1.The Neuroprotective Effect of Intravitreal Melatonin Injection in Pressure-induced Retinal Ischemia.
Seung Joon LEE ; Won Sub SON ; Hyung Woo KWAK
Journal of the Korean Ophthalmological Society 2001;42(4):638-646
PURPOSE: The authors sought to determine the neuroprotective effect of melatonin in a model of ischemic injury in rabbit retina. METHODS: Ischemia was induced by high intraocualr pressure. A dose of 100 microgram of melatonin or dimethyl sulfoxide(DMSO) alone was injected intravitreally just after the induction of ischemia. After 7 and 14 days, the neuroprotective effect of melatonin on ischemic retina was examined with light microscope and transmission electron microscope. RESULTS: The authors found reduction of cytoplasm of retinal ganglion cell(RGC), vacuole formation, chromatin condensation and rupture of nuclear membrane in ischemia-injured eyes treated with DMSO alone. But in melatonin treated eyes, we found that RGC layer's thickness and number of RGC reduced and destruction of cytoplasmic organells and nuclear damage were minimal. The partial recovery of wave is noted in melatonin-treated eyes after ischemia induction. CONCLUSIONS: The melatonin(100 microgram) protected the rabbit retina from high intraocular pressure-induced ischemic injury when administered intravitreally. Melatonin may be useful to decrease neuronal damage in the retina as a result of ischemic injury. But further investigations are neccesary to decide effective concentration, route and time of administration.
Chromatin
;
Cytoplasm
;
Dimethyl Sulfoxide
;
Ganglion Cysts
;
Ischemia*
;
Melatonin*
;
Neurons
;
Neuroprotective Agents*
;
Nuclear Envelope
;
Retina
;
Retinaldehyde*
;
Rupture
;
Vacuoles
2.Placental Site Nodules & Plaques: A clinicopathologic analysis of 14 cases.
Kyu Rae KIM ; Sun Won HONG ; Kyung Sub CHA ; In Pyong KWAK ; Tae Ki YOON
Korean Journal of Pathology 1992;26(1):53-61
Placental site nodules and plaques have been recently described to designated single or multiple, well-circumscribed, rounded lesions at the placental site, composed of viable or degenerating intermediate trophoblastic cells and extensive hyalinization between the cells. We described clinicopathologic findings of 14 cases of placental site nodules and plaques. The age of 14 patients ranged from 25 to 39(average 33) years and all of them had been pregnant in the past. Ten of them presented with vaginal spotting, which was preceded by recent pregnancy in only 3 cases. Three patients presented with secondary infertility and one with secondary infertility and vaginal spotting. Urine pregnancy tests were negative in all 14 cases at the time of presentation. Ultrasonographic examination disclosed abnormalities in only 3 cases and the remaining cases were normal. Hysterosalpingography was performed in 3 patients who presented with 2 degrees infertility and revealed moderate to severe intrauterine adhesions. Microscopically, chronic endometritis of varying degrees evidenced by plasma cells and eosinophiles were present in all cases and these were more prominent in the vicinity of the lesions. It is presumed that the placental site nodules and plaques are not sloughed at the time of menstruation and it may cause chronic endometritis or intrauterine adhesions at any time after previous delivery.
Pregnancy
;
Female
;
Humans
3.The Changes of the Retinal Ganglional Cells in the Pressure-induced Ischemic Rabbit Retina.
Tae Kwann PARK ; Won Sub SON ; Hyung Woo KWAK
Journal of the Korean Ophthalmological Society 2001;42(5):772-782
PURPOSE: There were many studies on the distributions of the retinal ganglion cells(RGC) in the experimental model of the retinal ischemia. RGC was known to be more sensitive to the ischemic injury than the other types of the retinal cells. So, we would identify the changes of the retinal ganglion cell morphologies and distribution after the iatrogenic retinal ischemia induced by intraocular pressure(IOP) elevation. METHODS: Eight pigmented and six white rabbits were used and retinal ischemia was induced by increasing IOP higher than 120 mmHg for 60 minutes. Electroretinogram were recorded at 6 days or 13 days, and histologic findings were observed at 7 or 14 days. RESULTS: After 7 days, RGC densities decreased, cytoplasmic staining disappeared, and the intranuclear hyperpigmentation was noted. RGC densities decreased significantly at 14 days. In the vertical retinal section, some flattening of retinal ganglion cell layer and inner plexiform layer was observed. Changes in the cellular morphologies were prominent. CONCLUSIONS: It may be more appropriate to examine both the retinal whole-mount and the vertical tissue section for the estimatation of the changes of retinal ganglion cell layer in the pressure-induced retinal ischemia.
Cytoplasm
;
Ganglion Cysts*
;
Hyperpigmentation
;
Ischemia
;
Models, Theoretical
;
Rabbits
;
Retina*
;
Retinal Ganglion Cells
;
Retinaldehyde*
4.The Neuroprotective Effect of alpha-phenyl-N-tert-butyl-nitrone (PBN) in the Argon Laser Induced Retinal Ischemia.
Hyung Kyu PARK ; Won Sub SON ; Hyung Woo KWAK
Journal of the Korean Ophthalmological Society 2002;43(3):599-607
PURPOSE: We examined the ability of alpha-phenyl-tert-butyl-nitrone (PBN), an electron spin trapper, to determine the neuroprotective effect in the argon laser induced ischemic rat retina model. METHODS: After ischemic condition of rat retina was induced by argon green laser, PBN was given intraperitoneally at 50 or 100 mg/kg and normal saline was injected to control group. After 24 hours, 48 hours, and 7 days, the neuroprotective effect of PBN was examined by electroretinogram (ERG) and after 7 days, the enucleation of eyes was performed and histologic findings were compared by light microscopy and transmission electron microscopy. RESULTS: We found relatively reduced amplitude of ERG wave in the PBN injected group but not so greatly reduced as in normal saline control group. The retinal ganglion cell (RGC) layer and the number of RGCs were affected by acute ischemic changes but in the group of PBN treatment, the cell membrane was well preserved and vecuoles formation, cytoplasmic destructions, nuclear chromatin condensation were reduced. CONCLUSIONS: Systemic administration of PBN can ameliorate an argon laser induced retinal ischemia. Further investigations are necessary to decide effective dose without toxicity and to find more convenient methods of administrations.
Animals
;
Argon*
;
Cell Membrane
;
Chromatin
;
Cytoplasm
;
Ischemia*
;
Microscopy
;
Microscopy, Electron, Transmission
;
Neuroprotective Agents*
;
Rats
;
Retina
;
Retinal Ganglion Cells
;
Retinaldehyde*
5.The Effect of Antiproliferative Drugs on the Collagen Matrix Cultured with Retinal Pigment Epithelial Cell and Choroidal Fibroblast.
Woo Jeung CHOI ; Woo Ho NAM ; Won Sub SON ; Hyung Woo KWAK
Journal of the Korean Ophthalmological Society 2001;42(7):1078-1087
PURPOSE: Epiretinal membrane in proliferative vitreoretinopathy (PVR) may cause tractional retinal detachment after vitreoretinal surgery. It has been thought that the proliferative membrane is mainly composed of choroidal fibroblasts and retinal pigment epithelial cells. Inspite of the technical advances, the treatment of PVR is still difficult. Therefore, the need for phamarcologic treatment of proliferative vitreoretinopathy is increasing. METHODS: In vitro models of proliferative vitreoretinopathy allow to identify the factors which may inhibit proliferation and contraction of collagen matrix by choroidal fibroblast and retinal pigment epithelial cells. Cultured choroidal fibroblasts and the RPE cells were plated to the collagen matrix and antiproliferative drugs was tested. RESULTS: Each antiproliferative drug showed the inhibition of collagen matrix contraction at following concentration: colchicine(0.1 microgram/ml), puromycin(1~10 microgram/ml), cytochalasin B(0.05 microgram/ml). Transmission electron micrograph of collagen matrices showed dense collagen fibers surrounding choroidal fibroblast and fine collagen fibers surrounding RPE cell. Scanning electron micrograph of collagen matrices contaning colchicine, puromycin, or cytochalasin B showed that collagen fibers were well preserved without distortion. All collagen matrices containing RPE cells showed more fine collagen fibers than those containing choroidal fibroblasts. CONCLUSION: Colchicine, puromycin, cytochalasin B showed inhibitory effect on cell mediated contraction in addition to potent antiproliferative effect. Retinal pigment epithelial cell played less significant role in causing PVR than choroidal fibroblast.
Choroid*
;
Colchicine
;
Collagen*
;
Cytochalasin B
;
Epiretinal Membrane
;
Epithelial Cells*
;
Fibroblasts*
;
Membranes
;
Puromycin
;
Retinal Detachment
;
Retinaldehyde*
;
Traction
;
Vitreoretinal Surgery
;
Vitreoretinopathy, Proliferative
6.Reoperation for Dysfunction of Cardiac Valve Prosthesis.
Jeong Seob YOON ; Chi Kyung KIM ; Kyu Do CHO ; Sung Ho LEE ; Moon Sub KWAK ; Se Wha KIM
The Korean Journal of Thoracic and Cardiovascular Surgery 1998;31(3):242-246
From January 1988 to December 1995, 27 patients, 11 men and 16 women, underwent surgical intervention at our institution for prosthetic valve dysfunctions. The mean age was 43.5+/-12.2 years. Seventeen (63.0%) patients had the mitral valve replacement, 8 (29.6%) the aortic valve, 1 (3.7%) the aortic composite graft, and 1 (3.7%) the tricuspid valve. Mean follow-up period was 49.5+/-30.9 months. In 12 bioprostheses, mean interval between the previous valve replacement and the reoperation was 104.9+/-34.9 months. The causes of redo surgery were structural deterioration of the prosthetic valve (12/12, 100%), paravalvular leak (2/12, 16.7%), and prosthetic valve endocarditis (1/12, 8.3%). In 15 mechanical prostheses, the mean interval was 55.2+/-43.7 months. The causes of redo surgery were pannus formation (8/15, 53.3%), paravalvular leak (4/15, 26.7%), and valve thrombosis (3/15, 20.0%). Posto-perative complications occurred in 7 patients (25.9%). There was no intraoperative death. But one patient, who received mechanical aortic valve replacement died on the 3rd postoperative day due to low cardiac output and multiorgan failure.
Aortic Valve
;
Bioprosthesis
;
Cardiac Output, Low
;
Endocarditis
;
Female
;
Follow-Up Studies
;
Heart Valve Prosthesis*
;
Heart Valves*
;
Humans
;
Male
;
Mitral Valve
;
Prostheses and Implants
;
Reoperation*
;
Thrombosis
;
Transplants
;
Tricuspid Valve
7.The Association between White Blood Cell Counts and Clustered Features of the Metabolic Syndrome.
Tae Soon CHOI ; Yoo Sun MOON ; Young Ho CHOI ; Seok Yun KO ; Kyung Sub KWAK ; Yun Ki KIM
Journal of the Korean Academy of Family Medicine 2004;25(1):34-39
BACKGROUND: Increased WBC counts have been associated with different components of metabolic syndrome (MS), accompanied by clustering of a number of risk factors for CHD. Because most individuals have one or more of the risk factors for CHD or a cluster of MS symptoms, it may not be appropriate to look only at isolated components. Therefore, the aim of the present study was to examine the association of WBC counts with clustered features of MS in Korean adults. METHODS: The subject of this study included 593 adults (males 344, females 249) aged 20 years or older. Among the subjects, we excluded those who did not have records of physical parameters and blood test results and those who did not complete the questionnaire. We also excluded acutely ill patients. Logistic regression analyses were used to evaluate the association between WBC counts and features of the MS, with an adjustment for age, smoking and alcohol consumption. RESULTS: The relative risks for obesity, hypertension, hypercholesterolemia, low HDL cholesterol levels, hypertriglyceridemia, high fasting plasma glucose levels and hyperuricemia compared with WBC counts <5.2 x 10(3) cells/microliter, increased as WBC counts increased. The relative risks for the presence of > or =1, > or = 2, > or = 3, > or = 4 features of the MS also increased as WBC counts increased. CONCLUSION: An increased, albeit normal, WBC counts associates with the cluster of MS of the so-called "insulin resistance syndrome" and suggest that an increased WBC counts may be yet another feature of this syndrome.
Adult
;
Alcohol Drinking
;
Blood Glucose
;
Cholesterol, HDL
;
Cluster Analysis
;
Fasting
;
Female
;
Hematologic Tests
;
Humans
;
Hypercholesterolemia
;
Hypertension
;
Hypertriglyceridemia
;
Hyperuricemia
;
Leukocyte Count*
;
Logistic Models
;
Obesity
;
Risk Factors
;
Smoke
;
Smoking
8.Surgical Treatment of Primary Cardiac Tumor: Report of 27 cases.
Sung Yong PARK ; Seok Whan MOON ; Chi Kyung KIM ; Kuen Hyon JO ; Young Pil WANG ; Moon Sub KWAK ; Se Wha KIM
The Korean Journal of Thoracic and Cardiovascular Surgery 1998;31(8):787-791
MATERIALS AND METHODS: Between 1979 and 1996, 27 patients with primary cardiac tumor underwent surgery at Catholic University Medical College. Mean age of patient was 45.1+/-3.03 ranging from 21 to 67 years old. Twenty-four cases were myxomas, 2 cases were chondrosarcoma, and remained case was angiosarcoma. Diagnosis was confirmed by echocardiography, cardiac angiography, CT scan, and MRI. The most common site of tumor origin was fossa ovalis limbus area (17cases:63%). A biatrial operative approach was commonly used in 15 cases and the tumor was removed through left atriotomy site. Complete excision of the tumor with a cuff of normal tissue was performed. All heart chambers were carefully explored for evidence of multicentric myxomas or other tumor debris. Most of the patients were improved on postoperative period compared to preoperative NYHA functional class. RESULTS: There was one operative death due to low cardiac output syndrome. Follow up period was 3 months to 17 years. There was 2 late deaths due to local recurrences. CONCLUSION: complete surgical excion is important for increasing cure rate. Malignancy cannot be ruled out even though preoperative echocardiography suggests benign nature. Chest CT or MRI is effective for further evalution in addition to echocardiography. In suspicious of malignancy, more extensive resection is essential and postoperative chemotheraphy or radiotherapy is useful.
Aged
;
Angiography
;
Cardiac Output, Low
;
Chondrosarcoma
;
Diagnosis
;
Drug Therapy
;
Echocardiography
;
Follow-Up Studies
;
Heart
;
Heart Neoplasms*
;
Hemangiosarcoma
;
Humans
;
Magnetic Resonance Imaging
;
Myxoma
;
Postoperative Period
;
Radiotherapy
;
Recurrence
;
Tomography, X-Ray Computed
9.Can Cilostazol Improve the Patency Rate of Native Arteriovenous Fistula in Hemodialysis Patients?.
Jung Sub KIM ; Mun Ki CHOI ; Bo Kyung CHOI ; Hee Sun LEE ; Naria LEE ; JungMin SON ; Eun Young SEONG ; Sang Heon SONG ; Soo Bong LEE ; Ihm Soo KWAK
Korean Journal of Nephrology 2010;29(4):474-481
PURPOSE: Vascular access failure is the most common reason for hospitalization among hemodialysis (HD) patients. Cilostazol, which has antiplatelet action and vasodialtory effects, significantly reduces the risk of restenosis after percutaneous coronary intervention in many patients. We conducted this study to evaluate the relationship between the use of antiplatelet agents, especially cilostazol, and arteriovenous fistula (AVF) patency in HD patients. METHODS: A total of 241 patients underwent native AVF creation from January 2001 to December 2008. Among these patients, we selected 86 patients excluding 38 patients (15.8%) with primary technical failure, 49 patients without complete data and 68 patients used cilostazol less than 1 month. Demographic characteristics, medication history and fistula failure rate were collected and analyzed to elucidate the effect of cilostazol to native AVF. RESULTS: From all groups, AVF failure occurred in 24 patients (27.9%). 28 patients received cilostazol (62.3 %) and mean duration of cilostazol therapy was 229.5+/-115.7 days. All patients were classified into two groups according to cilostazol (Cilostazol [n=28, 32.6%] vs. non-Cilostazol [n=58, 67.4%]. There was no statisticallly significant difference in failure rate between the two groups (32.1% vs. 25.9%, p=0.543). In diabetes group, patients who received statin have much lower AVF failure rate (0% vs. 32.4%, p=0.024). Logistic regression analysis showed that female was independent risk factor for access failure (HR 5.549, CI 1.104-27.877, p=0.037). CONCLUSION: Cilostazol and other antiplatelet agent had a no significant association with AVF patency. Female was an independent risk factor for access failure.
Arteriovenous Fistula
;
Female
;
Fistula
;
Hospitalization
;
Humans
;
Hydroxymethylglutaryl-CoA Reductase Inhibitors
;
Logistic Models
;
Percutaneous Coronary Intervention
;
Platelet Aggregation Inhibitors
;
Renal Dialysis
;
Risk Factors
;
Tetrazoles
;
Vascular Patency
10.Hemodynamic management during off-pump coronary artery bypass surgery: a narrative review of proper targets for safe execution and troubleshooting
Jae-Kwang SHIM ; Kwang-Sub KIM ; Pierre COUTURE ; André DENAULT ; Young-Lan KWAK ; Kyung-Jong YOO ; Young-Nam YOUN
Korean Journal of Anesthesiology 2023;76(4):267-279
Off-pump coronary surgery requires mechanical cardiac displacement, which results in bi-ventricular systolic and diastolic dysfunction. Although transient, subsequent hemodynamic deterioration can be associated with poor prognosis and, in extreme cases, emergency conversion to on-pump surgery, which is associated with high morbidity and mortality. Thus, appropriate decision-making regarding whether the surgery can be proceeded based on objective hemodynamic targets is essential before coronary arteriotomy. For adequate hemodynamic management, avoiding myocardial oxygen supply-demand imbalance, which includes maintaining mean arterial pressure above 70 mmHg and preventing an increase in oxygen demand beyond the patient’s coronary reserve, must be prioritized. Maintaining mixed venous oxygen saturation above 60%, which reflects the lower limit of adequate global oxygen supply-demand balance, is also essential. Above all, severe mechanical cardiac displacement incurring compressive syndromes, which cannot be overcome by adjusting major determinants of cardiac output, should be avoided. An uncompromising form of cardiac constraint can be ruled out as long as the central venous pressure is not equal to or greater than the pulmonary artery diastolic (or occlusion) pressure, as this would reflect tamponade physiology. In addition, transesophageal echocardiography should be conducted to rule out mechanical cardiac displacement-induced ventricular interdependence, dyskinesia, severe mitral regurgitation, and left ventricular outflow tract obstruction with or without systolic motion of the anterior leaflet of the mitral valve, which cannot be tolerated during grafting. Finally, the ascending aorta should be carefully inspected for gas bubbles to prevent hemodynamic collapse caused by a massive gas embolism obstructing the right coronary ostium.