Electrical stimulation of auricular acupressure for dry eye: A randomized controlled-clinical trial / 中国结合医学杂志

<p><b>OBJECTIVE</b>To evaluate the clinical efficacy of electrical stimulation (ES) of auricular acupressure on reducing the ocular symptoms and signs before and after treatment for dry eye.</p><p><b>METHODS</b>The inclusion criteria were the tear film break-up time (TFBUT) below 5 s and a Schirmer test-I below 5 mm in dry eyes with ocular symptoms for at least 6 months. Subjects were randomized into a treatment group (50 cases) with continuous low frequency ES under auricular acupressure at acupoints and a no ES under auricular acupressure (no-ES, control group, 50 cases) on the same acupoints. Auricular acupressure were stimulated with ES at 4 master points of both ears, which were performed twice a week for 4 weeks at each point for 30 s. The ocular symptoms, the TFBUT, and Schirmer test-I were evaluated before and after this procedure.</p><p><b>RESULTS</b>There were significantly better scores in TFBUT (P=0.032), the Schirmer test-I (P=0.044) and ocular symptoms (P=0.029) at 3 months post-treatment in the treatment group than in the control group. The total effective rate in the treatment group was accomplished in 41 (82%) of the 50 cases of dry eye.</p><p><b>CONCLUSIONS</b>Auricular acupressure with ES at auricular acupoint improves ocular symptoms and signs of dry eye for a period of at least 3 months.</p>

Effects of Repetitive Multiaxial 3-dimensional Rotation Training on Vestibulo-ocular Reflex / 대한평형의학회지

BACKGROUND AND OBJECTIVES: The parameters of vestibulo-ocular reflex (VOR) are believed to indicate the quantitative value of vestibular function and the differences in them are related to the susceptibility of motion sickness. The purpose of this study was to investigate the effects of repetitive multiaxial 3-dimensional rotation training on VOR parameters. MATERIALS AND METHODS: Fifteen healthy volunteers were randomly assigned to 3 different groups according to the mode of exercise training. Aerotrim exercise was done as a method of repetitive multiaxial 3-dimensional rotation training. The changes in VOR parameters after 9 weeks of exercise training in Aerotrim training group were compared with that of other groups. RESULTS: While the values of VOR gain in Aerotrim training group after 9 weeks of exercise training were significantly lower than baseline values at rotation frequencies of 0.01, 0.04, 0.08, 0.16, and 0.32 Hz, values of VOR gain in other groups showed no difference between before and after exercise training. In all groups, there were no significant differences in VOR phase and symmetry values between before and after exercise training. CONCLUSION: This study showed that VOR parameters changed after 9 weeks of repetitive multiaxial 3-dimensional rotation training, and vestibular habituation might eventually occur. Since vestibular habituation is known to contribute to mitigating the frequency and the degree of motion sickness, we suggest that repetitive multiaxial 3-dimensional rotation training can be used as the countermeasure for student pilots or astronauts, who are often exposed to unusual motion and positional status in actual 3-dimensional space.

Current Trends of Aerospace Medical Research and Spatial Disorientation / 대한평형의학회지

No abstract available.

Overview of Medical Examinations for Aircrew / 항공우주의학회지

Medical examinations for aircrew (MEA) have been applied in various extents since World War I, when medical fitness of aircrew began to be spotlighted as a major factor of flight safety and flight performance. The main purpose of MEA is to identify any presumptive medical defects that may cause sudden incapacitation and aircraft accident consequently. However, the value of medical screening tests has been debated for many years and raised questions of their effectiveness and aeromedical usefulness. Therefore, this review article focuses on diverse perspectives regarding MEA and tries to develop the most appropriate way of implementing medical examinations for insuring flight safety.

Aeromedical Consideration of Designing Attitude Indicator for Preventing Spatial Disorientation / 항공우주의학회지

To develop an aeromedical strategy to prevent aircraft accidents caused by spatial disorientation or loss of situational awareness, it is no wonder to say the first step may begin with understanding of operating principles of flight displays, especially attitude indicator. Therefore, this review article focused on explaining the unique aeromedical aspects of various types of attitude indicator. Also, the concept of newly developed attitude indicator was introduced to consider pros and cons of current design.

Microarray for Genes Associated with Signal Transduction in Diabetic OLETF Keratocytes

PURPOSE: The purpose of this study was to identify differences in signal transduction gene expression between normal and diabetic keratocytes stimulated with interleukin-1alpha (IL-1alpha) and tumor necrosis factor-alpha (TNF-alpha). METHODS: Normal and diabetic keratocytes were primarily cultured and treated with 20 ng/ml IL-1alpha and TNF-alpha for 6 h. cDNA was hybridized to an oligonucleotide microarray. Genes identified by the microarray were further evaluated by real-time PCR. RESULTS: Diabetic keratocytes over-expressed components of the MAPK and Notch pathways, and under-expressed components of the insulin, calcium, and TGF-beta pathways. Cytokine treated diabetic keratocytes differentially expressed components of the TGF-beta and MAPK pathways. After IL-1alpha and TNF-alpha treatment, nine genes were under-expressed, falling in the insulin, TGF-beta, and Toll-like receptor pathways. Real-time PCR showed a significant decrease in the IL-6 and TGF-beta2 genes and a significant increase in the Ppm1a gene. CONCLUSIONS: There were some differences in gene expression between normal and diabetic keratocytes related to signal transduction pathways, such as the insulin, MAPK, calcium, and TGF-beta pathways. In addition, IL-1alpha and TNF-alpha stimulating the insulin, TGF-beta, and Toll-like receptor signaling pathways may have different effects in diabetic keratocytes.

Hypertensive Arterial Change in Hindlimb Unloading Rats / 항공우주의학회지

BACKGROUND: In a condition of microgravity, arteries of upper body part are exposed to relative hypertensive stress, which is induced by headward fluid shift. We already have reported the increase of monocyte adhesion and intercellular adhesion molecule-I (ICAM-I) expression in carotid artery and thoracic aorta in the simulated microgravity. The purpose of this study was to identify the evidence of hypertensive arterial change in hindlimb unloading rats. METHODS: A total of 16 Sprague-Dawley rats were divided into the 2 and the 4 weeks hindlimb unloading groups and their control groups, respectively. After experimental exposure, the carotid artery, the thoracic/abdominal aorta, and the femoral artery were obtained from each experimental and control groups. The degree of matrix metalloproteinase (MMP)-2, MMP-9, and tissue inhibitor of MMPs type 1 (TIMP-1) expression were analyzed by immunohistochemical stain. RESULTS: The increase of MMP-2, 9 expression was noted in the carotid artery and the thoracic aorta from the 4 weeks hindlimb unloading group. On the other hand, the MMP-2, 9 expression was negligible in the abdominal aorta and the femoral artery of this group. In general, the findings of the 2 weeks hindlimb unloading group were similar to those of the control group. The TIMP expression was not found in all groups. CONCLUSION: We found the evidence of hypertensive arterial change by increased shear stress on upper body part's arteries in simulated microgravity. Considering the possible development of this change into hypertensive arterial damage with other cardiovascular risk factors, our findings can be highlighted as an important medical concern, especially in a long-term spaceflight.

Effect of Antivertigo Medications on Vestibular Function in Healthy Human Subjects / 항공우주의학회지

BACKGROUND: Motion sickness is one of the major problems of aerospace medical concern. Vestibule plays an important role in giving rise to motion sickness. Drugs preventing motion sickness have a suppressive effect on the vestibular function through the antagonistic effect to some receptors in vesibular nuclei and vomiting center of central nervous system. We identified and quantified the effects of anti-motion sickness drugs on vestibule-ocular reflex in healthy human subjects. METHODS: Fourty-five healthy male subjects were grouped to one of placebo, dimenhydrinate 50 mg, scopolamine (1 patch), or both scopolamine and dimenhydrinate group, and received rotation chair test before and after drug administration to obtain Vestibulo-ocular reflex (VOR) gain and phase in sinusoidal harmonic acceleration (SHA) with frequencies of 0.01, 0.02, 0.04 and 0.08 Hz. The delta gain and the delta phase by the drug administration were obtained and analyzed as pharmacodynamic effects. RESULTS: Baseline gain and phase data were not different by the groups in all SHA frequencies. VOR gains were significantly decreased by 0.15~0.17 after dimenhydrinate administration. In the scopolamine group, there were significant decreases in 0.04 and 0.08 Hz by 0.14 and 0.15, respectively, but no difference in 0.01 and 0.02 Hz was observed. Increasing tendency in VOR phase lead was observed, especially in dimenhydrinate, but not significantly. There was no additive effect on the reduction of VOR gain when the two drugs were co-administered. CONCLUSION: We quantitatively characterized how much the VOR parameters were changed by the drugs with different kinds of mechanism. Dimenhydrinate reduced the VOR gain by around 0.16. However, scopolamine probably has a minimal or no additive effect on VOR suppression.

Relationship between G-induced Loss of Consciousness and Parameters of Vestibulo-ocular Reflex / 항공우주의학회지

BACKGROUND: Vestibular reflexes, such as vestibulo-sympathetic reflex, have been considered as an important physiologic mechanism to maintain peripheral vascular resistance in case of orthostatic stress. Vestibular function may play an important role not only in maintaining spatial orientation, but also in determining G-tolerance. The purpose of this study was to investigate the possible contribution of vestibular function to G-tolerance. METHODS: Vestibular function was measured indirectly in 86 subjects by analyzing vestibulo-ocular reflex (VOR) using a rotating chair test. They were also exposed to +6Gz acceleration for 30 seconds with rapid onset run (1 G/sec). After G-exposure, they were classified into the Pass and the G-LOC group according to their success or failure to maintain consciousness during G-exposure. The VOR parameters of the G-LOC group were compared with those of the Pass group. RESULTS: While VOR gain values of one subset of the G-LOC group (low gain G-LOC group, N=8) were significantly lower than those of the Pass group at rotation frequencies of 0.02, 0.04, 0.08, and 0.32 Hz, VOR gain values of the other subset of the G-LOC group (high gain G-LOC group) were significantly higher than those of the Pass group at all rotation frequencies. There was no difference of VOR phase value between the Pass and the G-LOC groups. CONCLUSIONS:This study suggests the vestibular function may be involved in determining G-tolerance. According to VOR gain values, we were able to recognize two distinct G-LOC subgroups compared with the Pass group. The difference between afferent or efferent vestibular flows and target organ response can be a possible explanation for different VOR parameters of G-LOC subgroups.

Weightlessness-simulated Experimental Apparatus: Hindlimb Unloading Model in Rat-Technical Aspects / 항공우주의학회지

No abstract available.

Effects of Female Hormones and Menstrual Cycle on Female Relaxed G-Tolerance / 항공우주의학회지

BACKGROUND: With increasing number of female pilots who fly high-performance aircraft, the gender specific factors have become one of the most important aeromedical considerations. It has been raised that the changes of serum female hormone levels by menstrual cycle may affect vasoregulation and female G-tolerance ultimately. However, the exact relationship between serum female hormone levels and G-tolerance is still unknown. Moreover, well-controlled subjects without taking oral contraceptives are needed to examine the possible effect of menstrual cycle on female G-tolerance. The purpose of this study was to determine how female hormones and menstrual cycle affect female relaxed G-tolerance. METHODS: Eight female subjects were studied to test their relaxed G-tolerance. Seven out of 8 subjects had regular menstrual cycle during the study period. Each subject were exposed to human centrifuge once a week for 4 weeks (one complete menstrual cycle) and blood samplings were performed twice at 2nd and 4th week just before exposure to human centrifuge. The profile of centrifuge training consisted of gradual-onset run (0.1 G/sec) acceleration to the visual endpoint. RESULTS: The changes of 4 different serum female hormone levels failed to show any trend related to relaxed G-tolerance including estrogen. There was no significant difference in relaxed G-tolerance in any menstrual cycle time points. CONCLUSION: We conclude that the changes of female hormone levels and the menstrual cycle have no effect on female relaxed G-tolerance.

The Results of Aeromedical Consultation, ROKAF: 1991-2000

BACKGROUND: This study is aimed to analyze the results of aeromedical consultation of ROKAF for recent 10 years. METHODS: We reviewed the records of all ROKAF rated personnel who developed a medical problem requiring aeromedical consultation during the period from 1991 to 2000. RESULTS: We collected 263 cases. The most frequent clinical categories were ENT and musculoskeletal problems. In the group of fighter pilots, 30 cases were classified into permanent grounding. Chronic hepatitis and Herniated disc were the main causes. In the group of undergraduate pilots, aerotitis media by high altitude flight and airsickness by high performance flight, were the main causes. CONCLUSION: According to this study, we need to reinforce the supervision about the revealed major causes.

Diode Laser Photocoagulation for Retinopathy of Prematurity

Diode laser photocoagulation with laser ophthalmoscope has been shown to be effective and safe for treatment of threshold ROP. The purpose of this study are to deternine whether diode laser photocoagulation is really effective in reducing the likelihood of unfavorable regults in threshold stage. The eyes of neonates with birthweight of 2,500g or less, gestational age of 37 weeks or less, or exposure to increased ambient oxygen between May 1994 and October 1995 were examined, 21 eyes of threshold level of ROP and 2 eyes of prethreshold stage received diode laser photocoagulation. Nineteen(83%) of the 23 eyes that underwent laser photocoagulation had a favorable respons. Retinopathy of prematurity, however progressed to stage 4 in 2 eyes and stage 5 in 2 eyes. Two eyes in stage 4 achieved retinal reattachment after retinal buckling operation, but two eyes in stage 5 did not achieved retina1 reattachment. Regarding complications, one eye had retinal hemorihagic spot and one had presumed Bruch's membrane rupture. All infants had been followed up for minimum of 6 months. The results suggest that diode laser photocoagulation is an effective method in treatment of ROP, technically easier to administer without significant complication.

Diode Laser Photocoagulation for Retinopathy of Prematurity

Diode laser photocoagulation with laser ophthalmoscope has been shown to be effective and safe for treatment of threshold ROP. The purpose of this study are to deternine whether diode laser photocoagulation is really effective in reducing the likelihood of unfavorable regults in threshold stage. The eyes of neonates with birthweight of 2,500g or less, gestational age of 37 weeks or less, or exposure to increased ambient oxygen between May 1994 and October 1995 were examined, 21 eyes of threshold level of ROP and 2 eyes of prethreshold stage received diode laser photocoagulation. Nineteen(83%) of the 23 eyes that underwent laser photocoagulation had a favorable respons. Retinopathy of prematurity, however progressed to stage 4 in 2 eyes and stage 5 in 2 eyes. Two eyes in stage 4 achieved retinal reattachment after retinal buckling operation, but two eyes in stage 5 did not achieved retina1 reattachment. Regarding complications, one eye had retinal hemorihagic spot and one had presumed Bruch's membrane rupture. All infants had been followed up for minimum of 6 months. The results suggest that diode laser photocoagulation is an effective method in treatment of ROP, technically easier to administer without significant complication.

The Distribution of CD44 in Wound Healing of Rabbit Alkali Burn

An alkali burn of the cornea severely damages not only the epithelium but also the underlying keratocytes and endothelium, the extracellular matrix is thought to play an important role in burn wound healing of the cornea. The glycoprotein CD44 of extracellular matrix has been implicated in biological cell behavior, including lymphocyte binding to endothelial venules, embryonic development cell migration, cell differentiation, and tumor metastasis. The purpose of this study is to investigate the presence and distribution of CD44 in wound healing using immunohistochemical staining method after alkali burning of rabbit cornea. 2 hour after burn, there was no immunodeposit for CD44 at keratocytes and endothelial cells at denuded epithelial burn area. 4 hours postburn, the epithelial cell gradually migrated over the burn area from the peripheral unburn area and immunodepositive staining of the keratocytes was observed at the margin of burn site. 24 hours postburn, immunopositive reaction for CD44 at adjacent alkali burn area was more strongly labeled, but the peripheral epithelial response of unburn area was faintly labeled by them. 48 hours postburn, immunopositive reaction gradually shifted from the border portion of alkali burn to the center portion of burn site. On days 7, the epithelium was completely reepithelized over the burn area and 3 weeks postburn, immunostaining were demonstrated the entire layer of burn site. The recovering time of the nornal immunostaing for CD44 of the rabbit cornea from the alkali burn was taken about 7 weeks. Our results suggest that the CD44 protein can be seen in proliferating in the epithelial cells, the keratocytes end endothelial cells, and is thought to play an important role in wound healing of the alkali burn cornea.

Therapeutic Effect of Ganciclovir on Cytomegalovirus Retinitis

Cytomegalovirus(CMV) retinitis is the most common opportunistic retinal in fection seen in patients with AIDS. It is almost always progressive and, if untreated, often leads to blindness. The authors report a case of unilateral CMV retinitis in 29-year-old female with AIDS, who complained of decreased vision in the left eye. Fundus examination showed areas of dense white retinal necrosis, scattered hemorrhages and perivascular sheathings. On urine culture CMV was also isolated. Treatment with ganciclovir was started and during the 2 mon ths of treatment, the retinitis was markedly resolved and visual acuity was improved to 0.7. CMV retinitis did not develop in the right eye.

The Immunohistochemical Localization of CD44 in Rabbit and Human Cornea

The CD44 protein has a functional domain for binding hyaluronic acid, maintaining the integrity and structure of the epithelium. The purpose of this study is to evaluate the presence and comparison of distribution of CD44 in human and rabbit corneas using immunohistochemical staining method. Immunostaining for CD44 was observed in the epithelium, endothelium and human stromal keratocytes. In particular, the strong positive deposition for CD44 can be seen in basal and limbal layers of the epithelium and in the endothelium. Immunodeposits for CD44 in rabbit cornea were detected in superficial parts of the epithelium, while they were localized in deep stromal keratocytes and the endothelium. In conjunctival tissue, immunostaining for CD44 was found in the epithelium, connective tissue, and vascular endothelium in human specimen but was faintly demonstrated only in the extracellular matrix of connective tissue in the rabbit conjunctiva. No immunostaining for CD44 was seen in control case. Our results suggest that CD44 protein can be seen both in human and rabbit corneas. However, there was different distribution of CD44 between two specimens.