Confounding Effect in Clinical Research of Otolaryngology and Its Control / 中国医学科学杂志(英文版)

Confounding effect is a critical issue in clinical research of otolaryngology because it can distort the research's conclusion. In this review, we introduce the definition of confounding effect, the methods of verifying and controlling the effect. Confounding effect can be prevented by research's design, and adjusted by data analysis. Clinicians would be aware and cautious about confounding effect in their research. They would be able to set up a research's design in which appropriate methods have been applied to prevent this effect.They would know how to adjust confounding effect after data collection. It is important to remember that sometimes it is impossible to eliminate confounding effect completely, and statistical method is not a master key. Solid research knowledge and critical thinking of our brain are the most important in controlling confounding effect.

Genetic Effects on Sensorineural Hearing Loss and Evidence-based Treatment for Sensorineural Hearing Loss / 中国医学科学杂志(英文版)

In this article, the mechanism of inheritance behind inherited hearing loss and genetic susceptibility in noise-induced hearing loss are reviewed. Conventional treatments for sensorineural hearing loss (SNHL), i.e. hearing aid and cochlear implant, are effective for some cases, but not without limitations. For example, they provide little benefit for patients of profound SNHL or neural hearing loss, especially when the hearing loss is in poor dynamic range and with low frequency resolution. We emphasize the most recent evidence-based treatment in this field, which includes gene therapy and allotransplantation of stem cells. Their promising results have shown that they might be options of treatment for profound SNHL and neural hearing loss. Although some treatments are still at the experimental stage, it is helpful to be aware of the novel therapies and endeavour to explore the feasibility of their clinical application.

Categories and characteristics of BPH drug evaluation models: a comparative study / 中华男科学杂志

Benign prostatic hyperplasia (BPH) is a worldwide common disease in men over 50 years old, and the exact cause of BPH remains largely unknown. In order to elucidate its pathogenesis and screen effective drugs for the treatment of BPH, many BPH models have been developed at home and abroad. This article presents a comprehensive analysis of the categories and characteristics of BPH drug evaluation models, highlighting the application value of each model, to provide a theoretical basis for the development of BPH drugs.

Study on the stability of perceptual evaluation of voice quality / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To explore the factors that influence the stability of evaluation results judged by a jury through a standard research on perceptual evaluation measurements of voice quality.</p><p><b>METHODS</b>Voice samples from 300 patients with dysphonia and 100 control subjects with normal voice were recorded and assessed by a jury composed of 6 experienced listeners from different hospitals. The voice samples were discourse voices and ordered randomly 3 times, and the mean of 3 evaluations using visual analogue scale were the final results. The jury was instructed to classify voice samples according to the G (grade), R (rough) and B (breathy) components of the GRBAS scale on a 4-point scale ranging from 0 for normal to 3 for severe dysphonia. Κ value was used to analyze the concordance of evaluation results and regression analysis was used to research the effects of the extent of voice disorder to the stability of perceptual evaluation.</p><p><b>RESULTS</b>The discordance of evaluation existed both between the jury and in listeners themselves. The concordance of listeners themselves of each evaluation parameter was not bad, good, or even very good, and the concordance of evaluation of G was the best (κ value: 0.46 - 0.85), then R (κ value: 0.41 - 0.84) and B (κ value: 0.41 - 0.81). The concordance between the jury was worse than that in themselves. And except a listener whose concordance of evaluation was under the requirement, the concordance of evaluation of G was the best (κ value: 0.43 - 0.96), then R (κ value: 0.33 - 0.78) and B (κ value: 0.002 - 0.45). The stability of evaluation of normal voice and severe voice disorder was better than mild and moderate voice disorder.</p><p><b>CONCLUSIONS</b>The discordance between the jury was the main factor that influence the stability of perceptual evaluation. The evaluation parameters and extent of voice disorder will influence the stability of perceptual evaluation of the jury.</p>

Case-control survey on risk factors of benign vocal fold lesions / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To investigate the risk factors that may relate with benign vocal fold lesions including vocal fold nodule, vocal fold polyp, chronic laryngitis and Reinke's edema</p><p><b>METHODS</b>In present series, 321 cases who were performed laryngoscope were invited to participate the survey. Among them 168 cases with benign vocal fold lesions composed the case group. Another 153 cases with normal larynx composed the control group. Each case were undertook the same questionnaire. Logistic regression analysis was preformed to investigate the possible risk factors.</p><p><b>RESULTS</b>The result demonstrated the occurring of benign vocal fold lesions positively correlated to five factors, including occupation, work or residence environment noise, alcohol-consuming, voice-using hours per day and abuse of voice. Occupations with intensive voice-use were more vulnerable to developing these disorders. Occurring risk of occupations type II with moderate voice-use was 1.934 times than that of occupations type I with lesser voice-use (OR = 1.934). And risk of occupations type III with upper voice-use was 2.633 times than that of type I. Risk raised 1.302 times with each more hour of voice use per day. OR of the following factors of voice abuse, environment noise, alcohol-consuming was 4.744, 2.115 and 2.177, respectively.</p><p><b>CONCLUSIONS</b>The result suggested that people should abstain from alcohol, lowering the environment noise, prevent overuse and abuse of voice in order to decrease the prevalence of these disorders, which is especially important for the professional voice users, e. g. teachers or managers. The essential therapy for these disorders is to correct bad phonation habits.</p>

Electron microscopic observation of vocal fold polyps / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>The purpose of this study was to observe the ultrastructure of the fibroblasts, collagen and elastic fibers in vocal fold polyps.</p><p><b>METHODS</b>Ten vocal fold polyps and 3 normal vocal fold specimens obtained from total laryngectomy were studied by means of transmission electron microscope and scanning electron microscope.</p><p><b>RESULTS</b>The result showed that in vocal fold polyps, the quantity of fibroblasts increased and there were abundant organelles, suggesting that the fibroblast were in the status of activation. As the main cell to produce lamina propria extracellular matrix, the representation suggested that the extracellular matrix metabolism was active. Leucocytes soakage was observed, suggesting that the inflammation may play a role in the lesion. It was found by scanning electron microscopy that in case of lesions, collagen fibers and elastic fibers arrayed irregularly.</p><p><b>CONCLUSIONS</b>Under pathologic circumstance, fibroblasts, collagen and elastic fibers altered in morphology, which possibly induced the functional alteration.</p>

mRNA expression of extracellular matrix proteins of vocal fold polyps and Reinke edema / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To investigate the pathogenic mechanism of vocal fold polyps and Reinke's edema.</p><p><b>METHODS</b>A reverse-transcriptase polymerase chain reaction (RT-PCR) technique was adopted, mRNA levels of 9 proteins were measured in 12 vocal fold polyps, 2 Reinke's edema and 5 normal vocal folds (from total laryngectomy).</p><p><b>RESULTS</b>The results showed that in the vocal fold polyps, mRNA levels of collagenase and fibromodulin descended and levels of fibronectin increased (P < 0.05). mRNA levels of lysyl oxidase and hyaluronic acid synthase 2 had no statistic difference between lesions and normal vocal folds (P > 0.05). mRNA express of tropoelastin exon, elastase and hyaluronidase was positive in part of lesion tissue and positive in all normal vocal folds. mRNA of procollagen I was negative in both groups. In the Reinke's edema, mRNA express of fibronectin was close to vocal fold polyps and mRNA express of fibromodulin was close to normal vocal folds.</p><p><b>CONCLUSIONS</b>It was speculated phonation trauma and vocal fold restoring to trauma played an important role in pathogenic mechanism. Fibromodulin and fibronectin were two components involved in the disorders.</p>