慢性鼻窦炎嗅觉障碍的嗅粘膜病理学观察

目的观察慢性鼻窦炎嗅觉障碍患者的嗅粘膜病理变化及其与嗅觉障碍的治疗和预后的关系。方法对２３例住院行鼻内窥镜手术治疗的鼻窦炎患者的嗅粘膜进行了组织学观察。术前嗅觉检查均为嗅觉缺失，失嗅时间５～３０年，平均１１．８年。男１５例，女８例，年龄２６～７１岁，平均４８岁。结果２３例（２３侧）嗅粘膜均发现有病理组织学的改变，其中程度不等的嗅上皮萎缩１０侧次（４３．５％），程度不等的嗅细胞减少１６侧次（６９．６％），呼吸上皮化生６侧次（２６．１％），嗅腺粘液腺化生１０侧次（４３．５％）。术后随访２～６个月，嗅觉恢复或改善者１６例（６９．６％），为嗅上皮正常或轻中度病变者。嗅觉无变化７例（３０．４％），为嗅上皮中重度或重度病变者。结论嗅上皮病变程度与术后嗅觉恢复程度成正相关，嗅细胞的数量减少越明显，嗅觉障碍治疗的预后越差。     

Evaluation of olfactory function by topographic EEG analysis in patients with Parkinson''s disease

Olfactory function impairment has been observed in patients with idiopathic Parkinson's disease (PD) using psychophysical procedures. In this study, an electrophysiological technique based on spectral analysis and topographic EEG mapping was used to evaluate EEG arousal response to olfactory stimulation in ten normal subjects and ten PD patients in stage II according to Hoehn and Yahr's scale, all of whom had akinetic-rigid syndrome and were receiving chronic L-Dopa therapy. Olfactory function was stimulated using diluted benzaldehyde by means of an apparatus set up in our laboratory. Spontaneous and post-olfactory stimulus EEGs were recorded from 20 electrodes placed upon the scalp according to the Int. 10–20 System. Total EEG power (from 0.5 to 19.5 Hz) was evaluated over 10 sec. artefact-free epochs. An olfactory arousal reaction was detected in nine of the ten PD patients and was characterised by a significant decrease in total power similar to that observed in all of the 10 normal subjects; these variations in EEG were found in all but the anterior regions of the scalp. The use of this technique does not seem to reveal any clear alteration in the olfactory function of PD patients.

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Sommario Una alterazione della funzione olfattiva è stata osservata in pazienti affetti da morbo di Parkinson idiopatico (MP) impiegando metodiche psicofisiche. In questo studio è stata utilizzata una tecnica elettrofisiologica, basata sull'impiego dell'analisi spettrale e sulla rappresentazione in mappe del segnale EEG, al fine di valutare la reazione di arousal prodotta dalla stimulazione olfattiva in 10 soggetti normali di controllo ed in 10 pazienti affetti da MP, in stadio II secondo la scale di Hoehn e Yahr, con forma acinetico-ipertonica ed in terapia cronica con L-Dopa. La stimolazione olfattiva veniva condotta, utilizzando Benzaldeide diluita in olio di paraffina, mediante un'apparecchiatura messa a punto nel nostro laboratorio. L'EEG basale e dopo stimolo veniva registrato da 20 elettrodi disposti secondo il Sistema Internazionale 10–20; su epoche di 10 sec. prive di artefatti è stata calcolata la potenza totale (da 0.5 a 19.5 Hz) in corrispondenza di tutti gli electtrodi. Una reazione di arousal veniva rilevata in 9 su 10 pazienti con MP ed era caratterizzata da un decremento di potenza totale analogo a quello verificato nel gruppo di controllo; tali variazioni interessavano tutte le regioni dello scalpo tranne le anteriori. L'impiego di questa metadica oggettiva non sembra pertanto mettere in evidenza una chiara alterazione della funzione olfattiva in pazienti affetti da MP.

     

Can community-dwelling women reliably identify infected urine?

The purpose of this study was to evaluate whether community-dwelling women can reliably identify infected urine samples. A convenience sample of 25 women judged six urine samples. Of these, two were normal, two contained culture-proven infections, and two were intentionally abnormal because of ingestion of asparagus or vitamins. The women decided if each sample was infected based on its color, clarity, and odor. For the two normal samples, 56 and 96% women correctly identified them. Of the two samples positive for infection, women were correct 80 and 100% of the time. Of the two samples designed to be abnormal, women were correct in 92 and 64% of their evaluations. Using the 150 total evaluations of urine samples, the sensitivity was 90%, and the specificity was 77%. Based on this small sample, community-dwelling women can detect infected samples of urine. However, women should still be screened for factors that might have distorted normal urine. Presented in poster form at the American Urogynecology Society, Palm Springs, CA, October 2006.     

The issue of primary tastes versus a taste continuum

The concept of four primary tastes has been used to direct research and organize data in gustation. The attractive simplicity of this formulation has directed attention away from critical examinations of its validity. The present article shows that arguments used to support the concept of four tastes are equivocal. It is also suggested that the data are more consistent with the hypothesis that gustatory data have a more continuous organization which includes the familiar primary four. Data are considered at the stimulus, receptor, neural, and psychophysical levels.     

Olfactory toxicity: long-term effects of occupational exposures

Objective: To present and discuss the results of research on olfactory function impairments related to chronic occupational exposure to industrial chemicals. Methods: This review is mainly focused on the results of epidemiological studies on olfactory function, evaluated using quantitative testing methods, in workers chronically exposed to airborne industrial chemicals. Papers published in peer-reviewed scientific journals were mainly considered. Results: The prevalence of olfactory impairments related to occupational exposure to chemicals is unknown: frequencies ranging 0.5–5% of all olfactory dysfunctions have been proposed, considering both exposure to chemicals and the use of pharmaceutical drugs, but the real relevance of this problem is possibly overlooked, especially considering that occupational exposure may account for a significant part of “idiopathic” smell disorders, i.e., the 10–25% of all olfactory problems within the general population. An adverse effect has been reported in workers chronically exposed to some metals as cadmium, chromium, manganese, arsenic, mercury, and organic lead, and to other chemicals as acrylates, styrene, and solvent mixtures. The results of relevant studies are discussed. A problem in the evaluation of data is that different methods have been applied in different studies, affecting the comparability of results. Conclusions: To date, knowledge of the effect of chronic occupational exposure to industrial chemicals on olfactory function is largely incomplete, but supports the hypothesis that olfactory neuroepithelium is susceptible to environmental exposures to chemicals. Occupational-related olfactory impairment is usually sub-clinical, and can be only detected using adequate quantitative olfactory function testing procedures. Available data show the need for further good quality research in this field.     

Olfactory dysfunction and its measurement in the clinic and workplace

Objectives: To provide an overview of practical means for quantitatively assessing the sense of smell in both the clinic and workplace. To address basic measurement issues, including those of test sensitivity, specificity, and reliability. To describe and discuss factors that influence olfactory function, including airborne toxins commonly found in industrial settings. Methods: Selective review and discussion. Results: A number of well-validated practical threshold and suprathreshold tests are available for assessing smell function. The reliability, sensitivity, and specificity of such techniques vary, being influenced by such factors as test length and type. Numerous subject factors, including age, sex, health, medications, and exposure to environmental toxins, particularly heavy metals, influence the ability to smell. Conclusions: Modern advances in technology, in conjunction with better occupational medicine practices, now make it possible to reliably monitor and limit occupational exposures to hazardous chemicals and their potential adverse influences on the sense of smell. Quantitative olfactory testing is critical to establish the presence or absence of such adverse influences, as well as to (a) detect malingering, (b) establish disability compensation, and (c) monitor function over time.     

乙醇气味刺激食蟹猴的脑fMRI

目的 应用3.0T fMRI探讨食蟹猴经乙醇气味刺激引起的脑功能活动。方法 选取健康食蟹猴6只,麻醉后行乙醇气味刺激下的fMRI。采取"静息-刺激-静息"组块设计。刺激组块予乙醇气味刺激,静息组块无气味刺激。BOLD-fMRI扫描128 phase,整个猴脑扫描16层。采用SPM2软件随机效应模式t检验进行组分析。将统计结果覆盖于食蟹猴模板图像上。结果 乙醇气味刺激下,在额叶、颞叶、中央旁小叶、扣带回、豆状核、中央前回分别可以检测到正激活和负激活。结论 海马回钩和眶额回为嗅觉最高级中枢。fMRI可以显示额叶、颞叶的激活。气味刺激引起的中枢反应与中央旁小叶、扣带回、豆状核有密切关系。     

Measurement of chemosensory function

Although hundreds of thousands of patients seek medical help annually for disorders of taste and smell, relatively few medical practitioners quantitatively test their patients' chemosensory function, taking their complaints at face value. This is clearly not the approach paid to patients complaining of visual, hearing, or balance problems. Accurate chemosensory testing is essential to establish the nature, degree, and veracity of a patient's complaint, as well as to aid in counseling and in monitoring the effectiveness of treatment strategies and decisions. In many cases, patients perseverate on chemosensory loss that objective assessment demonstrates has resolved. In other cases, patients are malingering. Olfactory testing is critical for not only establishing the validity and degree of the chemosensory dysfunction, but for helping patients place their dysfunction into perspective relative to the function of their peer group. It is well established, for example, that olfactory dysfunction is the rule, rather than the exception, in members of the older population. Moreover, it is now apparent that such dysfunction can be an early sign of neurodegenerative diseases such as Alzheimer's and Parkinson's. Importantly, older anosmics are three times more likely to die over the course of an ensuring five-year period than their normosmic peers, a situation that may be averted in some cases by appropriate nutritional and safety counseling. This review provides the clinician, as well as the academic and industrial researcher, with an overview of the available means for accurately assessing smell and taste function, including up-to-date information and normative data for advances in this field.     

秀丽隐杆线虫嗅觉适应性的分子细胞生物学机制

嗅觉适应是动物的一项重要生理功能,可以保护自身细胞免受过度刺激,进而更好地应对周围环境变化。目前发现秀丽隐杆线虫嗅觉适应性主要与嗅觉神经元胞内信号分子和感受蛋白有关,如AWC神经元区域特异性环鸟苷酸（cGMP）反应、瞬时受体电位香草酸亚型（TRPV）离子通道蛋白OSM-9、细胞质基质抑制蛋白ARR-1和G蛋白信号通路中的甘油二酯（DAG）通路等均可以调控嗅觉适应,而神经环路方面的嗅觉适应性研究甚少。本文总结回顾了线虫嗅觉适应有关的分子细胞生物学机制,以期为高等生物嗅觉的研究提供参考。