The effect of non-diabetic chronic renal failure on olfactory function

Objectives

In chronic renal failure (CRF), deterioration of glomerular filtration results in accumulation of metabolites in the body which affect all organs. This study was performed to investigate the olfactory functions, and determine if hemodialysis or peritoneal dialysis improves olfactory function in non-diabetic CRF patients.

The effect of high altitude on olfactory functions

It is known that high-altitude trips cause nasal congestion, impaired nasal mucociliary transport rate, and increased nasal resistance, due to decreased partial oxygen pressure and dry air. It is also known that olfactory perception is affected by barometric pressure and humidity. The aim of the present study was to investigate whether olfactory function changes in relation to high altitude in a natural setting. The present study included 41 volunteers with no history of chronic rhinosinusitis or nasal polyposis. The study group consisted of 31 men (76 %) and 10 women (24 %); the mean age of the study population was 38 ± 10 years. Olfactory testing was conducted using “Sniffin’ Sticks” at a high altitude (2,200 ms) and at sea level. Odor test scores for threshold and identification were significantly better at sea level than at high altitude (p < 0.001). The major finding of this investigation was that olfactory functions are decreased at high altitudes.     

Pathology of the olfactory epithelium: smoking and ethanol exposure

OBJECTIVE: To investigate the effects of tobacco smoke on the olfactory epithelium. Cigarette smoking has been associated with hyposmia; however, the pathophysiology is poorly understood. The sense of smell is mediated by olfactory sensory neurons (OSNs) exposed to the nasal airway, rendering them vulnerable to environmental injury and death. As a consequence, a baseline level of apoptotic OSN death has been demonstrated even in the absence of obvious disease. Dead OSNs are replaced by the mitosis and maturation of progenitors to maintain sufficient numbers of neurons into adult life. Disruption of this balance has been suggested as a common cause for clinical smell loss. This current study will evaluate the effects of tobacco smoke on the olfactory mucosa, with emphasis on changes in the degree of OSN apoptosis. STUDY DESIGN: A rat model was used to assess the olfactory epithelium after exposure to tobacco smoke. METHODS: Rats were exposed to tobacco smoke alone (for 12 weeks), smoke plus dietary ethanol (for the final 5 weeks), or to neither (control). Immunohistochemical analysis of the olfactory epithelium was performed using an antibody to the active form of caspase-3. Positive staining for this form of the caspase-3 enzyme indicates a cell undergoing apoptotic proteolysis. RESULTS: Control rats demonstrated a low baseline level of caspase-3 activity in the olfactory epithelium. In contrast, tobacco smoke exposure triggered a dramatic increase in the degree of OSN apoptosis that affected all stages of the neuronal lineage. CONCLUSIONS: These results support the following hypothesis: smell loss in smokers is triggered by increased OSN death, which eventually overwhelms the regenerative capacity of the epithelium.     

A study on the mechanism of phleboid olfactory function

Phleboid olfactory test has wide clinical application for olfactory disturbance. Many unclarified aspects still remain concerning the mechanism of smell after an intravenous infusion of Alinamin. It is believed that when Alinamin is infused intravenously and byproducts are discharged from the blood into the alveoli, odorous substances reach the nasal cavity through exhalation. In order to clarify the mechanism of smell in more detail, we conducted the following experiments: 1) Cases of laryngectomy were examined to determine if intravenous infusion of Alinamin affected the olfactory organ. 2) Saliva specimens in healthy subjects were collected before and after intravenous infusion of Alinamin and examined for the presence of a secreted odorous substance using a functional test. 3) Healthy subjects who were inhibited in their sense of smell were examined for the presence of garlic odor after intravenous infusion of Alinamin. The results were as follows: 1) 80% of subjects of laryngectomy without cotton in the nares and 20% of subjects of laryngectomy with cotton in the nares perceived the garlic odor. 2) Garlic odorous substance was not recognized in saliva specimens collected before and after intravenous infusion of Alinamin. 3) The healthy subjects inhibited in their sense of smell and intravenously infused with Alinamin perceived the odor at the same time as exhalation. The above results indicated that the mechanism of smell after intravenous infusion of Alinamin occurred via exhalation, but not through the other routes.     

The effect of N-methyl-formimino-methylester on the neural olfactory threshold in albino mice

Summary The effects of N-methyl-formimino-methylester were studied in albino mice. Very short exposure (0.5 and 1 s) to the concentrated vapour led to an increase of the neural olfactory threshold to geraniol by a factor of 10⁵–10⁷. There was a slow recovery of the olfactory sensitivity and after about 40 days the threshold values returned to normal.Supported by the Deutsche Forschungsgemeinschaft and ABM Ia2-5100     

鼻咽癌患者放疗后嗅觉功能及嗅球体积和嗅沟深度的研究

目的　探讨放疗对鼻咽癌患者嗅觉功能以及嗅球体积和嗅沟深度的影响。方法　选取鼻咽癌放疗结束后1年以上的患者（测试组）及无嗅觉减退的健康受试者（对照组）各20例,采用TT嗅觉测试法检查所有受试者的嗅觉功能,并行嗅球体积、嗅沟深度MRI检查。结果  测试组TT嗅觉测试法嗅觉功能评分大于对照组,测试组 平均嗅球体积明显小于对照组。测试组与对照组平均嗅沟深度比较无差异。测试组嗅觉识别阈与嗅球体积呈负相关性（r =-0.641,P <0.05）,与嗅沟深度无关（r =-0.175,P >0.05）。结论　鼻咽癌放疗后嗅觉减退患者,嗅球体积减少,嗅沟深度不变;嗅觉功能与嗅球体积具有相关性,与嗅沟深度无关。     

Medicolegal screening of olfactory function

Prior to nose surgery the birhinal ability to smell should be tested routinely. From the medico-legal point of view a short screening-test consisting of 5 or 8 test items is not sufficient. It is recommended to use an identification test with 12 or 16 items. The results of these tests taken together with the patients' self estimation, the patients' history and the rhinoscopic findings offer a satisfactory evaluation of the patients' ability to smell in most cases. In case of discrepancies a more detailed test determining the TDI-value is recommendable. If the 16-identification test is used, it is sufficient to add the values of the threshold and the discrimination measurements with the "Sniffin' Sticks" to complete a full TDI score.     

Assessment the long-term effects of septoplasty surgery on olfactory function

Objectives: This research aimed to evaluate pre-operatively and post-operatively the olfactory function of patients who had undergone surgery in our clinic for chronic nasal blockage via the Connecticut Chemosensory Clinical Research Center (CCCRC) smell test.

Method: Thirty-seven patients (24 females, 13 males) were enrolled in this study. All had undergone surgery in our clinic due to chronic nasal blockage (not for smell dysfunction), having been diagnosed with septal deviation in conjunction with concha bullosa and/or inferior turbinate hypertrophy. This is a prospective study without a control group. The mean age was 33.74?±?8.98 (range =19–54). All of the operations were performed under general anesthesia. CCCRC smell tests were performed on every patient before the operation and at post-operative 1st week, 6th week, 6th month, and 1st year.

Results: In this study, we found that septoplasty, in conjunction with middle concha surgery and/or inferior concha radiofrequency, did not affect the olfactory function negatively.

Conclusion: Although nasal surgery has the potential to affect the smell function negatively, it was found that olfactory function was not affected after the surgery during a considerably long follow-up period. Moreover, an improvement in smell function was detected at post-operative 6th month and 1st year.     

男性嗅觉功能与嗅沟深度分析

目的分析健康男性嗅觉功能与嗅沟深度的关系。方法对38位男性健康志愿者（年龄19～45岁,平均35.07岁）用嗅棒测试法进行嗅觉功能测定,包括阈值、气味分辨和气味识别鉴定3部分检测。检测之后立即进行嗅沟MRI,通过MRI经球后冠状切面对嗅沟深度进行测量,对嗅觉功能与嗅沟深度进行直线相关分析并对左、右侧嗅沟进行配对t检验。结果嗅觉功能与左侧嗅沟深度相关（r=0.570,P=0.000）,未观察到与右侧相关性;右侧嗅沟较左侧深（t=0.454,P﹤0.05）。结论在嗅沟深度与嗅觉功能之间存在联系,嗅沟深度一侧化与嗅觉系统功能一侧化相关,嗅觉系统具有右侧优势;MRI测量嗅沟深度对评估嗅觉功能具有一定意义。