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S Bielamowicz

Publications and source records attributed to S Bielamowicz.

28 records · Page 2Linked to original sources
PubMed1995

Comparing reliability of perceptual ratings of roughness and acoustic measure of jitter.

Acoustic analysis is often favored over perceptual evaluation of voice because it is considered objective, and thus reliable. However, recent studies suggest this traditional bias is unwarranted. This study examined the relative reliability of human listeners and automatic systems for measuring perturbation in the evaluation of pathologic voices. Ten experienced listeners rated the roughness of 50 voice samples (ranging from normal to severely disordered) on a 75 mm visual analog scale. Rating reliability within and across listeners was compared to the reliability of jitter measures produced by several voice analysis systems (CSpeech, SoundScope, CSL, and an interactive hand-marking system). Results showed that overall listeners agreed as well or better than "objective" algorithms. Further, listeners disagreed in predictable ways, whereas automatic algorithms differed in seemingly random fashions. Finally, listener reliability increased with severity of pathology; objective methods quickly broke down as severity increased. These findings suggest that listeners and analysis packages differ greatly in their measurement characteristics. Acoustic measures may have advantages over perceptual measures for discriminating among essentially normal voices; however, reliability is not a good reason for preferring acoustic measures of perturbation to perceptual measures.

Female↗
PubMed1995

Cutaneous neuroendocrine (Merkel cell) carcinoma. A report of 35 cases.

Cutaneous neuroendocrine (Merkel cell) cancer (CNEC) is a rare skin tumor with a highly malignant nature. Initial treatment of this tumor has often been limited to a local excision. The medical records of 35 patients diagnosed with CNEC and treated at Southern California Kaiser Permanente Medical Group or UCLA Medical Center between 1980 and 1991 were reviewed. There were 26 male and 9 female patients were enrolled in this study. Minimum follow-up from date of diagnosis was 18 months, mean follow-up was 40 months; 25 patients presented with local disease (stage I) and 10 patients presented with regional disease (involved nodes, stage II). Patients who were treated initially with local therapy alone had a 65% recurrence rate and a 29% mortality rate, while those patients treated locoregionally at presentation had only a 27% recurrence rate and 14% mortality rate, although the majority presented with more advanced disease. Due to the high incidence of lymph node failure and death in patients treated locally versus locoregionally at presentation, we feel that planned locoregional treatment is indicated for all patients presenting with CNEC, regardless of stage.

Adult↗
PubMed1995

The effect of gas density on glottal vibration and exit jet particle velocity.

Although theoretical studies include a term for gas density in their mathematical descriptions of glottal aerodynamics, the effect of gas density on glottal vibration has not been examined empirically. In this study, an in vivo canine model was used to evaluate the effect of gas density on glottal vibration by comparing phonation with air and helium. With gas flow and nerve stimulation held constant, phonation with helium resulted in an increased exit jet particle velocity for helium (45 m/s) compared to air (34 m/s). However, the measured increase in helium velocity was less than predicted by a proportional relationship between transglottal pressure and dynamic pressure. This difference could be due to a change in the constant of proportionality or in the dynamic pressure loss coefficient associated with the use of helium.

Animals↗
PubMed1994

Merkel cell carcinoma: an aggressive skin neoplasm.

Merkel cell carcinoma (MCC) is an aggressive skin neoplasm of neuroendocrine origin. To clarify those factors important in improving survival, we retrospectively reviewed the charts of all patients with Merkel cell carcinoma treated at two tertiary referral centers. Eighty percent of the patients with stage I disease were initially treated with local therapy alone, while all of the patients with stage II disease were treated with local and regional therapy. The overall survival rate for all patients was 64%. Regardless of stage, patients treated with local excision alone had a 52% 5-year survival rate, while patients treated with local excision and lymph node dissection had an 87% survival rate. We conclude that the aggressive nature of this tumor warrants radical therapy.

Adult↗
PubMed1994

Changes in glottal area associated with increasing airflow.

Laryngeal resistance varies inversely with airflow during phonation. This study evaluated the morphological changes in the glottis that accompany decreases in laryngeal resistance at higher levels of airflow. An in vivo canine model of phonation and a video analysis system were used to assess changes in area. Four animals were examined stroboscopically as airflow increased, with constant recurrent laryngeal nerve stimulation. Glottal dynamics were evaluated by means of photoglottography, electroglottography, and measures of subglottic pressure. Analysis of digitized stroboscopic images indicated that increasing airflow had no obvious effect on the glottal chink (vocal process contact). Increasing airflow was associated with an increase in the area of peak opening and an increase in the glottal area integral.

Analysis of Variance↗
PubMed1994

Effects of RLN and SLN stimulation on glottal area.

In vivo canine experiments have demonstrated that vocal fold stiffness varies proportionately with changing levels of recurrent laryngeal nerve (RLN) and superior laryngeal nerve (SLN) stimulation. This study evaluated the morphologic changes in the glottis at varying levels of nerve stimulation and the presumed effects on laryngeal air particle velocity. Stroboscopic data from the in vivo canine model of phonation were examined under varying conditions of RLN and SLN stimulation. Computerized analysis of stroboscopic images was used to reconstruct the glottal area vs. time waveforms. As RLN stimulation increased, glottal area per cycle decreased (p < 0.05). However, as SLN stimulation increased, glottal area per cycle increased (p < 0.05). However, as SLN stimulation increased, glottal area per cycle increased (p < 0.05). These results support the hypothesis that increasing RLN stimulation at similar levels of SLN stimulation produces an increase in air particle velocity, whereas an increase in SLN stimulation causes a decrease in air particle velocity.

Airway Resistance↗
PubMed1993

Effect of tension, stiffness, and airflow on laryngeal resistance in the in vivo canine model.

This study used an in vivo canine model of phonation to determine the effects of airflow on glottal resistance at low, medium, and high levels of recurrent laryngeal nerve (RLN) and superior laryngeal nerve (SLN) stimulation. Static and dynamic trials of changing airflow were used to study the effects of airflow on glottal resistance during phonation. As reported previously, glottal resistance varies inversely as a function of airflow. Increasing levels of RLN stimulation resulted in a statistically significant increase in glottal resistance for each level of airflow evaluated. Variation in SLN stimulation had no statistically effects on the relationship between flow and resistance. At airflow rates greater than 590 milliliters per second (mL/s), glottal resistance approached 0.1 mm Hg per mL/s for all levels of RLN and SLN stimulation tested. These data support the collapsible tube model of phonation.

Airway Resistance↗
PubMed1993

Inverting papilloma of the head and neck: the UCLA update.

Inverting papilloma of the nose and paranasal sinuses is a benign disease with malignant potential. This disease is characterized by multiple recurrences, especially after minimal operative therapy. Controversy exists over the most appropriate treatment for this rare tumor. This review presents an update of the UCLA experience with inverting papilloma over the past four decades along with a review of the literature. A retrospective study of 61 patients seen at the UCLA Medical Center was conducted. The mean age at presentation was 63 years, with a male-to-female ratio of 2:1. The most common symptom at presentation was nasal obstruction (71%), followed by epistaxis (27%). Seventeen percent of the patients in this series either had concurrent squamous cell carcinoma of the nose or paranasal sinuses, or it developed. Patients treated with a lateral rhinotomy and medial maxillectomy had a recurrence rate of 30 percent. Those treated with a less aggressive operation had a recurrence rate of 71 percent. Despite a trend for a more conservative sinus operation in recent literature, we continue to advocate a lateral rhinotomy and medial maxillectomy as the treatment of choice for inverting papilloma of the head and neck.

Adult↗
PubMedDate not supplied

Surgical therapy of T1 and selected cases of T2 glottic carcinoma: cordectomy, horizontal glottectomy and CO2 laser endoscopic resection.

AIMS AND BACKGROUND: Among the different laryngeal neoplasms, glottic carcinoma is known to be one of the most suitable for functional management. Nevertheless, the best treatment for T1 and T2 glottic carcinoma, whether an open neck procedure, endoscopy or radiotherapy, with reference to recurrence, survival, and functional results, has long been debated. STUDY DESIGN: From February 1983 to September 1997, 83 patients with well to undifferentiated glottic carcinoma (48 pT1a, 14 pT1b, and 21 selected cases of pT2 with impairment of vocal cord mobility) were submitted to surgery at the Otorhinolaryngologic Section of the Department of Surgical Sciences and Organ Transplantations of Cagliari University. Surgical treatment included 30 laryngofissures with simple or enlarged cordectomy, 22 horizontal glottectomies and 31 endoscopic laser resections. A retrospective review of the records of the patients was performed in order to obtain a better understanding of the outcome of the three different surgical procedures in our institution. RESULTS: According to the Kaplan-Meier method, the probability of remaining free of local recurrence 3 years after primary surgery was 0.90 for the T1 group and 0.85 for the T2 group. The distribution of recurrences for cordectomy, glottectomy and CO2 laser at 3 years showed a cumulative probability of remaining free of disease after primary surgery of 0.86, 0.85 and 0.88. The probability of remaining free of local recurrence 3 years after salvage surgery was 0.96 for the T1 group and 0.95 for the T2 group. Analyzing the phenomena for type of surgical procedure, local control at 3 years after salvage surgery for cordectomy, glottectomy and exclusive CO2 laser was 0.93, 0.90 and 0.92, respectively. In the endoscopic group, local control rate after any type of salvage therapy modified the percentage at 3 years to 100%. Anterior commissure spread (AC1-AC2) resulted in a difference (not statistically significant) in local control between the group of patients without and with anterior commissure involvement. Laryngeal preservation was achieved in 93.7% (45/48) of patients who survived after salvage surgery following open neck procedures and in 100% of patients originally submitted to the endoscopic approach. CONCLUSIONS: In our experience, although open laryngeal procedures can be still considered a valid option in the treatment of T1 and selected cases of T2 glottic carcinoma, endoscopic laser excision offered an oncologically adequate alternative to the traditional techniques, with minimum discomfort for the patient and satisfactory preliminary functional results.

Adult↗