Effects of iontophoretically applied substance P, calcitonin gene-related peptide on excitability of dorsal horn neurones in rats

Spontaneous pain, allodynia and hyperalgesia are well known phenomena following peripheral nerve or tissue injury, and it is speculated that secondary hyperalgesia and allodynia, are generally thought to depend on a hyperexcitability (sensitization) of neurons in the dorsal horn. It is supposed that the sensitization may be due to various actions of neurotransmitters (SP, CGRP, excitatory amino acids) released from the primary afferent fibers. In this study, we examined effects of the iontophoretically applied SP and CGRP on the response to EAA receptor agonists (NMDA and non-NMDA) in the WDR dorsal horn neurones and see if the effects of SP or CGRP mimic the characteristic response pattern known in various pain models. The main results are summarized as follows: 1) SP specifically potentiated NMDA response. 2) CGRP non-specifically potentiated both NMDA and AMPA responses. Potentiation of NMDA response, however, was significantly greater than that of AMPA response. 3) 50% of SP applied cells and 15.8% of CGRP applied cells showed reciprocal changes(potentiation of NMDA response and suppression of AMPA response). These results are generally consistent with the sensitization characteristics in diverse pain models and suggests that the modulatory effects of SP and CGRP on NMDA and non-NMDA (AMPA) response are, at least in part, contribute to the development of sensitization in various pain models.

Incidence of presbycusis of Korean populations in Seoul, Kyunggi and Kangwon provinces

Presbycusis, a bilateral sensorineural hearing loss caused by changes in the inner ear, is related to multiple factors such as noise exposure and otologic disease. In institute-based studies, we tried to determine the incidence of presbycusis in Korean populations living in Seoul, Kyunggi and Kangwon provinces by gender and age groups. The subjects were people who had visited health promotion centers. Pure tone audiometry was done over 20 years on 6,028 subjects. In a community-based study, the subjects were elderly residents of Kanghwa-do area. There were no obvious factors that could cause hearing impairment in the subjects. For the pure tone audiometry, hearing threshold was obtained by using the six-dimension method. The incidence of presbycusis for subjects aged 65 years and older was 37.8% and 8.3% for > or = 27 dB HL criterion and > or = 41 dB HL criterion, respectively. The incidence increased with age. A statistically significant difference in the hearing threshold was found between men and women aged 65 years or older. No differences were found between the community-based study and the institute- based studies. There was a high incidence (about 40%) of presbycusis among Koreans aged 65 years or older (for > or = 27 dB HL criterion). With an aging population, we anticipate that this report could be used to provide a basic data for the study of presbycusis.

Noise level of drilling instruments during mastoidectomy

Exposure to intense noise has been identified as a potential risk in the development of hearing impairment. Social concern about excessive noise is increasing and this also extends to the operating room. A noise level study was performed in the operating room during mastoidectomy with a sound level meter and it was analyzed by a sound-analyzing program. The drilling instruments used included the Stryker, Midas, M.P.S. and Med-Next. The operator was exposed to sound levels from 69 to 83 dBA. The loudest drilling instrument was the Midas and it produced an average sound level of 83 dBA to the operator. The mean exposure time was 41 minutes during mastoidectomy. This is below the occupational noise-level regulations in Korea. However, considering that individual susceptibility to noise varies and that the otologic surgeon is repeatedly exposed to prolonged drilling noise, ear protection is recommended for the operators of high-speed drilling instruments.

Clinical Aspect of Acute Vestibular Neuritis / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: The etiology and pathophysiology of acute vestibular neuritis are largely unknown and its diagnostic criteria and clinical course also have not been established definitely. This study was performed to provide a basis for creating the classification system and diagnostic criteria of vestibular neuritis. MATERIALS AND METHODS:We studied sixty-seven patients who showed no subjective auditory symptoms, and who showed spontaneous nystagmus for more than 24 hours under ENG (Electronystagmography) after the onset of vertigo. We evaluated the frequency of nystagmus and the site of lesion, and looked for the presence of any combined infectious diseases. Eye tracking test with ENG and auditory test were performed. Bithermal caloric test was performed after disappearance of sponteneous nystagmus and canal paresis was calculated. RESULTS: We found 52 cases (78%) of unilateral single attack, 10 cases (15%) of unilateral recurrent attack, 4 cases (6%) of opposite recurrent attack and one case (1%) of bilateral simultaneous attack. For the presence of combined infectious diseases, we found 24 casees (36%) with URI, one case (2%) with mumps and three cases (5%) with Ramsay-Hunt syndrome. Ipsilateral sensorineural hearing loss at 8000 Hz was found in 10 cases (24%). Neurologic abnormality was found in 14 cases (21%), but not found in 53 cases (79%). The canal paresis on bithermal caloric response was more than 50% for 30 cases (68%), 26%-50% for 4 cases (9%), and in the normal range for 10 cases (23%). CONCLUSION: There are some cases of the acute vestibular neuritis that showed atypical clinical features (recurrent attack, bilateral attack), which is inconsistent with the Coates criteria. Appropriate classification system and diagnostic criteria for acute vestibular neuritis, including recurrent attack and bilateral attack, are required.

A Case of Kimura's Disease Arising from Epiglottis / 대한이비인후과학회지

Kimura's disease is a chronic inflammatory disease which commonly affects the head and neck regions in young oriental men. It is a rare disease and is found as tumor-like painless swelling with or without lymphadenopathy. However, it's treatment method is not clearly defined. The purpose of this article is to report a very unusual case which is often mistaken for a malignant tumor. A 15-year old male was seen with diffuse epiglottic swelling and cervical lymphadenopathy. CT and MRI showed diffusely enlarged epiglottis with homogenous ensity and bilateral multiple lymphadenopathy in internal jugular and spinal accessory chains. Biopsy of epiglottic mass was performed under the impression of malignant lymphoma. The histology revealed marked lymphoid follicular hyperplasia and massive interfollicular eosinophilic cell infiltration, which was compatible with Kimura's disease. The mass was partially excised especially in laryngeal surface area because the mass was not separated from epiglottis itself. After surgical removal, oral prednisolone was taken. The epiglottis was nearly returned to its normal figure after subsequent excision and vaporization with CO2 laser and neck nodes enlargements were spontaneously resolved. The etiology of this disease is still unknown. It is essential to differentiate it with malignant tumor through biopsy. When Kimura's disease is confirmed, combination of surgical excision and oral steroid appear to be effective therapeutic modality.

Intracellular acidosis decreases the outward Na(+)-Ca2+ exchange current in guinea pig ventricular myocytes

The Na(+)-Ca2+ exchange transport operating in outward mode has been suggested to cause Ca2+ entry during reperfusion or reoxygenation, exchanging extracellular Ca2+ for intracellular Na+ that has accumulated during ischemia or cardioplegia. During cardioplegia, however, an increase in Ca2+ entry via this mechanism can be decreased due to increased intracellular H+ activity and a decrease in cellular ATP content. In this study giant excised cardiac sarcolemmal membrane patch clamp technique was employed to investigate the effect of cytosolic pH change on the Na(+)-Ca2+ exchanger, excluding the effect of ATP, in guinea pig cardiac myocytes. The outward Na(+)-dependent current, which has a characteristics of Hill equation, was decreased as pH was decreased in the range of 7.5-6.5. The current density generated by the Na(+)-Ca2+ exchange transport was 56.6 +/- 4.4 pA/pF (Mean +/- S.E.M.) at pH 7.2 and decreased to 42.9 +/- 3.0 pA/pF at pH 6.9. These results imply that Na(+)-Ca2+ exchange transport, operating in a reverse mode during cardioplegia, decreases due to increased intracellular H+, and further suggest that consequent intracellular Na+ accumulation is one of aggravating factors for Ca2+ influx during reoxygenation or reperfusion.