Efflux of 45Ca was investigated in cultured bovine adrenal medulla cells with its relation to Ca influx. Carbachol caused a rapid and transient efflux of 45Ca from 45C preloaded cells which proceeded with a similar time course to 45Ca influx. Nicotine also caused efflux of 45Ca that is completely antagonized by hexamethonium, while muscarine and pilocarpine did not cause 45Ca efflux. Nicotine-induced efflux of 45Ca was abolished by the Ca-antagonist, diltiazem, and was not observed in Ca-free medium. These observations show that in bovine adrenal medulla, not only the influx of Ca but also the efflux of Ca are caused by nicotinic receptor stimulation and that the efflux of Ca is dependent on the Ca in the medium.

Adrenal Medulla↗

PubMed1984

Involvement of Na influx in acetylcholine receptor mediated secretion of catecholamines from cultured bovine adrenal medulla cells.

The role of sodium (Na) in stimulus-secretion coupling of adrenal medulla was investigated in primary culture of bovine adrenal medulla cells. In Na-free medium, the secretion of catecholamines and influx of 45Ca induced by carbachol were decreased to 30% and 18% of control responses, respectively. Carbachol induced secretion of catecholamines and influx of 45Ca were not inhibited by tetrodotoxin, a highly selective blocker of voltage dependent Na-channels. Carbachol caused a rapid influx of 22Na which was inhibited by hexamethonium but not by tetrodotoxin. Nicotine but not muscarine could be a substitute for carbachol and caused catecholamine secretion, 45Ca influx 22Na influx. Veratridine caused continuous secretion of catecholamines and influxes of 45Ca and 22Na which were blocked by tetrodotoxin. These results indicate that in cultured bovine adrenal medulla cells, stimulation of nicotinic receptor causes the influx of Na through receptor-mediated Na-channels but not through voltage-dependent Na-channels, and that influxed Na may facilitate the influx of Ca which triggers the secretory process. The sodium ion seems to be involved in the stimulus-secretion coupling evoked by physiological secretagogue in adrenal medulla.

Adrenal Medulla↗

PubMed1984

Bell's palsy. Nonrecurrent v recurrent and unilateral v bilateral.

Bell's palsy was classified into five categories--unilateral nonrecurrent , unilateral recurrent, simultaneous bilateral, alternating bilateral, and recurrent bilateral type--based on the clinical statistical study of two large series of patients with Bell's palsy treated at different locations in Japan. One series consisted of 1,217 patients and the other of 1,197 for a total of 2,414 patients in this study. The incidence of each type and the age and sex distributions were similar in the two groups. Clinical features of each type are described. The results imply that more specific causative factors trigger the recurrences and the simultaneous bilateral attacks.

Adolescent↗

PubMed1984

Development of an implantable hearing aid using a piezoelectric vibrator of bimorph design: state of the art.

A new, implantable hearing aid has been developed. An ultraminiature electric microphone placed under the skin of the external ear canal transduces sound waves into electrical impulses that are amplified with battery power. The amplified electrical impulses are fed into a piezoelectric vibrator directly in contact with the stapes. The vibrator transduces the electrical impulses into mechanical vibration with minimal consumption of electrical energy. Direct coupling of the vibrator to the stapes allows a high degree of fidelity in the perception of sound. The developmental process and the structure and function of each component are described together with clinical problems. Preliminary and tentative implantation of this new device during middle ear surgery indicated that it would be beneficial to patients who have suffered hearing loss from middle ear disease and whose condition does not lend itself to surgical correction.

Electric Power Supplies↗

PubMed1984

Relationship between activation and phosphorylation of tyrosine hydroxylase by 56 mm K+ in PC12 cells in culture.

Incubation of rat pheochromocytoma PC12 cells with 56 mM K+ is associated with increased activity and enhanced phosphorylation of tyrosine hydroxylase in the cells. The increase in the phosphorylation of tyrosine hydroxylase is observed after 30 sec of incubation with 56 mM K+; maximal phosphorylation is observed after 1 min of incubation. In contrast, although a significant increase in the activity of tyrosine hydroxylase is demonstrable after 30 sec of incubation with 56 mM K+, maximal activation is not attained until 3 min of incubation. Both the activation and increased phosphorylation of tyrosine hydroxylase exhibit a similar dependence upon potassium concentration in the incubation medium and are dependent on the presence of extracellular calcium. These results suggest that, although there is a relationship between activation and phosphorylation of tyrosine hydroxylase after potassium-evoked depolarization of rat pheochromocytoma PC12 cells in culture, this relationship may be complex.

Adrenal Gland Neoplasms↗

PubMed1984

Sound pickup utilizing an implantable piezoelectric ceramic bimorph element: application to the cochlear implant.

The degree of sound pickup possible with a piezoelectric ceramic bimorph element ( PCBE ) was tested as part of research on a total implantation system for a cochlear prosthesis. The PCBE functions as an electromechanical transducer and can be utilized as a device to sense vibration in the tympanic membrane by touching it to the malleus head. This method lends itself to the miniaturization and simplification required by an implantable device for sound pickup. The ability of the PCBE to function as a device to pick up sound was investigated using three normal human temporal bones. The sensitivity of the PCBE when coupled to the malleus was calculated as the ratio of the voltage generated by the PCBE to the sound pressure in front of the tympanic membrane, when these factors were processed with a spectrum analyzer. The best sensitivities registered with the three temporal bone specimens were -63, -61, -59 dB re 1 V/Pa, respectively, at 1 kHz. The frequency response curves had resonant frequencies at about 2 kHz and declined beyond 5 kHz. These results indicate that a PCBE coupled to the malleus head performs satisfactorily in regard to sound pickup and shows promise as a component of a totally implanted hearing system.

Bone Conduction↗

PubMed1983

Suppression by phospholipase A2 inhibitors of secretion of catecholamines from isolated adrenal medullary cells by suppression of cellular calcium uptake.

The involvement of phospholipase A2 in the secretion of catecholamines and cellular uptake of 45Ca2+ was investigated in isolated bovine adrenal medullary cells. In these cells, stimulation of cholinergic receptors by carbamylcholine causes the activation of receptor-linked Ca-channels and influx of Ca2+ is known to trigger the secretory process. Phospholipase A2 inhibitors, such as quinacrine, chloroquine, quinine and p-bromophenacyl bromide, all inhibited the secretion of catecholamines evoked by carbamylcholine in a dose-dependent manner. These phospholipase A2 inhibitors also inhibited the cellular uptake of 45Ca2+ evoked by carbamylcholine with similar dose-response curves to those for inhibition of catecholamine secretion. The inhibition by phospholipase A2 inhibitors was found to be distinct from inhibition by d-tubocurarine which competitively blocks acetylcholine receptors, and from inhibition by diltiazem which acts as a Ca-antagonist at Ca-channels. Phospholipase A2 inhibitors seem to suppress the secretion of catecholamines by interfering with the linkage between acetylcholine receptors and Ca-channels by the membrane effects including the inhibition of endogenous phospholipase A2 activity of the adrenal medullary cells.

Acetophenones↗

PubMed1983

Inhibition by alpha 2-adrenoceptor agonists of the secretion of catecholamines from isolated adrenal medullary cells.

In adrenal medullary cells, carbachol evokes the secretion of catecholamines with simultaneous uptake of 45Ca. Highly selective agonists for alpha 2-adrenoceptors, clonidine, naphazoline, guanfacine, tramazoline and oxymetazoline inhibited carbachol evoked secretion of catecholamines in a dose-dependent manner. These alpha 2-agonists also inhibited the uptake of 45Ca evoked by carbachol with similar dose-response curve to inhibition of catecholamine secretion. On the contrary, highly selective agonists for alpha 1-adrenoceptors, phenylephrine and norfenefrine did not inhibit the secretion of catecholamines and cellular uptake of 45Ca. The inhibition by alpha 2-agonists was not restored either by the increase in carbachol or Ca concentrations, suggesting that the mode of inhibition was distinct from competition at cholinergic receptors or Ca-channels. It is likely that alpha 2-agonists inhibited the secretion of catecholamines via the inhibition of Ca uptake which was probably caused through the activation of alpha 2-adrenoceptors.

Adrenal Medulla↗

PubMed1983

Trifluoperazine inhibits 45Ca2+ uptake and catecholamine secretion and synthesis in adrenal medullary cells.

In isolated adrenal medullary cells, carbamylcholine and high K+ cause the calcium-dependent secretion of catecholamines with a simultaneous increase in the synthesis of 14C-catecholamines from [14C]tyrosine. In these cells, trifluoperazine, a selective antagonist of calmodulin, inhibited both the secretion and synthesis of catecholamines. The stimulatory effect of carbamylcholine was inhibited to a greater extent than that of high K+. The inhibitory effect of trifluoperazine on carbamylcholine-evoked secretion of catecholamines was not overcome by an increase in either carbamylcholine or calcium concentration, showing that inhibition by trifluoperazine occurs by a mechanism distinct from competitive antagonism at the cholinergic receptor and from direct inactivation of calcium channels. Doses of trifluoperazine that inhibited catecholamine secretion and synthesis also inhibited the uptake of radioactive calcium by the cells. These results suggest that trifluoperazine inhibits the secretion and synthesis of catecholamines mainly due to its inhibition of calcium uptake. Trifluoperazine seems to inhibit calcium uptake by uncoupling the linkage between calcium uptake by uncoupling the linkage between cholinergic receptor stimulation and calcium channel activation.

Adrenal Medulla↗

PubMed1983

[Laryngeal cancer and use of laser surgery].

Explore the source record for details and available documents.

Adult↗

PubMed1982

alpha 2-Adrenergic receptors inhibit catecholamine secretion from bovine adrenal medulla.

Catecholamine secretion evoked by carbamylcholine from isolated bovine adrenal medullary cells was inhibited by alpha 2-agonist, clonidine, in a dose-dependent manner with IC50 value of 2.8 X 10(-5) M. [3H]Clonidine bound to adrenal medullary membranes with high affinity and saturable characteristics. These results suggest that alpha 2-adrenergic receptors which exist on adrenal medullary cells have inhibitory effect on the secretion of catecholamine from the cells.

Adrenal Medulla↗

PubMed1982

Endolymphatic-mastoid shunt operation: results of the 24 cases and revision surgery with the silastic sheet.

Endolymphatic-mastoid shunt operation due to Kitahara's method was performed on 24 patients with Meniere's disease. In 14 patients, the vertiginous attack was controlled with satisfactory preservation of hearing for longer than one year. In 2 patients, the vertiginous attack subsided but the hearing worsened. In the remaining 8 patients, long-term control of the vertiginous attack was not attained. Of these 8 recurrent cases, revision was performed on 4, revealing shunt obstruction with granulation or scar tissue. After reopening the endolymphatic sac, a large triangular Silastic sheet was placed into its lumen. The vertiginous attack was controlled thus far in the revised cases using this procedure.

Adult↗

PubMed1982

Renal clear cell carcinoma metastatic to the nose and paranasal sinuses.

Two cases of metastatic renal clear cell carcinoma to the nose and the paranasal sinuses are reported. Case 1 was a 73-year-old man with metastases to the bilateral maxillas and left cervical lymph nodes. These metastatic lesions were surgically eliminated together with the primary renal cancer. Case 2 was a 48-year-old man with a right maxilloethmoidal metastasis. Because of severe repeated bleeding and profound necrosis, conclusive diagnosis was hard to obtain. In both cases primary renal carcinoma was detected after the nasal tumors were confirmed to be a metastatic clear cell carcinoma. Early diagnosis and surgical removals of both primary and metastatic tumors are important to prolong the patient's life. When persistent epistaxis with intranasal necrotic mass occurs, the possibility of metastatic renal clear cell carcinoma should be considered.

Adenocarcinoma↗

PubMed1981

Averaged blink reflex test.

Averaging of blink reflex responses was of particular value in detecting a very small potential of R1 in patients with severe facial nerve palsy where the conventional single stimulation method proved inefficient. To find the most suitable interval of stimulation for averaging, the recovery cycle of R1 was studied. The result showed that the R1 recovery curve could be divided into four phases. The initial facilitation phase at the interval of 5 msec was followed by a brief phase of depression. It was further followed by a second facilitation phase with a maximum of about 60 msec. Lastly the recovery curve returned to almost the 100% level after 100 msec. Due to the second facilitation phase, stimuli given at the interval of 60 msec were efficient for averaging of blink reflex responses. Though R1 to the second stimulus at this interval might have overlapped with R2 to the first stimulus, averaging of responses made R1 more prominent and R2 more inconspicuous, because R1 had a constant latency and R2 a variable one to each stimulus.

Adult↗