Association of GSTP1 polymorphism and survival for esophageal cancer.

PURPOSE: Activity of glutathione S-transferase (GST) is associated with detoxification of xenobiotics and the maintenance of cell viability. Genetically variant GSTs produce different enzymatic activities. The clinical significance of this variation is still puzzling. We investigated whether genetic polymorphisms of GST including GSTP1, GSTM1, and GSTT1 affect survival among esophageal cancer patients. EXPERIMENTAL DESIGN: From 1996 to 2002, 233 patients with pathologically proven esophageal cancer were recruited from the Department of Surgery, National Taiwan University Hospital. GST genotypes, including GSTT1, GSTM1, and GSTP1, were determined by PCR or PCR-RFLP. The influence of the genetic polymorphisms on patient survival was estimated using the method of Kaplan-Meier survival function and Cox proportional hazards models. RESULTS: The mean survival times (months) of the GSTP1 Ile/Ile, Ile/Val, and Val/Val were 11, 10, and 7, respectively (P < 0.05). The more the patients carried GSTP1 variant Val alleles, the poorer the survival rate (adjusted hazard ratio, 1.36; 95% confidence interval, 1.01-1.84; Ptrend = 0.045). In contrast, no association of GSTT1 or GSTM1 genotypes with survival rate was noted. CONCLUSION: The presence of the GSTP1 variant allele (Val) is associated with a poorer prognosis of esophageal cancer.

Prognostic significance of six-month estimated glomerular filtration rate in cadaveric renal transplantation.

BACKGROUND AND PURPOSE: We hypothesized a linear relative-risk model for graft survival of cadaveric renal transplantation, with a 6-month estimated glomerular filtration rate (GFR) employed as the linear parameter quantifying functioning renal mass and the detrimental effects of early chronic allograft nephropathy. METHODS: A retrospective study was conducted in a 15-year series of cadaveric renal transplantations (n = 227) with cyclosporin-based immunosuppression in a single transplant center. The Cockcroft-Gault formula was used for estimation of GFR, with a correction factor of 0.85 used for women. Stepwise Cox's regression analyses were applied to examine the prognostic significance of the 6-month estimated GFR. RESULTS: The Kaplan-Meier 5- and 10-year graft survival rates for this study were 80.67% and 59.43%, respectively. From univariate analysis, recipient gender, acute rejection and 6-month estimated GFR were significantly associated with graft survival (p < 0.05). Acute rejection became less significant (p = 0.0033) than 6-month estimated GFR (p = 0.0001) when 6-month estimated GFR was introduced in the stepwise regression procedures. CONCLUSION: We demonstrated that 6-month estimated GFR is a significant prognostic indicator in cadaveric renal transplantation and is an essential parameter in the regression modeling of long-term graft survival.

Safrole-DNA adducts in tissues from esophageal cancer patients: clues to areca-related esophageal carcinogenesis.

Epidemiological studies have demonstrated that areca quid chewing can be an independent risk factor for developing esophageal cancer. However, no studies are available to elucidate the mechanisms of how areca induces carcinogenesis in the esophagus. Since the areca nut in Taiwan contains a high concentration of safrole, a well-known carcinogenic agent, we analyzed safrole-DNA adducts by the 32P-postlabelling method in tissue specimens from esophageal cancer patients. In total, we evaluated 47 patients with esophageal cancer (16 areca chewers and 31 non-chewers) who underwent esophagectomy at the National Taiwan University Hospital between 1996 and 2002. Of the individuals with a history of habitual areca chewing (14 cigarette smokers and two non-smokers), one of the tumor tissue samples and five of the normal esophageal mucosa samples were positive for safrole-DNA adducts. All patients positive for safrole-DNA adducts were also cigarette smokers. Such adducts could not be found in patients who did not chew areca, irrespective of their habits of alcohol consumption or cigarette smoking (p<0.001, comparing the areca chewers with non-chewers). The genotoxicity of safrole was also tested in vitro in three esophageal cell lines and four cultures of primary esophageal keratinocytes. In two of the esophageal keratinocyte cultures, adduct formation was increased by treatment with safrole after induction of cytochrome P450 by 3-methyl-cholanthrene. This paper provides the first observation of how areca induces esophageal carcinogenesis, i.e., through the genotoxicity of safrole, a component of the areca juice.

Acute hemodynamic study of Tai-Ta left ventricular assist device in a canine model.

A revised Tai-Ta centrifugal impeller pump was designed to study the interaction of the left ventricular assist device (LVAD) with the cardiovascular system in a canine model. Six healthy dogs weighing 12-16 kg were used. Blood flows in the aortic arch, the pulmonary artery (PA), and the LVAD outlet were measured simultaneously with the arterial blood pressure (ABP), the pump outflow pressure (POP), and the electrocardiograph (ECG). Normally, the blood flows in the aorta and the PA started at the S-wave of the ECG. When the LVAD was operated at a higher rotational speed (increased from 2900 to 5400 rpm), the ABP, POP, the pump flow, and the maximum rate of change of PA flow increased. However, the fluctuating amplitudes of ABP, POP, and the pump flow decreased significantly. The cardiovascular hemodynamics change with the pump speeds. For a typical 1.1-1.5 L/min cardiac output in canine, the revised LVAD was able to deliver a flow bypass ratio from 15% up to 100%. The LVAD outflow appeared to be pulsatile and matched the cardiac cycle, showing that the centrifugal impeller pump could be used as a pediatric assist device when cardiac function was impeded.

Rapid detection of human HLA transgenes in pigs by fluorescence in situ hybridization (FISH) for adjuvant study of human xenotransplantation.

OBJECTIVES: We have recently generated several lines of transgenic pigs for HLA-DP and -DQ to elucidate the role of HLA-II antigens in the modulation of cell-mediated rejection of xenotransplantation. Using fluorescence in situ hybridization (FISH) analysis, the aim of this study was to determine integration sites and to test zygosity of these transgenes in the piglets after cross mating. METHODS: Blood lymphocytes of transgenic pigs for HLA-DP and -DQ were collected and cultured. Chromosome spreads were prepared by standard methodology. Gene constructs of HLA-DP A1+B1, -DQ A1 & B1 were labeled with fluorescein isothiocyanate or Texas Red by nick-translation. Hybridization was based on a standard FISH protocol. RESULTS: FISH analysis revealed that the HLA-DP probe hybridized to porcine chromosome 6, while both HLA-DQ A1 and B1 probes hybridized to porcine chromosome 11 at the same site. There was no cross-hybridization of HLA transgenes to the swine leukocyte antigen complex. Mosaic integration of HLA-DQ transgenes in the genome of F0, but full penetrance in F1 after selective breeding was observed. Both HLA-DP and HLA-DQ lines were determined to be heterozygous at the integration site. CONCLUSION: By FISH, we have detected specific integration sites of the HLA-DP and -DQ transgenes in pig genome and determined mosaic levels and zygosity types of these transgenes. We conclude that FISH is both sensitive and labor-efficient in confirming and differentiating transgenic pigs for multiple rejection-regulatory genes by visualizing individual integration sites in chromosomes or interphase nuclei.

Comparison of histidine-tryptophan-ketoglutarate and Euro-Collins solutions for lung preservation using the minipig in situ warm ischemia model.

BACKGROUND AND PURPOSE: Reperfusion injury remains a common problem in lung transplantation. This study compared the effect of lung preservation with histidine-tryptophan-ketoglutarate (HTK), a relatively low potassium solution, and Euro-Collins (EC) solution by using a minipig in situ model of warm ischemia. METHODS: The left lungs of 5 minipigs were selectively flushed with EC solution. HTK was used for flush perfusion in 6 other minipigs. After 60 minutes of warm ischemia, the left lungs were reperfused. Hemodynamics, aerodynamics, and arterial blood gas were measured after the blood flow and ventilation of the contralateral lungs were temporally blocked. Bronchoalveolar lavage fluid (BALF) analysis, lung wet-to-dry weight ratio (W/D ratio) and histological analysis were done before perfusion (right lung) and 2 hours after reperfusion (left lung). RESULTS: This in situ model of warm ischemia induced significantly increased pulmonary arterial pressure, pulmonary vascular resistance, BALF albumin contents and neutrophil counts, histological injury score, lung W/D ratio and tissue myeloperoxidase assay. The HTK perfusion group had a significantly lower degree of lung injury than the EC perfusion group. CONCLUSIONS: Lung preservation with HTK solution resulted in better lung function after reperfusion than preservation by EC solution in this minipig model.

The role of B7 ligands (CD80 and CD86) in CD152-mediated allograft tolerance: a crosscheck hypothesis.

BACKGROUND: The regulatory mechanism by which the B7 ligands (CD80 and CD86) direct the CD28/CD152 costimulatory pathways is unclear. This study investigated the role of CD80 and CD86 in a CD152-mediated allograft tolerance model. METHODS: A low-responding cardiac transplant model (BALB/c-->B10.A) with possible long-term acceptance was used. Immunocytochemical and flow cytometric analyses of the graft-infiltrating cells were conducted to characterize this transplant model. The influence of anti-CD80 and anti-CD86 treatments on the proliferation and interleukin (IL)-2 productions of the tolerated splenocytes (SC) was analyzed. The role of CD80 and CD86 in the induction and maintenance of the graft acceptance in this transplant model were also tested. RESULTS: B10.A mice could accept the BALA/c cardiac allografts (11/22), and an anti-CD152 antibody blocked the graft acceptance (10/10). Immunocytochemical and flow cytometric analyses showed that CD152+ cells were predominant among the CD4+ cells infiltrating the 100-day grafts of the B10.A recipients (B10.A-100). Either anti-CD80 or anti-CD86 treatment significantly enhanced polyclonal proliferation and IL-2 production of the B10.A-100 SC. Blockade of either CD80 or CD86 prohibited the tolerance transmitted by adoptive transfer, and anti-CD80 or anti-CD86 plus skin grafting undermined the established allograft tolerance. CONCLUSIONS: Both CD80 and CD86 were essential for the induction and maintenance of the CD152-mediated allograft tolerance.

Video-assisted thoracic surgery for spontaneous pneumothorax: outcome of 189 cases.

The crucial role of video-assisted thoracic surgery (VATS) in the treatment of spontaneous pneumothorax is well acknowledged today. Experiences of such patients undergoing VATS were reported to evaluate the feasibility of such surgical approach. From January 1, 1996 to January 1, 2002, 189 patients (18.3%) underwent VATS treatment for first onset or recurrent primary pneumothorax (n = 134), secondary pneumothorax (n = 49), and re-do VATS (n = 6) pneumothorax of 1034 VATS procedures performed by one surgeon. The surgical approaches for these patients were through scope and working ports, and in six (3.2%) of them, the procedures were converted to open thoracotomy because of pleural adhesion or other causes. Bullae over apices or other sites of lung were identified in 164 (86.8%) patients. Mechanical pleurodesis with gauze abrasion or electrocoagulation was performed on all patients, and chemical pleurodesis with minocycline intrapleural injection or talc powder poudrage was performed on 144 (76.2%) of them. The bullae was excised with endo-GIA (n = 122), endo-loop (n = 23), electroablation (n = 9), and suturing through open or endoscopic port (n = 10). The operation time ranged from 23 to 355 minutes (42.4 +/- 12.6 minutes). The mean postoperative chest tube duration and hospital stay were 2.4 +/- 1.3 (range, 1-26) and 4.3 +/- 1.2 (range, 1-35) days. Complication occurred in 15 cases (7.9%), including 9 patients with persistent air-leakage (> 7 days), 3 patients with bleeding, 6 patients with pneumonia or ventilator dependence, and 3 patients with wound infection. Recurrence occurred in six (3.2%) patients. Two patients (1.1%) died of complications related to underlying disease (severe emphysema) postoperatively. VATS treatment is a good choice for the treatment of recurrent primary spontaneous pneumothorax. It can also be used for patients with first onset spontaneous or traumatic pneumothorax with persistent air leakage or secondary pneumothorax. We preferred bullectomy with endo-GIA because it was safer, and the specimen could possibly reveal the underlying disease.

Effect of Surgecel coverage with topical electrocauterization for preventing and sealing pulmonary air leakage.

Pleural tears usually occur after pneumolysis for dense adhesion or after cone biopsy of lung parenchyma. Repair of the tears is sometimes very difficult. Herein we compared different methods on a pig lung air leak model. Twenty pigs with pleural tears by surgical manipulation through sternotomy were not treated (n = 5) or treated by simple electroablation (n = 5), pleural coverage (n = 5), or Surgecel coverage with surface electroablation (n = 5). We evaluated their immediate and delayed treatment effect by measuring the critical leak pressure, degree of air leakage, and air leakage period and histological examination. It was found that Surgecel coverage with surface electrocauterization had similar early and delayed effects in sealing air leakage to pleural coverage and was much better than the other two groups (P < 0.05). We conclude that coverage with Surgicel with local electroablation can significantly decrease immediate and late air leakage from pleural tears.

Enduring effects of thoracoscopic Heller myotomy for treating achalasia.

Minimal invasive surgery using a laparoscopic or thoracoscopic approach for cardiomyotomy (Heller myotomy) has become a widely accepted procedure to treat achalasia of the esophagus. In this study, we evaluated the long-term results of Heller myotomy achieved by performing video-assisted thoracic surgery (VATS). We recruited patients with achalasia who had undergone VATS for Heller myotomy from 1991 to 2000 at the National Taiwan University Hospital. The myotomy was performed 6 cm above and 1 cm below the gastroesophageal junction. No fundoplication was performed during the procedure. The symptom score, which included dysphagia, regurgitation, and chest pain, was evaluated before and after surgery. Body weight was also recorded before and after surgery. The cases of 14 patients (4 men, 10 women) were studied. The mean patient age was 41.8 +/- 4.9 years. No postoperative mortality or morbidity was found in these patients. The follow-up duration was 56 +/- 7.17 months. The dysphasia score improved from 3.0 preoperatively to 0.79 +/- 0.30 postoperatively (p=0.001). The reflux score improved from 2.64 +/- 0.17 preoperatively to 0.50 +/- 0.20 postoperatively (p=0.001). All the improvements were still in place at the time of the most recent follow-up examinations. Heller myotomy to treat achalasia using a thoracoscopic approach can provide satisfactory long-term results.

Handport-assisted laparoscopic living-donor nephrectomy; initial experience in Taiwan.

The feasibility of handport-assisted laparoscopic living-donor nephrectomy in Taiwan was assessed by comparison with conventional open nephrectomy. Six serial patients undergoing laparoscopic living-donor nephrectomy (LLDN) were compared with six patients undergoing open donor nephrectomy. Body-mass index (BMI), operating time, hospital stay, and short-term graft function were assessed in both groups of patients. Handport-assisted LLDN was successfully attempted in all six patients. Mean ischemic time was 4.5 min in the laparoscopic group. There was no major complication in either group. Short-term graft function was good in all patients, except for one case of chronic rejection with mild azotemia in the open group. The length of stay was significantly longer in the open group, but the operation time of the laparoscopic group was much longer than that of the open group. There was no difference in the resumption of diet and in the use of narcotic analgesics in addition to patient-controlled analgesia. LLDN is a technically demanding approach. With handport assistance, the surgeons could shorten their learning curve. While initial graft function rates are equal to those of the open method, cosmesis and hospital stay are improved by the laparoscopic approach. Longer follow-up and larger patient numbers are needed to confirm these initial results in Taiwan.

Poland's syndrome with spontaneous pneumothorax: report of two cases.

Poland's syndrome is an uncommon congenital anomaly of the chest wall characterized by the absence of the pectoralis major muscle and other nearby musculoskeletal components. Many associated aberrations over the thoracic cage, intrathoracic organs, and upper limbs have been reported. However, spontaneous pneumothorax in these patients has not been reported. Here, we describe two patients with both Poland's anomaly and spontaneous pneumothorax. One patient was a 16-year-old boy with left chest wall hypoplasia and pneumothorax on the right side. The other was a 27-year-old man with right chest wall hypoplasia, hand brachydactyly, and pneumothorax. Pneumothorax in both patients was treated with bullectomy and mechanical pleurodesis with the aid of videothoracoscopy, and the postoperative courses were smooth. Blood supply disruption has been hypothesized as a pathogenic mechanism of both spontaneous pneumothorax and Poland's syndrome, suggesting an association between these two diseases.

Reduction of human-to-pig cellular response by alteration of porcine MHC with human HLA DPW0401 exogenes.

BACKGROUND: In pig-to-human discordant xenotransplantation, the xenograft can be rejected by a formidable human xenogenic T-cell response, even if the graft has gone through hyperacute rejection or delayed xenograft rejection (acute vascular rejection). We therefore examined, in this study, whether the human-to-pig cellular response could be attenuated through the generation of a transgenic pig for human HLA II. METHODS: With the technique of microinjection, we produced the HLA DPw0401 transgenic pig. The expression of the HLA DPw0401 gene on peripheral blood mononuclear cells (PBMCs) of the transgenic pig was examined by reverse transcriptase-polymerase chain reaction and flow cytometry. The antigenicity of the transgenic HLA DPw0401 molecule was tested by the HLA DPw0401-primed lymphocyte test reagent. The cellular response was analyzed by xenogenic mixed lymphocyte culture. RESULTS: The mRNA and protein of HLA DPw0401 were expressed in the PBMCs of the transgenic pig. The PBMCs of the HLA transgenic pig induced a stronger cellular reaction to HLA DPw0401-primed lymphocyte test reagents than the nontransgenic littermate pig (n=7, P<0.01). In direct xenogenic mixed lymphocyte culture with responders from HLA DPw0401(+) humans, the PBMCs from the HLA DPw0401 transgenic pig, as compared with those from the normal pig, induced a lower degree of xenogenic cellular response to human PBMCs (n=4, P=0.08). CONCLUSIONS: Our preliminary data demonstrated the possibility that the human HLA DPw0401 phenotype can be transferred onto porcine cells through the generation of HLA transgenic pigs and make the PBMCs of humans more tolerant to porcine cells.

Efficacy of low-dose mycophenolate mofetil therapy for Taiwanese renal transplantation patients receiving primary cyclosporine immunosuppression.

BACKGROUND AND PURPOSE: Mycophenolate mofetil (MMF) in combination with cyclosporine or tacrolimus prevents acute rejection and chronic allograft failure in renal transplantation in Western countries. We began to add low-dose MMF to primary cyclosporine immunosuppressive therapy in renal transplantation at the Department of Surgery of National Taiwan University Hospital in 1998. This study compared low-dose MMF to conventional therapy in Taiwanese renal transplant recipients. METHODS: This retrospective cohort study determined the efficacy of low-dose MMF therapy (1 g/day in divided doses). A total of 275 cases with allograft kidney transplants were grouped according to whether they received transplants before or after the adoption of MMF therapy (Period I: 1987-1993; Period II: 1994-1997; Period III: 1998-September 2000). The prognostic significance of MMF therapy and graft and patient survival rate in each time period were assessed. RESULTS: The 18-month graft survival rate was 84.9% in Period I, 86.3% in Period II, and 91.9% in Period III. The 5-year graft survival rates in Periods I and II were 69.3% and 76.6%, respectively. Acute rejection was significantly detrimental to graft survival (p = 0.048), while MMF therapy was significantly advantageous to graft survival (p = 0.015); treatment when MMF was available was also significantly associated with better graft survival (p = 0.043). There was a negative correlation between acute rejection and graft survival (p = 0.035); MMF therapy produced a protective effect on graft survival independent of acute rejection (p = 0.010). CONCLUSION: Low-dose MMF therapy significantly improved graft survival after renal transplantation in Taiwanese kidney allograft recipients.