult↗
PubMed1997

Frequency and effects of teachers' voice problems.

This study compared the frequency and effects of voice symptoms in teachers to a group of individuals employed in other occupations. Teachers were more likely to report having a voice problem (15 vs. 6%), having 10 specific voice symptoms, and having 5 symptoms of physical discomfort. They averaged almost 2 symptoms compared with none for nonteachers. Likewise, teachers were more likely to perceive that a voice problem would adversely affect their future career options, had done so in the past, and was limiting their current job performance. Over 20% of teachers but none of the nonteachers had missed any days of work due to a voice problem. These findings suggest that teaching is a high-risk occupation for voice disorders and that this health problem may have significant work-related and economic effects.

Adult↗
PubMed1997

Overlapping thin-section fast spin-echo MR of the large vestibular aqueduct syndrome.

PURPOSE: To evaluate a high-resolution, thin-section fast spin-echo MR imaging technique of the inner ear to identify the large vestibular aqueduct syndrome seen on temporal bone CT scans. METHODS: We retrospectively reviewed the temporal bone CT scans of 21 patients with hearing loss and enlarged bony vestibular aqueducts by CT criteria. High-resolution fast spin-echo MR imaging was then performed on these patients using dual 3-inch phased-array receiver coils fixed in a temporomandibular joint holder and centered over the temporal bones. MR imaging included axial and oblique sagittal fast spin-echo sequences. The diameter of the midvestibular aqueduct on CT scans and the signal at the level of the midaqueduct on MR images were measured on axial sequences, then compared. High-resolution MR imaging with the same protocol was performed in 44 control subjects with normal ears, and similar measurements were taken. RESULTS: The average size of the enlarged bony vestibular aqueduct on CT scans was 3.7 mm, and the average width of the signal from within the enlarged aqueduct on MR images was 3.8 mm. Statistical analysis showed excellent correlation. MR images alone displayed the enlarged extraosseous endolymphatic sac, which accompanies the enlarged aqueduct in this syndrome. Five ears in three patients with enlarged bony vestibular aqueducts on CT scans showed no evidence of an enlarged endolymphatic duct or sac on MR images. An enlarged endolymphatic sac was seen on MR images in one patient with a bony vestibular aqueduct, which had normal measurements on CT scans. MR imaging alone identified a single case of mild cochlear dysplasia (Mondini malformation). In the 88 normal ears studied, the average size of the endolymphatic sac at its midpoint between the common crus and the external aperture measured on MR images was 0.8 mm (range, 0.5 to 1.4 mm). In 25% of the normal ears, no signal was seen from within the vestibular aqueduct. CONCLUSION: Thin-section, high-resolution fast spin-echo MR imaging of the inner ear is complementary to CT in studying patients with the large vestibular aqueduct syndrome, as MR imaging better displays the soft tissue and fluid of the membranous labyrinth.

Adolescent↗
PubMed1996

Voice disorders in children.

Pediatric patients with voice or speech problems usually should receive a team assessment in which communication between the pediatrician or primary care physician, the otolaryngologist, and speech pathologist occurs. Although speech or voice problems may prompt an otolaryngologic evaluation, the voice or speech problem simply may be the manifestation or symptom of a larger or more complex disease process. Whether that is the case of hypernasal speech, eventually leading to the diagnosis of velocardiofacial syndrome, or bilateral vocal fold paralysis, eventually leading to the diagnosis of hydrocephalus, it is apparent that patients with speech or voice disorders may eventually require multidisciplinary evaluation. The outlook for children with speech and voice difficulties is better than ever. Recent equipment advances, such as flexible laryngoscopy, video stroboscopy, and nasometry, for detection, evaluation, and management of speech problems have created a better environment than ever existed for care of these problems. Much research is being performed in the area of pediatric voice and speech problems. The National Institute of Deafness and Communicative Disorders and the National Institute of Dental Research have funded and currently fund many projects in these areas. Many pediatric hospitals now have voice or speech disorder clinics in which multiple disciplines are brought together to evaluate children with these problems. Children benefit best when speech and voice problems are managed in an interdisciplinary setting when necessary and by professionals who have experience and training in these specialized pediatric problems. Given the local, professional, and national resources that are expended toward recognition and treatment of speech disorders in children, it is truly a tragedy when those resources cannot be brought to assist children with voice and speech problems. Although voice and speech problems usually are recognized by parents or concerned family members, this task may rest on the pediatrician or other primary caregiver.

Child↗
PubMed1996

Na+, K(+)-pump activity and skeletal muscle contractile deficits in the spontaneously hypertensive rat.

Skeletal muscles in an animal model of genetic hypertension (the spontaneously hypertensive rat. SHR) exhibit significant deficits in contractile performance. These deficits appear to be unrelated to the rise in blood pressure. Slow-twitch soleus muscles show a decrease in specific muscle tension and a reduced resistance to muscle fatigue during prolonged contractile activity. We tested the hypothesis that the reduced fatigue resistance occurs as a consequence of an impaired ability to maintain or restore Na+ and K+ balance across the sarcolemma during repeated contractions. This may result from a genetically based increase in the Na+ permeability of SHR muscles, coupled with a reduction Na+, K+ pump capacity as the animals mature. Soleus muscles in adult SHR exhibit a significant increase in intracellular Na+ content and a significant decrease in intracellular K+ content at rest. B6RB+ uptake in Na(+)-loaded hypertensive muscles is 45% less than predicted from the number of ouabain-binding sites available. Activation of Na+, K+ pumps using adrenaline or insulin produces a significantly smaller hyperpolarization in hypertensive soleus than in control muscles. Control soleus muscles are hyperpolarized for at least 10 min after a 4 min period of high-frequency activity, but hypertensive soleus muscles remain at resting polarity. Nonetheless, the number of ouabain-binding sites in hypertensive muscle is significantly greater than in control soleus, and binding affinities are similar. This apparent deficit in pump capacity might lead to a greater and more prolonged increase in extracellular K+ during repetitive contractions,and an associated decline in tension. Recently, we have been able to prevent the abnormal decrease in hypertensive soleus fatigue resistance by long-term treatment (8 weeks) with the Ca2+ blocker amlodipine. The therapy prevented or reversed the contractile deficits, but did not restore the responsiveness of the Na+, K+ pump to hormonal stimulation. The current data suggest that both a reduction in Na+, K(+)-pump capacity and changes in Ca2+ distribution play a role in the development of contractile deficits in hypertensive muscles.

Animals↗
PubMed1996

Regeneration and revascularization of a nerve-intact skeletal muscle graft in the spontaneously hypertensive rat.

Skeletal muscles in hypertensive subjects develop an increased resistance to insulin that reduces their ability to incorporate glucose and synthesize glycogen. Insulin is an anabolic hormone in muscle, and muscle insulin receptors bind the growth factor, insulin-like growth factor I (IGF-I), an important contributor to muscle development and regeneration. An increase in insulin resistance in hypertensive subjects might produce muscle atrophy and weakness or limit regenerative growth after injury. Regenerative muscle growth was assessed in 24-to 26-wk-old spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats by subjecting extensor digitorum longus (EDL), an ankle flexor, to a nerve-intact graft procedure. The procedure produces extensive muscle fiber and capillary degeneration, but has little effect on the muscle nerve. Muscle morphology and contractile function were examined in intact and regenerating EDL at 21, 42, and 63 days postgraft. Muscle revascularization was assessed histologically at the same time points. Severe established hypertension did not prevent the reestablishment of a structurally normal capillary network in injured muscles. SHR muscle fiber regeneration and maturation, however, were significantly depressed compared with WKY grafts. The reduced regenerative recovery of SHR EDL in adult animals with severe hypertension does not appear to be due to a failure to restore the muscle nerve or capillary network, but may reflect a reduced anabolic response to insulin or IGF-I.

Animals↗
PubMed1996

Immunocytochemical study of proteoglycans in vocal folds.

We evaluated the proteoglycan composition of normal vocal folds using immunocytochemical techniques. Frozen sections of 14 normal cadaveric vocal folds were obtained within 12 hours of death and sectioned immediately. Vocal fold sections were stained with antibodies against keratan sulfate, chondroitin sulfate, heparan sulfate proteoglycan (HSPG), decorin, and hyaluronate receptor. We found that the lamina propria has diffuse staining of fibrillar components with keratan sulfate and decorin. Intense staining was observed in the vocal ligament area with keratan sulfate. The HSPG was localized to be basement membrane zone. Chondroitin sulfate, HSPG, and hyaluronate receptor were detected in the cytoplasm of interstitial cells with immunocytochemical characteristics of macrophages. The keratan sulfate distribution suggests that fibromodulin may be significant in normal vocal folds. Production of HSPG and probably versican occurs in macrophages and fibroblasts in the lamina propria.

Chondroitin Sulfate Proteoglycans↗
PubMed1995

Unilateral endoscopic supraglottoplasty for severe laryngomalacia.

OBJECTIVE: To evaluate the effectiveness of unilateral supraglottoplasty in the treatment of children with severe laryngomalacia. DESIGN: Retrospective study. SETTING: Pediatric tertiary referral center. PATIENTS: Eighteen children with severe laryngomalacia. Indications for surgical intervention were obstructive apnea, failure to thrive, cyanosis, and/or cor pulmonale. INTERVENTIONS: Unilateral carbon dioxide laser removal of redundant supraglottic tissue (supraglottoplasty). OUTCOME MEASURES: Evaluation of relief of symptoms, need for subsequent contralateral procedure, and incidence of complications. RESULTS: Three patients required treatment of the opposite side at a later date. There were no complications. Obstructive apnea and weight gain improved in all. CONCLUSIONS: Unilateral supraglottoplasty can be used to treat severe laryngomalacia in most patients. A small percentage of patients will subsequently require a contralateral procedure. Unilateral supraglottoplasty may have less risk of complications than bilateral supraglottoplasty.

Acute Disease↗
PubMed1995

Clinical results of pharyngeal flap surgery: the Iowa experience.

Sixty-five patients with cleft palate, with or without cleft lip, who received previous pharyngeal flap surgery for chronic velopharyngeal dysfunction in our department, were examined for velopharyngeal status, speech production patterns, and evidence of nasal airway obstruction. Of the 65 subjects, 54 (83.1 percent) showed velopharyngeal function within normal limits, 43 (66.1 percent) showed normal or near-normal speech production, and 58 (89.2 percent) reported snoring sometimes or often. Of the 58 reporting snoring, electrocardiogram (ECG) data for 33 were examined for evidence of right ventricular hypertrophy. Only one (3 percent) of the 33 showed such possible indication. We conclude that by our methods, pharyngeal flap surgery is an effective treatment for velopharyngeal dysfunction. After surgery, patients may report symptoms of nasal airway obstruction during sleep but are not expected to show ECG changes in cardiac function resulting from oxygen deprivation.

Adolescent↗
PubMed1995

Benign pathologic responses of the larynx.

Benign laryngeal lesions were examined for patterns of injury indicated by deposition of fibronectin and collagen type IV. An immunoperoxidase technique was used to compare 33 fresh or paraffin-embedded tissues with regard to their staining of monoclonal antibodies directed against fibronectin and collagen type IV. Two types of patterns were recognized. One pattern showed intense fibronectin deposition in the superficial layer of the lamina propria, often coupled with basement membrane zone injury, indicated by thick collagen type IV bands. The other pattern showed rare basement membrane zone injury and very little fibronectin deposition. The first pattern correlated more with nodules, the second pattern more with Reinke's edema and some polyps. A better understanding of the effects of excessive deposition of structural glycoproteins such as fibronectin and of abnormal proteoglycan deposition may lead to a better characterization of vocal fold disease and its causation and, ultimately, better treatment.

Adult↗
PubMed1995

Advanced techniques in magnetic resonance imaging in the evaluation of the large endolymphatic duct and sac syndrome.

The purpose of this report is to compare temporal bone computed tomography (CT) to high-resolution magnetic resonance (MR) imaging using a novel thin-section fast spin echo (FSE) pulse sequence in identifying and characterizing patients with large vestibular aqueduct syndrome. Sixteen patients with sensorineural hearing loss and a CT diagnosis of large vestibular aqueduct(s) underwent high-resolution fast spin echo magnetic resonance imaging with dual, 3-in phased array receiver coils centered over the external auditory canals. Magnetic resonance imaging parameters included axial and oblique sagittal fast spin echo with an effective slice thickness of 1 mm contiguous. Thirty-eight patients with 76 normal inner ears who underwent MR imaging using this technique had their endolymphatic duct measured. MR alone identified the enlarged endolymphatic sac seen along with the large endolymphatic duct in all cases. Three cases (five inner ears) with enlarged bony vestibular aqueducts on CT showed no evidence of endolymphatic duct or sac enlargement on MR. MR alone identified a single case of mild cochlear anomaly in conjunction with an enlarged endolymphatic duct and sac. In the normal population the size of the normal endolymphatic duct at its midpoint measured from 0.1 to 1.4 mm. Thin-section, high-resolution fast spin echo MR imaging of the inner ear may be superior to CT in the evaluation of patients with the large vestibular aqueduct syndrome.

Adolescent↗