• Tuberculosis and Respiratory Diseases
• /
• v.48 no.2
• /
• pp.203-209
• /
• 2000

Background: Exercise is a very common precipitant of asthma. Bronche-constriction associated with exercise can occur in 75~90% of individuals with asthma The estimated prevalence(30~85%) of gastroesophageal reflux(GER) in patients with asthma is significantly higher than in general population. We performed pH monitoring during the exercise in order to evaluate whether exercise induced asthma(EIA) could be related to GER and acid reflux-induced esophagobronchial reflex-mediated bronchospasm might be a factor for EIA. Method: Following an overnight fast, 18 patients with a suspected EIA(6 men, 12 women) were studied. Monitoring of intraesophageal pH, ECG and spirometry was done for 1 hour before treadmill exercise. After baseline monitoring, subjects underwent symptom-limited treadmill exercise with Bruce protocol and continuous monitoring for 60 min after exercise. Spirometry was done at baseline prior to exercise, and repeated every 10 min after full exercise for 60 min. Results: Exercise-induced bronchoconstriction was noted in 15 patients, who performed MBPT and 12 patients confirmed for bronchial asthma and 3 patients were diagnosed exercise-induced astham. Five of 15 EIA patients demonstrated a pathologic degree of GER. Conclusion: We suggest that GER may be one of pathophysiologic factors of EIA and evoke further concentration on the GER in the EIA patients.

• International Journal of Highway Engineering
• /
• v.18 no.6
• /
• pp.145-152
• /
• 2016

OBJECTIVES : Visibility at night can be improved by using retroreflection for short distances and phosphorescent line markings for long distances. In this study, we analyzed the characteristics of the phosphorescent line marking through a laboratory luminance test. Field performance analysis was performed through tests conducted on the road. We also examined the luminance measurement methods using the digital image obtained during the phosphorescent visibility evaluation. METHODS : In this study, the laboratory luminance test of the phosphorescent line marking was conducted using seven specimens to characterize the luminance changes according to the type of the glass beads, the thickness of the phosphorescent line marking, and the brightness and irradiation time of the light source. Phosphorescent and general line markings were made at 150 m to investigate the field luminance performance. A preliminary review of the luminance measurement methods was made using a digital image from a digital single-lens reflex (DSLR) camera. The measured luminance ratio of the general and the phosphorescent line markings was compared with the calculated luminance ratio using luminance analysis. RESULTS : Through the laboratory luminance test, it was seen that the change in luminance, which corresponds to the brightness of the light source, appears large but the influence of the thickness and irradiation time is low. The field performance test of the phosphorescent line marking conducted on the road involved measuring the luminance on the day the marking was made and 7 days after the marking was made. The luminance was found to be $190mcd/m^2$ at 30 min after sunset and approximately $10-12mcd/m^2$ 4h after sunset. The results of the luminance test were captured using a digital image for each time group. The luminance ratio of the phosphorescent line marking, when compared to that of the general line marking, showed a similar trend within a 13% maximum error. Additionally, when this luminance ratio is compared to the direct field measurement, it could be confirmed that the luminance ratio, as captured in the digital image, showed a similar tendency. CONCLUSIONS : 1) The change in luminance corresponding to the brightness of the light source is significant in comparison with that corresponding to the thickness and the irradiation time. In addition, the results of the field test for the phosphorescent line marking satisfied the phosphorescent fire protection standard. 2) We examined the validity of the luminance measurement method using a digital image and we concluded that the change in the luminance ratio shows a similar tendency in both the cases. The results can form the basis for luminance measurement methodology for the construction and maintenance of phosphorescent line markings.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.25 no.4
• /
• pp.788-796
• /
• 1998

The purpose of this study was to investigate the effect of various electroacupuncture duration induced by acupuncture point-Zusanli ($S_{36}$) electrical stimulation on inhibition of amplitude of digastric electromyogram (dEMG) evoked by noxious electrical stimuli around the mental foramen. intraperitoneal sodium pentobarbital in an initial dose of 50mg/kg and maintenance doses of 4.5mg/kg/h were given through a cannula in the femoral vein using a constant infusion pump. A pair of stimulating electrodes were inserted for noxious stimuli around the mental foramen. An irritant electronic stimuli pulse (0.2 Hz, 0.1 ms duration) was produced with an intensity of about $1.5{\times}2$ times threshold for evoking the dEMG. The anterior belly of the digastric muscle was exposed and a pair of 0.1mm wire electrodes were inserted for dEMG recording. Acupuncture point stimulation on Zusanli (2 Hz, 250 ${\mu}s$, biphasic pulse, 2 V) was delivered by Dental Electronic Anesthesia (3M, U.S.A). For periods of electronic stimulation of 10, 20, and 30min, the amplitudes of dEMG were measured on the oscilloscope and on the monitor connected to the amplifier. The following results were obtained: The dEMG was decreased to 73.4% of that in the control set after 10 min electroacupunture stimulation (Group I); The dEMG was decreased to 77.1% (10min), 54.0.% (20min) of that in the control set after 20minutes of electroacupunture stimulation (Group II). The dEMG was decreased to 73.3% (10min), 61.9% (20min), 76.2% (30min) of that in the control set after 30 min of electroacupunture stimulation (Group III). From these results, it may be that in the electroacupuncture stimulation on the Zusnali resulted in a reduction of amplitude of dEMG and that the most effective electroacupuncture stimulation period was 20min.

• International Journal of Oral Biology
• /
• v.31 no.4
• /
• pp.113-118
• /
• 2006

In the primary sensory neuron of the mesencephalic trigeminal nucleus (MTN), the peripheral axon supplies a large number of annulospiral endings surrounding intrafusal fibers encapsulated in single muscle spindles while the central axon sends only a few number of synapses onto single ${\alpha}-motoneurons({\alpha}-MNs)$. Therefore, the ${\alpha}-{\gamma}$ linkage is thought to be very crucial in the jaw-closing movement. Spike activity in a ${\gamma}-motoneuron\;({\gamma}-MN)$ would induce a large number of impulses in single peripheral axons by activating many intrafusal fibers simultaneously, subsequently causing an activation of ${\alpha}-MNs$ in spite of the small number of synapses. Thus, the activity of ${\gamma}-MNs$ may be vital for modulation of jaw-closing movements. Independently of such a spindle activity modulated by ${\gamma}-MNs$, somatic depolarization in MTN neurons is known to trigger the oscillatory spike activity. Nevertheless, the trafficking of these spikes arising from the two distinct sources of MTN neurons is not well understood. In this short review, switching among multiple functional modes of MTN neurons is discussed. Subsequently, it will be discussed which mode can support the ${\alpha}-{\gamma}$ linkage. In our most recent study, simultaneous patch-clamp recordings from the soma and axon hillock revealed a spike-back-propagation from the spike-initiation site in the stem axon to the soma in response to a somatic current pulse. The persistent $Na^+$ current was found to be responsible for the spike-initiation in the stem axon, the activation threshold of which was lower than those of soma spikes. Somatic inputs or impulses arising from the sensory ending, whichever trigger spikes in the stem axon first, would be forwarded through the central axon to the target synapse. We also demonstrated that at hyperpolarized membrane potentials, 4-AP-sensitive $K^+$ current ($IK_{4-AP}$) exerts two opposing effects on spikes depending on their origins; the suppression of spike initiation by increasing the apparent electrotonic distance between the soma and the spike-initiation site, and the facilitation of axonal spike invasion at higher frequencies by decreasing the spike duration and the refractory period. Through this mechanism, the spindle activity caused by ${\gamma}-MNs$ would be safely forwarded to ${\alpha}-MNs$. Thus, soma spikes shaped differentially by this $IK_{4-AP}$ depending on their origins would reflect which one of the two inputs was forwarded to the target synapses.

• The Korean Journal of Physiology
• /
• v.19 no.2
• /
• pp.139-153
• /
• 1985

The passive tilt has been performed to study the orthostasis on the cardiovascular system. The orthostasis due to upright tilt was demonstrated as follows: the venous return, cardiac output and systemic arteiral blood pressure were decreased, whereas there was concomitant increase of heart rate, through the negative feedback mediated by such as the baroreceptor . Previous investigators have suggested that the tolerance to the orthostasis could he increased by blocking the cholinergic fiber with atropine which prevented vasodilation and bradycardia through the vasovagal reflex during the orthostasis. However, this hypothesis has not been clearly understood. This study was attempted to clarify the effect of atropine on the tolerance of the cardiovascular system to the upright and head-down tilt, and to investigate the change of the blood flow through head and lower leg with Electromagnetic flowmeter in both tilts before and after atropine state. Fourteen anesthetized dogs of $10{\sim}14kg$ were examined by tilting from supine position to $+77^{\circ}$ upright position (orthostasis), and then to $-90^{\circ}$ head-down position (antiorthostasis) for 10 minutes on each test. And the same course was taken 20 minutes after intravenous administration of 0.5mg atropine. The measurements were made of the blood flow(ml/min.) on the carotid artery, external jugular vein, femoral artery and femoral vein. At the same time pH, $PCO_2$, $PO_2$ and hematocrit (Hct) of the arterial and venous blood, and heart rate(HR) and respiratory rate (RR) were measured. The measurements obtained from upright and head-down tilt were compared with those from supine position. The results obtained are as follows: In upright tilt, the blood flow both on the artery and the vein through head and lower leg were decreased, however the decrement of blood flow through the head was greater than the lower leg And the atropine attenuated the decrement of the blood flow on the carotid artery, but not on the vessels of the lower leg. HR was moderately increased in upright tilt, but slightly in head-down tilt. The percent change of HR after the atropine administration was smaller than that before the atropine state in both upright and head-down tilts. Before the atropine state, RR was decreased in upright tilt, whereas increased in head-down tilt. However after the atropine state, the percent change of RR was smaller than that of before the atropine state in both upright and head-down tilts. In upright tilt, venous $PCO_2$ was increased, but arterial $PO_2$ and venous $PO_2$ were slightly decreased. Hct was increased in both upright and head-down tilts. The findings of blood $PCO_2$, $PO_2$ and Hct were not interferred by the atropine. In conclusion, 1;he administration of atropine is somewhat effective on improving the cardiovascular tolerance to postural changes. Thus, atropine attenuates the severe diminution of the blood flow to the head during orthostasis, and also reduces the changes of HR and RR in both orthostasis and antiorthostasis.

• Journal of Yeungnam Medical Science
• /
• v.6 no.1
• /
• pp.151-163
• /
• 1989

Nerve conduction studies help delineate the extent and distribution of the neural lesion. The nerve conduction was studied on upper(median, ulnar and radial nerves) and lower(personal, posterior tibial and sural nerves) extremities in 83 healthy subjects 23 to 66 years of age. and normal values were established(Table 1). The mean motor terminal latency (TL) were : median. 3.6(${\pm}0.6$)milliseconds ; ulnar. 2.9(${\pm}0.5$) milliseconds ; radial nerve. 2.3(${\pm}0.4$) milliseconds. Mean motor nerve conduction velocity(MNCV) along distal and proximal segments: median. 61.2(${\pm}9.1$) (W-E) and 57.8(${\pm}13.2$) (E-Ax) meters per second ; ulnar. 63.7(${\pm}9.1$) (W-E) and 50.(${\pm}10.0$) meters per second. Mean sensory nerve conduction velocity(SNCV) : median. 34.7(${\pm}6.7$) (F-W), 63.7(${\pm}7.1$) (W-E) and 62.8(${\pm}12.3$) (E-Ax)meters per second ; ulnar. 38.0(${\pm}6.7$)(F-W), 63.4(${\pm}7.5$) (W-E) and 57.0(${\pm}10.1$) (E-Ax)meters per second ; radial, 45.3(${\pm}6.8$) (F-W) and 64.2(${\pm}11.0$) (W-E) meters per second ; sural nerve, 43.4(${\pm}6.1$) meters per second. The amplitudes of action potential and H-reflex were also standardized. Mean H latency was 28.4(${\pm}3.2$) milliseconds. And. the fundamental principles, several factors altering the rate of nerve conduction and clinical application of nerve stimulation techniques were reviewed.

• The Korean Journal of Pharmacology
• /
• v.20 no.2
• /
• pp.15-21
• /
• 1984

It was aimed to study the effects of ${\alpha}_2-adrenoceptor$ agonists on the sleeping time in $one{\sim}two-day-old$ chickens. Furthermore, it was also evaluated whether ${\alpha}_1-adrenoceptor$ agonist and antagonist might affect the sleeping in the chickens and discussed in relation with opiate receptor. 1) Guanabenz, clonidine, guanfacine and B-HT 933 decreased the latency of the loss of righting reflex in a dose-dependent manner, but B-HT 920 and oxymetazoline slightly prolonged it. 2) ${\alpha}_2-Adrenoceptor$ agonists produced dose·related increase in sleeping time. The potency was guanabenz>clonidine>oxymetazoline${\geq}$B-HT 933${\geq}$B-HT 920>guanfacine in this order. 3) ${\alpha}_2-Adrenoceptor$ antagonists decreased guanabenz-induced sleeping time in a dose ·dependent manner. The rank order of ${\alpha}_2-adrenoceptor$ antagonists was yohimbine>rauwolscine>piperoxan${\geq}$RX 781094. 4) Sleeping time caused by both ethanol and hexobarbital was not affected by yohimbine in chickens. 5) Methoxamine and phenylephrine showed little significant effect on the guanabenz-induced sleeping time. However, prazosin increased it. Paradoxically, corynanthine rather caused to decrease it. These results suggest that the stimulation of central ${\alpha}_2-adrenoceptor$ mediates sleeping, however it is remained uncertain in the role of central ${\alpha}_1-adrenoceptor$ in chickens. In addition, the one~two-day-old chickens may be considered as a useful, inexpensive and simple experimental model to evaluate the in vivo pharmacological action of the ${\alpha}_2-adrenoceptor$ agonist and antagonist related to sedation.

• Tuberculosis and Respiratory Diseases
• /
• v.42 no.5
• /
• pp.744-751
• /
• 1995

Background: Asthma is an inflammatory disease because there are many inflammatory changes in the asthmatic airways. Axon reflex mechanisms may be involved in the pathogenesis of asthma. Sensory neuropeptides are involved in this inflammation, which is defined as neurogenic inflammation. Substance p, neurokinin A, and neurokinin B may be main neuropeptides of neurogenic inflammation in airways. These tachykinins act on neurokinin receptors. Three types of neurokinin receptors, such as $NK_1$, $NK_2$, and $NK_3$, are currently recognized, at which substance p, neurokinin A, and neurokinin B may be the most relevant natural agonist of neurogenic inflammation in airways. The receptor subtypes present in several tissues have been characterized on the basis of differential sensitivity to substance p, neurokinin A, and neurokinin B. Plasma extravasation and vasodilation are induced by substance p more potently than by neurokinin A, indicating NK1 receptors on endothelial cells mediate the response. But airway contraction is induced by neurokinin A more potently than by substance P, indicating the $NK_2$ receptors in airway smooth muscles. These receptors are used to evaluate the pathogenesis of brochial asthma. FK224 was identified from the fermentation products of Streptomyces violaceoniger. FK224 is a dual antagonist of both $NK_1$ and $NK_2$ receptors. Purpose: For a study of pathogenesis of bronchial asthma, the effect of FK224 on plasma extravasation induced by vagal NANC electrical stimulation was evaluated in rat airway. Method: Male Sprague-Dawley rats weighing 180~450gm were anesthetized by i.p. injection of urethane. Plasma extravasation was induced by electrical stimulation of cervical vagus NANC nerves with 5Hz, 1mA, and 5V for 2 minutes(NANC2 group) and for sham operation without nerve stimulation(control group). To evaluate the effect of FK224 on plasma extravasation in neurogenic inflammation, FK224(1mg/kg, Fujisawa Pharmaceutical Co., dissolved in dimethylsulphoxide; DMSO, Sigma Co.) was injected 1 min before nerve stimulation(FK224 group). To assess plasma exudation, Evans blue dye(20mg/kg, dissolved in saline) was used as a plasma marker and was injected before nerve stimulation. After removal of intravascular dye, the evans blue dye in the tissue was extracted in formamide($37^{\circ}C$, 24h) and quantified spectrophotometrically by measuring dye absorbance at 629nm wavelength. Tissue dye content was expressed as ng of dye per mg of wet weight tissue. The amount of plasma extravasation was measured on the part of airways in each groups. Results: 1) Vagus nerve(NANC) stimulation significantly increased plasma leakage in trachea, main bronchus, and peripheral bronchus compared with control group, $14.1{\pm}1.6$ to $49.7{\pm}2.5$, $17.5{\pm}2.0$ to $38.7{\pm}2.8$, and $12.7{\pm}2.2$ to $19.1{\pm}1.6ng$ of dye per mg of tissue(mean ${\pm}$ SE), respectively(p<0.05). But there was not significantly changed in lung parenchyma(p>0.05) 2) FK224 had significant inhibitory effect upon vagal nerve stimulation-induced airway plasma leakage in any airway tissues of rat,such as trachea, main bronchus, and peripheral bronchus compared with vagus nerve stimulation group, 49%, 58%, and 70%, respectively(p<0.05). Inhibitory effect of FK224 on airway plasma leakage in neurogenic inflammation was revealed the more significant in peripheral bronchus, but no significant in lung parenchyma. Conclusion: These results suggest that FK224 is a selective NK receptor antagonist which effectively inhibits airway plasma leakage induced by the endogenous neurotransmitters relased by neurogenic inflammation in rat airway. Tachykinin receptor antagonists may be useful in the treatment of brochial asthma.