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.

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.

A partial cDNA sequence for the gene linked to the von Hippel-Lindau (VHL) syndrome was reported in 1993. Mutation or loss of both VHL alleles has been documented in sporadic renal cell carcinomas and in the neoplasms that arise in von Hippel-Lindau kindreds. We have determined that the protein product of the VHL gene is an approximately 30 kilodalton cytoplasmic protein. The renal carcinoma cell line 786-O is known to harbour a VHL mutation and, as shown here, fails to produce a wild-type VHL protein. Reintroduction of wild-type, but not mutant, VHL into these cells had no demonstrable effect on their growth in vitro but inhibited their ability to form tumours in nude mice.

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Proteoglycans, particularly hyaluronic acid, play important roles in determining biomechanical properties of tissue oscillation. Future research will likely make these proteins of important therapeutic interest.

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This article discusses the molecular composition of the vocal fold and the relationship of fibrous molecules to the biomechanical and physiological performance of the tissue. The components of the extracellular matrix may be divided into fibrous proteins and interstitial proteins. The fibrous proteins, consisting of collagens and elastins, are the focus of this report. Elastin concentration varies by tissue depth in the vocal folds. Variation of elastin by age is reported, but some controversy exists. The biomechanical terms of stress and strain (and stress-strain curves of human vocal folds) are related to the fibrous proteins of the vocal folds. The fibrous proteins, their role in stress, and their effect on the dynamic range of vocal pitch are presented.

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