Establishment of particulate matterinduced lung injury model in mouse / 한국실험동물학회지

Background@#Particulate matter (PM) is one of the principal causes of human respiratory disabilities resulting from air pollution. Animal models have been applied to discover preventive and therapeutic drugs for lung diseases caused by PM. However, the induced severity of lung injury in animal models using PM varies from study to study due to disparities in the preparation of PM, and the route and number of PM administrations. In this study, we established an in vivo model to evaluate PM-induced lung injury in mice. @*Results@#PM dispersion was prepared using SRM2975. Reactive oxygen species were increased in MLE 12 cells exposed to this PM dispersion. In vivo studies were conducted in the PM single challenge model, PM multiple challenge model, and PM challenge with ovalbumin-induced asthma using the PM dispersion. No histopathological changes were observed in lung tissues after a single injection of PM, whereas mild to moderate lung inflammation was obtained in the lungs of mice exposed to PM three times. However, fibrotic changes were barely seen, even though transmission electron microscopy (TEM) studies revealed the presence of PM particles in the alveolar macrophages and alveolar capillaries. In the OVA-PM model, peribronchial inflammation and mucous hypersecretion were more severe in the OVA+PM group than the OVA group. Serum IgE levels tended to increase in OVA+PM group than in OVA group. @*Conclusions@#In this study, we established a PM-induced lung injury model to examine the lung damage induced by PM. Based on our results, repeated exposures of PM are necessary to induce lung inflammation by PM alone. PM challenge, in the presence of underlying diseases such as asthma, can also be an appropriate model for studying the health effect of PM.

Establishment of particulate matterinduced lung injury model in mouse / 한국실험동물학회지

Background@#Particulate matter (PM) is one of the principal causes of human respiratory disabilities resulting from air pollution. Animal models have been applied to discover preventive and therapeutic drugs for lung diseases caused by PM. However, the induced severity of lung injury in animal models using PM varies from study to study due to disparities in the preparation of PM, and the route and number of PM administrations. In this study, we established an in vivo model to evaluate PM-induced lung injury in mice. @*Results@#PM dispersion was prepared using SRM2975. Reactive oxygen species were increased in MLE 12 cells exposed to this PM dispersion. In vivo studies were conducted in the PM single challenge model, PM multiple challenge model, and PM challenge with ovalbumin-induced asthma using the PM dispersion. No histopathological changes were observed in lung tissues after a single injection of PM, whereas mild to moderate lung inflammation was obtained in the lungs of mice exposed to PM three times. However, fibrotic changes were barely seen, even though transmission electron microscopy (TEM) studies revealed the presence of PM particles in the alveolar macrophages and alveolar capillaries. In the OVA-PM model, peribronchial inflammation and mucous hypersecretion were more severe in the OVA+PM group than the OVA group. Serum IgE levels tended to increase in OVA+PM group than in OVA group. @*Conclusions@#In this study, we established a PM-induced lung injury model to examine the lung damage induced by PM. Based on our results, repeated exposures of PM are necessary to induce lung inflammation by PM alone. PM challenge, in the presence of underlying diseases such as asthma, can also be an appropriate model for studying the health effect of PM.

The Validity of Intraoperative Brainstem Auditory Evoked Potentials (BAEPs) for the Postoperative Hearing Impairments in Microvascular Decompression (MVD) / 대한마취과학회지

BACKGROUND: Intraoperative brainstem auditory evoked potentials reduced the sensorineural hearing loss (SNHL) after microvascular decompression (MVD) This study was performed to evaluate the validity of BAEP parameters of latency or amplitude to SNHL. METHODS: 557 patients out of 930 hemifacial spasm patients performed MVD, who were free from hearing impairment preoperatively, were enrolled in this study. Maximal changes of BAEPs wave V latency and amplitude during MVD were retrospectively sought according to postoperative SNHL. Sensitivity, specificity and positive predictability of wave V latency and amplitude were also sought according to the postoperative SNHL with a critical value of 1.0 msec prolongation and 40% decrease, respectively. RESULTS: Wave V latency of BAEPs prolonged less in patients with normal hearing outcome (0.44 +/- 0.63 msec) than in the patients with temporary or permanent SNHL (1.23 +/- 0.56 msec, 1.33 +/- 0.33 msec). Wave V amplitude also decreased less in the patients with normal hearing outcome (5.4 +/- 15.8%) than in the patients with transient or permanent SNHL (42.8 +/- 31.7%, 60.0 +/- 34.7%). While sensitivity, specificity and predictability of prolongation of wave V latency at a value of 1.0 msec for SNHL, were 52.5%, 76.4% and 14.7%, respectively, those of decrease in the amplitude of wave V for SNHL at a value of 40% were 35.0%, 93.6% and 29.8%, respectively. CONCLUSIONS: Decrease of the amplitude of wave V seems to have higher specificity, predictability and lower sensitivity for SNHL than the prolongation of wave V latency.

Surgical Managements of Anal Stricture

Anal stricture is a mechanical narrowing of the anal canal due to contracture of the epithelial lining which has been supplanted by fibrous connective tissue. We reviewed 82 patients with anal strictures who were admitted at Song-Do Colorectal Hospital from Jan. 1994 to Dec. 1996. The etiology of the strictures were injection therapy with necrotizing agent in 62 patients(78%), secondary to hemorrhoid and fistular operations in 13 patients(17%), and other causes in 7 patients(8.5%). The degree of anal stricture was mild in 40 patients, moderate in 33 patients, and severe in 9 patients. The operation methods used to treat the anal strictures were infernal sphincterotomy in 27 patients, local advancement flap in 42 patients, and rotational flap in 13 patients; the selection of the operation method was based on the cause, severity and level of the stricture. During the local advancement or rotational flap operation, a concurrent internal sphincterotomy was also employed in selected patients who had a fibrotic muscular component contributing to the stricture. We preferred to use a sliding skin graft in the advancement flap operation and a C-flap in rotational flap operation. According to a follow-up study with an average follow-up of 20 months, 24 of the 27 patients with mild stricture, 19 of the 24 patients with moderate stricture, and 7 of the 8 patients with severe stricture had good results, and remained 3 patients with mild stricture, 5 patient with moderate stricture, and 1 patient with severe stricture had fair results. Mild anal strictures were effectively treated by sphincterotomy or one or two sliding skin grafts, moderate to severe anal strictures with diaphragmatic type were treated by anorectoplasty, and moderate to severe low anal stoictures with annular type were effectively treated by two or three sliding skin grafts. Based on these results, sliding skin grafts should be effective in most cases of moderate to severe anal canal stricture, although occasionally a rotational flap may be indicated in cases of severe lack of the anoderm.

Percutaneous Multiple Knowles Pinning in Femur Neck Fractures / 대한정형외과학회잡지

Femoral neck fracture has given marked attention to the orthopaedic surgeon due to complications, such as avascular necrosis of femoral head, non-union and degenerative arthritis, moveover common in older age group since early part of the 20th century. It is one of disabling and unsolved problems, so various techniques and implants were introduced and applied. Percutaneous Knowles pinning is one of simple, safe and reasonably effective method in treating femoral neck fracture, provided it is performed correctly. Nineteen cases of femoral neck fracture treated with precutaneous Knowles pinning at the Department of Orthopaedic Surgery, National Medical Center were analyzed and following result were obtained. l. Among the 19 cases, 13 cases were female and 6 cases were male, and high incidence was noted in older age group. 2. The amout of bleeding during operation was less than 100ml and the operative time was less than one and half hour under the local anesthesia in majority. 3. Good result was obtained in the group of operation less than 3 days after initial injury compared to more than 3 days group. 4. There was high complication rate in poor group than acceptable group according to Garden alignment index and we could predict the end result by aid of alignment index. 5. There was no cast immobilization in case of stable reduction, good fixation and good Rapport. 6. Bony union was established within 4.7 months in non-displaced fracture and 7.3 months in displaced fracture in average. 7. There were 1 case of avascular necrosis. 3 cases of non-union and 2 cases of degenerative osteoarthritis and poor results were correlated with Garden stage.