PubMed Health⌕ Search

Biomedical subjects

Song Wan

Publications and source records attributed to Song Wan.

17 recordsLinked to original sources
PubMed2002

Tumor p16M is a possible marker of advanced stage in non-small cell lung cancer.

BACKGROUND AND OBJECTIVES: The inactivation of the tumor suppressor gene p16 by methylation (p16M) has been recognized recently as an important process in the oncogenesis for a variety of carcinomas. There have been few reports of its use in lung cancer. We investigate p16M in patients with non-small cell lung cancer (NSCLC). METHODS: p16M in tumor, plasma, and pleural lavage fluid from patients with resectable NSCLC were investigated by using methylation-specific polymerase chain reaction. RESULTS: Of the 33 patients studied, 14 (42%) had p16M tumors. There was a significant association between p16M tumors and advanced TNM staging (stage III or IV, P=0.047, Fisher exact test). Circulating p16M was identified in 2 of the 14 patients with p16M tumor and was also associated with advanced TNM staging (P=0.049). The presence of plasma p16M in NSCLC patients and in p16M tumor patients was associated with poor survival and shorter disease-free survival (P=0.0028, P=0.0039, Kaplan-Meier log rank). In addition, p16M was present in three preresectional and four postresectional lavage samples. Preresectional p16M was associated with poor survival and shorter disease-free survival (P=0.0085). p16M tumor involving the visceral pleura was significantly associated with positive p16M postresectional lavage. CONCLUSIONS: Positive tumor and plasma p16M indicate advanced staging in NSCLC. Patients with plasma and preresection pleural lavage p16M have shorter survival. Further research in this direction is warranted.

Adult↗
PubMed2002

A new technological approach to nonanatomical pulmonary resection: saline enhanced thermal sealing.

BACKGROUND: This is the first clinical report on the feasibility study of two new devices (monopolar Floating Ball and bipolar Sealing Forceps; TissueLink Medical Inc, Dover NH) that incorporated the novel technology of saline enhanced thermal sealing. METHODS: From December 2000 to December 2001, 25 patients (mean age, 54.8 years) with peripheral lung nodules planned for either diagnostic or therapeutic wedge resection were recruited for the study. When the nodule lay deep to a flat lung surface, video-assisted thoracic surgical resection using the modified Perelman technique with the Floating Ball (TissueLink Medical Inc) was preferred. In other patients, the Sealing Forceps (TissueLink Medical Inc) were used for video-assisted thoracic surgical wedge resection. RESULTS: There were no mortality or major intraoperative complications. The Floating Ball was used exclusively in 11 patients; the Sealing Forceps were used in 9 patients; and a combination of the two devices was used in 5 patients. The mean operation time was 70.3 minutes. Average chest drain duration was 3.9 days, and postoperative hospital stay was 5.2 days. There were 2 patients with persistent air leak more than 1 week, one who resolved spontaneously, and the other who required reoperation for control. One patient had pulmonary embolism after a technically uneventful procedure. There have been no late complications after an average follow-up of 10 months. CONCLUSIONS: The devices appear to be technically safe. The Floating Ball has definite advantages over the conventional diathermy and can be adapted to the Perelman procedure using the video-assisted thoracic surgical approach. The Sealing Forceps hold promise to reduce overall consumable costs compared with conventional staplers. These devices should complement the surgeon's existing armamentarium. Comparative studies with conventional instruments are warranted to further define the role of these new devices in thoracic operations.

Adult↗
PubMed2002

Expression of FHL2 and cytokine messenger RNAs in human myocardium after cardiopulmonary bypass.

BACKGROUND: Proinflammatory cytokines such as tumor necrosis factor alpha (TNF-alpha), interleukin (IL)-6, and IL-8 have been implicated in myocardial injury following cardiopulmonary bypass (CPB). However, little evidence is currently available to directly confirm such a relationship. We have previously documented that a newly discovered 'four and a half LIM-only protein 2' (FHL2) is exclusively expressed in myofibres. We hypothesized that the upregulation of FHL2 is proportional to the degree of myocardial injury and investigated the myocardial expression of FHL2 together with these cytokine messenger RNAs (mRNAs) during clinical CPB. METHODS: Intermittent hypothermic blood cardioplegia was used in all patients. Atrial myocardial biopsies were obtained immediately at the onset and at the end of CPB in 33 consecutive patients undergoing valvular or coronary artery surgery. TNF-alpha, IL-6, and IL-8 mRNA expressions in these myocardial samples were determined by semi-quantitative reverse transcription-polymerase chain reaction. Myocardial FHL2 expression was determined by Western blot analysis. Serum levels of the MB isoenzyme of creatine kinase (CK-MB) and cardiac troponin-I (cTnI) before surgery and 24 h after the end of CPB were also measured. RESULTS: The duration of aortic crossclamping and CPB was 70+/-33 and 99+/-37 min, respectively. No elevated myocardial TNF-alpha mRNA expression was found after CPB. IL-6 mRNA expressions were detected in 14 pairs of the myocardial biopsies and were elevated in 11 (33%) post-CPB biopsies. Similarly, IL-8 mRNA expressions were detected in 19 pairs of samples and were elevated in 14 (42%) post-CPB biopsies. Among the 17 pairs of biopsies with positive FHL2 expression, FHL2 levels were increased in 11 (33%) post-CPB samples. Moreover, the elevated FHL2 expression was associated with an increase in IL-6 (P=0.018) and IL-8 (P=0.024) mRNA expression after CPB. Postoperative CK-MB and cTnI levels were significantly higher in patients with myocardial FHL2 expressions than those without (CK-MB, 13.5+/-2.3 vs. 6.5+/-0.8 ng/ml, P=0.022; cTnI, 10.7+/-2.0 vs. 3.5+/-0.6 ng/ml, P=0.0013). CONCLUSIONS: Our findings demonstrate for the first time that both IL-6 and IL-8 mRNAs are upregulated in human cardiac myocytes following CPB and these cytokines may be involved in myocardial ischemia-reperfusion injury, as reflected by their association with an increased expression of FHL2.

Adult↗
PubMed2002

Is hyperamylasemia after cardiac surgery due to cardiopulmonary bypass?

Although hyperamylasemia has been reported in a large proportion of patients undergoing cardiac surgery with cardiopulmonary bypass, its clinical significance and pathogenetic mechanisms remain poorly understood. The study was designed to investigate whether avoidance of cardiopulmonary bypass would limit amylase elevation. Serum levels of amylase and lipase were measured preoperatively as well as 24 and 48 hours postoperatively in 58 patients undergoing elective coronary artery bypass grafting. Three surgical approaches were used: cardiopulmonary bypass (n = 32) and off-pump through a median sternotomy (n = 14) or a left minithoracotomy (n = 12). There was no hospital mortality or postoperative abdominal complications. Transient hyperamylasemia occurred in 14 patients: 7 (22%), 5 (36%), and 2 (17%) in the respective groups. The increase in amylase levels was similar among the groups. However, no lipase elevation was detected in any patient. There was no clear correlation between hyperamylasemia and increased creatinine levels. Perioperative plasma calcium levels were normal in patients who had hyperamylasemia. Our results indicate that hyperamylasemia after bypass surgery is not related to the use of cardiopulmonary bypass or the mode of surgical access.

Aged↗
PubMed2002

Cardiac operation with associated pulmonary resection: a word of caution.

Pulmonary tuberculosis reactivation is an unusual cause of respiratory failure after cardiac surgery. Fulminating tuberculosis was reactivated in a 50-year-old man after combined coronary artery bypass grafting and pulmonary resection on cardiopulmonary bypass. Clinicians should be aware of the immunosuppressive effects associated with cardiopulmonary bypass, and the consequent potential for tuberculosis reactivation.

Cardiopulmonary Bypass↗
PubMed2002

Freestyle xenograft implantation technique for reducing aortic insufficiency.

The Freestyle aortic xenograft has been shown to be safe and effective for aortic valve replacement. However,implantation is often complicated by aortic valve insufficiency, which could lead to premature valve failure. We describe an implantation technique that can potentially prevent aortic insufficiency.

Aortic Valve Insufficiency↗
PubMed2002

Pulmonary dysfunction after cardiac surgery.

Postoperative lung injury is one of the most frequent complications of cardiac surgery that impacts significantly on health-care expenditures and largely has been believed to result from the use of cardiopulmonary bypass (CPB). However, recent comparative studies between conventional and off-pump coronary artery bypass grafting have indicated that CPB itself may not be the major contributor to the development of postoperative pulmonary dysfunction. In our study, we review the associated physiologic, biochemical, and histologic changes, with particular reference to the current understanding of underlying mechanisms. Intraoperative modifications aiming at limiting lung injury are discussed. The potential benefits of maintaining ventilation and pulmonary artery perfusion during CPB warrant further investigation.

Cardiopulmonary Bypass↗
PubMed2002

Cytokine responses to myocardial revascularization on cardiopulmonary bypass: intermittent crossclamping versus blood cardioplegic arrest.

BACKGROUND: The inflammatory responses to the different myocardial protection approaches have not been thoroughly investigated. We sought to study the cytokine responses to cardiopulmonary bypass (CPB) using the intermittent aortic crossclamping with ventricular fibrillation (IAC) versus blood cardioplegic arrest (BC) techniques. METHODS: Perioperative plasma levels of tumor necrosis factor a (TNF-alpha), interleukins (IL) 6, 8, 10, and cardiac troponin-I (cTnI) were measured serially before surgery, at the end of surgery, and 2, 24, and 48 hours after elective coronary revascularization in 31 patients (IAC: n=15; BC: n=16). RESULTS: Demographics, preoperative status, and number of grafts (IAC: 2.7 +/- 0.6; BC: 3.0 +/- 0.4) were similar between groups. No major complications occurred in either group. The total ischemic time and duration of CPB were shorter in group IAC (17 +/- 5 and 58 +/- 10 min vs 45 +/- 14 and 81 +/- 21 min; both p<0.01). Although the intergroup difference in postoperative cTnI levels was not statistically significant, the release of both TNF-alpha and IL-8 were higher in group IAC than in group BC. However, IL-6 and IL-10 levels were lower after surgery in group IAC. CONCLUSION: Despite the duration of ischemia and CPB being shorter, intermittent aortic crossclamping is associated with an enhanced pro-inflammatory but a reduced anti-inflammatory response compared to the cardioplegic arrest technique. Its clinical relevance needs to be further defined.

Aged↗
PubMed2002

The geometry of unstented and stented pig common carotid artery bypass grafts.

The long-term success of arterial bypass grafting with autologous saphenous veins is limited by neointimal hyperplasia (NIH), which seemingly develops preferentially at sites where hydrodynamic wall shear is low. Placement of a loose-fitting, porous stent around end-to-end, or end-to-side, autologous saphenous vein grafts on the porcine common carotid artery has been found significantly to reduce NIH, but the mechanism is unclear. In a preliminary study, we implanted autologous saphenous vein grafts bilaterally on the common carotid arteries of pigs, placing a stent around one graft and leaving the contralateral graft unstented. At sacrifice 1 month post implantation, the grafts were pressure fixed in situ and resin casts were made. Unstented graft geometry was highly irregular, with non-uniform dilatation, substantial axial lengthening, curvature, kinking, and possible long-pitch helical distortion. In contrast, stented grafts showed no major dilatation, lengthening or curvature, but there was commonly fine corrugation, occasional slight kinking or narrowing of segments, and possible long-pitch helical distortion. Axial growth of grafts against effectively tethered anastomoses could account for these changes. CFD studies are planned, using 3D MR reconstructions, on the effects of graft geometry on the flow. Abnormality of the flow could favour the development of vascular pathology, including NIH.

Animals↗
PubMed2002

Pulsatile extracorporeal circulation--let it be?

Cardiopulmonary bypass (CPB) is known to induce a whole body inflammatory response. Since the 1970's, a number of trials have explored the effects of pulsatile CPB on systemic organ function and inflammatory response. Clinical benefits of neuroprotection, improved myocardial and splanchnic perfusion, as well as attenuated systemic inflammatory response have been reported. However, skepticism for pulsatile CPB remains because of inconsistencies of clinical benefits and 'non-standardized' trials. Tarcan and colleagues compared clinical, haemodynamic, biochemical and haematological parameters in patients with chronic obstructive pulmonary disease undergoing CPB with pulsatile flow versus those without. They found higher circulating white cell count and lower neutrophil count at 1 hour post-operatively in the pulsatile group compared with non-pulsatile group, which was attributed to higher pulmonary neutrophil sequestration. In addition, the pulsatile CPB group had lower pulmonary vascular resistance at 1 hour post-operatively and shorter ventilation time. In the current study, confirmation for pulmonary neutrophil sequestration in the form of bronchoalveolar lavage (BAL) or histology would have been welcomed, and additional markers such as neutrophil elastase or matrix metello-proteinases in BAL, and other measurements of lung function may help clarify the association between neutrophil sequestration, lung injury and clinical endpoints. The role of pulsatile CPB in certain high-risk patients remain uncertain, and until more definite evidence of benefit is available, we should be cautious of its universal application.

Cardiopulmonary Bypass↗
PubMedDate not supplied

Systematic organ protection in coronary artery surgery with or without cardiopulmonary bypass.

Coronary artery bypass grafting with cardiopulmonary bypass (CPB) is known to be associated with a systemic inflammatory response, which contributes to the development of postoperative complications including multiple organ dysfunction. Off-pump coronary surgery has been shown to attenuate the inflammatory injury compared to the conventional approach, thereby reducing the incidence of postoperative cardiopulmonary, renal, or neurological dysfunction. It is believed that off-pump experience may greatly impact on improving the outcome of coronary surgery in certain high-risk patients. Moreover, a better understanding of the underlying mechanism would also help to improve our current CPB management. Accumulating evidence to date indicates that a balance between pro- and antiinflammatory responses is crucial in limiting the extent of such systemic inflammatory injury following surgical myocardial revascularization.

Cardiac Surgical Procedures↗
PubMedDate not supplied

Oxidative stress, nitric oxide, and vascular disease.

Superoxide (O2-) is a key risk factor for cardiovascular disease (CVD), including atherogenesis, reperfusion injury, angina, restenosis following balloon angioplasty, and vein graft failure. Axiomatically, O2- reacts with nitric oxide (NO) to form peroxynitrite (ONOO) resulting in a depletion of endogenous vascular NO, which is now firmly associated with CVD. Furthermore, risk factors for CVD, in particular diabetes mellitus (DM), dyslipidemia, and hyperhomocysteinemia are all associated with oxidative stress OS. Antioxidant therapies, including the gene transfer of antioxidant enzymes, are potentially valuable in the treatment of CVD.

Apoptosis↗
PubMedDate not supplied

Video-assisted thoracic surgery in spontaneous pneumothorax.

The proven safety and efficacy of minimal access video-assisted thoracic surgery has changed the way that spontaneous pneumothorax is managed. This review presents some of the experiences of the decade, discusses the controversies and reviews the current video-assisted thoracic surgical management of spontaneous pneumothorax.

Adolescent↗