BACKGROUND AND OBJECTIVES: Thrombin and its interaction with platelets play a pivotal role in arterial thrombus formation. Hirudin, an anticoagulant agent derived from medicinal leeches(Hirudo medicinalis), is a unique and specific thrombin inhibitor with no effect on other serine protease. We investigated the inhibitory effect of hirudin on platelet deposition in a rabbit carotid artery eversion model of acute arterial thrombosis. MATERIALS AND METHODS: The everted arterial segments were perfused with 111 Indium-labeled human platelets only(control, n=8), and a mixed solution of 111 Indium-labeled human platelets and hirudin(30, 45, 60, 90 microgram/ml, n=3, respectively). Platelet deposition was calculated by a gamma-counter and confirmed by scanning electron microscopy. RESULTS: 1) Indium-111 labeling efficiency of platelets was 87.0+/-6.6%, and the aggregation of platelets was not changed after labeling. The number of platelets perfused through each arterial segment was 4.3 +/-0.2x10(8) platelets/ml. 2) The control group showed a platelet deposition rate of 23.9+/-7.0 % and a number of platelet deposition of 9.8+/-2.5x10(8) platelets/cm2 . 3) Platelet deposition of arteries perfused with hirudin(60 microgram/ml) was significantly decreased compared with that of the control group(2.9+/-0.6 vs 9.8+/-2.5x10(8)/cm2 , p<0.05). 4) The number of deposited platelets in hirudin-perfused arteries was dose-dependently decreased(30 microgram/ml:6.7+/-1.4x10(8) /cm2 , 45 microgram/ml: 4.8+/-1.7x10(8) /cm2 , 60 microgram/ml: 2.9+/-1.8x10(8)/cm2, 90 microgram/ml:2.9+/-1.4x10(8)/cm2: p<0.05 vs. control, respectively). 5) Scanning electron microscopic examination revealed significantly reduced platelet deposition in hirudin-perfused groups compared with control group. CONCLUSION: Hirudin inhibits effectively platelet deposition and arterial thrombus formation in a rabbit carotid artery eversion model. The antiplatelet effect of hirudin in this model suggests that hirudin may be an useful antithrombotic agent therapeutically useful in the prevention of acute arterial thrombus formation.
Arteries ; Blood Platelets ; Carotid Arteries* ; Hirudins* ; Humans ; Microscopy, Electron, Scanning ; Serine Proteases ; Thrombin ; Thrombosis

Increasing vigorous chemotherapy for cancers including primary and matastatic tumors has resulted in prolonged survival. However, there has been an associated increase in neurotoxicity as a result of it. All classes of chemotherapeutic agents contain drugs that are potentially neurotoxic. The authors has studied three cases of leukoencephalopthies developed during adjunctive therapy with 5-flurouracil and cisplatin for adenocarcinoma of the stomach. None of the patients had evidence of metastasis or any previous neurologic diseases. The duration of chemotherapy before onset of neurological symptoms ranged from 8 to 12 weeks. Two of the 3 patients presented progressive decline in mental status and ataxia after 2~3 weeks, while the third one had two unexplained episodes of loss of consciousness. In all of these patients, magnetic resonance imagings demonstrated prominent periventricular white matter lesions. Cerebral biopsies were performed stereotaxically in 2 patients. The morphological features were active demyelinating disease and edema. All three patients had improved after the cessation of chemotherapy and a short course of corticosteroid therapy, suggesting that these alarming events such as nausea, vomiting dizziness, dysarthria, and mental change were a toxic reversible side effects from these chemotherapeutic agents. This syndrome may represent the pathological basis for 5-fluorouracil neurotoxicity, however we cannot completely exclude the role of cisplatin in the occurences of the above syndromes.
Adenocarcinoma ; Ataxia ; Biopsy ; Cisplatin* ; Demyelinating Diseases ; Dizziness ; Drug Therapy ; Dysarthria ; Edema ; Fluorouracil ; Humans ; Leukoencephalopathies* ; Nausea ; Neoplasm Metastasis ; Stomach ; Unconsciousness ; Vomiting

OBJECTIVE: Radiation injury includes radiation necrosis and apoptosis. The purpose of this study is whether steroids and calcium channel blockers are effective for the prevention of single high dose irradiation-induced apoptosis in the rat brain. METHODS: Eighty Sprague-Dawley rats were divided into four experimental groups: Control(nontreated, n=20), Dexamethasone-treated(0.1mg/kg, n=20), Prednisolone-treated(2mg/kg, n=20), Nimodipine-treated (0.5mg/kg, n=20). After drug was administered, the right hemisphere of rat's brain was exposed to a single 10Gy dose of gamma rays using Ir-192. All brains underwent histological examination at 1 week, 2 weeks, 4 weeks, and 8 weeks after irradiation to evaluate cortical thickness and number of apoptotic cells. Apoptotic cells were detected by TUNEL assay. RESULTS: In nimodipine-treated group, apoptotic cell count was reduced significantly, compared to that of control(non treated) group at 4 and 8 weeks after irradiation(p<0.05). The decrease of cortical thickness was reduced significantly in nimodipine-treated group, compared to that of control group(p<0.05). There was no significant changes in the number of apoptotic cells and cortical thickness in prednisolone and dexamethasone-treated groups compared with those of control. CONCLUSION: These results suggest that nimodipine treatment may have effects on the prevention of radiation-induced apoptosis. If it could be established that calcium channel blockers inhibit radiation injury, they might be useful in radiation therapy. Further investigation of calcium channel blockers including dosage effectiveness, intracellular calcium ion concentration and effects on tumor tissue are necessary to clarify the usefulness of nimodipine.
Animals ; Apoptosis* ; Brain* ; Calcium Channel Blockers ; Calcium Channels* ; Calcium* ; Cell Count ; Dexamethasone ; Gamma Rays ; In Situ Nick-End Labeling ; Necrosis ; Nimodipine ; Prednisolone ; Radiation Injuries ; Rats* ; Rats, Sprague-Dawley ; Steroids

The authors present a statistical survey of the general incidence, age distribution, and preferential site of 631 tumors of the brain which have been surgically treated at Korea university medical center, department of neurosurgery over the last period of 10 years from 1985 to 1994. Among them 269 cases were males and 362 were females. Of the 631 intracranial neoplasms verified histologically, tumors of neuroepithelial tissue comprised 34%(212 cases), tumors of meninges 23%(148 cases), pituitary adenoma 18%(114 cases), metastatic tumors 8%(50 cases), neurilemmomas 8%(49 cases), germ cell tumors 3%(13 cases), cyst and tumor like lesions 3%(16 cases), and lymphomas 1%(5 cases). Of the 178 gliomas, astrocytic tumors comprised 83%(148 cases), oligodendroglial tumors 11%(20 cases), ependymal tumors 3%(6 cases) and mixed gliomas 1.7%(3 cases). Brain tumors occurred most frequently in the age group of 45-50 years, as seen by an incidence of 63 cases(10%). The male to female ratio was 0.74: 1. Tumors that showed a definitive preponderance of females over males were meningiomas, neurilemmomas, and pituitary adenomas. Supratentoral and infratenorial cases were 73%(461 cases) and 26%(162 cases), respectively and the remaining cases involved both sites. Of the 114 cases of childhood and adolescent tumors, 60 were male and 54 were female. Supratentorial tumors were 56% and infratentorial were 44%. The tumors in order of frequency were astrocytomas(28%), primitive neuroectodermal tumors(21%), craniopharyngioma(10%) and so on. Meningiomas occurred most frequently in parasagittal/falx area(25%), followed by cerebral convexity 23%, sphenoid 14%, posterior fossa 13%. Among pituitary adenomas, prolactinomas(32%) were the most common and followed by null cell adenomas 31%, growth hormone cell adenomas 15%, mixed GH-PRL cell adenomas 11%.
Academic Medical Centers ; Adenoma ; Adolescent ; Age Distribution ; Astrocytoma ; Brain Neoplasms* ; Brain* ; Female ; Glioma ; Growth Hormone ; Humans ; Incidence ; Korea* ; Lymphocytes, Null ; Lymphoma ; Male ; Meninges ; Meningioma ; Neoplasms, Germ Cell and Embryonal ; Neural Plate ; Neurilemmoma ; Neurosurgery ; Pituitary Neoplasms ; Supratentorial Neoplasms

Background: During the lockdown period associated with the coronavirus disease 2019 (COVID-19) pandemic, increased mortality rates among patients with COVID-19 have been reported. This study aimed to analyze the mortality rate of osteoporotic hip fractures in patients who were COVID-19-positive after the lockdown during the Omicron period. Methods: A retrospective study was performed with 194 patients who were aged 70 years or more and diagnosed with osteoporotic hip fracture. The patients were divided into two groups according to their COVID-19 diagnoses. Surgery was performed within 10 days of diagnosis. Age, sex, past medical history, time until surgery, postoperative complications, and the primary outcome of mortality rate at 30 and 90 days were analyzed. Results: Among the 194 patients, 13 and 181 were in the COVID-19-positive and negative group, respectively. The total, 30-day, and 90-day mortality rates in the control and COVID-positive group were 11% and 0% (P=0.368), 1.7% and 0% (P=1.000), and 5.0% and 0% (P=1.000), respectively. No significant differences were observed in age, sex, history, time to surgery, postoperative complications, or postoperative mortality. In 1:1 propensity score matching, the time to surgery was 5.34 days in patients who were COVID-19-positive, and 3.00 days in patients who were COVID-19 negative, with no statistical significance (P=0.09). Age, sex, medical history, postoperative complications, and postoperative mortality were not significantly different between the groups. Conclusions Regardless of the COVID-19 diagnosis, surgical treatment without delay is believed to result in positive outcomes in older patients with osteoporotic hip fractures, as no significant differences in mortality rate and respiratory complications were observed between patients who were COVID-19-positive and those who were COVID-19 negative.

No abstract available.
Stroke*

Systemic sclerosis (SS) is a connective tissue disease and cardiac involvement is common. Primary cardiac involvement such as conduction system disturbances and arrhythmias can also occur. However, reports of sustained ventricular tachycardia (VT) are rare. We report a case of catheter ablation of sustained ventricular tachycardia in a patient with systemic sclerosis using a conventional mapping system. A 64-yr-old woman with a 10-yr history of SS was referred for management of her ventricular tachycardia. There was no structural abnormality in cardiac chambers. However, electrophysiologic study revealed electrical substrate of ventricular tachycardia which could be ablated with pacemapping and substrate mapping. This case demonstrated successful conventional mapping and catheter ablation in a hemodynamically unstable patient with SS.
*Catheter Ablation ; Electrocardiography ; Female ; Humans ; Middle Aged ; Scleroderma, Systemic/*complications/*diagnosis ; Tachycardia, Ventricular/*etiology/physiopathology/*surgery

A case of 39-year-old diabetic patient with a calcitonin and somatostatin secreting pancreatic islet tumor is presented. He had suffered from chronic diarrhea and dyspepsia for 10 years and was diagnosed with diabetes 2 years ago. Abdominal CT revealed a huge abdominal mass which was considered as a neuroendocrine tumor after US-guided needle biopsy. A distal pancreatectomy and splenectomy were performed. Histologically, tumor cells, amanged in solid sheets, showed small nuclei without significant atypia and granular eosinophilic cytoplasm. Tumor cells showed strong immunoreacitivity for calcitonin and somatostatin. The serum clacitonin was markedly elevated (268.7 pmol/L, normal range; 0.9-7.6 pmol/L). After resection of the tumor, diarrhea and dyspepsia diappeared, and oral glucose tolerance test showed normal glucose tolerance with normalization of calcitonin.
Adult ; Biopsy, Needle ; Calcitonin* ; Cytoplasm ; Diabetes Mellitus* ; Diarrhea ; Dyspepsia ; Eosinophils ; Glucose ; Glucose Tolerance Test ; Humans ; Islets of Langerhans* ; Neuroendocrine Tumors ; Pancreatectomy ; Reference Values ; Somatostatin* ; Splenectomy ; Tomography, X-Ray Computed

BACKGROUND AND OBJECTIVE: The purpose of this study was to develop a new type of coronary stent-graft, using surface modification of polymeric synthetic graft materials, to improve biocompatibility. MATERIALS AND METHODS: Three different polymers, Dacron, GoreTex and Teflon were tested. During the surface-modification process, hydroxybutyl acrylate (HBA) choline, an excellent blood-compatible phospholipid, was stably grafted onto the polymer surface. The optimal conditions for maximizing the amount of HBA choline grafted onto the polymeric surface were determined by quantitative analysis. The surface-modified polymers were then tested for their biocompatibility using an in vitro platelet adhesion test. Thereafter, stent-grafts were constructed with each of three different types of surface-modified polymer and implanted in porcine coronary arteries to compare their biocompatibility in vivo. RESULTS: In the platelet adhesion test, all the surface-modified polymers showed better biocompatibility than the control polymers. The in vitro biocompatibility correlated positively with the increasing quantity of grafted HBA choline. In the animal experiment, the surface-modified Teflon stent-graft showed the best biocompatibility. Whereas, all pigs implanted with the modified Dacron and GoreTex stent-grafts died within 48 hours of the implantation, five out of the six pigs with the Teflon stent-grafts remained alive at after the 4th week. In four of the five surviving pigs, angiography, intravascular ultrasound (IVUS) and histological evaluations demonstrated the patency of the stent-grafts, with a uniform neointima formation covering the entire stent-graft, without stent thrombosis or chronic inflammatory cells. CONCLUSION: The surface-modified Teflon coronary stent-grafts showed good in vitro and in vivo biocompatibility. Further animal and clinical studies will be required to validate the efficacy of the surface-modified polymer stent-grafts.
Angiography ; Animal Experimentation ; Animals ; Blood Platelets ; Choline ; Coronary Disease ; Coronary Vessels ; Neointima ; Polyethylene Terephthalates ; Polymers* ; Polytetrafluoroethylene ; Stents ; Swine ; Thrombosis ; Transplants ; Ultrasonography

BACKGROUND/AIMS: Some clinical and laboratory parameter are predictors to determine steroid treatment failure in patients acute severe ulcerative colitis. We aimed to validate previous models in the Korean patients. METHODS: This study was conducted retrospectively with 70 patients who were diagnosed with severe ulcerative colitis (UC) between January 2001 and June 2011. The rate of treatment failure was investigated using predictors or numerical scoring systems from prior studies. RESULTS: Twelve (17.2%) patients failed to respond to steroid therapy. The logistic regression analysis revealed that stool frequency on the fifth day and colonic dilatation were the only independent predictive factors related to treatment failure. Formulated numerical risk scores based on mean stool frequency, colonic dilatation, and hypoalbuminemia were significantly higher in the non-responding group than those in the responding group (P<0.001). Using another scoring system (stool frequency on the third day+1.4xC-reactive protein [CRP]), treatment failure rate was significantly higher in the group in which the score was >8 than in the group with a score <8 (30.8% vs. 8.6%, P=0.042). Lastly, treatment failure rate was higher in the group (stool frequency >8 plus CRP >4.5 mg/dL or bloody stool plus CRP >4.3 mg/dL) than those of the other group at the third day (40% vs. 7.3%, P=0.004; 33.3% vs. 5.2%, P=0.014, respectively). CONCLUSIONS: Stool frequency and CRP level were the meaningful parameters among the predictors for steroid treatment response. Furthermore, several predictive models for steroid treatment failure in western countries seem to be of value for use in the Korean population.
Adrenal Cortex Hormones ; Colitis, Ulcerative ; Colon ; Dilatation ; Humans ; Hypoalbuminemia ; Logistic Models ; Retrospective Studies ; Treatment Failure ; Ulcer