The downregulation of asparagine synthetase expression can increase the sensitivity of cells resistant to l-asparaginase.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to C Y Luo.
Explore the source record for details and available documents.
BACKGROUND: This study evaluates whether systemic steroid pretreatment enhances neuroprotection during deep hypothermic circulatory arrest (DHCA) compared with steroid in cardiopulmonary bypass (CPB) prime. METHODS: Four-week-old piglets randomly placed into two groups (n = 5 per group) were given methylprednisolone (30 mg/kg) into the pump prime (group PP), or pretreated intravenously 4 hours before CPB (group PT). All animals underwent 100 minutes of DHCA (15 degrees C), were weaned off CPB, and were sacrificed 6 hours later. Postoperative changes in body weight, bioimpedance, and colloid oncotic pressure (COP) were measured. Cerebral trypan blue content, immunohistochemical evaluation of transforming growth factor-beta1 (TGF-beta1) expression, and caspase-3 activity were performed. RESULTS: Percentage weight gain (group PP 25.0% +/- 10.4% versus group PT 12.5% +/- 4.0%; p = 0.036), and percentage decrease in bioimpedance (PP 37.2% +/- 14.5% versus PT 15.6% +/- 7.9%; p = 0.019) were significantly lower, whereas postoperative COP was significantly higher in group PT versus group PP (PT 15.3 +/- 1.8 mm Hg versus PP 11.6 +/- 0.8 mm Hg; p = 0.003). Cerebral trypan blue (ng/g dry tissue) was significantly lower in group PT (PT 5.6 x 10(-3) +/- 1.1 x 10(-3) versus PP 9.1 x 10(-3) +/- 5.7 x 10(-4); p = 0.001). Increased TGF-beta1 expression and decreased caspase-3 activity were shown in group PT. CONCLUSIONS: Systemic steroid pretreatment significantly reduced total body edema and cerebral vascular leak and was associated with better immunohistochemical indices of neuroprotection after DHCA.
Postoperative brachial plexus injury, often manifesting as a variety of upper extremity neuropathies, is a recognized and not uncommon complication following cardiac surgery that requires a median sternotomy. In general, the vast majority of its neurological symptoms are transient and need no treatment. Nevertheless, in very rare cases, the peripheral neuropathies will persist and cause disability. We treated a 67-year-old male patient complicated by permanent paresthesia and paralysis of the left upper extremity after an eventful coronary artery bypass surgery. The nerve conduction measurements and electromyography all revealed a C5 to T1 lesion. After carefully reviewing the surgical course and referring to the published literature, we tentatively concluded that compression or overstretching produced by wide and prolonged sternal separation of the brachial plexus was the most likely etiology. Asymmetrical traction of the sternal halves during internal mammary artery harvesting might also have contributed to this nerve injury. We surmised, therefore, that brachial plexus injury could be minimized by an exact median sternotomy, a lower position and the smallest possible opening for the sternal retractor, and the avoidance of constant and asymmetrical traction on the sternal halves.
A method of separation and quantitation of monoester, diester and triester in food additive sucrose fatty acid esters by TLC with dual-wavelength TLC scanner in the sawtooth scanning mode is described. The detective wavelength was 530 nm and the reference wavelength was 700 nm. A mixture of chloroform, methanol, acetic acid and water (80:10:8:1, V/V) was used as mobile phase. The calibration curve was linear over a range from 4 micrograms to 60 micrograms with correlation coefficients of 0.9949-0.9980. The average recoveries were 96.45%-98.73% (n = 3, RSD = 2.7%-3.2%). This method is accurate, simple and dependable, with a wide range of linearity. It has been applied to the analysis of various samples and can be used for the quality control of the food additive sucrose fatty acid ester.
Malignant lymphoma infiltrating the abdominal aorta and resulting in an aortic aneurysm has never been documented. We report here a case of angiocentric T-cell lymphoma in a 33-year-old man who for months presented intermittent fever, splenomegaly, and an abdominal pulsatile mass. Angiography revealed extensive aneurysmal dilatation of the infrarenal abdominal aorta, bilateral iliac artery, and right common femoral artery. Splenic abscess and infected abdominal aortic aneurysm were initially suspected. An urgent splenectomy and aneurysmectomy with an aortic bifemoral bypass were performed. Pathological examination of the aortic aneurysm showed extensive necrosis, severe atherosclerosis, and lymphoma cell infiltration of the aortic wall. The lymphoid cells in the aorta and spleen were stained positive for CD45RO, CD56, and CD8, but negative for CD4 and CD19. Double-labeling immunohistochemistry and in situ hybridization using EBER1 for Epstein-Barr virus (EBV) revealed positive nuclear staining in the atypical T-lymphoid cells. This is the first definitive proof of peripheral T-cell lymphoma involving the abdominal aorta. Our evidence also supports that the EBV infection of T cells could be responsible for the atherosclerosis and hypertriglyceridemia, and the angiocentricity of the tumor cells apparently results in the presenting atherosclerotic aortic wall destruction, providing an additional causative concept for abdominal aortic aneurysm.
Pulmonary artery leiomyosarcoma is a rare but highly lethal disease, and can be mistaken for pulmonary thromboembolism. We report a case of pulmonary artery leiomyosarcoma managed with surgical resection, chemotherapy, and radiotherapy. A 57-year-old woman was admitted with complaints of aggravated dyspnea. She was initially treated with oxygen therapy and heparinization for a suspected pulmonary embolism. Echocardiography revealed a dilated right atrium and ventricle and severe tricuspid regurgitation, with an estimated systolic right ventricular pressure of 95 mm Hg; a shadow of a mass in the main pulmonary artery was also noted. Right ventriculography revealed a filling defect, and to-and-fro motion of the mass in the main pulmonary artery. The left pulmonary artery was almost totally occluded by the mass. The patient's condition improved dramatically after palliative excision of the mass and patch reconstruction of the outflow tract of the right ventricle with a bicuspid xenograft. Pathologic examination of the mass revealed leiomyosarcoma. Chemotherapy and radiotherapy were subsequently administered and follow-up imaging studies 3 months postoperatively revealed no recurrence of the tumor. The patient remains well, more than 1 year after treatment. This report emphasises that pulmonary artery sarcoma should be considered in the differential diagnosis in cases of suspected pulmonary thromboembolism.
Five patients, aged between 64 and 75 years with Salmonella-infected abdominal aortic aneurysms were surgically treated between 1993 and 1995 at the National Cheng Kung University Hospital. Cultures of aneurysmal wall tissue and blood yielded Salmonella enteritidis Group B in three patients and Salmonella choleraesuis in the remaining two. All patients presented with fever and abdominal or back pain. Pulsatile masses were noted in only two patients. Infrarenal abdominal infected aneurysms were demonstrated by computed tomography and aortography in each patient. The five patients underwent aneurysmal resection with in situ graft reconstruction from 1 to 20 days after the diagnosis was made. The graft was wrapped with an omental pedicle. Duodenal repair was performed in one patient due to an aortoduodenal fistula found during surgery. He died 19 days after surgery because of duodenal leakage and uncontrolled sepsis. Four patients survived and remained well 11 to 34 months (mean, 25 mo) after surgery. Postoperatively, only one patient developed adhesion ileus and required enterolysis. Parenteral antimicrobial therapy was continued in all patients after surgery for 2 to 4 weeks; only one patient had an additional 4 months of oral antibiotics. Although the number of patients was small, the survival rate was high, at 80%. Our experience suggests that Salmonella-infected aneurysms of the abdominal aorta can be successfully treated by resection of the aneurysm with extensive debridement followed by in situ graft interposition with omentum wrapping. Once diagnosed, the patients should be scheduled for surgery as soon as possible. Antibiotics should be continued parenterally for at least 2 to 4 weeks postoperatively. While long-term suppressive antibiotic therapy is usually recommended, it might not be essential with our surgical approach.
An 8-year-old girl with tetralogy of Fallot (TF) and double ventricular septal defects (VSDs) was reported. The additional VSD was a muscular inlet type. A split patch technique was used to cover both VSDs during the total correction. Follow-up echocardiogram demonstrated no residual shunt nor significant tricuspid valve regurgitation. The patient is doing well 2 years after operation.
From December 1990 to July 1994, 10 infants with simple transposition of the great arteries (TGA) underwent the Senning procedure at National Cheng Kung University Medical College. Their ages ranged from 1 to 8 months (mean, 4.8 +/- 2 months), and their body weight ranged from 3.5 to 7.5 kg (mean, 5.7 +/- 1.2 kg). Four infants were treated with the conventional method by covering the sinoatrial (SA) node with the anterior right atrial flap (group 1). The other six patients had modified procedures, having the suture line across the caval vein, caudal to the SA node (group 2). Three of the group 1 patients experienced junctional rhythm temporarily, another had SA node dysfunction for 1 week postoperatively. In group 2, all patients were in sinus rhythm except one, who returned to sinus rhythm on the second postoperative day. There was one (10%) surgical mortality, a patient in group 1, and one (10%) late mortality, in group 2. The clinical follow-up interval was 6 to 46 months (mean, 28.8 mo). All survivors were in sinus rhythm, and echocardiographic studies demonstrated no difference between the two groups as to conduit obstruction or degree of tricuspid valve regurgitation. In conclusion, in situations that require atrial switch for the correction of TGA, a suture line across the caval vein, caudal to the SA node, may be a useful modification to prevent arrhythmias.
An eight-month-old male infant with corrected transposition of the great arteries and severe systemic atrioventricular valve regurgitation due to "Ebstein-like anomaly" is reported. Through a midline sternotomy and transeptal approach, a 20 mm Medtronic Hall aortic mechanical valve was reversely implanted into the systemic atrioventricular valve. Anti-platelet drugs (acetylsalicylic acid and dipyridamole) were prescribed for prevention of thromboembolism. The patient is doing well three years after operation.
Our previous finding that normal serum immunoglobulins bind to internal platelet proteins on Western blots led us to further identify these proteins and determine the possible significance of autoantibodies against them. A 95-Kd protein reactive with immunoglobulins in most normal sera and easily confused with gpIIIa was shown to be a fragment of vinculin generated by calpain proteolysis. Identity was established by peptide sequencing of the protein purified from platelets stored without specific protease inhibitors. Normal immunoglobulins bound intact vinculin (117 Kd) and metavinculin (152 Kd), and their 105-, 95-, and 80- to 85-Kd proteolytic fragments. IgG in 89%, and IgA and IgM in 100% of normal sera reacted in titers of 10 to 1,000 with purified vinculin. In addition, IgG in 79%, and IgA and IgM in 93% of normal sera reacted in titers of 10 to 5,000 with talin (235 Kd), another cytoskeletal protein, and its 200-Kd proteolytic fragment. IgGs in sera from animals of several different phylogenetic classes also reacted with human vinculin and talin on Western blots. Frequency of occurrence, titers, and classes of antivinculin and antitalin autoantibodies in patients with thrombocytopenia did not differ discernibly from those of normal individuals. These antibodies had no effect on platelet aggregation or clot retraction, and no apparent pathogenic significance, but their widespread presence and the variability in extent of proteolysis of platelet preparations used for Western blots can complicate interpretation of patterns obtained with sera from patients with presumed immune-mediated thrombocytopenias.
Pulmonary hemangiomatosis is a rare, usually fatal disorder characterized by diffuse proliferation of blood vessels within the thorax. We describe a 7-year-old boy with cavernous-type pulmonary hemangiomatosis successfully treated with interferon alfa-2a. He presented with respiratory distress and hemoptysis that were alleviated during a 2-year follow-up period.
An 18-year-old girl with pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries (MAPCAs) was reported. Her left-side pulmonary artery was absent, and the blood flow to the left lung was derived from two MAPCAs. One-stage correction, including the left-side thoracotomy and followed by the median sternotomy, was performed. A handmade trifurcated valved conduit was used to connect the right ventricle and the distal pulmonary arteries. The patient was doing well 3 years after the operation.
BACKGROUND: Coronary artery bypass grafting (CABG) is the most common procedure performed in adult cardiovascular surgery. The most frequently used conduit is the greater saphenous vein. Using traditional methods, the complication rate of the leg is relatively high (up to 24%). To decrease the complication rate, we used the Endo-Path to harvest the greater saphenous vein. METHODS AND RESULTS: From May 1997 through March 1999, a total of 135 patients received the CABG operation. We excluded the patients who died immediately postoperatively or had concomitant surgical procedures. Sixty patients received the endoscopic saphenous vein harvest procedure (group A), while another 59 patients (group B) did not. No important differences were noted between the two groups in respect to the number of distal anastomoses, length of harvested vein, total surgical time, and length of ICU stay. However, the leg wound complication rate decreased from 20.3% to 5.0% (p < 0.001). CONCLUSIONS: Although the long-term patency rate needs time to be proven, the endoscopic greater saphenous vein harvest method is an attractive and effective method.
Replacement of the mitral valve in the presence of extensive calcification of the posterior annulus is a technical challenge. The heavily calcified annulus often results in difficulties of seating the prosthesis and later periprosthetic leakage. A radical calcium debridement may leave a friable and thin annulus that contributes to the risks of prosthesis dehiscence and ventricular perforation. To avoid technical difficulties and associated catastrophic complications, we devised a new technique of mitral valve replacement that allows a surgeon to implant a prosthesis securely. This technique involves inserting a larger single tilting disc mechanical valve (Medtronic Hall disc) with intra-atrial anchorage over the posterior sector of the calcified annulus, orienting the working (major) orifice of the mechanical valve anteriorly, and thereby tilting the lesser occluder segment of the disc upward into the atrium and away from the calcification in diastole. By utilizing this method, we have successfully performed mitral valve replacement in two patients who exhibited massive calcification of the posterior mitral annulus. Postoperative transeosophageal echocardiography showed excellent hemodynamic performance of the implanted valves. We therefore recommend this simple, safe, and time-saving procedure as a feasible method to deal with this surgical dilemma.
The possibility of a residual shunt is a major drawback to current minimally invasive procedures for the treatment of patent ductus arteriosus (PDA). From April 1997 to October 1999, 30 patients (10 males, 20 females) underwent PDA ligation by a modified technique that uses a pusher for securing the ligate of PDA via posterolateral minithoracotomy at our hospital. No complication or mortality occurred. Postoperative echocardiography also revealed no residual shunt. In this article, we introduce this simple, safe procedure for PDA ligation.
Intensive care management of the injured child requires a multidisciplinary approach and meticulous attention to detail. However, the overwhelming majority of injured children are cared for by surgeons in surgical intensive care units (ICU) that see both adult and pediatric patients. There have been no previous reports of studies comparing the outcome in surgical ICUs (SICU) dealing with patients of all ages versus the outcome in pediatric ICUs (PICU). This study sought to determine differences in the outcome of pediatric intensive care between the SICU and PICU of our hospital. From Jan. 1989 to Aug. 1995, 118 children (68 boys and 50 girls), with an average age of 9.19 years (range: 3 months to 16 years), were admitted to our SICU. During the same period, 65 children (42 boys and 23 girls), with an average age of 5.04 years (range: 2 months to 16 years), were admitted to our PICU. Most of these patients received surgical intervention and were exclusively under surgeons' management. The decision to admit patient to the SICU or PICU was made by surgeon based on the availability of ICU beds. Pediatric risk of mortality (PRISM) score was used as a scoring system to assess disease severity in children. The most common cause for admission in both ICUs was traffic accidents. The average hospitalization duration in the SICU was 4.06 days (range 1 day to 23 days) and 3.34 days (range 1 day to 17 days) in the PICU. The average PRISM score was 7.87 (range 0-41) in the SICU and 6.48 (range 0-35) in the PICU. The overall mortality rate in the SICU was 12.7% (15/118) and 7.7% (5/65) in the PICU. There was a significant difference in patients' age and operative status but no significant difference in admission duration, PRISM score, and mortality rate between the SICU and PICU groups. The regression coefficients of the selected predictor variables and the impact on outcome showed one more score of PRISM would increase 1.5 fold of risk to become poor outcome while operation had lower risk (0.1 fold) to develop poor outcome. In conclusion, disease diversity and severity were similar among PICU and pediatric SICU patients in this study. The outcome was better in PICU patients although the difference was not statistically significant. The PRISM score is a useful measure to predict poor outcome in ICU patients after adjustment with confounders.