Intracellular calcium kinetics after odorant stimulus in olfactory receptor cells isolated from mice

cAMP and IP3 act as secondary messengers in olfactory signal transduction and when activated, stimulate calcium levels in olfactory receptor cells. Little is known however, about the causal mechanism. We studied calcium kinetics in mouse olfactory receptor cells after odorant stimuli. Olfactory receptor cells were isolated from female BALB/c mice, treted with trypsin, and stained with Fura-2/AM. Changes in intracellular Ca2+ concentrations in stained cells were measured with a fluorescent microscopic image-processing device (ARGUS-50; Hamamatsu Photonix, Japan). We found that intracellular Ca2+ concentrations rose after exposure to a set of odorants, including 3-ethoxy-4-hydroxy-benzaldehyde, caprylic acid, heptanoic acid, nonanoic acid, eugenol, phenethyl alcohol, and n-amyl acetate. Adding 2', 5'-dideoxyadenosine, a cAMP inhibitor, beforehand suppressed olfactory receptor cell response to odorants. Intracellular Ca2+ concentrations increased substantially in response to stimulation by odorants in calcium-free Ringer's solution, but only a slight increase was seen in intracellular calcium concentration in response stimulation by a high concentration of K+ (145.6 mM) in calcium-free Ringer's solution. The increase in intracellular Ca2+ concentration after odorant stimuli was suppressed when olfactory receptor cells were pretreated with ryanodine, which releases Ca2+ from intracellular stores. These findings suggest that elevated Ca2+ concentrations may be involved in releasing Ca2+ from intracellular calcium stores in mouse olfactory receptor cells, in which cAMP functions as a secondary messenger in olfactory signal transduction.     

The risk to olfaction from nasal surgery

Implicit in all types of nasal surgery is the potential for worsening of olfactory function. Not only can injury occur to the delicate olfactory neuroepithelium itself, but also more indirect disturbances are engendered by pharmacologic agents, distortions of intranasal anatomy, persistent mucosal edema or crusts, and other processes. This study examined 93 patients undergoing various types of nasal surgery, including ethmoidectomy, polypectomy, Caldwell-Luc procedure, open reduction of nasal fracture, closed reduction of nasal fracture, rhinoplasty, and septoplasty. Factors considered as contributing to loss of olfactory acuity were age, gender, use of general anesthesia, and type of operation. The University of Pennsylvania Smell Identification Test (UPSIT), a 40-item, microencapsulated scratch-and-sniff procedure, was used to ascertain olfactory ability. Sixty-one patients (66%) had either improved or unchanged UPSIT scores after surgery; the remaining 32 patients (34%) had a decline in score. One patient (1%) became anosmic. Statistical treatment of outcome data using analysis of covariance with repeated measures showed no effect of age, gender, type of operation, or anesthetic.     

Cytochemical studies of Ca++-ATPase activity in the vestibular epithelia of the guinea pig

We used ultracytochemistry to examine Ca++-ATPase activity in the vestibular epithelia of the guinea pig. Many reaction products were found along the basolateral plasma membrane of the vestibular dark cell. There were also marked reaction deposits on the apical and lateral cell membranes of the transitional cells, and the utricular and saccular wall cells. Both sensory and supporting cells showed Ca++-ATPase activity along their ciliary membrane and apical-lateral cell surfaces. Our findings indicate that the Ca++-ATPase activity found on the plasma membrane is closely related to Ca++-transport across the plasma membrane. When either Ca++ or ATP was omitted from the incubation medium, enzyme activity (as seen by the staining reaction present) was completely abolished. Our present results suggest that Ca++-ATPase located in the vestibular epithelia plays a significant role in the regulation of the Ca++-concentration in the vestibular endolymph.     

Cytochemical localization of Ca++-ATPase activity in the lateral cochlear wall of the guinea pig

Ca++-ATPase activity was examined cytochemically in the lateral cochlear wall of the guinea pig. The reaction products showing Ca++-ATPase activity were found along the folded plasma membrane of the strial marginal cells. In contrast, little or no reaction was seen on the apical surfaces of these cells. There were also marked reaction products on the microvilli and the endolymphatic cell surface of Reissner's membrane, and the apical and lateral plasma membranes of the spiral prominence and the external sulcus cells. These reactions completely disappeared when Ca++ or ATP was removed from the incubation medium. Our results strongly suggest that Ca++-ATPase plays an important role in Ca++ transport system for the regulation of Ca++ concentration in the cochlear endolymph.     

Characteristics of olfactory disorders in relation to major causes of olfactory loss

OBJECTIVE: To investigate the consequences of olfactory loss and explore specific questions related to the effect of duration of olfactory loss, degree of olfactory sensitivity, and cause of the olfactory loss. PATIENTS: A total of 278 consecutive patients with hyposmia or anosmia were examined. RESULTS: Causes of olfactory loss were categorized as follows: trauma (17%), upper respiratory tract infection (URI) (39%), sinonasal disease (21%), congenital anosmia (3%), idiopathic causes (18%), or other causes (3%). Our data suggest that (1) recovery rate was higher in URI olfactory loss than in olfactory loss from other causes; (2) likelihood of recovery seemed to decrease with increased duration of olfactory loss; and (3) the elderly are more prone to URI olfactory loss than younger patients. Regarding changes in quality of life (QoL), we found that (1) in most patients olfactory loss caused food-related problems; (2) loss in QoL did not change with duration of olfactory loss; (3) younger patients had more complaints than older ones, and women had more complaints than men; (4) complaint scores were higher in hyposmic patients than in anosmic patients; and (5) self-rated depression did not relate to measured olfactory function. CONCLUSIONS: Among many complaints of olfactory loss, the predominant ones were food related. This loss in QoL seemed to be of greater importance in younger than in older people, and women seem to be affected more strongly than men.     

Clinical observations on parosmia]

We reviewed the clinical records of 15 patients with parosmia examined in our department from April 1987 to September 1990. Seven (29.2%) of 24 patients with olfactory disturbance caused by traumatic injury complained of parosmia. Eight (23.2%) of 34 patients with olfactory disturbance caused by influenza also showed parosmia. The incidence of parosmia between two groups was not statistically significant (p greater than 0.05). Parosmia was observed in none of 42 patients with olfactory disturbance caused by nasal-paranasal diseases. All patients (n:15) always perceived odors as unpleasent. Twelve of them had spontaneous parosmia, and three patients recognized the unpleasant smell when an odor came. In comparison with the auditory system, we speculated that spontaneous parosmia resembles tinnitus. The cause of tinnitus is recognized as a disturbance of the auditory nerve (the first order neuron). Tinnitus is rare in patients with conductive hearing loss, and cases of olfactory disturbance of the "respiratory dysosmia" did not complain of parosmia. Post-traumatic olfactory disturbance is caused by transection of the fila olfactoria, which is part of an olfactory neuron, while post-inflammatory olfactory disturbance is caused by damage to olfactory receptor cells. Furthermore, the fact that the incidence of parosmia between the two groups was not statistically significant suggests the same etiological mechanism in receptor cells. We consider that parosmia is caused by damage to olfactory sensory neurons.     

A study on the prognostic significance of qualitative olfactory dysfunction

We investigated the frequency and prognostic significance of qualitative olfactory dysfunction (parosmia, phantosmia) in a retrospective patient based study. A total of 392 patients with impairment of olfaction were tested at least two times for their olfactory function using the “Sniffin’ Sticks”. The mean interval between the first and the last test was 11 months. At the first visit 34% of all patients reported parosmia. Parosmia was most frequent in patients with postinfectious olfactory loss (56%), and less frequent in idiopathic, posttraumatic, sinunasal disease with frequencies of 10, 14, and 28%, respectively. In contrast, only 12% of all patients had phantosmias, with no significant differences between the patient groups. Improvement of olfactory function was found in 23% of all patients (n = 90). Pre-existing parosmia or phantosmia had no significant effect on recovery rate. Regarding qualitative olfactory dysfunction, 29% of those patients reporting parosmia reported relief of this symptom after an average of 12 months, whereas 53% of phantosmic patients lost phantosmia during the observation period. Although it has been suggested that olfactory distortion s could be regarded as an indicator of early recovery of decreased olfactory sensitivity, the current data indicate that occurrence of parosmia or phantosmia has little prognostic value. Phantosmia disappears at a faster rate than parosmia. These insights into qualitative olfactory dysfunction are regarded to be significant in the counseling of patients with olfactory loss.     

Odor stick identification test for Japanese patients with olfactory disturbances

In recent years, a new stick-type odor identification test, the odor-stick identification test for Japanese (OSIT-J) has been developed in Japan. Thirteen odors familiar to Japanese people are used in this test. The OSIT-J is an olfactory discrimination test and is significantly correlated with the average recognition threshold of T & T olfactometry, which is the standard olfactory acuity test used in Japan. In this study, we evaluated the accuracy of the OSIT-J in patients with olfactory disturbances. We compared the OSIT-J and T & T olfactometry results and examined the sensitivity and specificity of the OSIT-J. Using the OSIT-J, olfactory disturbances were diagnosed in more than 70% based on the average recognition threshold determined by T & T olfactometry. OSIT-J is a simple test and is recommended for use in clinical practice for evaluating olfactory disturbances.     

Calcium transport in the endolymphatic sac

Ca++ activity and DC potential were measured in vivo in the endolymphatic sac (ES) of guinea pigs by means of double-barrelled ion-sensitive microelectrodes. We found a positive DC potential of 14 mV and a Ca++ activity of 4.7 X 10(-4) M. Anoxia induced a decrease in the DC potential and an increase in Ca++ activity; however, no negative DC potential was measured during permanent anoxia. The Ca++ activity measured was in agreement with the Ca++ value calculated with the Nernst equation, assuming a positive DC potential. On the basis of these data, it was suggested that the Ca++ in the ES is in electrochemical equilibrium with the surrounding fluid and no active Ca++ transport is necessary in the ES of guinea pigs.     

Intranasal trigeminal chemosensitivity in patients with postviral and post-traumatic olfactory dysfunction

Abstract Conclusions: The olfactory and intranasal trigeminal systems are closely connected. With regard to intranasal trigeminal event-related potential (ERP), patients with olfactory dysfunction (OD) showed longer latency and lower amplitude, which indicated decreased trigeminal sensitivity. Different age, etiology, and olfactory status also affect trigeminal sensitivity differently. Objective: OD is a common symptom in the rhinology clinic. ERP is considered an important method to evaluate chemosensitivity. The aim of this study was to investigate changes of intranasal trigeminal sense in patients with postviral OD (PVOD) and post-traumatic OD (PTOD). Methods: A total of 96 participants (30 healthy adults and 66 patients with OD) aged 20-65 years were investigated. The T&T olfactometer, the Sniffin' Sticks olfactory test, and trigeminal ERPs (tERPs) were used. We evaluated trigeminal sensitivity influenced by different factors (age, etiology, and olfactory status) in healthy subjects with normal olfactory function and in patients with PVOD and PTOD. Results: Patients with OD showed higher trigeminal thresholds than normal controls. Compared with controls, N1/P2 latencies of tERPs increased and amplitudes decreased in patients with OD. Older subjects showed longer latencies and lower amplitudes than young subjects in both controls and the OD group. Patients with PTOD exhibited worse psychophysical olfactory function and decreased trigeminal sensitivity.     

Examination and classification of human olfactory mucosa in patients with clinical olfactory disturbances

Summary To determine objectively the degree of olfactory disturbance, we biopsied the olfactory mucosa from patients who complained of anosmia. The olfactory disturbances in this study were caused by choanal atresia, chronic sinusitis, viral inflammation, and head trauma, as well as by congenital and idiopathic anosmia. The biopsy specimens were examined by light microscopy and the degree of mucosal degeneration present was classified according to five grades. The clinical courses of the patients studied paralleled the changes found in the olfactory mucosa.     

Examination and classification of human olfactory mucosa in patients with clinical olfactory disturbances

To determine objectively the degree of olfactory disturbance, we biopsied the olfactory mucosa from patients who complained of anosmia. The olfactory disturbances in this study were caused by choanal atresia, chronic sinusitis, viral inflammation, and head trauma, as well as by congenital and idiopathic anosmia. The biopsy specimens were examined by light microscopy and the degree of mucosal degeneration present was classified according to five grades. The clinical courses of the patients studied paralleled the changes found in the olfactory mucosa.     

嗅觉功能障碍患者鼻内三叉神经功能的评估

目的探讨嗅觉障碍患者鼻内三叉神经功能的改变。方法 303例受试者中健康人100名,嗅觉功能障碍患者203例,分别采用T&T嗅觉计定量检查法(T&T)、嗅觉事件相关电位(olfactory event-related potentials,oERPs)和三叉神经事件相关电位(trigeminal event-related potentials,tERPs)进行嗅觉和三叉神经功能检测。结果 T&T识别域结果表明嗅觉功能障碍患者跟健康人比较差异有显著性意义(P<0.05)。oERPs和tERPs结果显示嗅觉功能障碍患者跟健康人比较N1、P2波潜伏期延长,差异有显著性意义(P<0.05)。结论嗅觉功能障碍患者多伴有三叉神经敏感性的下降,青年患者下降尤为显著,其下降程度与性别关系不大。研究证实两种化学感受系统之间存在联系,联合检测可有助于临床的诊断和治疗。     

Study on normal and otosclerotic bone cell cultures: an advance in understanding the pathogenesis of otosclerosis

The authors first reviewed the main theories concerning the pathogenesis of otosclerosis and studied the morphologic and functional characteristics of cell cultures derived from normal and otosclerotic bones. Light transmission and scanning electron microscopy did not permit definite identification of the cultured cells as predominantly osteoblasts, nor did these techniques show significant differences between cultured cells derived from normal and pathologic bone. Functional tests of the cell cultures proved more interesting. First, the bony nature of the cultured cells was demonstrated by studying the intracellular 45Ca++ uptake after stimulation with calcitonin and dybutryl-cAMP. Second, cell cultures derived from otosclerotic bone behaved differently from those derived from normal bone. Their peak uptake of calcium appeared later, and post-stimulatory values were higher, suggesting that cells derived from otosclerotic bone store a greater quantity of 45Ca++. Furthermore, after stimulation with calcitonin and propranolol, we observed an inhibition of the calcium uptake and decreased intracellular cAMP levels in normal bone cell cultures. In contrast, the cell cultures derived from otosclerotic bone exhibited an initial inhibition of calcium absorption followed by massive calcium penetration. The response of adenylate cyclase to the action of Mg++, Ca++, and F- ions was evaluated in cultures derived from normal bone, otosclerotic bone, and normal skin fibroblasts. The resulting data show that activation due to Mg++ is much lower in cultured cells derived from otosclerotic bone than in those from either normal bone or skin fibroblasts. No significant differences were found after Ca++ inhibition in any of the cell cultures. Moreover, in cell cultures derived from normal bone, F- ions induced a strong activation that was lower than the levels observed in cultures of otosclerotic bone or in normal fibroblasts. We hypothesize that an alteration at the calcitonin receptor site is responsible for the difference in calcium uptake and cAMP levels observed in the cells derived from otosclerotic bone as compared to those cultured from normal cells.     

Ca++ activity in the endolymphatic space

We measured Ca++ activity in the different parts of the endolymphatic space by using a double-barrelled electrode with calcium liquid ionic exchanger. In the region of the endolymphatic sac, Ca++ activity (4.7 X 10(-4) M) was much higher than in the cochlear duct (2.7 X 10(-5) M) and semicircular canal (2.6 X 10(-4) M). These findings suggest that Ca++ may also have a significant role in abnormal states.     

Chronic sinusitis and anosmia: pathologic changes in the olfactory mucosa

OBJECTIVES: To evaluate histological changes in the olfactory mucosa of patients with chronic rhinosinusitis These results are analyzed in light of current understanding of the pathophysiology of anosmia secondary to nasal and sinus disease. STUDY DESIGN: Prospective study of olfaction on patients undergoing sinus surgery for the management of chronic rhinosinusitis. METHODS: Thirty patients, aged 22 to 39 years, underwent olfactory biopsy at the time of surgery with evaluation by a pathologist. Inflammatory changes were graded as mild (normal), moderate, or severe. Clinical olfactory function was evaluated using the University of Pennsylvania Smell Identification Test (UPSIT). The results correlated with the degree of olfactory dysfunction. RESULTS: Of the 30 patients 19 had unequivocal olfactory mucosa in the biopsy specimen. Eleven had only respiratory or indeterminate mucosa. Nine patients demonstrated normal olfactory mucosa and normal olfactory function (UPSIT > 35). Ten patients demonstrated pathological changes in the olfactory mucosa with an influx of lymphocytes, macrophages, and eosinophils Of these 10 patients, 7 had olfactory deficits as determined by UPSIT. The remaining three patients had normal olfactory function despite moderate chronic inflammation. These studies indicate that the olfactory mucosa is capable of mounting an inflammatory response similar to that seen in the respiratory mucosa of patients with chronic sinusitis These data suggest that the olfactory deficits in these patients may be the result of inflammatory changes within the olfactory mucosa in addition to any alteration in airflow to the olfactory cleft.     

Safety and usefulness of the long-term intranasal topical treatment with steroids for olfactory dysfunction

Intranasal topical steroids are commonly used for the treatment of olfactory dysfunction. Although the side effects are considered to be minimal, these have not been studied in detail. We examined the side effects of intranasal topical treatment with steroids in patients with olfactory dysfunction. We treated 62 patients with intranasal topical application of 0.1% betamethasone sodium phosphate (Rinderone) administered to the olfactory clefts. After treatment for 1 or 2 months, serum ACTH or cortisol was reduced in 42 (68% of total) patients, however, no clinical symptoms associated with steroid side effects were observed. The treatment was discontinued in 8 of these patients, who elected to withdraw from the treatment. In these patients, the serum ACTH or cortisol returned to normal a month after stopping the treatment. In the remaining 34 patients, the topical treatment was continued and in only 4 of these patients, minor steroid-associated side effects such as the sensation of facial swelling and facial hair thickening, appeared 2-5 months after beginning the treatment. These side effects disappeared within a month after stopping the treatment. Regarding the therapeutic efficacy, in 18 (78%) of the 23 patients who continued treatment for an average period of 5 months, steroid treatment significantly improved their olfactory dysfunction. In conclusion, although it is important to consider the potential side effects of long-term intranasal topical treatment with steroids for olfactory dysfunction, this treatment is a highly effective method against olfactory dysfunction with minimal side effects.     

Clinical significance of results from olfactory testing

BACKGROUND: Although widely used in healthy subjects and patients with olfactory loss, the significance of changes of scores from validated olfactory tests is unknown. AIM AND METHODS: The aim of the present study was to relate the self-assigned changes of olfactory function in terms of "better," "unchanged," and "worse" in patients with smell disorders with the results from olfactory testing by means of a validated test set. Olfactory function of 83 anosmic or hyposmic patients (40 women, 43 men; age 12-84 yr) was tested on two occasions (mean interval 136 days, minimum 7 days, maximum 6.7 yr). Olfactory function was assessed using a validated technique ("Sniffin' Sticks"). This test consists of three subtests, one for odor threshold (T), odor discrimination (D), and odor identification (I), with possible results ranging up to 16 points each. From the sum of the results from the three subtests a composite "TDI" score was obtained. RESULTS: Forty-four patients indicated an improvement of olfactory function, whereas 39 patients reported no change. No subject reported deterioration of olfactory sensitivity. Subjects assigned to group BETTER had higher TDI scores in the second olfactory tests than subjects assigned to the group UNCHANGED, both in absolute terms and as compared with the first olfactory test (effect "test occasion" by "self-assessed improvement," P < .001). There was no significant difference between groups with respect to age and sex (P = .99 and .84, respectively). Logistic regression showed that more than 60% of the subjects reported an improvement of olfactory sensitivity when the TDI score increased by 5.5 points. CONCLUSION: We show that there is a statistically significant relation between measured and perceived improvement of olfactory function in patients who first presented with the diagnosis of anosmia or hyposmia. The results indicate that improved olfactory function in patients with olfactory deficiency is perceived as such in everyday life and is quantitatively related to an improvement in the composite TDI score of the "Sniffin' Sticks" olfactory test battery. This is the basis for the application of a specific therapy for olfactory loss because of a possible gain in quality of life for the patients.     

抑郁症大鼠鼻黏膜组织形态学观察及神经生长因子的表达

目的:建立抑郁症大鼠模型,观察其鼻腔黏膜组织形态学变化及神经生长因子(NGF)的表达。方法:30只SD大鼠分为抑郁模型组、正常对照组,两组各15只。应用慢性不可预见性中等强度应激刺激制作抑郁症动物模型。用敞箱实验和体液消耗实验检测大鼠行为变化后,处死实验动物,取鼻腔黏膜做形态学切片,进行苏木精-伊红染色和NGF免疫组织化学染色。应用医学数码图像分析技术,检测比较抑郁模型组和正常对照组大鼠鼻腔黏膜组织的NGF蛋白的表达差异。结果:正常对照组鼻黏膜苏木精-伊红染色均未见充血水肿和炎性细胞浸润,抑郁模型组53%鼻黏膜苏木精-伊红染色出现轻度水肿充血和炎性细胞浸润;正常对照组鼻黏膜NGF免疫组织化学染色均为阴性,抑郁模型组53%鼻黏膜NGF免疫组织化学染色为阳性,2组之间差异有统计学意义(P<0.01)。结论:抑郁症大鼠在长期受到各种外界的应激刺激后可能出现鼻腔通气不畅,分泌物过多等鼻炎症状。NGF可能是通过免疫调节作用,促进免疫细胞的增生及聚集,诱导各种递质的释放,增加神经纤维本身的敏感性以及神经肽的产生,促进神经源炎的形成,并增加鼻黏膜的反应性。     

Trigeminal event-related potentials in patients with olfactory dysfunction

OBJECTIVE: There are mutual interactions between the olfactory and trigeminal systems. The purpose of this study was (1) to assess trigeminal sensitivity using chemosensory event-related potentials (CSERPs) in patients with olfactory dysfunction and (2) to evaluate whether trigeminal ERPs were different with regard to the presence or absence of olfactory ERPs. MATERIALS AND METHODS: Prospective study of 60 patients who presented with olfactory dysfunction (postinfectious olfactory loss: n = 19, posttraumatic olfactory loss: n = 28, and olfactory loss due to idiopathic, or toxic causes: n = 13). All patients were extensively evaluated with an orthonasal olfactory test based on the "Sniffin' Sticks". In addition, chemosensory ERPs were recorded in response to olfactory and trigeminal stimulation. RESULTS: Olfactory/trigeminal ERPs were recorded in 25/60 patients, respectively. Patients with no detectable olfactory ERPs, considered as severely affected, demonstrated an altered trigeminal sensitivity as indicated by an increase in P2 latencies and a decrease in both, P2 and N1-P2 amplitudes compared to patients with detectable olfactory ERPs. A regression analysis showed a negative relation between P2 latencies and the "Sniffin' Sticks"score (r = -0.46, p < 0.001). CONCLUSIONS: Patients with severe olfactory dysfunction demonstrated decreased trigeminal sensitivity as indicated by electrophysiological measures. This study supports the idea of interactions between the chemical senses. Whether altered responses to trigeminal stimulation may be used as a prognostic measure related to recovery from olfactory loss remains to be demonstrated.