Effect of pH Change on Vascular Smooth Muscle Contractility in Rat Superior Mesenteric Artery and Its Branches / 대한흉부외과학회지

BACKGROUND: Extracellular and intracellular pH (pHo and pHi), which can be changed in various pathological conditions such as hypoxia, affects vascular contractility. To elucidate the mechanism to alter vascular contractility by pH, the effects of pH on reactivity to vasocontracting agents, intracellular Ca2+ influx, and Ca2+ sensitivity in vascular smooth muscle were examined. MATERIAL AND METHOD: Isometric contractions in rat superior mesenteric arteries (SMA) were observed. Intracellular Ca2+ concentration ([Ca2+]i) was recorded by microfluorometer using Fura-2/acetoxylmethyl ester in muscle cells. pHo was increased from 7.4 to 7.8 or decreased to 6.9 or 6.4. pHi was decreased by applying NH4+ or propionic acid or modulated by changing pHo after increasing membrane permeability using beta-escin. RESULT: Decreases in pHo from 7.4 to 6.9 or 6.4 shifted concentration-response curve by norepinephrine (NE) or serotonin (SE) to the right and significantly increased half maximal effective concentration (EC50) to NE or SE. Increase in pHo from 7.4 to 7.8 shifted concentration-response curve by norepinephrine (NE) or serotonin (SE) to the left and significantly reduced EC50 to NE or SE. NE increased [Ca2+]i in cultured smooth muscle cells from SMA and the increased [Ca2+]i was reduced by decreases in pHo. NE-induced contraction was inhibited by NH4+, whereas the resting tension was increased by NH4+ or propionic acid. When the cell membrane of SMA was permeabilized using beta-escin, SMA was contracted by increasing extracellular Ca2+ concentration from 0 to 10micrometer and the magnitude of contraction was decreased by a decrease in pHo and vice versa. CONCLUSION: From these results, it can be concluded that a decrease in pHo might inhibit vascular contraction by reducing the reactivity of vascular smooth muscle to vasoactive agents, Ca2+ influx and the sensitivity of vascular smooth muscle to Ca2+.

Oxidized Low-density Lipoprotein- and Lysophosphatidylcholine-induced Ca2+ Mobilization in Human Endothelial Cells

The effects of oxidized low-density lipoprotein (OxLDL) and its major lipid constituent lysophosphatidylcholine (LPC) on Ca2+ entry were investigated in cultured human umbilical endothelial cells (HUVECs) using fura-2 fluorescence and patch-clamp methods. OxLDL or LPC increased intracellular Ca2+ concentration ([Ca2+]i), and the increase of [Ca2+]i by OxLDL or by LPC was inhibited by La3+ or heparin. LPC failed to increase [Ca2+]i in the presence of an antioxidant tempol. In addition, store-operated Ca2+ entry (SOC), which was evoked by intracellular Ca2+ store depletion in Ca2+-free solution using the sarcoplasmic reticulum Ca2+ pump blocker, 2, 5-di-t-butyl-1, 4-benzohydroquinone (BHQ), was further enhanced by OxLDL or by LPC. Increased SOC by OxLDL or by LPC was inhibited by U73122. In voltage-clamped cells, OxLDL or LPC increased [Ca2+]i and simultaneously activated non-selective cation (NSC) currents. LPC-induced NSC currents were inhibited by 2-APB, La3+ or U73122, and NSC currents were not activated by LPC in the presence of tempol. Furthermore, in voltage-clamped HUVECs, OxLDL enhanced SOC and evoked outward currents simultaneously. Clamping intracellular Ca2+ to 1 micrometer activated large-conductance Ca2+-activated K+ (BKCa) current spontaneously, and this activated BKCa current was further enhanced by OxLDL or by LPC. From these results, we concluded that OxLDL or its main component LPC activates Ca2+-permeable Ca2+-activated NSC current and BKCa current simultaneously, thereby increasing SOC.

The Effect of Hypoxia on the Release of Endothelium-derived Relaxing Factor in Rabbit Thoracic Aorta / 대한흉부외과학회지

BACKGROUND: To clarify the effect of hypoxia on vascular contractility, we tried to show whether hypoxia induced the release of endothelium-derived relaxing factor (EDRF) and the nature of the underlying mechanism for this release. MATERIAL AND METHOD: Isometric contractions were observed in rabbit aorta, and the released EDRF from the rabbit aorta was bioassayed by using rabbit denuded carotid artery. The intracellular Ca2+ concentration ([Ca2+]i) in the cultured rabbit aortic endothelial cells was recorded by a microfluorimeter with using Fura-2/AM. Hypoxia was evoked to the blood vessels or endothelial cells by eliminating the O2 in the aerating gases in the external solution. Chemical hypoxia was evoked by applying deoxyglucose or CN-. RESULT: Hypoxia relaxed the precontracted rabbit thoracic aorta that had its endothelium, and the magnitude of the relaxation was gradually increased by repetitive bouts of hypoxia. In contrast, hypoxia-induced relaxation was not evoked in the aorta that was denuded of endothelium. In a bioassay experiment, hypoxia released endothelium-derived relaxing factor (EDRF) and the release was inhibited by L-NAME or the K+ channel blocker tetraethylammonium (TEA). In the cultured endothelial cells, hypoxia augmented the ATP-induced increase of the intracellular Ca2+ concentration ([Ca2+]i) and this increase was inhibited by TEA. Furthermore, chemical hypoxia also increased the Ca2+ influx. CONCLUSION: From these results, it can be concluded that hypoxia might induce the release of NO from rabbit aortic endothelial cells by increasing [Ca2+]i.

Stress Fracture of the First Rib / 대한흉부외과학회지

Isolated stress fracture of the first rib is rare, and repeated muscular pulling and fatigue of bone is thought to be responsible for this fracture. The diagnosis can be made by taking a thorough history and performing chest roentgenography, computed tomography or magnetic resonance imaging. Conservative treatment generally cures this condition. We report here on a case of exercise-induced isolated stress fracture of the first rib in a non-athlete college student and we review the related articles.

Pulmonary and Endobronchial Mucormycosis in a Diabetic Patient: A Case Report

Pulmonary mucormycosis is an opportunistic infection manifested by a fatal angioinvasive fungal pneumonia in immunocompromised patients or those suffering from uncontrolled diabetes. The radiologic findings are nonspecific, but there have been several reports of cases of pulmonary mucormycosis in which characteristic endobronchial lesions were present, with a more indolent clinical course in diabetic patients. We describe a case of pulmonary mucormycosis in a diabetic patient in whom endobronchial involvement was apparent.

Comparison Between Ligation Through Thoractomy and Video-assisted Clipping / 대한흉부외과학회지

BACKGROUND: This study was aimed at analyzing the preoperative conditions post-operative results indication and methods of surgical closure of patent ducturs arteriosus in prematures low birth weight infants and neonates. PATIENTS AND METHODS: We retro-spectively studied two groups of patients (prematures group and neonates group) who underwent surgical closure of the patent ductus arteriosus between March 1995 and June 1998. RESULTS: The premature group consisted of 9 patients(3 males and 6 females) Their mean gestational period was 30.7 weeks(ranging from 26 weeks to 33 weeks) mean age 27.8 days(11 days to 55 days) and mean body weight 1.56 kg. Prominent preoperative symptoms were dependency on mechanical ventilation generalized edema and hepatomegaly. We performed PDA ligation via thoracotomy in all premature patients. The neonate group consisted of 16 patients and their mean body weight was 3.75 kg. Major symptoms of this group was tachypnea and intercostal retraction resistant to medical treatment. We performed video-assisted PDA clipping to them all. There were no postoperative complications or operation-related mortality in both groups. Comparing the ratio of size of PDA(mm)/body weight(kg) the ratio of premature group (ligation through thoracotomy) was higher than that of neonate group ( video-assisted clipping) that is 3,89:1.21(p=0.03) CONCLUSION: We conclude that the surgical closure of PDA can be a safe method of treatment for prematures low birth weight infants and neonates with compromised general conditions. Choice of surgical technique depends on the surgeon's preference but there was a tendency to choose the ligation method through thoracotomy for patients with small body weight and large PDA.

Clinical Analysis of Varicose Veins in the Lower Extremities: an analysis of 227 operative cases / 대한흉부외과학회지

BACKGROUND: To know the clinical aspects of varicose vein and the effectiveness of operative treatment, the patients who had been operated during the five and a half years were reviewed. MATERIAL AND METHOD: From September 1993 to February 1999, 227 patients with varicose vein were operated upon. These patients were reviewed with history taking, physical examination, laboratory tests, operation and follow up visits at an out patient department. RESULT: The ages of the patients were from 20 to 69 years, mean 40.2 years. varicose veins. Occupations of the patients include housewives, store or factory owners, cooks, waiter or waitresses in a restaurant, salary men(women), teachers, hair stylists, professional athletes, in sequence, most of them require standing all day long. The 126 women had experienced child birth, among them 116 patients delivered more than 2 babies. All patients had protruding leg veins as the symptom. Most of them(61%) had pain. Other additional symptoms were heaviness, heatness, tingling, cramp, fatigue, etc. 68.3% of the patients had the symptoms for more than 10 years. Anatomical location of varicose vein was in long saphenous vein in 157 patients, in small saphenous vein in 27, and in other regions(combined or perforating vein) in 43 patients. There was no operative mortality. There were 2 patients who underwent reoperation due to recurrence during this study period. In one patient, it recurred in the distal perforating vein in small saphenous vein. The other patient had recurrence at the saphenofemoral junction in groin. The patients are doing well after the reoperation, but a long term observation is needed. CONCLUSION: Clinical aspects of varicose vein were reviewed. For the patients with varicose vein who had saphenofemoral regurgitation, operative treatment seemed to bea safe and effective modality of treatment.

Lobectomy in Pulmonary Infections in Chronic Granulomatous Disease of Childhood: A Case Report / 대한흉부외과학회지

Chronic granulomatous disease in childhood is a rare inheritable disorder of phagocytic cells in which defective production of the reactive intermediates of oxygen predisposes the patient to severe recuring pyogenic infections. The lung is the most common site of infection and pulmonary disease is the primary cause of death for greater than 50% of children with chronic granulomatous disease. Although the role of surgery in management of this disease remains undefined, rapid diagnosis of the underlying pulmonary problem is crucial to determine the most appropriate antimicrobial therapy and surgical techniques such as lobectomy of involved areas lead to more rapid recovery and thus allow the antibiotics to be more efficacious in these cases. We have treated a one month old male baby who had the chronic granulomatous disease with pulmonary infection. Wide surgical resection of the affected lobe and use of antibiotics and antifungals were carried out with good clinical results. He was well after the operation.

A Case of Ruptured Tricuspid Valve Due to Nonpenetrating Cardiac Injury Detected by Echocardiography

Cardiac contusion is an increasingly recognized entity in patients with nonpenetrating chest injury. Unifortunately, the diagnosis of cardiac trauma, particularly cardiac contusion, is imprecise and may be confounded by the presence of associated injuries, hypoxia, shock, and metabolic abnormalities. Symptomatic cardiac injury follwing blunt chest trauma is relatively rare, and valvular injury is even rarer. The valves most commonly affected are mitral and tricuspid. Although tricuspid regurgitations are usually asymptomatic and can resolve spontaneously, recent developments in echocardiography made possible the precise diagnosis of valvular injuries noninvasively, The authors report the case of tricuspid regurgitation incidentally detected by echocardiography in a construction worker who had suffered multiple fractures.

Severe Tricuspid Regurgitation Following Blunt Chest Trauma - Successful Repair by PTFE Chordal Replacement and Ring Annuloplasty: A Case Report / 대한흉부외과학회지

We report a successful repair of severe traumatic tricuspid regurgitation by PTFE chordal replacement and ring annuloplasty. A 64-year-old man with multiple trauma was referred to our department because of cardio- megaly on chest roentgenogram. Echocardiography showed moderate amount of pericardial effusion and severe tricuspid regurgitation with rupture of anterior papillary muscle. But he experienced progressive dyspnea, and chest roentgenogram showed progressive cardiomegaly. He underwent operation 4 months after trauma. The nterior papillary muscle was reinserted, and the valve was repaired by PTFE chordal replacements and ring annuloplasty. Postoperatively, the patient's functional status was improved, and there was trivial tricuspid regurgitation on echocardiographic examination.

Clinical use of centrifugal biomedicus pump / 대한흉부외과학회지

No abstract available.