Intratumoral gene expression of dihydrofolate reductase and folylpoly-c-glutamate synthetase affects the sensitivity to 5-fluorouracil in non-small cell lung cancer.

BACKGROUND: Various factors related to the sensitivity of non-small cell lung carcinoma (NSCLC) to 5-fluorouracil (5-FU) have been reported, and some of them have been clinically applied. In this single-institutional prospective analysis, the mRNA expression level of five folic acid-associated enzymes was evaluated in surgical specimens of NSCLC. We investigated the correlation between the antitumor effect of 5-FU in NSCLC using an anticancer drug sensitivity test and the gene expression levels of five enzymes. MATERIALS AND METHODS: Forty patients who underwent surgery for NSCLC were enrolled, and the antitumor effect was measured using an in vitro anticancer drug sensitivity test (histoculture drug response assay) using freshly resected specimens. In the same sample, the mRNA expression levels of five enzymes involved in the sensitivity to 5-FU were measured in the tumor using real-time PCR. The expression levels and the result of the sensitivity test were compared. RESULTS: No correlation was found between dihydropyrimidine dehydrogenase (DPD), orotate phosphoribosyltransferase (OPRT), or DPD/OPRT expression and the antitumor effects of 5-FU. On the other hand, a correlation was found between thymidylate synthase (TS), folylpoly-c-glutamate synthetase (FPGS), and dihydrofolate reductase (DHFR) expression and 5-FU sensitivity. CONCLUSION: Expression of FPGS and DHFR may be useful for predicting the efficacy of 5-FU-based chemotherapy for NSCLC.

Beneficial effects of a cardiac support device on left ventricular remodeling after posterior myocardial infarction: an evaluation by echocardiography, pressure-volume curves and ventricular histology.

PURPOSE: Posterior myocardial infarction (MI) can induce LV remodeling and ischemic mitral regurgitation (IMR). The protective effects of a cardiac support device (CSD) against LV remodeling and IMR after posterior MI have been poorly documented. METHODS: Posterior MI was induced by ligation of the left circumflex coronary artery in beagle dogs. After 7 days, the dogs were randomized to a CSD placement (CSD group, n = 8) or no treatment (CTL group, n = 8). RESULTS: At 3 months after MI, the LV remodeling was less marked and the LV and RV systolic functions were better in the CSD group than in the CTL group. Neither the RV nor LV diastolic function (min dP/dt, Tau and EDPVR) was disturbed by the CSD. IMR was consistently prevented in our canine model. CONCLUSION: Early application of a CSD after posterior MI can attenuate LV remodeling without causing any deterioration of the biventricular diastolic function.

[A case of bacterial aneurysm complicated by severe infectious endocarditis].

We report a case of bacterial aneurysm complicated by severe infectious endocarditis. A 34-year-old man developed idiopathic fever and general fatigue persisting for a month. He was admitted to our institution, and examinations revealed severe bacterial endocarditis with vegetation at the mitral valve and mitral incompetence. Right after admission, he suddenly developed acute cardiac infarction and cardiac arrest due to occlusion of the coronary artery by emboli from vegetation of the mitral valve. After achieving a good recovery, magnetic resonance (MR) imaging demonstrated an unruptured bacterial aneurysm at the distal branch of the left middle cerebral artery (MCA) supplying the left parietal lobe 5 days after admission, and T2* weighted images demonstrated multiple signal loss lesions, which were suspected of being thrombosed bacterial micro-aneurysms or micro-vasculitis. Although there was a risk of aneurysm rupture, we decided to proceed with mitral valve replacement by an artificial heart valve made of carbon, and repeatedly observed an unruptured bacterial aneurysm by serial MR imaging and angiography. Due to the preceding cardiac surgery, we were able to completely cure the severe infection and prevent new embolic showers. Under administration of antibiotics, the bacterial cerebral aneurysm did not increase over a period of 4 weeks, and finally the aneurysm disappeared about 6 weeks after admission. Although the timing of treatment of an unruptured bacterial aneurysm and cardiac surgery for infectious endocarditis associated with a bacterial cerebral aneurysm are controversial, we think that proceeding with cardiac surgery and observing the unruptured bacterial aneurysm by repeated MR imaging and angiography under administration of antibiotics was an appropriate strategy in this case.

Adventitial delivery of platelet-derived endothelial cell growth factor gene prevented intimal hyperplasia of vein graft.

BACKGROUND: Platelet-derived endothelial cell growth factor (PD-ECGF), also known as thymidine phosphorylase (TP) reportedly inhibits vascular smooth muscle cells (VSMCs) migration and proliferation. We hypothesized that adventitial administration of the PD-ECGF/TP gene will suppress intimal hyperplasia and prevent vein graft failure. METHODS: The study used 68 female rabbits. Rabbit jugular vein was autogenously transplanted into carotid artery with a cuff anastomotic technique. To define vascular wall gene transfer efficiency, poloxamer hydrogel (20%) containing plasmid vector encoding the LacZ gene and different concentrations of trypsin (0%, 0.1%, 0.25%, and 0.5%, n = 5 for each group) was applied to the adventitia of the vein graft. Gene transfer efficiency was evaluated 7 days later by X-gal staining. An additional 48 rabbits received poloxamer hydrogel (20%) containing 0.25% trypsin and the human PD-ECGF/TP gene, LacZ gene, or saline. Intima thickness was evaluated at 2 and 8 weeks after grafting (n = 8 for each group at each time point). Transgene expression was examined by reverse transcriptase-polymerase chain reaction, immunoblotting assay, and immunohistochemical staining. Immunohistochemical staining was also used to determine VSMC proliferation, heme oxygenase-1 expression, and macrophage infiltration. RESULTS: Incorporation of trypsin into the poloxamer hydrogel significantly increased vessel wall gene transfer. Trypsin at 0.25% and 0.5% resulted in higher gene transfer at the same level without effecting intimal hyperplasia and inflammation; thus, trypsin at 0.25% concentration was used for subsequent experiments. Compared with the LacZ and saline groups, grafts receiving the PD-ECGF/TP gene significantly reduced intimal thickness at 2 and 8 weeks after treatment. The ratio of proliferative VSMC was lower in PD-ECGF/TP treated grafts. Histologic examination of the PD-ECGF/TP transgene grafts demonstrated high expression of heme oxygenase-1, which has been reported to inhibit VSMC proliferation, suggesting that heme oxygenase-1 may be important in the inhibition effect of PD-ECGF/TP on VSMC. No neoplastic or morphologic changes were found in the remote organs. CONCLUSIONS: A safe and highly efficient gene transfer method was developed by using poloxamer hydrogel and a low concentration of trypsin. Neointimal hyperplasia was significantly reduced by adventitial application of the PD-ECGF/TP gene to the vein graft. Our data suggest that adventitial delivery of the PD-ECGF/TP gene after grafting may be promising method for preventing vein graft failure.

Platelet-derived endothelial cell growth factor gene therapy for limb ischemia.

OBJECTIVES: Platelet-derived endothelial cell growth factor (PD-ECGF) is identical to thymidine phosphorylase (TP), and it can induce angiogenesis, including arteriogenesis, in chronically ischemic canine myocardium. Because its effect on peripheral arterial disease has not been elucidated, we investigated whether overexpression of PD-ECGF/TP could ameliorate chronic limb ischemia in rabbits. METHODS: Left femoral arteries were resected from 24 male rabbits. After 10 days, a plasmid vector containing human PD-ECGF/TP complimentary DNA was injected into 10 sites in the adductor muscles. Control groups received either the LacZ plasmid vector or saline vehicle only (n = 8 per group). Blood pressure was measured in the calf before surgery, at the onset of ischemia, 10 days later, and 20 and 30 days after gene transfer. Collateral vessel development and limb perfusion were assessed by angiography, and resected tissues underwent molecular and histologic examination. RESULTS: In the PD-ECGF/TP group, human PD-ECGF/TP messenger RNA and protein were still detected at 30 days after treatment. Calf blood pressure decreased significantly after femoral artery resection in all three groups. It subsequently showed a greater increase in the PD-ECGF/TP group than in either control group, and the difference was significant at 20 days after treatment (PD-ECGF/TP, 97.4 +/- 7.4; LacZ, 58.6 +/- 6.9; saline, 41.3 +/- 3.6). Immunohistochemical staining demonstrated an increased ratio of capillaries and arterioles to muscle fibers in the PD-ECGF/TP group (2.14 +/- 0.13 and 1.51 +/- 0.06), but not in the LacZ group (1.39 +/- 0.04 and 0.71 +/- 0.05) or the saline group (1.34 +/- 0.05 and 0.71 +/- 0.04, P < .01). The angiographic score was higher in the PD-ECGF/TP group (0.96 +/- 0.08) than in the LacZ group (0.50 +/- 0.02) or saline group (0.51 +/- 0.03) at 30 days after gene transfer (P < .01). CONCLUSIONS: This study demonstrated that PD-ECGF/TP gene transfer induced angiogenesis and decreased ischemia in a rabbit hindlimb model by promoting arteriogenesis, suggesting that targeting this gene may be a promising therapeutic strategy for peripheral vascular disease.

Adventitial inversion technique without the aid of biologic glue or Teflon buttress for acute type A aortic dissection.

OBJECTIVE: This study was performed to evaluate the clinical usefulness of the adventitial inversion technique in acute type A aortic dissection, with special attention to the impact of this procedure on the postoperative status of false lumen evaluated by computed tomographic scan. METHODS: From March 2001 to November 2004, 18 consecutive patients underwent emergent surgery for acute type A aortic dissection. Supracoronary graft replacement was performed in all the patients (ascending aorta/hemiarch replacement: 13/18=72%, total arch replacement: 5/18=28%). The adventitial inversion technique was used for both the proximal and the distal stump constructions of the dissected aortic wall without the aid of Teflon felt or biologic glue. Aortic regurgitation was treated with resuspension of the aortic commissures. RESULTS: There were two hospital deaths and the overall hospital mortality rate was 11.1%. The mean postoperative blood loss was 635+/-214 ml and no reexploration was required in any of the patients. Postoperative computed tomography showed closure of the false lumen in aortic root, aortic arch, and proximal descending thoracic aorta in all of the surviving patients. Postoperative echocardiography demonstrated no aortic regurgitation in any of the patients. Two patients died late postoperatively from unrelated causes to aortic dissection. The remaining 14 patients are doing well without a second-stage operation for aortic root or distal aortic lesions during the follow-up period of 7-51 months (mean: 28+/-14 months). CONCLUSIONS: The adventitial inversion technique provides an excellent immediate hemostasis and facilitates thrombotic closure of the proximal and the distal false lumen in the treatment for acute type A aortic dissection.

Preoperative detection of pleural adhesions by chest ultrasonography.

BACKGROUND: The presence of pleural adhesions may render video-assisted thoracoscopic surgery difficult or impossible. The aim of this study was to assess the value of chest ultrasonography in the detection of pleural adhesions prior to thoracotomy. METHODS: Between October 2001 and September 2002, 42 consecutive patients undergoing thoracotomies (including video-assisted thoracic surgery) were evaluated with chest ultrasonography. These patients underwent a preoperative ultrasonic examination of the chest wall using a 7-MHz linear ultrasound probe at 7 points along the chest wall. We measured the movement of the visceral pleural slide. RESULTS: When restricted viscera sliding was defined as less than 1 cm of excursion at the upper thoracic wall during exaggerated respirations, ultrasonography demonstrated a sensitivity of 63.6%, a specificity of 79.4%, a negative predictive value of 87.7%, a positive predictive value of 50.0%, and an overall accuracy of 75.6%. When restricted viscera sliding was defined as less than 2 cm of excursion at the lower thoracic wall during exaggerated respirations, ultrasonography demonstrated a sensitivity of 81.5%, a specificity of 81.0%, a negative predictive value of 96.0%, a positive predictive value of 44.0%, and an overall accuracy of 81.0%. CONCLUSIONS: Chest ultrasonography is moderately accurate in detecting the presence and location of pleural adhesions. Use of preoperative chest sonographic findings to plan trocar placement and to determine the need for an open approach is valuable in helping prevent visceral injury and facilitating video-assisted thoracoscopic surgery.

Triangle target principle for the placement of trocars during video-assisted thoracic surgery.

OBJECTIVE: The baseball-diamond principle is generally used for trocar placement during video-assisted thoracic surgery; however, we are unable to treat all peripheral lung lesions using this principle. Therefore, we have developed another method for determining trocar placement based on a modification of the conventional principle. We have termed this method the triangle target principle. This report describes the instrument positioning that we now use for many video-assisted thoracic surgical procedures. METHODS: We position 3 trocars in an equilateral triangle, with the target lesion at the apex. One vertex of the base becomes the site of the first trocar placement for introduction of the thoracoscopic camera. Another vertex of the base becomes the site for the second trocar for forceps or the endoscopic stapler. The third trocar is for forceps and is inserted to create the vicinity of target lesion. Four types of the triangle target principle were developed according to sites of the target lesion. RESULTS: Between January 2000 and December 2002, we used this principle for 161 patients who underwent video-assisted thoracic surgery and all intrathoracic lesions were accessible except in 3 patients requiring intraoperative modifications. CONCLUSIONS: We conclude that video-assisted thoracic surgery by this principle is more effective and easier than the conventional principle to treat intrathoracic disease.

Gene therapy for chronic myocardial ischemia using platelet-derived endothelial cell growth factor in dogs.

Platelet-derived endothelial cell growth factor (PD-ECGF), also known as thymidine phosphorylase (TP), has been reported to possess angiogenic activity and to inhibit apoptosis. This study was performed to determine whether PD-ECGF/TP can be used to ameliorate chronic myocardial ischemia. Myocardial ischemia was created in 40 mongrel dogs by placement of an ameroid constrictor on the proximal left anterior descending coronary artery (LAD). Plasmid vector encoding human PD-ECGF/TP cDNA (pCIhTP group; n = 12), empty vector pCI (pCI group; n = 12), or saline (Saline group; n = 12) was directly injected into the LAD territory 3 wk after ameroid constrictor implantation. Myocardial blood flow was detected using PET at baseline, 3 wk after ameroid constrictor implantation, and 2 wk after therapeutic treatment. At the end of the experiment, the hearts were isolated for biological and histological analysis. In the pCIhTP group, the transfected heart strongly expressed PD-ECGF/TP. The size of the infarct was smaller in the pCIhTP group than in the pCI or Saline group. The number of apoptotic myocardial cells was decreased in the pCIhTP group compared with the control groups based on triple immunohistochemical staining for von Willebrand factor, alpha-actin smooth muscle cells, and single-strand DNA. The level of proapoptotic protein Bax markedly decreased in the pCIhTP group compared with the other groups. Double immunohistochemical staining for von Willebrand factor and alpha-actin smooth muscle cells demonstrated that angiogenesis and arteriogenesis occurred, and paralleled the changes in myocardial blood flow and myocardial function in the pCIhTP group. We conclude that genetic approaches using PD-ECGF/TP to target the myocardium are effective for alleviating chronic myocardial ischemia.

Role of MMPs and plasminogen activators in angiogenesis after transmyocardial laser revascularization in dogs.

We examined the role of matrix metalloproteinases (MMPs), tissue inhibitors of MMP (TIMPs), and plasminogen activator (PA) in transmyocardial laser revascularization (TMLR)-induced angiogenesis. TMLR was accomplished with a carbon dioxide laser in seven dogs whose left anterior descending coronary artery (LAD) was ligated. Seven control dogs underwent only LAD ligation, and four dogs underwent a sham operation, consisting only of a left thoracotomy. Two weeks later, transmural myocardial samples were harvested from the distributions of the LAD and the left circumflex artery for substrate zymography, immunohistochemical staining, and in situ zymography. MMP-1, MMP-2, TIMP-1, TIMP-2, and urokinase-type PA levels in the distribution of the LAD were higher in the laser group than in the control or sham group. Counts of von Willebrand factor-positive microvessels and smooth muscle alpha-actin-positive arterioles demonstrated that the angiogenesis and ateriogenesis was promoted in the laser group and correlated directly with the number of MMP-stained microvessels. We conclude that TMLR induces the expression of MMPs, TIMPs, and urokinase-type PA and that these proteinases play an important role in angiogenesis after TMLR.