Biomedical subjects

Nadine P Connor

Publications and source records attributed to Nadine P Connor.

At least 19 recordsLinked to original sources

PubMed2006

Impact of conventional radiotherapy on health-related quality of life and critical functions of the head and neck.

PURPOSE: Head-and-neck radiotherapy is associated with significant morbidities. Our purpose was to document impact of morbidities by use of multiple objective measures and health-related quality of life (HR-QOL). METHODS AND MATERIALS: Ten head-and-neck cancer patients were evaluated before receiving conventional head-and-neck radiotherapy and at 1 month and 6 months after treatment. We evaluated weight, saliva production, diet, swallow function, auditory function, and HR-QOL. RESULTS: After radiotherapy, weight was reduced in 89% of subjects. Salivary function was significantly reduced and did not resolve by 6 months. Diet impairment and abnormalities in swallowing function persisted at 6 months. Perception of physical functioning was reduced after treatment, and swallowing, coughing, and dry-mouth symptoms increased. Very few changes were observed in auditory function. CONCLUSIONS: Conventional head-and-neck radiotherapy is associated with substantial functional deficits and diminished HR-QOL. Deficits reported here can serve as a baseline for comparison with results derived from new radiotherapy-treatment techniques.

Aged↗

PubMed2006

Symptoms of extraesophageal reflux in a community-dwelling sample.

OBJECTIVES: Extraesophageal reflux disease (EERD) is linked with serious and varied health concerns. The authors' goal was to determine the prevalence of EERD and the effect on health-related quality of life in adults within a large community-based sample. STUDY DESIGN: Survey study conducted in a community setting. METHODS: In the Madison, Wisconsin area, 1845 adult subjects were surveyed. Main outcome measures were frequently of GERD and laryngeal symptoms, the Medical Outcomes Trust Short Form 12 (SF-12), Voice Handicap Index (VHI), and Quality of Life in Reflux and Dyspepsia (QOLRAD) questionnaires. RESULTS: More than 66% of subjects reported either GERD or laryngeal symptoms, and 26% reported both GERD and laryngeal symptoms (which reflect symptoms commonly reported for EERD). In addition, 39% of our sample took medicine for heartburn. Forty-four percent of subjects with both GERD and laryngeal symptoms reported occasional breathing difficulties, and 38% of these subjects reported a voice disorder. Significant reductions in perceived quality of general health, digestive health, and voice-related quality of life were found in subjects with both GERD and laryngeal symptoms, in comparison with subjects manifesting each symptom group alone, or in subjects with no symptoms. CONCLUSIONS: The presence of GERD and laryngeal symptoms, and their concurrence, was identified in a substantial number of subjects. The GERD and laryngeal symptoms surveyed represent those most commonly reported for EERD. Because EERD has been linked with tissue damage and reductions in health-related quality of life, it is important to identify these persons and provide treatment before progression of the condition.

Adolescent↗

PubMed2006

Cutaneous tissue flap viability following partial venous obstruction.

BACKGROUND: Venous outflow obstruction is the most common cause of tissue failure after microvascular reconstructive surgery. If it is not recognized early, there is an increased risk of tissue damage and loss. Currently, however, there are no adequate models for the study of this clinical problem. The purpose of this study was to develop a partial congestion model for the study of skin flap physiology in response to varying levels of occluded venous outflow. METHODS: Nine mixed-breed pigs were equally divided into three experimental groups (0 percent, 20 percent, and 50 percent venous outflow) to determine the effects of varying venous outflow on cutaneous flap color, oxygen tension, and edema. A cutaneous pedicle flap model and a partial congestion system were used to observe changes in variable venous obstruction. RESULTS: Only 0 percent venous outflow resulted in progressive color change across time. In addition, 0 percent venous outflow demonstrated significantly different oxygen tension levels relative to the other groups. Twenty percent venous outflow resulted in significant edema formation relative to the other groups. The 50 percent group showed an increase in oxygen tension from the second hour of venous obstruction to the end of the experiment. CONCLUSIONS: Tissue flap color is the clinical standard on which flap health is measured. After 8 hours, only complete venous occlusion resulted in significant color change. However, physiological changes that could affect tissue flap health were noted with only partial venous occlusion, including the development of edema formation. Accordingly, subtle color change could indicate partial venous congestion and may warrant intervention by the surgeon.

Animals↗

PubMed2005

Endolymphatic sac decompression as a treatment for Meniere's disease.

OBJECTIVES/HYPOTHESIS: Endolymphatic sac decompression is a surgical treatment option for patients with medically intractable Meniere's disease. However, effectiveness is debated because published data show great variability. Outcome-based research studies are useful in incorporating the patient's perspective on the success of treatment. To further assess effectiveness of endolymphatic sac decompression, we performed a prospective study to examine both symptom-specific and general health outcomes. STUDY DESIGN: Prospective, observational outcome study. METHODS: Nineteen patients with endolymphatic sac decompression responded to symptom-specific questionnaires and the Medical Outcomes Short-Form 36 Health Survey (SF-36) before and after surgery. Follow-up ranged from 6 to 58 months with a mean duration of 50 months. RESULTS: Overall measures of physical health were significantly improved following endolymphatic sac decompression (P = .04), whereas overall measures of mental health were unchanged (P = .74). Role Physical and Social Functioning scores were significantly improved following endolymphatic sac decompression (P = .04 and P = .03, respectively). Study patients scored significantly lower (P < .05) than SF-36 normative data in 6 of 10 categories before endolymphatic sac decompression but patient scores were not significantly different from normal scores in all but one category (General Health) following endolymphatic sac decompression. The mean number of vertigo episodes was significantly reduced from an average of 8.3 times per month to an average of 2.6 times per month following endolymphatic sac decompression (P = .006). Ninety-five percent of patients (18 of 19 patients) reported improvement in symptoms (frequency, duration, or intensity) of vertigo and 37% (7 of 19 patients) reported complete resolution of vertigo. CONCLUSION: Endolymphatic sac decompression significantly improved perception of physical health, as well as symptom-specific outcomes, in patients with medically intractable Meniere's disease.

Adult↗

PubMed2005

Effect of deficits in laryngeal sensation on laryngeal muscle biochemistry.

Swallowing deficits in elderly people are significant clinical problems and may be associated with impaired pharyngolaryngeal sensation. However, the extent to which sensory innervation affects the motor system is unclear. Our purpose was to examine differences in biochemical properties of laryngeal muscles following sensory nerve ablation. We used sodium dodecyl sulfate-polyacrylamide gel electrophoresis to evaluate laryngeal muscles of young and old Fischer 344/Brown Norway rats, and rats that underwent sensory ablation via bilateral section of the superior laryngeal nerve, internal branch (SLNi), or mixed sensory-motor nerve ablation via left-sided recurrent laryngeal nerve (RLN) section. In lateral thyroarytenoid muscle, a reduction was found in the proportion of the most rapidly contracting myosin heavy chain isoform (type 2B) with SLNi section, RLN section, and aging. Section of the SLNi did not alter the proportion of any myosin heavy chain isoform within the lateral cricoarytenoid or posterior cricoarytenoid muscles, but RLN section resulted in a reduction in the proportion of type 2B. Accordingly, alteration in biochemical properties of the lateral thyroarytenoid muscle alone was demonstrated following sensory ablation. We conclude that sensory changes may affect properties of laryngeal muscles, and may thus have an impact on motor control during critical functions, such as airway protection during swallowing.

Animals↗

PubMed2005

Alterations in contractile properties of tongue muscles in old rats.

OBJECTIVES: Fatigue and weakness are well-known signs of aging that are related to sarcopenia, or loss of skeletal muscle mass, organization, and strength. Sarcopenia may affect swallowing. The tongue plays a vital role in swallowing, but there is limited knowledge regarding age-related changes in lingual muscle contractile properties. Our purpose was to determine whether alterations in tongue force, temporal features of tongue muscle contraction, and fatigability are manifested as a function of aging in old rats. METHODS: We evaluated tongue muscle contractile properties in young and old Fischer 344/Brown Norway rats. Contractions were elicited via bilateral electrical stimulation of the hypoglossal nerves. RESULTS: Maximum tongue forces and fatigability were not significantly altered in old animals, but aging was associated with significantly longer twitch contraction time and longer half-decay recovery time intervals (p < .01). CONCLUSIONS: The results indicated that old animals generated sufficient maximum tongue forces, but were slower in achieving these forces than young animals. These findings are consistent with reports of altered temporal parameters of tongue actions during swallowing in humans, and suggest that a disruption in the timing of muscle contraction onset and recovery may contribute to the altered tongue kinetics observed with aging.

Age Factors↗

PubMed2004

Therapeutic potential of growth factors for aging voice.

OBJECTIVES/HYPOTHESIS: It has been reported that in aged vocal folds, dense collagen deposition takes place and hyaluronic acid decreases in the lamina propria, which are thought to contribute to the vocal problems occurring with age (presbyphonia). To restore aged vocal folds to their younger state, it seems crucial to address these age-related lamina propria changes. Intervention that might increase hyaluronic acid and decrease collagen would appear to be a potentially useful approach. The present study examined the effects of growth factors on aged fibroblasts in terms of the production of hyaluronic acid and collagen type I. STUDY DESIGN: In vitro study using animal model. METHODS: Fibroblasts were harvested from young and aged rat vocal folds and cultured with or without hepatocyte growth factor and/or basic fibroblast growth factor at different concentrations. Subsequently, the production of hyaluronic acid and collagen type I was examined in the supernatant culture media using enzyme-linked immunosorbent assay. RESULTS: Aged fibroblasts produced less hyaluronic acid than younger fibroblasts. When aged and young fibroblasts were cultured with basic fibroblast growth factor, hyaluronic acid production increased and collagen type I production decreased regardless of the concentration, whereas the effects of hepatocyte growth factor appeared to vary with concentration. The basic fibroblast growth factor also was associated with stimulation of growth of aged fibroblasts. CONCLUSION: The present results suggest that growth factors, especially basic fibroblast growth factor, may have therapeutic potential in restoration of aged vocal fold.

Aging↗

PubMed2004

Remodeling of neuromuscular junctions in aged rat genioglossus muscle.

Speech and swallowing disorders represent a large clinical problem in elderly persons. Poor lingual control is associated with both speech and swallowing impairment. Studies of limb and laryngeal muscles suggest that age-related musculoskeletal changes may be characterized by remodeling of muscles, nerves, and their connections at neuromuscular junctions (NMJs). To evaluate dynamic remodeling of NMJ structure in the tongue as a function of aging, we studied tongues from 10 aged and 10 young rats. A fluorescent, triple-labeled, immunohistochemical technique was used with genioglossus (GG) muscle samples to allow confocal microscopic visualization of receptor clusters, nerve terminals, axons, and synaptic vesicles. Normal axon terminals and receptor clusters were easily identified in young rat GG muscles, whereas aging induced a significantly higher degree of receptor dispersal. These results suggest that NMJ remodeling is found in aged GG muscles and may underlie the progressive neuromuscular changes observed in the elderly.

Aging↗

PubMed2003

Comparing a mechanical device with medicinal leeches for treating venous congestion.

OBJECTIVE: To compare mechanical device therapy to medicinal leech therapy for treating venous congestion. STUDY DESIGN: Fasciocutaneous flaps of 9 x 7-cm (porcine model, n = 11) were elevated and the associated veins clamped for 15 hours. Device-treated flaps (n = 6) were treated with up to 3 devices/flap. Leech-treated flaps (n = 5) were treated with 75 leeches/flap (5 leeches/hour). Treatment evaluation parameters included: blood volume removed, skin color, surface perfusion, tissue oxygen tension, and endpoint histology. RESULTS: No significant differences were seen in blood volume removed, surface perfusion, and oxygen tension. However, significant differences were seen in skin color change over time. Histological assessment showed mild congestion in 5/5 leech-treated flaps and 2/6 device-treated flaps. CONCLUSION: Device therapy was comparable to leech therapy for decongesting a 9 x 7-cm flap over a 15-hour period. However, digital images and significant differences in skin color change over time demonstrate that device therapy promotes more global decongestion versus leech therapy.

Animals↗

PubMed2003

Comparison of resorbable poly-L-lactic acid-polyglycolic acid and internal Palmaz stents for the surgical correction of severe tracheomalacia.

Tracheomalacia (TM) is associated with expiratory airway collapse and potentially fatal respiratory distress. Internal and external tracheal stents and, recently, resorbable biopolymers have been used to treat this condition. In this study, the efficacy and biocompatibility of internal Palmaz stents and external poly-L-lactic acid-polyglycolic acid (PLPG) stents were compared in a model of severe TM induced in piglets. The tracheas were repaired with one of two stenting methods, and the animals survived for up to 16 weeks. Weight gain, adverse respiratory signs and symptoms, tracheal or lung histopathologic changes, and internal and external tracheal diameters were measured. The animals in the PLPG group uniformly were free of respiratory distress and tracheal stenosis or inflammation, whereas all animals in the Palmaz group developed respiratory distress as a result of pneumonia or tracheal stenosis caused by intraluminal granulation tissue. In conclusion, superior efficacy of external, resorbable PLPG stents was found relative to internal Palmaz stents for the surgical repair of severe TM.

Animals↗

PubMed2002

Evaluation of performance characteristics of the medicinal leech (Hirudo medicinalis) for the treatment of venous congestion.

Medicinal leeches (Hirudo medicinalis) are a standard treatment for venous congestion, a complication that can occur after reconstructive surgery. If the cause of venous congestion cannot be surgically corrected, then medicinal leeches are used to temporarily increase perfusion levels and maintain physiologic requirements within the congested tissue. Leeches increase perfusion within congested tissue by actively drawing off blood as a bloodmeal. Furthermore, the leech bite continues to bleed and relieve congestion after detachment because of the anticoagulation effects of leech saliva left behind in the bite. In a porcine model, a 10 x 10 cm cutaneous flank flap was congested by clamping the venae comitantes. Four medicinal leeches were allowed to attach to the congested flap, and parameters of active feeding and passive bleeding after detachment were recorded. The average bloodmeal volume for the medicinal leeches was 2.45 ml. Average passive bleeding for the first 2 and 4 hours after leech detachment totaled 2.21 and 2.50 ml, respectively, with 90 percent of passive bleeding occurring within 5 hours after detachment. Laser Doppler imaging indicated that the spatial arrangement of surface perfusion increases were localized to a 1.6-cm-diameter circle around the leech head (bite) and corresponded well with the visual return of normal skin tones to the same area. This study provides a realistic and quantitative estimate of the spatial and volumetric characteristics of leech feeding and passive bleeding using a clinically relevant model of acute, severe congestion.

Animals↗

PubMed2002

Neuromuscular junction changes in aged rat thyroarytenoid muscle.

Dynamic remodeling of neuromuscular junction (NMJ) structure is postulated as a cause of age-related muscular atrophy. Direct study of NMJ morphology in laryngeal muscles is important to our understanding of age-related decrements in voice and swallowing. The morphology of NMJs was studied in a rat model to compare young and old specimens of thyroarytenoid muscle--a muscle critical to airway protection and phonation. Fluorescent, triple-label immunohistochemical analysis and confocal microscopic visualization were used to analyze the structure of NMJs. We found that laryngeal NMJs underwent significant changes that were similar to those observed after denervation. Specifically, the axon terminal area was significantly reduced, there were a number of postsynaptic acetylcholine receptor areas unoccupied by nerve terminals, and there was increased variability in end plate architecture in the old muscles. The results of this study increase our understanding of the age-related morphological changes in the larynx, and may serve as a baseline to test the effectiveness of future interventions.

Age Factors↗

PubMed2002

Laryngeal-respiratory kinematics are impaired in aged rats.

Fatigue and weakness in the elderly are the functional consequences of underlying neuromuscular decline. However, little is known about the manifestations of aging in the larynx. This study evaluated the manner in which laryngeal senescence affects laryngeal-respiratory kinematics by videorecording laryngeal motion in both young and old rats. Recorded images were digitized, and glottal displacement and movement rate were measured. The results indicated that the amplitude of change in glottal angle was significantly diminished, and laryngeal movement durations were prolonged in the old animals. These findings may be due to functional constraints on the respiratory system, impaired laryngeal-respiratory interactions, or decrements in vocal fold tension with age. Because of the serious and pervasive nature of dysphagia and communicative impairments in the elderly, research that specifically examines the manifestations and causes of these impairments is of great importance.

Aging↗

PubMed2002

Glottal configuration, acoustic, and aerodynamic changes induced by variation in suture direction in arytenoid adduction procedures.

Arytenoid adduction is a phonosurgical procedure in which the arytenoid cartilages are approximated to reduce posterior glottal gap size and improve voice. Voice outcomes following arytenoid adduction are not always optimal. The goal of this study was to systematically vary suture direction and force of pull on the arytenoid cartilages in a human excised laryngeal model to determine the optimal combination of factors for reducing glottal gap and improving voice. Several factors demonstrated significant effects. Changes in suture direction and force of pull affected glottal configuration in both the horizontal and vertical planes. Increased force of pull on the muscular process resulted in increased adduction of the vocal process for all suture directions. Changes in suture direction and force of pull also affected acoustic and aerodynamic measures of induced voice. Therefore, voice outcomes can be optimized with arytenoid adduction if the vocal fold plane is accurately adjusted.

Acoustics↗

PubMed2002

Age-related alterations in myosin heavy chain isoforms in rat intrinsic laryngeal muscles.

Deficits in voice and swallowing are found in the elderly, but the underlying neuromuscular mechanisms are unclear. A potential mechanism may be denervation-induced muscle fiber transformation to a slower-contracting type of muscle fiber. This study examined young, old, and denervated rat laryngeal muscles (lateral thyroarytenoid, lateral cricoarytenoid, and posterior cricoarytenoid) to examine differences in myosin heavy chain (MHC) composition. Results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis analyses indicated that all muscles were composed predominately of type IIB MHC. With aging and denervation, type IIB was reduced and type IIX, a slower-contracting isoform, was increased in the lateral thyroarytenoid and lateral cricoarytenoid muscles. In the posterior cricoarytenoid muscle, the MHC composition was relatively unchanged. These findings suggest that aging may affect laryngeal adductory function by altering muscle fiber type composition to a slower-contracting isoform, in a manner similar to that observed with denervation.

Age Factors↗

PubMedDate not supplied

Effect of topical mitomycin on skin wound contraction.

OBJECTIVE: To evaluate the effect of different dosing regimens of mitomycin on skin wound contraction. METHODS: Full-thickness skin wounds were created in 5 groups of hairless mice, which represented different dosing regimens or a sterile water control: A, control; B, mitomycin (0.5 mg/mL) applied immediately after creation of the lesion (day 1); C, mitomycin (1.0 mg/mL) applied on day 1; D, mitomycin (0.5 mg/mL) applied on days 1 and 3; and E, mitomycin (1.0 mg/mL) applied on days 1 and 3. Wound surface area was measured immediately after drug application (day 1), and thereafter every 3 to 5 days until day 29 by means of computer-assisted image analysis. RESULTS: All dosing regimens of mitomycin application resulted in an initially exponential rate of wound contraction that was significantly slower than in the sterile water control group, with a significantly larger wound surface area on day 29. Wound area in the control group contracted approximately 9 times more rapidly than in the treatment groups. No difference was observed among the different dosing regimens. CONCLUSION: Application of mitomycin, at the lowest dose and frequency of application used in this study, resulted in improved outcomes with regard to contraction of full-thickness skin wounds.

Administration, Topical↗

PubMedDate not supplied

Testing a device to replace the leech for treating venous congestion.

OBJECTIVE: To test the effectiveness of a device designed to promote decongestion and tissue survival of a fasciocutaneous flap during 15 hours of complete venous obstruction. METHODS: In a porcine model, a 9 x 7-cm fasciocutaneous flap was elevated and the associated veins were clamped, causing complete venous obstruction for 15 hours in 6 control and 6 treatment animals. Up to 3 devices were used to treat the flap in a predetermined pattern. Control flaps were not treated. Measures of treatment efficacy included blood volumes removed; changes in skin color, surface perfusion, and tissue oxygen tension; and end point histologic findings. RESULTS: Control flaps were characterized by progressive darkening of skin color, undetectable surface perfusion, and low levels of oxygen tension. Histologic assessment showed severe congestion and extravasation of blood and distinct signs of necrosis. In contrast, treated flaps had significant improvements in skin color, surface perfusion, and subcutaneous oxygen tension. Histologic analysis showed little, if any, congestion and no signs of necrosis. Mean blood volume removed was 29.5 mL/h. CONCLUSION: The device was effective in decongesting a large area of tissue during 15 hours of complete outflow obstruction, based on quantitative measurements of tissue health and viability.

Animals↗

PubMedDate not supplied

Anastomoses between the cervical branch of the facial nerve and the transverse cervical cutaneous nerve.

Head and neck surgeons must possess a thorough knowledge of facial nerve anatomy to avoid inducing iatrogenic injury during surgery. Anastomoses of the cervical branch (CB) of the facial nerve and the transverse cervical cutaneous nerve (TCCN) are poorly documented in our field. Knowledge of these anastomoses and their positions allows for (1) preservation of high CBs that contribute to lower lip depressor function, and (2) identification of the facial nerve in retrograde dissections. Our objective was to improve understanding of facial nerve anatomy by describing these anastomoses. The communicating branch between the TCCN and the CB was evaluated in 22 adult neck halves (11 cadavers). The facial nerve was exposed, and the CB was traced anteriorly. The TCCN was identified and traced superiorly to its anastomosis(es) with the CB. The distance from each anastomosis to the selected landmarks was recorded. Between the CB and the TCCN, 33 anastomoses were identified, with at least 1 anastomosis per hemineck and 2 anastomoses in 11 heminecks. Anastomoses were identified along the inferior border of the submandibular gland (SMG; 20 specimens) or posterior to the SMG (12 specimens). Five specimens had both anastomoses near the inferior border of the SMG, and 6 specimens had 1 anastomosis near the inferior border and 1 posterior to the SMG. Communication between the TCCN and the CB is regularly present. Its anatomic locations are either posterior to the SMG, often within the parenchyma of the parotid gland, or near the inferior border of the SMG. Awareness of these anastomoses allows a method for identification and preservation of the CB of the facial nerve as well as a starting point for retrograde facial nerve dissections.

Facial Nerve↗