Progenitor cell-based myelination as a model for cell-based therapy of the central nervous system

Diseases of the brain and spinal cord are especially daunting challenges for cell-based strategies of repair, given the multiplicity of cell types within the adult central nervous system, and the precision with which they must interact in both space and time. Nonetheless, a number of diseases are especially appropriate for cell-based therapy, in particular those in which single phenotypes are lost. Foremost among these are the disorders of myelin, in which oligodendrocytes are the specific and often sole victims of the underlying disease process. These include not only the vascular, traumatic, and inflammatory demyelinations of adulthood, but also the congenital and childhood dysmyelinating syndromes of the pediatric leukodystrophies. These congenital disorders of myelin formation and maintenance may present especially compelling targets for cell-based neurological therapy.

Revisiting the Pitch Controversy: Changes in Speaking Fundamental Frequency (SFF) After Management of Functional Dysphonia

Speaking fundamental frequency (SFF) and its perceptual correlate "habitual pitch" have been considered important and contentious parameters in voice assessment and treatment. In clinical circles, disagreement exists regarding the role of habitual pitch in the development, maintenance, and treatment of disordered voices. Despite these divergent opinions, few studies have objectively evaluated SFF changes associated with voice improvement after therapy. To determine whether consistent directional and magnitude changes in SFF occur after management, pretreatment and posttreatment audio recordings of 40 women with functional dysphonia were analyzed. All subjects were treated with manual circumlaryngeal therapy, a treatment approach that does not directly target pitch as a perceptual entity to be manipulated. Results indicated that, as a group, no significant change in mean SFF was observed after successful management. Although no consistent directional pattern was identified, 80% of the subjects experienced pitch changes greater than one semitone; this suggests that voice improvement is often accompanied by a shift in SFF. Clinical implications of the data are discussed.

Velopharyngeal port status during classical singing

PURPOSE

This investigation was undertaken to examine the status of the velopharyngeal (VP) port during classical singing.

METHOD

Using aeromechanical instrumentation, nasal airflow (mL/s), oral pressure (cm H2O), and VP orifice area estimates (cm2) were studied in 10 classically trained sopranos during singing and speaking. Each participant sang and spoke 3 nonsense words-/hampa/, /himpi/, and /humpu/-at 3 loudness levels (loud vs. comfortable vs. soft) and 3 pitches (high vs. comfortable vs. low), using a within-subject experimental design including all possible combinations.

RESULTS

In general, nasal airflow, oral pressure, and VP area estimates were significantly greater for singing as compared to speech, and nasal airflow was observed during non-nasal sounds in all participants. Anticipatory nasal airflow was observed in 9 of 10 participants for singing and speaking and was significantly greater during the first vowel in /hampa/ versus /himpi/ and /humpu/. The effect of vowel height on nasal airflow was also significantly influenced by loudness and pitch.

CONCLUSIONS

The results from this investigation indicate that at least some trained singers experience regular VP opening during classical singing. Vowel height seems to influence this effect. Future research should consider the effects of voice type, gender, experience level, performance ability, and singing style on VP valving in singers.

Voice Disorders in the General Population: Prevalence, Risk Factors, and Occupational Impact

OBJECTIVES

Epidemiologic studies of the prevalence and risk factors of voice disorders in the general adult population are rare. The purpose of this investigation was to 1) determine the prevalence of voice disorders, 2) identify variables associated with increased risk of voice disorders, and 3) establish the functional impact of voice disorders on the general population.

STUDY DESIGN

Cross-sectional telephone survey.

METHODS

A random sample (n = 1,326) of adults in Iowa and Utah was interviewed using a questionnaire that addressed three areas related to voice disorders: prevalence, potential risk factors, and occupational consequences/effects.

RESULTS

The lifetime prevalence of a voice disorder was 29.9%, with 6.6% of participants reporting a current voice disorder. Stepwise logistic regression identified specific factors that uniquely contributed to increased odds of reporting a chronic voice disorder including sex (women), age (40-59 years), voice use patterns and demands, esophageal reflux, chemical exposures, and frequent cold/sinus infections. However, tobacco or alcohol use did not independently increase the odds of reporting of a chronic voice disorder. Voice disorders adversely impacted job performance and attendance, with 4.3% of participants indicating that their voice had limited or rendered them unable to do certain tasks in their current job. Furthermore, 7.2% of employed respondents reported that they were absent from work 1 or more days in the past year because of their voice, and 2% reported more than 4 days of voice-related absence.

CONCLUSIONS

The results of this large epidemiologic study provide valuable information regarding the prevalence of voice disorders, factors that contribute to voice disorder vulnerability, and the functional impact of voice problems on the general population.

Spectral moments of the long-term average spectrum: sensitive indices of voice change after therapy?

Voice clinicians require an objective, reliable, and relatively automatic method to assess voice change after medical, surgical, or behavioral intervention. This measure must be sensitive to a variety of voice qualities and severities, and preferably should reflect voice in continuous speech. The long-term average spectrum (LTAS) is a fast Fourier transform-generated power spectrum whose properties can be compared with a Gaussian bell curve using spectral moments analysis. Four spectral moments describe features of the LTAS: Spectral mean (Moment 1) and standard deviation (Moment 2) represent the spectrum's central tendency and dispersion, respectively. Skewness (based on Moment 3) and kurtosis (based on Moment 4) represent the spectrum's tilt and peakedness, respectively. To examine whether the first four spectral moments of the LTAS were sensitive to perceived voice improvement after voice therapy, this investigation compared pretreatment and posttreatment voice samples of 93 patients with functional dysphonia using spectral moments analysis. Inspection of the results revealed that spectral mean and standard deviation lowered significantly with perceived voice improvement after successful behavioral management (p < 0.001). However, changes in skewness and kurtosis were not significant. Furthermore, lowering of the spectral mean uniquely accounted for approximately 14% of the variance in the pretreatment to posttreatment changes observed in perceptual ratings of voice severity (p < 0.001), indicating that spectral mean (ie, Moment 1) of the LTAS may be one acoustic marker sensitive to improvement in dysphonia severity.

Sid4: A secreted vertebrate immunoglobulin protein with roles in zebrafish embryogenesis

The small members of the immunoglobulin superfamily (IGSF) are a molecularly diverse group of proteins composed solely of immunoglobulin domains. They may be secreted or tethered to the cell mebrane via GPI linkages and are proposed to have important functions in vivo. However, very few small IGSFs have been functionally characterized. During an ongoing in situ hybridization analysis of expressed sequence tags in zebrafish we identified secreted immunoglobulin domain 4 (sid4), a gene encoding a soluble vertebrate protein composed solely of four immunoglobulin domains. Throughout development, sid4 is expressed in regions of the embryo undergoing active cell division and migration. Functional analysis using morpholino antisense oligonucleotides demonstrates that timing of gene expression is normal in morphants, but these embryos are smaller and exhibit defects in epiboly and patterning of axial and prechordal mesoderm. Analyses of chordin, pax2, krox20, and dlx2 expression in morphants demonstrate that early brain patterning is normal but later organization of hindbrain neurons and development of cranial neural crest are perturbed. Levels of apoptosis in morphants were normal prior to 90% epiboly, but were elevated after 10 h post-fertilization (hpf). Apoptosis does not account for early patterning defects of axial mesoderm, but likely contributes to overall reduction in embryo size. Phylogenetic analysis demonstrates that Sid4 is strikingly similar to the fibronectin binding Ig domains of Perlecan/HSPG2. Overall, our data demonstrate a fundamental role for sid4, possibly as a co-factor in extracellular matrix (ECM) interactions, in processes underlying tissue patterning and organogenesis in a vertebrate.

Acoustic Prediction of Voice Type in Women with Functional Dysphonia

The categorization of voice into quality type (ie, normal, breathy, hoarse, rough) is often a traditional part of the voice diagnostic. The goal of this study was to assess the contributions of various time and spectral-based acoustic measures to the categorization of voice type for a diverse sample of voices collected from both functionally dysphonic (breathy, hoarse, and rough) (n=83) and normal women (n=51). Before acoustic analyses, 12 judges rated all voice samples for voice quality type. Discriminant analysis, using the modal rating of voice type as the dependent variable, produced a 5-variable model (comprising time and spectral-based measures) that correctly classified voice type with 79.9% accuracy (74.6% classification accuracy on cross-validation). Voice type classification was achieved based on two significant discriminant functions, interpreted as reflecting measures related to "Phonatory Instability" and "F(0) Characteristics." A cepstrum-based measure (CPP/EXP ratio) consistently emerged as a significant factor in predicting voice type; however, variables such as shimmer (RMS dB) and a measure of low- vs. high-frequency spectral energy (the Discrete Fourier Transformation ratio) also added substantially to the accurate profiling and prediction of voice type. The results are interpreted and discussed with respect to the key acoustic characteristics that contributed to the identification of specific voice types, and the value of identifying a subset of time and spectral-based acoustic measures that appear sensitive to a perceptually diverse set of dysphonic voices.

Intensive stuttering modification therapy: a multidimensional assessment of treatment outcomes

Nineteen adults who stutter participated in a 3-week intensive stuttering modification treatment program (the Successful Stuttering Management Program [SSMP]). A series of 14 fluency and affective-based measures were assessed before treatment, immediately after treatment, and 6 months after treatment. Measures included stuttering frequency; the Stuttering Severity Instrument for Children and Adults, Third Edition (SSI-3); a self-rating of stuttering severity; the Perceptions of Stuttering Inventory (PSI); the Locus of Control of Behavior Scale; the Beck Depression Inventory; the Multicomponent Anxiety Inventory IV (MCAI-IV); and the State-Trait Anxiety Inventory. Statistically significant improvements were observed on 4 of the total 14 measures immediately following treatment and on 4 measures at 6 months posttreatment. Statistically significant improvements observed immediately posttreatment included scores on the SSI and the Struggle, Avoidance, and Expectancy subscales of the PSI. Sustained statistically significant improvements at 6 months posttreatment were observed only on client-reported perceptions of stuttering (the Avoidance and Expectancy subscales of the PSI) and 2 specific affective functioning measures (the Psychic and Somatic Anxiety subscales of the MCAI-IV). The SSMP generated some anxiolytic effects but was ineffective in producing durable reductions of core stuttering behaviors, such as stuttering frequency and severity. The discussion focuses on the strengths, weaknesses, and durability of the SSMP treatment approach.

Task Specificity in Adductor Spasmodic Dysphonia Versus Muscle Tension Dysphonia

OBJECTIVES

Adductor spasmodic dysphonia (ADSD) has been characterized as a "task specific" laryngeal dystonia, meaning that the severity of dysphonia varies depending on the demands of the vocal task. Voice produced in connected speech as compared with sustained vowels is said to provoke more frequent and severe laryngeal spasms. This study examined the diagnostic value of "task specificity" as a marker of ADSD and its potential to differentiate ADSD from muscle tension dysphonia (MTD), a functional voice disorder that can often masquerade as ADSD.

STUDY DESIGN

Case-control study.

METHODS

Five listeners, blinded to the purpose of the study, used a 10 cm visual analogue scale to rate dysphonia severity of subjects with ADSD (n = 36) and MTD (n = 45) producing either connected speech or a sustained vowel "ah."

RESULTS

In ADSD, dysphonia severity for connected speech (M = 6.22 cm, SD = 2.56) was rated significantly more severe than sustained vowel productions (M = 4.8 cm, SD = 2.8 [t (35) = 3.67, P < .001]). In MTD, however, no significant difference in severity was observed for the connected speech sample (M = 5.98 cm, SD = 2.83 versus the sustained vowel M = 5.86 cm, SD = 2.87 [t (44) = 0.378, P = .707]). The receiver operating characteristic (ROC) curve, an index of the accuracy of task specificity as a diagnostic marker, revealed that a 1 cm difference criterion correctly identified 53% of ADSD cases (sensitivity) and 76% of MTD cases (specificity) (chi2 (1) = 6.88, P = .0087).

CONCLUSIONS

Reduced dysphonia severity during sustained vowels supports task specificity in ADSD but not MTD and highlights a valuable diagnostic marker whose recognition should contribute to improved diagnostic precision.

Finding Approximate POMDP solutions Through Belief Compression

Standard value function approaches to finding policies for Partially Observable Markov Decision Processes (POMDPs) are generally considered to be intractable for large models. The intractability of these algorithms is to a large extent a consequence of computing an exact, optimal policy over the entire belief space. However, in real-world POMDP problems, computing the optimal policy for the full belief space is often unnecessary for good control even for problems with complicated policy classes. The beliefs experienced by the controller often lie near a structured, low-dimensional subspace embedded in the high-dimensional belief space. Finding a good approximation to the optimal value function for only this subspace can be much easier than computing the full value function. We introduce a new method for solving large-scale POMDPs by reducing the dimensionality of the belief space. We use Exponential family Principal Components Analysis (Collins, Dasgupta & Schapire, 2002) to represent sparse, high-dimensional belief spaces using small sets of learned features of the belief state. We then plan only in terms of the low-dimensional belief features. By planning in this low-dimensional space, we can find policies for POMDP models that are orders of magnitude larger than models that can be handled by conventional techniques. We demonstrate the use of this algorithm on a synthetic problem and on mobile robot navigation tasks.

Occupational risk factors associated with voice disorders among teachers

PURPOSE

This study was designed to determine the occupational risk factors associated with voice disorders among schoolteachers, a high-risk population for developing voice problems.

METHODS

Telephone interviews were completed by 1243 teachers from Utah and Iowa. Response rates were 98% and 95%, respectively. Bivariate analyses were computed and assessed using chi-square test and Cochran-Mantel-Haenszel test, and logistic regression analyses were performed and resulting odds ratios assessed using 95% confidence intervals.

RESULTS

Teachers of vocal music, drama, other performing arts and chemistry were at significantly greater risk of having a voice disorder (OR=2.2, 95% CI: 1.2-4.0; OR=2.1, 95% CI: 0.9-4.8; OR=1.6, 95% CI: 1.0-2.4; OR=2.0, 95% CI: 1.1-3.4), while teachers of special and vocational education had a significantly lower risk (OR=0.5, 95% CI: 0.3-0.7; OR=0.6, 95% CI: 0.4-0.9). When adjusted for the intensity of vocalization, only teachers of chemistry were significantly at risk (OR=2.0, 95% CI: 1.1-3.5) while teachers of special education continued to have less of a risk (OR=0.5, 95% CI: 0.4-0.8). Chronic voice disorders were more prevalent among teachers of vocal music (OR=4.1, 95% CI: 2.2-7.9) and less prevalent among teachers of vocational education (OR=0.29, 95% CI: 0.09-0.95).

CONCLUSIONS

These findings suggest that teachers of specific courses are at greater risk of developing a voice disorder.

Voice disorders in teachers and the general population: effects on work performance, attendance, and future career choices

To examine the frequency and adverse effects of voice disorders on job performance and attendance in teachers and the general population, 2,401 participants from Iowa and Utah (n1 = 1,243 teachers and n2 = 1,279 nonteachers) were randomly selected and were interviewed by telephone using a voice disorder questionnaire. Teachers were significantly more likely than nonteachers to have experienced multiple voice symptoms and signs including hoarseness, discomfort, and increased effort while using their voice, tiring or experiencing a change in voice quality after short use, difficulty projecting their voice, trouble speaking or singing softly, and a loss of their singing range (all odds ratios [ORs] p <.05). Furthermore, teachers consistently attributed these voice symptoms to their occupation and were significantly more likely to indicate that their voice limited their ability to perform certain tasks at work, and had reduced activities or interactions as a result. Teachers, as compared with nonteachers, had missed more workdays over the preceding year because of voice problems and were more likely to consider changing occupations because of their voice (all comparisons p <.05). These findings strongly suggest that occupationally related voice dysfunction in teachers can have significant adverse effects on job performance, attendance, and future career choices.

Prevalence of voice disorders in teachers and the general population

Over 3 million teachers in the United States use their voice as a primary tool of trade and are thought to be at higher risk for occupation-related voice disorders than the general population. However, estimates regarding the prevalence of voice disorders in teachers and the general population vary considerably. To determine the extent that teachers are at greater risk for voice disorders, 2,531 randomly selected participants from Iowa and Utah (1,243 teachers and 1,288 nonteachers) were interviewed by telephone using a voice disorder questionnaire. Prevalence-the number of cases per population at risk at a specific time-was determined. The prevalence of reporting a current voice problem was significantly greater in teachers compared with nonteachers (11.0% vs. 6.2%), chi(2)(1) = 18.2, p <.001, as was the prevalence of voice disorders during their lifetime (57.7% for teachers vs. 28.8% for nonteachers), chi(2)(1) = 215.2, p <.001. Teachers were also significantly more likely than nonteachers to have consulted a physician or speech-language pathologist regarding a voice disorder (14.3% vs. 5.5%), chi(2)(1) = 55.3, p <.001. Women, compared with men, not only had a higher lifetime prevalence of voice disorders (46.3% vs. 36.9%), chi(2)(1) = 20.9, p <.001, but also had a higher prevalence of chronic voice disorders (>4 weeks in duration), compared with acute voice disorders (20.9% vs. 13.3%), chi(2)(1) = 8.7, p =.003. To assess the association between past voice disorders and possible risks, adjusted odds ratios (ORs) were estimated using multiple logistic regression. The results identified that being a teacher, being a woman, being between 40 and 59 years of age, having 16 or more years of education, and having a family history of voice disorders were each positively associated with having experienced a voice disorder in the past. These results support the notion that teaching is a high-risk occupation for voice disorders. Important information is also provided regarding additional factors that might contribute to the development of voice disorders.

An evaluation of the effects of three laryngeal lubricants on phonation threshold pressure (PTP)

Clinicians frequently offer advice to performers and voice-disordered patients aimed ostensibly to manipulate the water content and/or viscosity of the mucus blanket covering the vocal folds. To evaluate the relative effects of three potential laryngeal lubricants on phonatory function (ie, water, Mannitol--an osmotic agent, and Entertainer's Secret Throat Relief (Kli Corp., Carmel, IN)--a glycerin-based product), phonation threshold pressure (PTP) was measured in 18 healthy, vocally normal female participants twice before (baseline) and then four times after 2 ml of each substance were nebulized. PTP is the minimum subglottal pressure required to initiate vocal fold oscillation, and the lowering of PTP is assumed to correspond to physiologically more efficient phonation and reduced phonatory effort. Over a 3-week period, participants were tested on three separate occasions (at 1-week intervals). On each occasion, a different nebulized treatment was administered. PTP for both comfortable and high fundamental frequency productions was measured using an oral pressure-flow system (Perci-Sars, MicroTronics Corp., Chapel Hill, NC). Analysis of the results revealed that Mannitol, an agent that encourages osmotic water flux to the luminal airway surface, lowered PTP immediately after its administration (ie, p = 0.071, for high-pitched productions only). However, the duration of its PTP lowering effect was less than 20 minutes. The other two substances did not demonstrate any significant postadministration effect on PTP.

Voice, speech, and swallowing outcomes in laser-treated laryngeal cancer

OBJECTIVE

To describe preliminary voice, speech, and swallowing outcomes in patients treated by endoscopic laser excision of laryngeal cancer with or without adjuvant radiation therapy.

STUDY DESIGN

Retrospective review.

METHODS

Seventeen surgically treated patients (five T2 glottic and 12 clinically staged T2 supraglottic squamous cell carcinomas) participated in the study. Self-ratings of voice (Voice Handicap Index) and swallowing (M. D. Anderson Dysphagia Inventory) were completed, as well as independent auditory-perceptual ratings of voice and speech recordings.

RESULTS

Although no significant difference between Voice Handicap Index, M. D. Anderson Dysphagia Inventory, and listener ratings was identified based on tumor site and irradiation status, there was a trend toward poorer outcomes in patients who received adjuvant radiation therapy. Whereas the patients having supraglottic cancer tended to report better voice but poorer swallowing outcomes, the glottic cancer group displayed the opposite pattern. Severity on Voice Handicap Index correlated significantly with listener severity ratings of speech, suggesting that the patients' perception of their voice handicap was similar to the listeners' judgments of their speech severity.

CONCLUSIONS

The results suggest the following trends: 1) Adjuvant radiation therapy was associated with poorer outcomes for voice, speech, and swallowing and may be associated with more impairment than surgery alone and 2) poorer outcomes on voice and swallowing were observed for the glottic and supraglottic cancer groups, respectively. To bolster these preliminary findings, additional outcomes studies in patients treated with conservation therapy are needed.

Three treatments for teachers with voice disorders: a randomized clinical trial

Voice problems are a common occupational hazard of teaching school, yet few studies exist that have objectively evaluated treatment approaches aimed at rehabilitating these occupation-related voice disorders. This randomized clinical trial used patient-based treatment outcome measures to evaluate the effectiveness of three treatment programs. Sixty-four teachers with voice disorders were randomly assigned to 1 of 3 treatment groups: voice amplification using the ChatterVox portable amplifier (VA; n = 25), resonance therapy (RT; n = 19), and respiratory muscle training (RMT; n = 20). Before and after a 6-week treatment phase, all teachers completed (a) the Voice Handicap Index (VHI; B. H. Jacobson et al., 1997), an instrument designed to appraise the self-perceived psychosocial consequences of voice disorders, and (b) a voice severity self-rating scale. Both intention-to-treat and as-treated analyses revealed that only the VA and RT groups reported significant reductions in mean VHI scores and in voice severity self-ratings following treatment. Furthermore, results from a posttreatment questionnaire regarding the perceived benefits of treatment showed that compared to RT and RMT, teachers in the VA group reported significantly more overall voice improvement, greater vocal clarity, and greater ease of speaking and singing voice following treatment. These findings replicate previous results from an earlier clinical trial confirming the efficacy of VA and provide new evidence to support RT as an effective treatment alternative for voice problems in teachers. The results are discussed in the context of uneven levels of self-reported compliance and disparate dropout rates among the treatment groups.

Functional dysphonia

Functional dysphonia-a voice disturbance in the absence of structural or neurologic laryngeal pathology-is an enigmatic and controversial voice disorder that is frequently encountered in multidisciplinary voice clinics. Poorly regulated activity of the intrinsic and extrinsic laryngeal muscles is cited as the proximal cause of functional dysphonia, but the origin of this dyregulated laryngeal muscle activity has not been fully elucidated. Several causes have been cited as contributing to this imbalanced muscle tension; however, recent research evidence points to specific personality traits as important contributors to its development and maintenance. Voice therapy by an experienced speech-language pathologist remains an effective short-term treatment for functional dysphonia in the majority of cases, but less is known regarding the long-term fate of such intervention. Further research is needed to better understand the pathogenesis of functional dysphonia, and factors contributing to its successful management.

Shoulder and elbow function following Marchetti-Vicenzi humeral nail fixation

Humeral nailing has been associated with reduction of shoulder and elbow function. We present the results of fixation of 15 diaphyseal humeral fractures with Marchetti-Vicenzi nails (B Braun Medical Aesculap). Shoulder and elbow functions were assessed by the Constant shoulder and Mayo elbow scoring systems. The average Constant Shoulder score was good (82.5/100) and the average Mayo Elbow Score was excellent (95.4/100). The indications for surgery included nonunion, pathological fractures and poor fracture position. The mean follow-up was 67 weeks with an average interval to surgery of 19 weeks. The mean time to union was 19 weeks. All the fractures united without any patient requiring any further procedure. There were two postoperative radial nerve palsies and one median nerve palsy, however two patients had complete recovery and one had partial recovery of the radial nerve. There was one deep infection requiring removal of the implant. There were no implant failures. Based on our experience, the Marchetti-Vicenzi humeral nail appears as a relatively safe implant and its use has been associated with preservation of good shoulder and elbow functions.

The ChatterVox portable voice amplifier: a means to vibration dose reduction?

By speaking loudly for extended periods, teachers are vulnerable to laryngeal and voice changes associated with vocal fold "vibration overdose." Voice clinicians frequently recommend voice amplification ostensibly designed to reduce vibration dose and improve voice. However, there are few data regarding the degree of vocal loudness attenuation achieved by specific amplification devices. The purpose of this investigation was to examine the effectiveness of the ChatterVox Portable Voice Amplification System (Siemens Hearing Instruments) for reducing the sound pressure level (SPL) of a speaker's voice during a simulated classroom lecture. Ten participants were instructed to continuously read one of two phonetically balanced passages while amplified and unamplified. Voice intensity measurements were obtained at three inches from the mouth (i.e., mouth level) and at the back of a classroom in both amplified and unamplified conditions. When amplified with the ChatterVox, speakers experienced an average decrease in vocal intensity at mouth-level of 6.03 dB SPL (p < 0.002). Furthermore, an average increase of 2.55 dB SPL (p < 0.038) at the back of the classroom was observed. Collectively, these results indicate that the ChatterVox amplification device reduced the speaker's vocal intensity level at the microphone, while it augmented the voice heard at the back of the classroom. By inference, this degree of vocal attenuation at mouth level should contribute to a desirable reduction in vibration dose, thus lowering the risk of vibration overdose.

Voice amplification versus vocal hygiene instruction for teachers with voice disorders: a treatment outcomes study

Voice problems are common among schoolteachers. This prospective, randomized clinical trial used patient-based treatment outcomes measures combined with acoustic analysis to evaluate the effectiveness of two treatment programs. Forty-four voice-disordered teachers were randomly assigned to one of three groups: voice amplification using the ChatterVox portable amplifier (VA, n = 15), vocal hygiene (VH, n = 15), and a nontreatment control group (n = 14). Before and after a 6-week treatment phase, all teachers completed: (a) the Voice Handicap Index (VHI), an instrument designed to appraise the self-perceived psychosocial consequences of voice disorders; (b) a voice severity self-rating scale; and (c) an audiorecording for later acoustic analysis. Based on pre- and posttreatment comparisons, only the amplification group experienced significant reductions on mean VHI scores (p = .045), voice severity self-ratings (p = .012), and the acoustic measures of percent jitter (p = .031) and shimmer (p = .008). The nontreatment control group reported a significant increase in level of vocal handicap as assessed by the VHI (p = .012). Although most pre- to posttreatment changes were in the desired direction, no significant improvements were observed within the VH group on any of the dependent measures. Between-group comparisons involving the three possible pairings of the groups revealed a pattern of results to suggest that: (a) compared to the control group, both treatment groups (i.e., VA and VH) experienced significantly more improvement on specific outcomes measures and (b) there were no significant differences between the VA and VH groups to indicate superiority of one treatment over another. Results, however, from a posttreatment questionnaire regarding the perceived benefits of treatment revealed that, compared to the VH group, the VA group reported more clarity of their speaking and singing voice (p = .061), greater ease of voice production (p = .001), and greater compliance with the treatment program (p = .045). These findings clearly support the clinical utility of voice amplification as an alternative for the treatment of voice problems in teachers.

Fibroma induction in rat skin following single or multiple doses of 1.0 GeV/nucleon 56Fe ions from the Brookhaven Alternating Gradient Synchrotron (AGS)

Rat skin was exposed to the plateau region of the 1.0 GeV/nucleon 56Fe beam at the Brookhaven AGS. Rats were irradiated or not with single of split doses of 56Fe or argon; some 56Fe-exposed rats were fed 250 ppm retinyl acetate continuously in the lab chow beginning 1 week before irradiation. All lesions were noted, photographed and identified for eventual histological diagnosis. The preponderance of the tumors so far are fibromas. The data show that single doses of 56Fe ions are 2 or 3 fold more effective than argon in producing tumors at 4.5 Gy but are about equally effective at 3.0 Gy and 9.0 Gy. The presence of 250 ppm retinyl acetate in the lab chow reduced the incidence of tumors by about 50-60% in comparison to groups exposed only to the radiation. These are preliminary findings based on only about one-fourth the eventual number of tumors expected.

An evaluation of the effects of two treatment approaches for teachers with voice disorders: a prospective randomized clinical trial

Teachers commonly report voice problems and often seek medical assistance for voice-related complaints. Despite the prevalence of voice disorders within this occupation, there are no studies evaluating the effectiveness of treatment programs designed to remedy the voice problems of teachers. To assess the functional effects of two voice therapy approaches, 58 voice-disordered teachers were randomly assigned to 1 of 3 groups: vocal hygiene (VH, n = 20), vocal function exercises (VFE, n = 19), and a nontreatment control group (CON, n = 19). Subjects completed the Voice Handicap Index (VHI)-an instrument designed to appraise the self-perceived psychosocial consequences of voice disorders-before and following a 6-week treatment phase. The VFE and VH subjects also completed a posttreatment questionnaire regarding the perceived benefits of treatment. Only the group who adhered to the VFE regimen reported a significant reduction in mean VHI scores (p <.0002). Furthermore, when compared to the VH group, the exercise group reported more overall voice improvement (p < .05) and greater ease (p < .02) and clarity (p < .01) in their speaking and singing voice after treatment. These findings suggest that the VFE should be considered as a useful alternative or adjunct to vocal hygiene programs in the treatment of voice problems in teachers.

Protein kinase C regulates transcription of the human guanylate cyclase C gene

Guanylate cyclase C is the receptor for the bacterial heat-stable enterotoxins and guanylin family of peptides, and mediates its action by elevating intracellular cGMP levels. Potentiation of ligand-stimulated activity of guanylate cyclase C in human colonic T84 cells is observed following activation of protein kinase C as a result of direct phosphorylation of guanylate cyclase C. Here, we show that prolonged exposure of cells to phorbol esters results in a decrease in guanylate cyclase C content in 4beta-phorbol 12-myristate 13-acetate-treated cells, as a consequence of a decrease in guanylate cyclase C mRNA levels. The reduction in guanylate cyclase C mRNA was inhibited when cells were treated with 4beta-phorbol 12-myristate 13-acetate (PMA) in the presence of staurosporine, indicating that a primary phosphorylation event by protein kinase C triggered the reduction in RNA levels. The reduction in guanylate cyclase C mRNA levels was not due to alterations in the half-life of guanylate cyclase C mRNA, but regulation occurred at the level of transcription of guanylate cyclase C mRNA. Expression in T84 cells of a guanylate cyclase C promoter-luciferase reporter plasmid, containing 1973 bp of promoter sequence of the guanylate cyclase C gene, indicated that luciferase activity was reduced markedly on PMA treatment of cells, and the protein kinase C-responsive element was present in a 129-bp region of the promoter, containing a HNF4 binding element. Electrophoretic mobility shift assays using an oligonucleotide corresponding to the HNF4 binding site, indicated a decrease in binding of the factor to its cognate sequence in nuclear extracts prepared from PMA-treated cells. We therefore show for the first time that regulation of guanylate cyclase C activity can be controlled at the transcriptional level by cross-talk with signaling pathways that modulate protein kinase C activity. We also suggest a novel regulation of the HNF4 transcription factor by protein kinase C.

Feeding motivation in swine: Relation with insulin, glucose and free fatty acids in portal and jugular blood, and involvement of cholecystokinin

The control of feeding motivation was studied in eight castrated male pigs (92.9 ± 1.5 kg) surgically fitted with jugular and portal vein catheters. The first part of the experiment was set up as a cross-over design. Two weeks after surgery, four pigs were fasted for 24 h (FAST) while the remaining four were fed ad libitum (CTL). Three days later, the same procedure was repeated with the treatments reversed. Blood samples were collected every 4 h during the first 16 h of these two 24-h periods. After each 24-h period, pigs were subjected to a feed motivation test during which blood samples were obtained every 5 min for 60 min for CTL pigs and until 30 min after cessation of eating in FAST pigs. Three days later, the second part of the experiment was conducted. Five of the eight pigs were fasted for another 24 h, injected i.v. with 70 μg kg–1 BW of a cholecystokinin (CCK) receptor antagonist (MK-329), and subsequently subjected to a feed motivation test. Insulin, glucose and FFA concentrations were greater (P < 0.001) in portal than jugular blood. Fasting decreased insulin concentrations in both portal and jugular blood, decreased glucose in portal blood only, and increased FFA in jugular blood only. The number of pushes (P < 0.05), duration of eating (P < 0.001) and amount of feed eaten during the feed motivation test (P < 0.01) were all increased by fasting, and were further increased with MK-329 injection. Results indicate that CCK is involved in the control of satiety in pigs and that concentrations of insulin, glucose and FFA in the jugular vein may not always be representative of concentrations in the portal vein. Key words: Swine, insulin, glucose, cholecystokinin, feeding motivation, fast

Whole-body protein metabolism and plasma profiles of amino acids and hormones in growing barrows fed diets adequate or deficient in lysine

Eighteen growing barrows (body weight: 26.6 ± 1.4 kg) were assigned (day 0) to one of three levels of dietary lysine: to be deficient (0.45%; L1), to achieve (0.75%; L2), or to exceed (0.98%; L3) National Research Council (NRC) (1988) lysine requirements (as-fed basis), according to a completely randomized block design. Nitrogen balance was measured over a 6-d period (days 10 to 16). On day 16, pigs were moved into respiratory chambers and received a 6-h continuous i.v. infusion of NaH13CO3 (1.66 µmol h−1 kg−1, preceded by a priming dose of 2.35 µmol kg−1) on day 17. The following day, pigs received an i.v. infusion of L-[1-13C]leucine (11.07 µmol h−1 kg−1, preceded by a priming dose of 11.07 µmol kg−1). Average daily gain and nitrogen retention increased (P < 0.10) by 36 and 20%, respectively, as dietary lysine content increased from L1 to L3. Leucine irreversible loss rate increased (P < 0.05) by 14% from diets L1 to L3, while leucine oxidation remained constant (P > 0.10) between diets. In consequence, fractional oxidation decreased (P < 0.05) by 20%, from L1 to L3. Protein synthesis and degradation increased (P < 0.05) from diets L1 to L2, but the values for the diets L2 and L3 were similar. Insulin levels tended to increase from L1 to L3 (P < 0.10), while that of triiodothyronine decreased from diets L1 to L3 (P < 0.05). Daily feed intake, nutrient digestibility, energy metabolism and plasma concentrations of insulin-like growth factor 1 and growth hormone were not affected (P > 0.10) by treatments. In conclusion, the improvement in protein gain associated with increasing lysine supplementation to achieve lysine requirement involved a general stimulation of whole-body turnover, protein synthesis being increased to a larger extent than protein degradation. Key words: Pigs, protein, metabolism, hormone, lysine, leucine

Personality and voice disorders: a multitrait-multidisorder analysis

To examine whether personality has causal, concomitant, or outcome status in common voice disorders, a vocally normal control group and 4 groups with voice disorders--functional dysphonia (FD), vocal nodules (VN), spasmodic dysphonia (SD), and unilateral vocal fold paralysis (UVFP)--were compared using the Multidimensional Personality Questionnaire (MPQ). Univariate and discriminant analyses confirmed that the FD and VN groups differed significantly from each other, the controls, and the other voice-disordered groups at both a superfactor and lower-trait level of personality description. The FD group was introverted, stress reactive, alienated, and unhappy. The VN group was described as socially dominant, stress reactive, aggressive, and impulsive. Comparisons involving the SD, UVFP, and the control subjects did not identify consistent personality differences. While group trends supported the central tenets of a trait theory outlining the dispositional bases of FD and VN, further research is needed to elucidate the specific causal mechanism(s) in individual cases. The disability hypothesis, which suggests that personality features represent the negative effects of vocal disability, was not strongly supported.

Organochlorine exposures and breast cancer risk in New York City women

A hospital-based case-control study of breast cancer risk related to organochlorine (OC) exposure was conducted in a multiethnic setting in New York City. We enrolled 175 breast cancer patients and 355 control patients. The overall racial/ethnic distribution was 57% Caucasian, 21% Hispanic, 22% African-American; cases and controls were frequency-matched by age and race/ethnicity. Tumor markers (estrogen and progesterone receptors, p53, erbB-2) were assessed and organochlorines (DDE, DDT, trans-nonachlor, and higher (HPCB) and lower (LPCB) chlorinated biphenyls) were measured in blood serum. Tumors among minority women were of slightly higher stage than among Caucasians, but tumor markers were similar across the racial/ethnic groups. DDE levels were highest among African-American and Hispanic women; DDT was highest among Hispanics; HPCBs were highest among African-Americans; LPCBs were lowest among Hispanics; and trans-nonachlor was highest among African-Americans. However, OC levels were not associated with risk for breast cancer, nor did OCs differ with respect to tumor stage or tumor markers. Higher DDE levels were associated with increasing body mass index (BMI), but with decreasing level of education, frequency of nulliparity, and frequency of family history of breast cancer. HPCB levels decreased with BMI and were not correlated with breast cancer risk factors. These relationships can be attributed to historical patterns of exposure and to metabolic differences in OCs related to BMI.

Effect of aluminum on the production of siderophore by Rhizobium sp. (Cicer arietinum)

Rhizobium sp. strain BICC 651 in the presence of 100 microM Al3+ produced a threefold higher level of siderophore than in the control culture under iron limitation during the stationary phase. Al3+ in increasing concentrations resulted in decreased growth, and the effect was alleviated by the addition of iron. Siderophore production decreased gradually in Al3+-treated culture as well as in the control with the addition of increasing concentrations of Fe3+, and at 50 microM Fe3+ the level of siderophore was practically undetectable. The siderophore binds Fe3+ and also Al3+. The outer membrane protein profiles of the bacteria grown in the presence or absence of Al3+ were indistinguishable.

Personality and voice disorders: a superfactor trait analysis

To determine whether personality factors play causal, concomitant, or consequential roles in common voice disorders, a vocally normal control group and four groups with voice disorders-functional dysphonia (FD), vocal nodules (VN), spasmodic dysphonia (SD), and unilateral vocal fold paralysis (UVFP)-were compared on measures of personality and psychological adjustment. Superfactor group comparisons revealed that the majority of FD and VN subjects were classified as introverts and extraverts, respectively. Comparisons involving the SD, UVFP, and control subjects did not identify consistent personality differences. The disability hypothesis, which suggests that personality features and emotional maladjustment are solely a negative consequence of vocal disability, was not supported. Personality variables and their behavioral consequences may therefore contribute to FD and VN. Results are presented within the context of a dispositional theory offered by Roy and Bless (2000a).

Vocal violence in actors: an investigation into its acoustic consequences and the effects of hygienic laryngeal release training

Acoustic analysis techniques were used to investigate the short-term consequences of vocally violent behavior, and to compare voice production before and after training in hygienic laryngeal release (HLR) techniques. Twenty-seven actors ranging in age from 17 to 48 years were audiorecorded before and after multiple productions of 4 vocally violent behaviors: grunting, groaning, sobbing, and shouting. After training in HLR techniques, the experimental protocol was repeated. Audiorecordings of vowels (produced at 3 pitch levels: modal F0, minimum F0, maximum F0) before and after vocal violence, and before and after HLR training, were analyzed using the Multidimensional Voice Program (4305, Kay Elemetrics Corp, Lincoln Park, NJ). After vocal violence, no consistent acoustic changes were detected for voice generated at modal and minimum F0; however, significant increases in both fundamental frequency range and maximum F0 were observed. After training in HLR techniques, acoustic measures sensitive to pitch and amplitude perturbation, and non-harmonic noise, improved across pitch levels. The results also indicated that vocal training does defend the laryngeal system from undesirable changes related to vocally violent maneuvers that might surface at the extremes of an actor's pitch range. Because the HLR technique used in this investigation was multimodal, interesting questions are raised regarding which aspect of training is primarily responsible for the observed effects. Further study is required to identify such factors.

Personality traits and psychological factors in voice pathology: a foundation for future research

It has been argued that personality, emotions, and psychological problems contribute to or are primary causes of voice disorders and that voice disorders in turn create psychological problems and personality effects. This article (a) briefly reviews the literature surrounding the role of psychological and personality processes in individuals with functional dysphonia (FD), vocal nodules (VN), and spasmodic dysphonia (SD); (b) provides an overview of recent concepts in personality and trait structure; and (c) summarizes the fundamental tenets of a theoretical synthesis proposed by Roy and Bless (2000) to explain the dispositional bases of FD and VN. This theory links FD and VN to the signal sensitivities and behavioral response biases of neurotic introverts and neurotic extraverts, respectively. In a companion article, the merits of the Roy and Bless theory are evaluated.