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Biomedical subjects

D G Hanson

Publications and source records attributed to D G Hanson.

At least 37 records · Page 2Linked to original sources
PubMed1998

Effect of tape recording on perturbation measures.

Tape recorders have been shown to affect measures of voice perturbation. Few studies, however, have been conducted to quantitatively justify the use or exclusion of certain types of recorders in voice perturbation studies. This study used sinusoidal and triangular waves and synthesized vowels to compare perturbation measures extracted from directly digitized signals with those recorded and played back through various tape recorders, including 3 models of digital audio tape recorders, 2 models of analog audio cassette tape recorders, and 2 models of video tape recorders. Signal contamination for frequency perturbation values was found to be consistently minimal with digital recorders (percent jitter = 0.01%-0.02%), mildly increased with video recorders (0.05%-0.10%), moderately increased with a high-quality analog audio cassette tape recorder (0.15%), and most prominent with a low-quality analog audio cassette tape recorder (0.24%). Recorder effect on amplitude perturbation measures was lowest in digital recorders (percent shimmer = 0.09%-0.20%), mildly to moderately increased in video recorders and a high-quality analog audio cassette tape recorder (0.25%-0.45%), and most prominent in a low-quality analog audio cassette tape recorder (0.98%). The effect of cassette tape material, length of spooled tape, and duration of analysis were also tested and are discussed.

Humans↗
PubMed1998

Glottographic signal perturbation in biomechanically different types of dysphonia.

Glottographic signals may be superior to acoustic signals for tracking glottal source perturbations, since supraglottal vocal tract effects on glottographic signals are relatively minimal compared with the acoustic signal as measured beyond the lips. This study compared the ability of differing signals to differentiate among normal voices and abnormal voices that were due to two categories of biomechanical disease. Acoustic, electroglottographic, and photoglottographic signals recorded during vowel phonation sustained by 26 normal subjects and 65 patients were measured for perturbations of frequency and amplitude. One-way analysis of variance (ANOVA) revealed that amplitude perturbation measures from photoglottographic signals significantly differentiated neuromuscular from mass lesion sources of dysphonia. Acoustic and electroglottographic signal perturbations differentiated between normal and abnormal voices but did not distinguish between the dysphonic characteristics of neuromuscular disorders and those of mass lesions of the vocal folds.

Acoustics↗
PubMed1998

Integrated analyzer and classifier of glottographic signals.

Electroglottography (EGG) and photoglottography (PGG) are two plausible methods to study voice production for monitoring the patterns of laryngeal vibrations. It has been suggested that measures such as open quotient and speed quotient calculated from glottographic signals can provide useful information regarding pathological phonation. In this paper, an integrated analyzer and classifier of glottographic signals was implemented. The system makes it possible to calculate the measures from digitized EGG and PGG signals automatically in order to examine vocal fold abnormality. The system developed several techniques to extract features from glottographic signals and proposed a statistical classification method that can possibly aid the diagnosis process. To check the reliability of the system, a training set and a test set of glottographic signals from normal people and patients with recurrent/superior laryngeal paralysis were analyzed and classified by the system. The results showed that the system is a useful tool for quantitative study of phonatory pathophysiology and can be used by the examiner who is interested in the clinical examination of glottographic signals. Moreover, glottographic techniques may have some clinical applications in the quantitative documentation of phonatory function in patients with voice disorders but requires further evaluation before clinical application.

Electrodiagnosis↗
PubMed1998

Quantitative measurement of mucosal wave by high-speed photography in excised larynges.

The movement characteristics of mucosal waves of the vocal fold are important components in normal phonation. Quantitative studies of the mucosal wave have used stroboscopic techniques from a supraglottic view. The current study measured displacement of mucosal epithelium during experimental phonation by using high-speed photography from an infraglottic view. Effects of thyroarytenoid contraction, increased mean airflow rate, and variation of vocal fold length were examined in canine larynges. Top and bottom vocal fold "lip" amplitude, fundamental frequency, and phase difference were the dependent variables examined. Thyroarytenoid contraction increased the amplitude of the top and bottom lips, decreased the fundamental frequency, and increased the phase difference. Increase in airflow through the glottis decreased the top lip amplitude and phase difference and appeared to increase the fundamental frequency and to decrease the bottom lip amplitude. Vocal fold lengthening decreased the bottom lip amplitude and increased the fundamental frequency and appeared to decrease the top lip amplitude and phase difference.

Animals↗
PubMed1998

Finite element modeling of vocal fold vibration in normal phonation and hyperfunctional dysphonia: implications for the pathogenesis of vocal nodules.

A computer model of the vocal fold was developed using finite element modeling technology for studying mechanical stress distribution over vibrating vocal fold tissue. In a simulated normal phonation mode, mechanical stress was found to be lowest at the midpoint of the vocal fold and highest at tendon attachments. However, when other modes predominated, high mechanical stress could occur at the midpoint of the vocal folds. When a vocal fold mass was modeled, high shearing stress occurred at the base of the modeled vocal fold mass, suggesting that the presence of a vocal nodule or polyp is associated with high mechanical stress at the margins of the mass. This finding supports a hypothesis that mechanical intraepithelial stress plays an important role in the development of vocal nodules, polyps, and other lesions that are usually ascribed to hyperfunctional dysphonia.

Computers↗
PubMed1998

Expression of the adenocarcinoma-related antigen recognized by monoclonal antibody 44-3A6 in salivary gland neoplasias.

The monoclonal antibody 44-3A6 detects a cell-surface protein that has been shown to be a useful marker in distinguishing adenocarcinomas from other histologic tumor types in a variety of tissues. The objective of this study was to determine whether 44-3A6 could be used as a tool in the classification of salivary gland neoplasms. These complex tumors share overlapping pathologic features but distinct clinical outcomes. This study used 44-3A6 to immunohistochemically describe the pattern and frequency of this antigen in salivary gland neoplasms. Formalin-fixed, paraffin-embedded tissue sections of 22 benign and 26 malignant salivary tumors were evaluated. The patient population consisted of 25 (52.1%) women and 23 (47.9%) men selected from archival pathology files to reflect a range of salivary gland diseases. Normal surrounding salivary glands were found to have intense focal staining almost exclusively localized to ductal luminal cells. There was little staining of either myoepithelial or acinar cells. A wide spectrum of expression was found between and within tumor types, but a trend toward more expression of this antigen with decreasing differentiation was seen. A significant increase in staining was also seen in those tumors with ductal differentiation (n = 41) as opposed to those with predominantly acinar (i.e., acinic cell carcinoma) or myoepithelial (i.e., myoepithelioma; n = 8) differentiation (2.6 vs. 1.3, p < 0.05). No correlation was found between staining intensity and facial paralysis, pain, skin involvement, TNM stage, residual disease, or disease-free or total survival. Therefore this antigen appears to designate a duct luminal phenotype in normal and neoplastic salivary tissues.

Adenocarcinoma↗
PubMed1997

Cytoplasmic localization of endothelial constitutive nitric oxide synthase in endometrial carcinomas.

BACKGROUND: Production of nitric oxide by nitric oxide synthase (NOS) has been implicated in numerous physiologic and pathophysiologic processes including mutagenesis. This study was designed to examine the expression of the endothelial constitutive isoform of NOS (ecNOS) in endometrial carcinomas. METHODS: Fifty endometrial carcinomas (42 endometrioid, 4 serous papillary, 2 clear cell, and 2 adenosquamous carcinomas) and 21 normal endometrial gland tissue specimens (5 cases of proliferative, 5 early secretory, 5 mid-secretory, and 5 late secretory and 1 menstrual phase endometrium), previously formalin fixed and paraffin embedded, were immunostained using a commercially available anti-ecNOS monoclonal antibody. Localization of ecNOS staining to the plasma membrane, cytoplasm and nuclei was graded with respect to overall staining intensity (0-3+ scale) and frequency (percentage of immunoreactive cells). RESULTS: Relatively little staining for ecNOS was localized to the plasma membrane in either normal or neoplastic tissues. Normal and hyperplastic endometrial glands demonstrated moderate cytoplasmic and weak nuclear staining in a small percentage of cells. While ecNOS expression was most prominent in epithelial cells, weak expression was also rarely noted in endometrial stroma, blood vessel walls, and endothelium. We found a broad range of ecNOS expression in endometrial carcinomas, predominantly localized to the cytoplasm and nuclei. No statistically significant difference in ecNOS staining frequency or intensity was found between different histologic subtypes of endometrial carcinomas. No apparent correlation was found between ecNOS expression and tumor stage, grade, extension to the lower uterine segment or cervix, nodal or distant metastases, recurrence, or final patient status among patients with endometrioid adenocarcinomas. Endometrioid tumors invading more than 1/2 of myometrial thickness (n = 18) had significantly higher cytoplasmic staining intensity than those tumors limited to the inner 1/2 of myometrium (n = 27; 2.0 vs. 1.3, p < 0.04). Furthermore, a trend toward shorter disease-free survival was noted with increased staining intensity and decreased staining frequency. CONCLUSIONS: Cytoplasmic and nuclear expression of ecNOS, which is primarily limited to the glandular elements of normal endometrium, is also found to be expressed in endometrial carcinoma. Increased ecNOS staining intensity and decreased frequency tends to correlate with decreased disease-free survival. Lastly, increased cytoplasmic ecNOS staining intensity correlates with increased myometrial invasion.

Adult↗
PubMed1997

Acoustic measurement of change in voice quality with treatment for chronic posterior laryngitis.

Sixteen patients who had symptoms and signs of chronic posterior laryngitis were evaluated before, during, and after treatment with omeprazole and nocturnal antireflux precautions. Data were analyzed for patients who complained of some hoarseness, who had no smoking history, and who completed all of the voice recording protocol. The patients' voices were recorded before, during, and following treatment with omeprazole and nocturnal antireflux precautions. Voice quality was analyzed by perceptual analysis, and acoustic signal data were measured for jitter, shimmer, and signal-to-noise ratio. Measures of jitter, shimmer, and signal-to-noise ratio changed significantly with treatment of posterior laryngitis (p < .01 for change in each of the measures). Acoustic measures showed some trend of deterioration with cessation of treatment, although the overall improvement in acoustic measures of voice quality was still statistically significant after treatment with omeprazole was discontinued. Although perceived abnormality of voice increased and decreased with the magnitude of measured perturbation of the acoustic signal for some patients, the perceptual assessments were not highly correlated with acoustic measures for individual patients, and the perceptual analysis group data did not show a significant change with time during treatment, in contrast to the significance of change in acoustic measures. The data demonstrate that acoustic measures of jitter, shimmer, and signal-to-noise ratio improve significantly with antisecretory and antireflux treatment of chronic posterior laryngitis, and that for individual patients, these are changes that are detected by trained listeners, but not at statistically high levels of confidence.

Adult↗
PubMed1996

Videolaryngoscopic evaluation of laryngeal intubation injury: incidence and predictive factors.

Bedside videolaryngoscopy of 73 cardiovascular surgical patients was performed before and after intubation to identify risk factors, incidence, and site of injury to the larynx. Nineteen of 44 patients with abnormal preintubation examination findings had granulation tissue present on a vocal process, compared With 3 of 20 patients who had normal findings on preintubation examination (p < 0.05). Recent smoking history was elicited from 2 of 20 patients who had normal findings on preintubation examination and from 20 of the 44 patients who had abnormal findings on preintubation examination (p < 0.01). Laryngeal nerve paresis was identified in 21 of 64 patients after extubation and was present in 7 patients before intubation. Videolaryngoscopy provides a high-quality permanent record of the laryngeal examination and is easily obtained in the critical care setting. Preintubation videolaryngeal evaluation may identify those at risk for more significant intubation injury.

Adult↗
PubMed1996

Effects of two breath-holding maneuvers on oropharyngeal swallow.

This study quantified the effects of the supraglottic maneuver (SGM) and super supraglottic maneuver (SSGM) on laryngeal and pharyngeal movements before and during swallow. Simultaneous videofluoroscopic and videoendoscopic examinations of oropharyngeal swallowing were performed in eight healthy volunteers with and without maneuvers. Data analysis compared 1) temporal relationships of oropharyngeal events, 2) airway conditions at the time of selected oropharyngeal events, and 3) biomechanical computer analysis of swallowing events. Using these maneuvers, normal subjects produced earlier cricopharyngeal opening, prolonged pharyngeal swallow, some degree of laryngeal valving before swallow, and change in extent of vertical laryngeal position before swallow. These changes are more successful and maintained longer with the SSGM than the SGM. We concluded that breath-holding maneuvers alter not only airway conditions before swallow but also both the temporal relationships and biomechanical events during oropharyngeal swallow.

Adult↗
PubMed1995

Serum immunoglobulins specific for intracellular proteins of squamous cell carcinoma.

OBJECTIVE: To determine an autologous humoral immune response to squamous cell carcinoma (SCC) intracellular proteins in patients with SCC. DESIGN: Intracellular proteins were isolated from 25 different cultured SCC lines. The proteins were used as a source of antigens to measure IgA, IgE, and IgG responses in the serum samples of patients and controls. Antibody response was assessed in both unfractionated and fractionated intracellular proteins. PATIENTS: The serum samples of 65 patients with SCC and of 65 age- and gender-matched controls were tested. RESULTS: Antibodies to SCC intracellular proteins were detected in the serum samples of 40 (62%) of the 65 patients with SCC and in the serum samples of 46 (71%) of 65 controls. Thirty (46%) of the patients with SCC and 40 (62%) of the controls had IgE responses, 18 (28%) of the patients and one (2%) of the controls had IgA responses, and 17 (26%) of the patients and 14 (22%) of the controls had IgG responses. An inverse relation was noted between detectable IgE responses and IgA or IgG responses in the patients and the controls. The analysis of antibody response indicated that 28 molecules were recognized predominantly by the serum samples of patients with SCC, but not by the serum samples of controls. CONCLUSIONS: A substantial proportion of patients with SCC and of controls exhibited an autologous humoral immune response to SCC intracellular proteins. The IgE responses to SCC intracellular proteins were inversely related to IgA or to IgG responses. Different antibody isotypes normally cause markedly different immune functions, and may suggest different roles for the existent immune responses to SCC antigens. We identified many tumor-associated antigens that were selectively recognized by the serum samples of patients with SCC. These antigens could be used to define molecular studies of immune surveillance and selection, and may represent appropriate targets for immunotherapy.

Autoradiography↗
PubMed1995

Patients with Meniére's disease possess IgE reacting with herpes family viruses.

OBJECTIVE: To determine if patients with Meniere's disease possess serum IgE specific for herpes simplex virus (HSV) type 1, HSV type 2, Epstein-Barr virus, and/or cytomegalovirus. DESIGN: A modified radioallergosorbent test method was employed wherein each serum sample was processed with recombinant protein A to remove competing non-IgE antibodies, and HSV-1, HSV-2, cytomegalovirus, and Epstein-Barr viral proteins were used as potential antigens. PATIENTS: Ten patients with long-standing active Meniere's disease were tested. Ten age- and gender-matched patients with allergic rhinitis but without Meniere's disease served as control subjects. RESULTS: IgE specific for HSV-1, HSV-2, Epstein-Barr virus, and/or cytomegalovirus was found in the serum sample of nine of 10 patients with Meniere's disease but only in four of 10 control serum samples. Of the positive subjects tested, seven patients with Meniere's disease were positive for IgE for at least three viruses compared with only two control subjects. CONCLUSIONS: (1) Most patients with Meniere's disease possess virus-specific IgE in their serum samples; (2) four viruses of the herpes family are capable of inducing such IgE-mediated sensitization; and (3) latent virus-specific, IgE-mediated inflammation may be an important factor in the initiation and/or sustenance of Meniere's disease.

Case-Control Studies↗
PubMed1995

Clinical measurement of mucosal wave velocity using simultaneous photoglottography and laryngostroboscopy.

Simultaneous glottal transillumination or photoglottography (PGG), electroglottography (EGG), and video laryngostroboscopy were used to measure the traveling wave velocity of the vibrating vocal folds during phonation in human subjects. The duration of travel was calibrated from the PGG signal, while the displacement of the upper and lower lips of the vibrating vocal folds was calibrated from parallel laser beams projected onto the vocal folds. The mucosal wave velocity varied with the portion of the glottal cycle. The amplitude of displacement correlated positively with the intensity of phonation and negatively with the fundamental frequency and was decreased for breathy and pressed phonation modes. The velocity of the opening phase segment of the PGG signal directly correlated with the top lip displacement of the vibrating vocal fold, and bottom lip displacement correlated with the closing phase of the PGG signal. Therefore, with suitable calibration, the effects of mucosal lateral displacement may be measured from a PGG signal. Simultaneous measures of PGG, EGG, and stroboscopy provide a three-dimensional representation of glottal vibration that can be numerically analyzed.

Adult↗
PubMed1995

Outcomes of antireflux therapy for the treatment of chronic laryngitis.

This study examined outcomes of antireflux and antacid treatment for the signs and symptoms of chronic laryngitis. Patients from a referral institutional practice with chronic laryngitis symptoms, without other apparent causes of laryngeal inflammation, were followed up and examined at progressive stages of antireflux treatment as a case series outcome study. The cases included unselected individuals with a diagnosis of chronic (> 3 months' duration) laryngitis. Patients with chronic throat complaints were treated with nocturnal antireflux precautions, with addition of famotidine 20 mg or omeprazole 20 mg at bedtime for patients who did not respond to antireflux precautions alone. The outcome measures were resolution of symptoms, and change in findings on telescopic laryngoscopy. Chronic throat symptoms of 93 of 182 patients (51%) responded to nocturnal antireflux precautions alone. The complaints of an additional 48 patients resolved with the addition of famotidine 20mg at bedtime to antireflux precautions (77% response). The symptoms of 34 of the remaining 41 patients responded to treatment with omeprazole 20 mg at bedtime. Therefore, symptoms of 96% of patients responded to treatment aimed at preventing reflux of gastric acid. The remaining patients with refractory symptoms had a partial response or no response or chose fundoplication. Erythema and granular mucositis were the most common laryngoscopic findings. Ulceration and granuloma formation were less common, but also responded to antireflux treatment. Some (7) patients required high doses of omeprazole or fundoplication to achieve symptomatic relief and healing of chronic inflammatory changes of the posterior larynx. Relapse of symptoms was common when treatment was stopped.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Evaluation and treatment of the unilateral paralyzed vocal fold.

The evaluation and treatment of patients with unilateral vocal fold paralysis have evolved as improvements in objective measurements of phonatory function and new modalities for treatment have developed. A thorough history, physical examination, subjective voice evaluation, objective voice analysis, and electromyography are used to make a diagnosis, determine the cause, and plan treatment. The goal of treatment of the patient with a unilateral vocal fold paralysis is to restore normal phonatory function without aspiration. Multiple modalities have developed to allow for restoration of nearly normal phonatory function, and these include voice therapy alone or in combination with injection medialization, laryngoplastic phonosurgery, or laryngeal reinnervation. Otolaryngologists should be familiar with the incidence, cause, evaluation, and state-of-the-art treatment of unilateral vocal fold paralysis of optimize patient care and avoid suboptimal results often seen with antiquated or inappropriate treatment.

Humans↗
PubMed1993

Bacterial allergy in nasal polyposis. A new method for quantifying specific IgE.

OBJECTIVES: To determine (1) if bacteria-specific serum IgE levels can be more effectively measured by first absorbing competing IgG antibodies from serum and (2) if patients with chronic paranasal sinus disease exhibit a high positive prevalence of bacteria-specific serum IgE. DESIGN: A modified radioallergosorbent test method was employed wherein each serum sample was absorbed with recProtein A to remove competing non-IgE antibodies, and purified proteins extracted from 16 individual bacteria were used as potential allergens. PARTICIPANTS: Twenty-four patients with nasal polyposis and 14 with chronic sinusitis, all refractory to conventional medical therapy and requiring endoscopic sinusotomies, were tested. Tested as controls were 10 subjects with chronic allergic rhinitis, without a history of chronic sinus disease, and possessing total serum IgE and inhalant-specific IgE levels equal to or higher than the patient group. RESULTS: (1) Pretreatment of serum samples with recProtein A resulted in an increase of bacteria-specific radioallergosorbent test sensitivity. (2) Seventeen of 24 patients with polyps, eight of 14 with chronic sinusitis, and one of 10 with chronic allergic rhinitis were determined to be IgE positive when tested with this assay. CONCLUSIONS: (1) Bacteria-specific serum IgE can be quantified; (2) most patients with nasal polyposis and/or chronic sinusitis possess bacteria-specific IgE in their serum, while subjects with only allergic rhinitis do not; and (3) multiple bacterial species isolated from chronically infected sinuses are capable of inducing IgE-mediated sensitization.

Antibodies, Bacterial↗
PubMed1992

Voice.

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Humans↗