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Anthony P C Yim

Publications and source records attributed to Anthony P C Yim.

At least 19 recordsLinked to original sources
PubMed2006

Video-assisted thoracic surgery lobectomy for lung cancer is associated with less immunochemokine disturbances than thoracotomy.

OBJECTIVE: Major surgery is immunosuppressive and could have an impact on postoperative tumor immunosurveillance and recurrence in cancer patients. Low circulating levels of insulin growth factor binding protein (IGFBP)-3 have been linked to advance prostate and the development of colonic cancers. This prospective study examined the early postoperative circulating levels of IGFBP-3, matrix metalloproteinase (MMP)-9, and tissue inhibitor of metalloproteinase (TIMP)-1 in early stage non-small cell lung cancer (NSCLC) patients undergoing major lung resection by VATS versus thoracotomy. METHODS: Forty-two consecutive patients with resectable primary NSCLC were assigned to VATS or thoracotomy approach over a 7-month-period. Blood samples were collected preoperatively and postoperatively on days (POD) 1 and 3 for enzyme linked immunosorbent assay determination of IGFBP-3, MMP-9 and TIMP-1 levels in the serum. RESULTS: There were no demographic differences between the two groups. VATS lung resection was associated with lower levels of MMP-9 and TIMP-1 on POD1 (median 628 vs 1311ng/ml, p=0.009; and 131 vs 211ng/ml, p=0.004, respectively) but higher levels of IGFBP-3 on POD3 (1366 vs 1144ng/ml, p=0.02), when compared with the thoracotomy approach. There was no perioperative mortality. CONCLUSIONS: VATS major lung resection for NSCLC is associated with higher circulating levels of IGFBP-3, and lower levels of MMP-9 and TIMP-1, compared to the thoracotomy approach. The clinical relevance of these postoperative changes on tumor biology following lung resection for cancer warrants further investigation.

Aged↗
PubMed2006

Pre-emptive local anesthesia for needlescopic video-assisted thoracic surgery: a randomized controlled trial.

OBJECTIVE: Studies in other surgical specialties have suggested that pre-emptive wound infiltration using a local anesthetic may reduce post-operative pain. We report the first randomized trial to assess the use of pre-emptive local anesthesia in video-assisted thoracic surgery (VATS). METHOD: Thirty-one consecutive patients undergoing bilateral needlescopic VATS sympathectomy for palmar hyperhidrosis were studied prospectively. Each patient acted as their own control. For each patient, one side was randomized to receive 10ml 0.5% bupivicaine injected to the port sites before incision, and the contralateral control side to receive 10ml saline. Pain severity on a visual analog scale (VAS) was recorded for each chest side at 4h, 1 day and 7 days following surgery. All patients were blinded to the results of randomization throughout the study. RESULTS: Follow up was complete for all patients. At 7 days after surgery, wound pain was significantly reduced by pre-emptive local anesthesia, with 10 (62.5%) of the 16 patients having residual pain reporting less pain on the pre-treated side (p=0.039). There was a trend for reduced pain on the pre-treated side at the other time points. Pain reduction by pre-emptive local anesthesia was not correlated with any demographic or clinical variable. Chest wall paresthesia distinct from localized wound pain was noted by six patients (19.4%), but was not reduced by pre-emptive local anesthesia. Overall, the post-operative discomforts felt by the patients after needlescopic VATS were mild, and did not cause significant functional disturbances. CONCLUSION: Pre-emptive wound infiltration with a local anesthetic may reduce post-operative wound pain in needlescopic VATS procedures.

Adolescent↗
PubMed2006

Vasorelaxation induced by vascular endothelial growth factor in the human internal mammary artery and radial artery.

OBJECTIVES: Due to potential therapeutic value of vascular endothelial growth factor (VEGF) in coronary artery disease, the effect and mechanism of VEGF in human arteries used as coronary bypass grafts become important but not fully understood. VEGF-mediated endothelial regulation in vasorelaxation was studied in internal mammary artery (IMA) and radial artery (RA), compared with that of the classical agent-acetylcholine (ACh). The role of nitric oxide (NO), prostacyclin (PGI2), and endothelium-derived hyperpolarizing factor (EDHF) was investigated. METHODS: VEGF- and ACh-induced responses were measured in RA and IMA with or without endothelium and in the absence or presence of inhibitors of nitric oxide synthase or prostacyclin. In addition, the VEGF-induced PGI2 was measured by enzyme immunoassay. RESULTS: VEGF induced similar relaxation in RA (59.2+/-9.3%) and IMA (56.1+/-6.4%) that was significantly inhibited by N(omega)-nitro-L-arginine (L-NNA) plus oxyhemoglobin (HbO) (IMA: 24.9+/-4.3%, P=0.03 vs. RA: 25.0+/-8.6%, P=0.01) or by indomethacin (INDO) (IMA: 21.8+/-2.5%, P=0.000 vs. RA: 30.0+/-6.6%, P=0.04) with more inhibition in IMA than RA (P<0.05). In addition, the VEGF-induced PGI2 was significantly higher in IMA than RA (11.5+/-2.1 vs. 4.9+/-1.1 pg/ml/mg, P=0.002). INDO+L-NNA+HbO reduced the VEGF-induced relaxation to 20.8+/-4.6% in RA vs. 4.8+/-1.6% in IMA (P=0.01). In contrast, the maximal relaxation induced by ACh in RA (55.9+/-6.0%) and IMA (48.5+/-5.3%) was largely inhibited by L-NNA in IMA and RA (14.7+/-3.0%, P=0.000 vs. 15.2+/-3.2%, P=0.004) but little affected by INDO. CONCLUSIONS: VEGF induces similar relaxation in IMA and RA with significantly more PGI2-mediated relaxation and higher stimulated PGI2 level in IMA but more EDHF-mediated relaxation in RA. In comparison, ACh-induced relaxation mainly depends on NO. Thus, our study reveals a significant difference in the mechanism of the endothelium-dependent relaxation induced by VEGF and ACh.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed2006

Differential, time-dependent effects of perivenous application of fibrin glue on medial thickening in porcine saphenous vein grafts.

OBJECTIVE: Neointimal and medial thickening play a critical role in late vein graft failure following CABG. Previous ex vivo experiment suggested that perivenous application of fibrin glue may reduce the damage in the circular smooth muscle cell layer of the media of the vein graft shortly after exposing to arterial pressure. However, the in vivo as well as the longer term impact of this intervention remain unknown. METHODS: Bilateral saphenous vein-carotid artery interposition grafting was performed in eight large white pigs (35-45 kg). In each pig, one of the grafts was randomly selected to receive perivenous fibrin glue support while the contralateral graft served as control. At 1 and 4 months following surgery (n=4 pigs in each group), all 16 patent vein grafts were removed and pressure-fixed. Multiple histological sections from each graft were prepared. Proliferating cell nuclear antigen (PCNA) was detected by immunocytochemistry. Vein graft morphology was assessed using computer-aided planimetry. RESULTS: Although perivenous application of fibrin glue had little effects either on medial thickness 1 month after implantation or on PCNA index, it significantly increased medial thickness (control: 0.37+/-0.02 mm; treated: 0.55+/-0.02 mm, p<0.001) and total wall thickness (control: 0.75+/-0.04 mm; treated: 0.92+/-0.04 mm, p=0.008) at 4 months (mean+/-SEM; n=4 in each group). CONCLUSIONS: Our data indicated that perivenous application of fibrin glue enhances graft thickening and as such does not constitute a strategy for preventing late vein graft failure after CABG.

Anastomosis, Surgical↗
PubMed2006

The use of gabapentin for post-operative and post-traumatic pain in thoracic surgery patients.

OBJECTIVE: The pain following thoracic surgery and trauma is often refractory to conventional analgesic strategies. However, it shares key characteristics with neuropathic pain which gabapentin, an anticonvulsant, has been proven to effectively treat. To our knowledge, this is the first prospective study assessing the use of gabapentin in cardiothoracic surgery patients. METHODS: Gabapentin was prescribed to 60 consecutive out-patients with refractory pain persisting at four weeks or more after thoracic surgery or trauma. Follow-up of 45 patients (75%) was performed for a median of 21 months (range: 12-28), and clinical data collected prospectively. The mean age of these patients was 51.6 years (range 22-83). Of these 45 patients, 22 had received video-assisted thoracic surgery (VATS), 8 had received thoracotomy, 3 had received median sternotomy, and 12 were treated for blunt chest trauma. RESULTS: The mean duration of pre-treatment refractory pain was 5.76 months (range 1-62). The mean duration of gabapentin use was 21.9 weeks (range 1-68). No deaths or major complications were encountered. Minor side effects-mostly somnolence and dizziness-occurred in 18 patients (40.0%), causing 3 patients (6.7%) to discontinue gabapentin. Overall, 33 patients (73.3%) noted reduction of pain. Chest wall paresthesia distinguishable from wound pain was relieved in 24 (75.0%) of 32 affected patients. Severe initial pain was significantly correlated with pain relief using gabapentin (p=0.009). No other demographical or clinical variable correlated with benefit or side effects. Satisfaction with gabapentin use was expressed by 40 patients (88.9%). Side effects were not a source of dissatisfaction in any patient. CONCLUSIONS: Gabapentin appears safe and well tolerated when used for persistent post-operative and post-traumatic pain in thoracic surgery patients, although minor side effects do occur. Gabapentin may relieve refractory chest wall pain in some of these patients, particularly those with more severe pain. Further studies are warranted to define the role of gabapentin in cardiothoracic surgical practice.

Adult↗
PubMed2006

Increased thromboxane B(2) levels are associated with lipid peroxidation and Bcl-2 expression in human lung carcinoma.

There is little information regarding simultaneous investigations of thromboxane A(2) (TXA(2)) lipid peroxidation and Bcl-2, three cancer-related agents, and analyses of their relationships in lung cancer. The present study was to study thromboxane B(2) (TXB(2)), a stable metabolite of TXA(2), lipid peroxidation and Bcl-2 expression in 52 non-small cell lung carcinoma (NSCLC) tissue samples. The level of thiobarbituric acid reactive substances (TBARS), an index for lipid peroxidation was significantly increased in the lung tumor tissues, compared with non-tumor tissues. TXB(2) was much higher in the tumor tissues than non-tumor tissues. Interestingly, the concentration of TXB(2) in samples from those who smoked was higher than that from those who did not smoke. The expression of Bcl-2 was significantly elevated in the tumor tissues, compared to the non-tumor tissues. There was also a positive correlation between TXB(2) and TBARS in tumor tissues; advanced stage cancers had higher levels of TXB(2). This finding supports the idea that TXB(2) may have a role in promoting tumor growth. In conclusion, our study demonstrates that the production of TXB(2) is increased in lung tumor tissues and that such an increase can result in lipid peroxidation which may be met by an elevation in Bcl-2 expression.

Carcinoma, Non-Small-Cell Lung↗
PubMed2006

Role of NO and EDHF-mediated endothelial function in the porcine pulmonary circulation: comparison between pulmonary artery and vein.

OBJECTIVE: To compare electrophysiological measurement of nitric oxide (NO) release and endothelium-derived hyperpolarizing factor (EDHF)-mediated endothelial function in porcine pulmonary arteries and veins. METHODS: Isolated pulmonary interlobular arteries (PA) and veins (PV) were obtained from a local slaughterhouse. By using a NO-specific electrode and a conventional intracellular microelectrode, the amount of NO released from endothelial cells and hyperpolarization of smooth muscle cells were investigated. The bradykinin (BK)-induced relaxation in the precontraction by U(46619) was examined in the absence or presence of N(G)-nitro-l-arginine (l-NNA), indomethacin (INDO) plus oxyhemoglobin (HbO). RESULTS: The basal release of NO was 7.0+/-1.2 nmol/L in PA (n=8) and 5.5+/-1.6 nmol/L in PV (n=8, p<0.01). BK-induced release of NO was 160.4+/-10.3 nmol/L in PA (n=8) and 103.0+/-14.7 nmol/L in PV (n=8, p<0.001) with longer releasing duration in PA than in PV (14.3+/-1.3 vs. 12.1+/-0.8 min, p<0.01). BK evoked an endothelium-dependent hyperpolarization and relaxation that were reduced by l-NNA, INDO, and HbO (hyperpolarization: 12.8+/-1.3 vs. 8.0+/-1.4 mV in PA, n=6, p<0.001 and 8.3+/-1.4 vs. 3.0+/-0.8 mV in PV, n=6, p<0.001; relaxation: 92.8+/-3.1% vs. 19.6+/-11.1% in PA n=8, p<0.001 and 70.3+/-7.9% vs. 6.0+/-6.8% in PV, n=8, p<0.001). Both hyperpolarization (8.0+/-1.4 vs. 3.0+/-0.8 mV, p<0.001) and relaxation (19.6+/-11.1% vs. 6.0+/-6.8%, p<0.01) were greater in PA than in PV. CONCLUSIONS: Both NO and EDHF play an important role in regulation of porcine pulmonary arterial and venous tones. The more significant role of NO and EDHF is revealed in pulmonary arteries than in veins.

Animals↗
PubMed2006

Apoptosis induced by troglitazone is both peroxisome proliferator-activated receptor-gamma- and ERK-dependent in human non-small lung cancer cells.

The role of the peroxisome proliferator-activated receptor-gamma (PPARgamma) in cell differentiation, cell-cycle arrest, and apoptosis has attracted increasing attention. We have recently demonstrated that PPARgamma ligands-troglitazone (TGZ) induced apoptosis in lung cancer cells. In this report, we further studied the role of ERK1/2 in lung cancer cells treated by TGZ. The result demonstrated that TGZ induced PPARgamma and ERK1/2 accumulation in the nucleus, in which the co-localization of both proteins was found. The activation of ERK1/2 resulted in apoptosis via a mitochondrial pathway. Both PPARgamma siRNA and U0126, a specific inhibitor of ERK1/2, were able to block these effects of TGZ, suggesting that apoptosis induced by TGZ was PPARgamma and ERK1/2 dependent. Inhibition of ERK1/2 by U0126 also led to a significant decrease in the level of PPARgamma, indicating a positive cross-talk between PPARgamma and ERK1/2 or an auto-regulatory feedback mechanism to amplify the effect of ERK1/2 on cell growth arrest and apoptosis. In addition to ERK1/2, TGZ also activated Akt. Interestingly, inhibition of ERK1/2 prevented the activation of Akt whereas the suppression of Akt had no effect on ERK1/2, suggesting that Akt was not necessary for TGZ-PPARgamma-ERK pathway. However, the inhibition of Akt promoted the release of cytochrome c, suggesting the activation of Akt may have a negative effect on apoptosis induced by TGZ. In conclusion, our study has demonstrated that TGZ, a synthetic PPARgamma ligand, induced apoptosis in NCI-H23 lung cancer cells via a mitochondrial pathway and this pathway was PPARgamma and ERK1/2 dependent.

Apoptosis↗
PubMed2006

Inflammatory response to pulmonary ischemia-reperfusion injury.

Lung ischemia-reperfusion (IR) injury is one of the most important complications following lung transplant and cardiopulmonary bypass. The pulmonary dysfunction following lung IR has been well documented. Recent studies have shown that ischemia and reperfusion of the lung may each play significant yet differing roles in inducing lung injury. The mechanisms of injury involving neutrophil activation, and the release of numerous inflammatory mediators and oxygen radicals also contributes to lung cellular injury, pneumocyte necrosis, and apoptosis. We herein review the current understanding of the underlying mechanism involved in lung IR injury. The biomolecular mechanisms and interactions which lead to the inflammatory response, pneumocyte necrosis, and apoptosis following lung IR therefore warrant further investigation.

Humans↗
PubMed2006

Effect of hypoxia-reoxygenation on endothelial function in porcine cardiac microveins.

BACKGROUND: The cardiac venous system possesses up to 30% of total coronary vascular resistance and the effect of hypoxia-reoxygenation (H-R) and St Thomas (ST) cardioplegic solution on the vein is unknown. We investigated the effects of H-R, with or without ST, on endothelium-derived hyperpolarizing factor (EDHF)-mediated relaxation in porcine cardiac microveins under clinically relevant temperatures. METHODS: The microveins (diameter 200 to 450 microM) mounted in a myograph were subjected to hypoxia (Po2 < 5 mm Hg) for 30 minutes in Krebs solution (n = 8) or for 60 minutes in Krebs (n = 8) or in ST at 37 degrees C (n = 8) or 4 degrees C (n = 8), followed by 30-minute reoxygenation. The microvein was precontracted with thromboxane A2 mimetic U46619 (-7 log M) and the EDHF-mediated relaxation was induced by bradykinin (-10 to -6 log M) in the presence of indomethacin, NG-nitro-L-arginine, and oxyhemoglobin before and after H-R. RESULTS: The maximal EDHF-mediated relaxation was significantly reduced after 30-minute hypoxia (38.7 +/- 2.0% vs 61.1 +/- 2.3%, n = 8, p < 0.001) or 60-minute hypoxia in either Krebs or ST at 37 degrees C (Krebs: 27.8 +/- 1.2% vs 56.6 +/- 2.5%, n = 8, p < 0.001; ST: 23.8 +/- 4.1% vs 57.1 +/- 1.5%, n = 8, p < 0.001). The relaxation was significantly less after prolonged H-R in Krebs (p < 0.001). Incubation in Krebs or ST at 4 degrees C also reduced the EDHF-mediated relaxation (Krebs: 25.3 +/- 3.3%, n = 8, p < 0.001; ST: 29.1 +/- 4.4%, n = 8, p < 0.001) and there were no significant differences between Krebs and ST regarding the relaxation at either 37 degrees C or 4 degrees C (p > 0.05). CONCLUSIONS: We conclude that (1) H-R impairs EDHF-mediated relaxation in the coronary microveins with more severe injury during prolonged H-R and (2) ST does not provide protection to the EDHF-mediated relaxation impaired by H-R at either 37 degrees C or 4 degrees C.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed2006

Analgesic effect of electroacupuncture in postthoracotomy pain: a prospective randomized trial.

BACKGROUND: The role of electroacupuncture in postthoracotomy pain control is uncertain. We conducted a pilot study to evaluate the role of electroacupuncture in the management of early postthoracotomy wound pain. METHODS: A total of 27 patients with operable non-small cell lung carcinoma who received thoracotomy were recruited and randomized to receive either electroacupuncture or sham acupuncture in addition to routine oral analgesics and patient-controlled intravenous analgesia for postoperative pain control. All patients received acupuncture twice daily with visual analog pain score recorded for the first 7 postoperative days. Specific chest acupoints (LI 4, GB 34, GB 36, and TE 8) were targeted. Patient-controlled analgesia was used for the first 3 postoperative days in all patients, and the cumulative dosage used was recorded. RESULTS: Two patients were excluded after randomization because of complications unrelated to acupuncture. Interventions and data collection were completed for the remaining 25 patients (13 in the electroacupuncture group; 12 in the sham acupuncture group). There was a trend for lower visual analog scale pain scores in the electro-acupuncture group between postoperative days 2 and 6, although this did not reach statistical significance. The cumulative dose of patient-controlled analgesia morphine used on postoperative day 2 was significantly lower in the electroacupuncture group (7.5 +/- 5 mg versus 15.6 +/- 12 mg; p < 0.05). Such delay of onset of pain control may be related to the frequency of electroacupuncture used. CONCLUSIONS: Electroacupuncture may reduce narcotic analgesic usage in the early postoperative period. A prospective randomized controlled trial using different electroacupuncture frequency is warranted to verify this benefit.

Acetaminophen↗
PubMed2006

Video-assisted thoracic surgery pulmonary resection for lung cancer in patients with poor lung function.

BACKGROUND: The aim of this study is to evaluate the early outcome of patients with poor lung function who underwent video-assisted thoracic surgery (VATS) pulmonary resection for primary non-small cell lung carcinoma. METHODS: We reviewed retrospectively the records of patients with lung cancer undergoing VATS lung resection over a period of 5 years. Twenty-five patients with preoperative poor lung function defined as forced expiratory volume in 1 second less than 0.8 L or the percentage predicted value for forced expiratory volume in 1 second less than 50% were identified. Thirteen patients underwent VATS lobectomies and 12 VATS wedge resections. Data were analyzed with respect to demographics, risk factors, and early postoperative outcome and survival. RESULTS: There were 8 cases of morbidities (29%) and no surgical mortality. Five of these 8 patients had respiratory-related complications after surgery. A deterioration in pulmonary performance as indicated by the Eastern Cooperative Oncology Group (ECOG) score was seen in 7 patients (28%), with only 1 patient having an ECOG score greater than 2. No patient required home oxygen supplementation beyond the third month postoperatively. After a median follow-up period of 15.1 months (range, 1 to 24), 5 patients died. Only 1 patient (4%) died of a respiratory complication (pneumonia 6 weeks after surgery). The other 4 deaths were due to recurrent or metastatic disease. The actuarial survival rates at 1 and 2 years were 80% and 69%, respectively. CONCLUSIONS: Video-assisted thoracic surgery pulmonary resection for cancer in patients with poor lung function can achieve acceptable functional and oncologic outcome.

Aged↗
PubMed2006

Invited commentary.

Explore the source record for details and available documents.

Bronchial Fistula↗
PubMed2006

Jia-Si Huang: "A surgeon and something more".

In contrast to many industrialized countries, the growth of thoracic surgery in China was much more difficult over the first 5 decades under the ever-changing political and harsh socioeconomic conditions. As a matter of fact, the struggle to establish this specialty in a developing country with more than one fifth of the world population was certainly one of the most crucial challenges in the last century. The unique story of a pioneering Chinese thoracic surgeon--Dr Jia-Si Huang (1906-1984) was a glorious example of heroic leadership and self sacrifice. His fundamental role in developing cardiothoracic surgery in China was clearly reflected not only by some first-in-China operations he personally performed, but also by his continued contributions in educating younger generations of Chinese surgeons.

China↗