Effect of 9-cis-retinoic acid on oral squamous cell carcinoma cell lines.

Retinoic acid (RA) has been shown to be effective in suppressing premalignant lesions and preventing second primary malignancies in patients cured of squamous cell carcinoma of the head and neck. However, the precise mechanisms of these effects are still uncertain. In the present study, we examined the effect of 9-cis-RA on the growth of six oral cancer cell lines (HSC-2, HSC-3, HSC-4, Ca9-22, Ho-1-N-1 and Ho-1-u-1). In addition, the relationship among growth and differentiation of tumor cells, RA responsiveness and the expression of nuclear retinoic acid receptors were also investigated. Among the six cell lines examined, five (HSC-2, HSC-3, HSC-4, Ca9-22 and Ho-1-u-1) displayed growth inhibition after treatment with 1x10(-6) M 9-cis-RA, while Ho-1-N-1 cells were resistant to 9-cis-RA. The expression level of RARbeta in 9-cis-RA resistant Ho-1-N-1 cells was very low in comparison with the sensitive cell lines. On the other hand, all of the six the cell lines expressed RARalpha, RARgamma, and RXRalpha at various levels. 9-cis-RA induced accumulation of cell population in G1 phase in HSC-3 cells on the 6th day of the treatment, followed by a marked reduction in the levels of hyperphosphorylated pRB, whereas p53 level was not altered. Interestingly, 9-cis-RA induced transiently the expression of p21(Waf1/Cip1), p27(Kip1), p300, CBP, BAX, Bak and bcl-2 proteins, respectively. This effect was associated with reduction of cyclin D1, cdk4 and CDK-activating kinase (cyclin H and cdk7) protein in HSC-3 cells. These results suggest that the growth inhibitory effect of 9-cis-RA on oral squamous cell carcinoma may depend on the expression levels of RARs, especially RARbeta proteins and RXRalpha proteins, and that 9-cis-RA may provide a powerful therapeutic agent for head and neck cancers.

Cholinergic and glutamatergic transmission in medial vestibular nucleus neurons responding to lateral roll tilt in rats.

The responses of the medial vestibular nucleus (MVN) neurons to lateral tilt and the neurotransmitters mediating otolith information to MVN neurons were investigated using rats. A computer-operated goniometer was tilted 20 degrees clockwise and counterclockwise at an angular speed of 5 degrees /s and paused in the inclined positions for 10 s to record neuronal responses in the static phase. The 185 MVN neurons recorded were classified into eight types according to their responses to tilt (alpha, beta, gamma, delta, epsilon, zeta, eta and theta). A majority showed increased firing in response to ipsilateral tilting and decreased firing in response to contralateral tilting (alpha type: 31.4%) or exhibited the reverse pattern (beta type: 36.8%). Further, other groups of neurons increased (gamma type) or decreased (delta type) firing rates to either side tilting and increased (epsilon and zeta type) or decreased (eta and theta type) firing only on one side. Atropine or L-glutamic acid diethyl ester hydrochloride (GDEE) applied microiontophoretically antagonized tilt-induced firing of alpha type neurons in 58.8% or 60.0%, respectively, and of beta type neurons in 66.7% or 58.3%, respectively. When the effects of atropine and GDEE were examined in the same neurons, antagonizing effects of both drugs on tilt-induced firing were obtained in 28.6% and 40.0% of alpha and beta type neurons, respectively. These results suggest that both acetylcholine and glutamate act as neurotransmitters in the transmission of otolith information to most MVN neurons.

alpha(1)-adrenoceptor subtypes and effect of alpha(1A)-adrenoceptor agonist NS-49 on guinea pig nasal mucosa vasculature.

It is now clear that alpha(1)-adrenoceptors comprise a heterogeneous family. In the present study, we characterized the alpha(1)-adrenoceptor subtype in the nasal mucosa vasculature of guinea pigs. A rectangular strip of guinea pig nasal mucosa was suspended in an organ bath containing Krebs' bicarbonate solution. Changes in tension were recorded isometrically. Concentration-response curves for agonists were obtained in a cumulative manner. Noradrenaline produced the greatest contraction of the nasal mucosa vasculature. NS-49 ((R)-(-)-3'-(2-amino-1-hydroxyethyl)-4'-fluoromethane sulfonanilide hydrochloride) and oxymetazoline worked as partial agonists. The intrinsic activities of NS-49 and oxymetazoline were 0.50+/-0.22 and 0.29+/-0.17, respectively, compared with noradrenaline (=1.00). Prazosin and the putative alpha(1A)-adrenoceptor antagonists WB-4101 (2-(2,6-dimethoxyphenoxyethyl)aminomethyl-1,4-benzodioxane) and 5-methylurapidil antagonized the response to noradrenaline competitively (pA(2) for prazosin<9.0). Conversely, putative alpha(1B) and alpha(1D)-adrenoceptor antagonists (spiperone and BMY7378 (8-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-8-azaspiro[4, 5]decane-7,9-dione), respectively) did not antagonize competitively. These results suggest that the alpha(1A)-subtype is predominant and that the alpha(1L) (or alpha(1N)) subtype may also be present in the guinea pig nasal mucosa vasculature. Furthermore, NS-49 might prove to be a nasal mucosa vasoconstrictor, which will improve nasal obstruction.

Effect of JTH-601, a putative alpha(1L)-adrenoceptor antagonist, on guinea pig nasal mucosa vasculature.

The existence of alpha(1)-adrenoceptors with low affinity for prazosin, an alpha(1L) subtype, has been proposed in addition to alpha(1)-adrenoceptor subtypes with high affinity for prazosin, i.e. the alpha(1H) group: alpha(1A), alpha(1B) and alpha(1D) subtypes. In the present study, we investigated the effect of JTH-601 (3-(N-[2-(4-hydroxy-2-isopropyl-5-methylphenoxy)ethyl]-N-methylaminomethyl)-4-methoxy-2,5,6-trimethylphenol hemifumarate), a putative alpha(1L)-adrenoceptor antagonist, on the isolated guinea pig nasal mucosa vasculature. JTH-601 (0.01-0.03 microM) competitively antagonized the noradrenaline-induced contraction of the tissue in a concentration-dependent manner. The pA(2) value for JTH-601 was 8.14 +/- 0.04 (means +/- SEM, n = 6). The data suggests that the alpha(1L)-subtype is involved in the noradrenaline-induced contraction of the guinea pig nasal mucosa vasculature.

Thickening of sphenoid sinus mucosa during the acute stage of pituitary apoplexy.

The authors treated two patients with pituitary apoplexy in whom magnetic resonance (MR) images were obtained before and after the episode. Two days after the apoplectic episodes, MR imaging demonstrated marked thickening of the mucosa of the sphenoid sinus that was absent in the previous studies. The relevance of this change in the sphenoid sinus was investigated. Retrospective evaluations were performed using MR images obtained in 14 consecutive patients with classic pituitary apoplexy characterized by acute onset of severe headache. The mucosa of the sphenoid sinus had thickened predominantly in the compartment just beneath the sella turcica, in nine of 11 patients, as ascertained on MR images obtained within 7 days after the onset of apoplectic symptoms. This condition improved spontaneously in all four patients who did not undergo transsphenoidal surgery. The sphenoid sinus mucosa appeared to be normal on MR images obtained from three patients at the chronic stage (> 3 months after onset). The incidence of sphenoid sinus mucosal thickening during the acute stage was significantly higher in the patients with apoplexy than that in the 100 patients without apoplexy. A histological study conducted in four patients who underwent transsphenoidal surgery during the early stage showed that the subepithelial layer of the sphenoid sinus mucous membrane was obviously swollen. The sphenoid sinus mucosa thickens during the acute stage of pituitary apoplexy. This thickening neither indicates infectious sinusitis nor rules out the choice of the transsphenoidal route for surgery.

Nitroxidergic vasodilator nerve in the canine nasal mucosa.

The canine nasal mucosa was studied by in vitro bioassay. Non-adrenergic, non-cholinergic (NANC) vasodilator response to transmural electrical stimulation was observed in the presence of guanethidine and atropine. This vasodilator response was abolished by NG-nitro-L-arginine (L-NA) which is an inhibitor of nitric oxide (NO) formation but not by NG-nitro-D-arginine. The inhibitory effect of L-NA was partially reversed by treatment with L-arginine but not with D-arginine. The vasodilator response was significantly suppressed by tetrodotoxin. The present results indicate that NO may mediate neurogenic vasodilation in the canine nasal mucosa.

Increased expression of inducible nitric oxide synthase in nasal epithelial cells in patients with allergic rhinitis.

OBJECTIVES: Although ciliated epithelial cells of human nose and paranasal sinuses have recently been reported to be the major source of locally detected nitric oxide (NO), changes to the NO production by these cells and their functional roles remain uncertain in relation to allergic rhinitis. The objective of this study is to investigate differences in the ability of induction of nitric oxide synthase (NOS) isoforms by nasal epithelial cells. STUDY DESIGN: Epithelial cells of the inferior turbinate taken from 12 normal subjects and 12 allergic patients against house dust mite were used. Samples from the house dust group were taken both before and after antigen provocation. METHODS: Immunoreactivity for two NOS isoforms, inducible NOS (iNOS) and endothelial NOS (eNOS), was examined by the laser scanning confocal microscope. The labeled cells were processed into digital images, and the fluorescence intensity was assessed quantitatively. RESULTS: The degree of iNOS expression of the epithelial cells was significantly elevated in the house dust group compared with that of the control group. The expression appeared identical both before and after antigen provocation in the house dust group. On the other hand, there was no significant difference in eNOS expression between the two groups. CONCLUSIONS: We assume that the increased iNOS expression of the epithelial cells in the house dust group might result from stimulated secretion of proinflammatory cytokines during allergic responses. This further suggests profound contribution of nasal epithelial cells to modifying the airway clearance through the production of high levels of NO.

Analysis of local cytokine gene expression in patients with allergic rhinitis treated with CO2 laser surgery.

OBJECTIVES/HYPOTHESIS: Laser surgery of the inferior turbinates has become a popular surgical treatment for patients with allergic rhinitis, particularly for those who have persistent nasal obstruction and do not respond well to pharmacological therapy. The aim of this study was to investigate the effects of the laser surgery on local cytokine gene expression at the mucosal surface in relation to the improvement of nasal symptoms. STUDY DESIGN: A prospective analysis of 25 patients with allergic rhinitis caused by the house dust mite who underwent laser surgery twice with a 1-month interval on an outpatient basis. Fifteen healthy volunteers served as normal control subjects. METHODS: Improvement of the nasal symptoms was evaluated on a graded scale. Nasal mucosal cells were obtained by brushing from the inferior turbinate at each visit. The expression of messenger RNA (mRNA) encoding granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin (IL)-6, IL-8, RANTES (regulated on activation, normal T-cell expressed and secreted), and eotaxin was semiquantitatively analyzed by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: Two months after treatment, the nasal symptom scores significantly decreased from baseline. The decrease was most apparent in nasal obstruction. RT-PCR analysis revealed that a significant decrease in IL-8 and RANTES expression (P < .001 and P = .012, respectively) was observed after successive laser treatment, and the reduction in these cytokines was significantly correlated. On the other hand, mRNA expression of GM-CSF, IL-6, and eotaxin remained unchanged. CONCLUSIONS: This study provided evidence that the expression of local inflammatory cytokines can be attenuated in part by CO2 laser treatment, which may be closely related to the clinical effectiveness of this procedure.

Recurrent lower gingival squamous cell carcinoma spreading along the pathway of the inferior alveolar nerve.

Computed tomography images showed recurrent lower gingival squamous cell carcinoma spreading from the mandibular foramen to the middle cranial fossa. This extensive tumor spread followed exactly the same anatomic pathway as the inferior alveolar nerve. Histopathologic examination revealed squamous cell carcinoma. Tumor spread was thought to be caused by perineural invasion. This case demonstrates computed tomography features of perineural tumor spread along the inferior alveolar nerve.

Effect of streptomycin intoxication on vestibular nerve regeneration and posture recovery.

The action of streptomycin sulfate (SM) on the regenerative process of the vestibular nerve and posture recovery was studied, using bull frogs. The vestibular nerve was sectioned in various conditions with intact endorgan or with SM intoxication. When the nerve was sectioned with the hair cells left intact, the nerve regenerated well and body balance recovered to normal. However, when neural regeneration was blocked, recovery was incomplete. SM intoxication resulted in various degrees of hair cell damage. Degree of posture recovery correlated well with the number of hair cells. When the nerve was sectioned after damaging the hair cell, the nerve failed to regenerate and posture recovery was incomplete. These results suggest that the degree of posture recovery depends on hair cell function and neural regeneration. Furthermore, neural regeneration is strongly influenced by hair cell function.

Formation and fate of giant otoconia of the guinea pig following streptomycin intoxication.

Formation and fate of abnormal (giant) otoconia of the guinea pig following streptomycin intoxication were investigated using scanning electron microscopy. The giant otoconia formed as multifaceted morphology in their early developmental period. They grew up the the transitional type and finally to the cylindrical type. It has been suggested that the giant otoconia found following streptomycin intoxication may be formed mainly by dissolution of normal otoconia due to the loss of environmental calcium, followed by recrystallization as giant crystals. These phenomena seemed to be closely related to the otoconial dynamics which may regulate calcium ion homeostasis of the endolymph.

Functional role of nitric oxide in the nasal mucosa of the guinea pig after instillation with lipopolysaccharide.

Nitric oxide (NO) has been found to have various actions in the body. Recently, considerable attention has been focused on the intimate relationship between the intracellular production of NO and morphological or functional changes in ciliated cells. The aim of this study was to clarify the functional significance of NO in the nasal mucosa. Healthy, adult, pigmented guinea pigs were randomly divided into one control and three experimental groups. The animals were instilled with either lipopolysaccharide (LPS) only or LPS plus dexamethasone or NG-nitro L-arginine methyl ester (L-NAME). The effect of NO on the nasal epithelium was analyzed morphologically by scanning electron microscopy and physiologically by ciliary beat frequency (CBF) measurement. The origin of NO was also investigated using a fluorescent indicator for NO, namely 4,5-diaminofluorescein diacetate. LPS induced damage of cilia 3 days after the first instillation, while dexamethasone or L-NAME seemed to attenuate the effect of LPS. NO production was localized in ciliated cells and the main source of NO in ciliated cells is suggested to be inducible NO synthase. The greater number of ciliated cells of LPS-treated animals produced a larger amount of NO compared with normal animals. LPS also induced a decrease in CBF, which was inhibited by dexamethasone or L-NAME. It is suggested that NO may play an important role in pathological changes in the nasal mucosa.

Enhancement of GABA-mediated inhibition of rat medial vestibular nucleus neurons by the neurosteroid 20-hydroxyecdysone.

In vivo electrophysiological and patch-clamp studies were performed to determine whether 20-hydroxyecdysone (20-HE), a neurosteroid, influenced neuronal activities of the medial vestibular nucleus (MVN) using chloral hydrate-anesthetized rats and dissociated MVN neurons, respectively. Single neuronal activities of MVN were extracellularly recorded with a glass-insulated silver wire microelectrode attached along a seven-barreled micropipette. Each micropipette was filled with 20-HE, glutamate, bicuculline or 2 M NaCl. These chemicals were applied microiontophoretically to the immediate vicinity of the target neurons. Microiontophoretically applied 20-HE (20-80 nA) dose-dependently decreased rotation-induced firings of both type I and II neurons, which were identified according to their responses to horizontal sinusoidal rotations. Microiontophoretically applied bicuculline, a GABAA receptor antagonist, inhibited 20-HE-induced decreases in neuronal firing of MVN. These findings suggest that 20-HE potentiates the action of GABA, probably by acting directly on the GABAA receptor of MVN neurons. In addition, microiontophoretically applied 20-HE decreased firings induced by glutamate in both type I and II neurons. This decrease by 20-HE was also antagonized with bicuculline. Furthermore, the effects of 20-HE on GABA-induced currents in acutely dissociated MVN neurons were investigated using the whole-cell patch-clamp technique. Under voltage-clamp conditions, GABA (10 microM)-induced currents were potentiated in the presence of 20-HE (100 microM). These findings suggest that 20-HE inhibits MVN neurons by acting on the modulatory site on GABA receptor-ion channel complexes to potentiate GABA inhibition.

Scanning electron microscopic observation of the statocyst in the crayfish Procambarus clarkii Girard.

The statocyst in the crayfish Procambarus clarkii was investigated using scanning electron microscopy. The statocyst contains static hairs arranged in four group, i.e. lateral, medial, proximal, and distal. All the hairs are the same in basic structure. They differ in length and diameter and in their position with respect to the other hairs in the group and to the statolith. In terms of morphological polarization, the hairs in the lateral and medial groups are polarized toward the center of the crescent, while the hairs in the proximal group are polarized away from the center of the crescent. In the distal group, most hairs are polarized toward the center of the crescent, while some hairs are at random. This morphological polarization may be consistent with that of functional polarization. The statolith overlays the lateral and medial hair groups. The hairs in the distal group do not touch the statolith, whereas the hairs in the proximal group make contact with it from the side. It has been therefore indicated that the lateral, medial and proximal groups could detect gravity and linear acceleration like macular end organs and distal group could detect angular acceleration like semicircular canal in mammals.

Sem studies of the inflammatory changes of the middle ear mucosa.

Mucosal specimens of the middle ear from patients who had chronic otitis media were studied and compared with normal middle ear specimens using a scanning electron microscope. The epithelia in chronic otitis media were usually thick and those surface structures varied depending on the area in which the biopsy was taken. Moreover, the structure was not uniform even in the same specimen. Some areas showed a great number of secretory cells, while others demonstrated high population of ciliated cells. Areas with loss of the superficial layer were also observed in a few cases. There were less ciliated cells than we expected. They were not evenly distributed, except for the eustachian tube region. Morphologically, most of these ciliated cells seemed to be normal, and a few isolated atrophic ones were also observed. In cholesteatoma cases, squamous epithelia with desquamating, flat and keratinized cells were observed.

In vitro calcium ion turnover in otoconia of the guinea pig.

In vitro calcium ion turnover into otoconia of adult guinea pigs was investigated by the use of tetracycline. The incubation in tetracycline in vitro clearly demonstrated the deposition of tetracycline (fluorescence) on the outer surface of otoconia. Levels of Ca2+ uptake in utricular otoconia were higher than those in saccular otoconia. In vitro uptake and/or exchange of Ca2+ was greater in fluid with a high K+/Na+ ratio than in fluid in which the ratio was low. It has been thus indicated that a high K+/Na+ ratio in normal endolymph should be more suitable for Ca2+ uptake and/or exchange to maintain the ionic environment in the inner ear. Sodium dodecyl sulfate treatment of otoconia increased the Ca2+ uptake. The ability of the otoconia to take up Ca2+ appears to decline with age. It has been indicated that the organic matrix of otoconia may be one of the inhibitory factors for Ca2+ uptake in old animals.

Acoustic neuroma presenting with sudden and fluctuating hearing loss--a case report.

A case of acoustic neuroma presenting with sudden and fluctuating hearing loss is reported. The patient was a 38-year-old Japanese woman who noticed a sudden onset of hearing loss and tinnitus in the right ear. With a provisional diagnosis of sudden deafness, she was subjected to conservative therapy, including steroid hormone. The hearing started to recover and reached a normal level 2 months after the treatment. Meanwhile, the results of an ABR and plain skull X-rays aroused a suspicion of acoustic neuroma. She was operated on via a middle cranial fossa approach and an acoustic neuroma occupying the internal auditory meatus was removed.

Simultaneous pleomorphic adenomas of the right parotid and ipsilateral submandibular glands.

A case of simultaneous pleomorphic adenomas of the right parotid and ipsilateral submandibular glands was reported. The patient was a 68-year-old woman who had a ten-year history of an otherwise asymptomatic non-enlarging mass in the parotid gland and a slowly enlarging mass in the submandibular gland. Microscopically, the parotid tumor consisted of predominant spindle-shaped cell proliferations with myxoid stroma in places. The submandibular gland tumor showed tubular and trabecular formations with stroma consisting of hyalinized fibrous connective tissues. Simultaneous pleomorphic adenomas in the salivary glands are so rare that only 23 cases can be found in the literature. Additionally, only five tumors occurring simultaneously in the parotid and submandibular glands are reported in the literature. Our case seems to be the sixth of simultaneous pleomorphic adenomas of the parotid and submandibular glands.

Neurilemmoma of the larynx: (a case report).

The authors have treated a 61-year-old woman with neurilemmoma of the larynx. The tumour was located in the submucosal region of the arytenoid on the right side of the larynx. Surgical resection of the tumour had to be done by external neck excision instead of endoscopically.

Modulation of ciliary activity by tumor necrosis factor-alpha in cultured sinus epithelial cells. Possible roles of nitric oxide.

The primary function of well-differentiated ciliated epithelium in the paranasal sinus is to eliminate harmful agents through the beating action of cilia. Respiratory epithelium also contributes to local inflammatory processes through the release of various proinflammatory cytokines. Recently, considerable attention has been focused on the intimate relationship between the cytokine-dependent regulation of the ciliary beat frequency (CBF) and intra-cellular production of nitric oxide (NO) in ciliated epithelial cells. The aims of this study are to examine the effect of tumor necrosis factor-alpha (TNF-alpha), one of the major proinflammatory cytokines, on the ciliary activity of human sinus epithelial cells and to assess the hypothesis that NO is involved in this regulatory mechanism. Human maxillary or ethmoidal sinus mucosa (n = 23) were cultured by the explant-outgrowth method. CBF of the outgrowth ciliated cells was measured by the photoelectrical method before and after being treated with TNF-alpha (0.1, 1 and 10 ng/ml) or dexamethasone (10(-6) M and 10(-7) M). We also investigated the expression of nitric oxide synthase (NOS) isoforms, enzymes responsible for NO synthesis, by fluorescent immunohistochemistry. TNF-alpha increased CBF at relatively low concentrations (0.1 and 1 ng/ml) and decreased CBF at a high concentration (10 ng/ml). Dexamethasone decreased CBF at a concentration of 10(-6) M. Fluorescent immunohistochemistry demonstrated that the expression of inducible NOS was augmented by TNF-alpha and attenuated by dexamethasone, whereas that of endothelial NOS remained unchanged. We conclude that human sinus epithelial cells potentially contribute to the inflammatory process by regulating their ciliary motility through an NO-dependent pathway. Proinflammatory cytokines and steroids are able to modulate this mechanism by the induction or inhibition of expression of different NOS isoforms.