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OBJECTIVES To repair unexpected damage of the pulmonary artery (PA) during thoracic surgery, fibrinogen/thrombin-based collagen fleece (TachoComb® [TC]) can be applied as a haemostatic material. The progression of vessel restoration with TC has not been elucidated. In this study, we investigate details of the healing process with TC after PA injury using a canine model. METHODS Left thoracotomy was performed on female beagles under general anaesthesia. PA injury was induced and repaired using TC. Repair sites were histologically evaluated 2, 4 and 8 weeks after surgery (n = 3 in each group). RESULTS Haemostasis of PA injury was achieved promptly after TC application. After surgery, no bleeding was found in the thoracic cavity, and no repair sites revealed stenosis, thrombi or false aneurism formation. Two weeks after surgery, inflammatory cells had infiltrated around the vascular defect, and vascular endothelium had regenerated on the innermost surface of TC applied to the defect. At Week 4, elastic and smooth muscle fibres had begun to extend into the defect between the endothelial layer and collagen fleece. By Week 8, elastic fibres and smooth muscle had completely regenerated in the medial layer. The adventitial layer had also fully regenerated. CONCLUSIONS Haemostasis of injured PA using TC was safe and reliable. TC provided a mechanical scaffold on which vascular regeneration occurred. Three layers reconstructed in the PA defect were identical to those in normal structures. [ABSTRACT FROM AUTHOR]

Functional modulation of regulatory T cells (T-regs) is one possible approach to cancer immunotherapy. In this study, we investigated whether low-dose basiliximab, a chimeric anti-CD25 monoclonal antibody, could suppress the T-regs function not by depletion but by inactivation, and increase immune responses. Peripheral blood mononuclear cells from healthy donors and patients with malignancy were collected. We tried T-regs inactivation using various concentrations of basiliximab before induction of lymphokine-activated killer (LAK) cells. We measured cell proliferation, lymphocyte phenotype, intracellular T-regs maker, and Th1/2 cytokines production. Our results showed that the optimal concentration of basiliximab for specifically down-modulating only T-regs was 0.001 μg/ ml. The reduction of Th-2 cytokine secretion with concomitant APC induction without suppressing cell proliferation offers the promise of a novel adoptive immunotherapy to cancer patients. [ABSTRACT FROM AUTHOR]

OBJECTIVES The study aimed to evaluate the prognostic significance of carcinoembryonic antigen levels in pleural lavage fluid (p-CEA) in patients with completely resected non-small-cell lung cancer (NSCLC). METHODS We examined 72 patients who underwent curative surgical resections. Pleural lavage fluid was collected at thoracotomy before lung resection. Pleural lavage cytology and p-CEA were determined. The relationships between p-CEA and clinicopathological factors were analysed. RESULTS Four patients (5.6%) had positive pleural lavage cytologies. The median p-CEA was 65.2 ng/g protein (range, 0–7331.7). p-CEA was significantly correlated with pleural invasion and CEA levels in serum (s-CEA). Receiver operating characteristic curve analysis identified an optimal cut-off of 38 ng/g protein for p-CEA for predicting recurrence [area under the curve (AUC) = 0.669; sensitivity = 91.7%; specificity = 43.7%; 95% confidence interval (CI) = 0.541–0.796; P = 0.020], whereas this could not be identified for s-CEA (AUC = 0.535; 95% CI = 0.392–0.678; P = 0.629). With a mean follow-up period of 57.5 months, 5-year disease-free survival (DFS) rates were 86.5% for p-CEA ≤38 ng/g protein and 47.7% for p-CEA >38 ng/g protein (P = 0.0013). Even for patients with Stage I lung cancer, 5-year DFS rates were 88.2 and 53.8%, respectively (P = 0.017). Multivariate Cox analysis revealed that p-CEA was a significant independent factor for DFS and overall survival. CONCLUSIONS Intraoperative p-CEA may be a more powerful prognostic determinant than s-CEA for patients with NSCLC. [ABSTRACT FROM PUBLISHER]

A loss of human leukocyte antigen (HLA) expression in clinical tumors is one of their escape mechanisms from immune attack by HLA-restricted effector cells. In this study, the induction of HLA-unrestricted effector cells, gamma delta T cells, using zoledronate (ZOL) and interleukin (IL)-2 in vitro was investigated in patients with metastatic cancer. Peripheral blood mononuclear cells (PBMCs) from 10 cancer patients (8 colorectal and 2 esophageal) with multiple metastases and ascites lymphocytes from 3 cancer patients (1 gastric and 2 colorectal) were stimulated with varied concentrations of ZOL plus 100 U/ml IL-2 for 48 hr followed by culturing with IL-2 alone for 12 days. Lymphocyte proliferative responses were determined using 3H-TdR uptakes and interferon (IFN)-gamma production was evaluated using enzyme-linked immunosorbent assay. Surface phenotyping was performed using flow cytometry. Cytotoxic activity of effector cells was determined using 51Cr-releasing assay. It was found that proliferative responses of PBMCs were significantly stimulated with ZOL plus IL-2 when compared with IL-2 alone, showing 200 to 500-fold expansions for 2 weeks, although ZOL alone induced no response. The optimal concentration of ZOL was 1-5 microM. Ascites lymphocytes could also be stimulated with ZOL plus IL-2. The proliferative responses were remarkable in patients whose PBMCs could produce high levels of IFN-gamma during an initial 48-hr stimulation using ZOL plus IL-2. Removal of an adherent cell fraction before the induction augmented the proliferative responses in patients who otherwise had low-grade proliferative responses. Generated cells comprising approximately 90 or 20% in PBMCs from healthy donors or cancer patients, respectively, expressed gamma delta-type T-cell receptor. Gamma delta T cells showed high cytotoxic activity against CD166-positive TE12 and TE13 cancer cells but not against CD166-negative MKN45 cells. The cytotoxic activity against TE13 cells was augmented when target cells were pre-treated overnight with ZOL. These results suggest that ZOL in the presence of IL-2 can efficiently stimulate the proliferation of gamma delta T cells, which have cytotoxic properties against cancer cells. The use of zoledronate-activated killer (ZAK) cells should be encouraged in possible adoptive immunotherapy trials for patients with incurable cancer.

The CD4+CD25high regulatory T (Treg) cells have been demonstrated to negatively modulate anti-tumor immune responses in cancer patients. In this study, effects of low dose anti-CD25 antibody (Ab) to attenuate Treg cells were investigated in cancer patients in vitro and in vivo. Peripheral blood mononuclear cells (PBMCs) from cancer patients were cultivated in vitro in the presence of a high-affinity chimeric anti-CD25 Ab (basiliximab). The CD4+CD25high population, interferon-gamma (IFN-gamma) production and FOXP3 expression were analyzed using flow cytometry (FCM), enzyme-linked immunosorbent assay and reverse transcriptase-polymerase chain reaction (RT-PCR) analysis, respectively. During in vivo studies, basiliximab was administered intravenously on day 1, followed by AIT using autologous activated lymphocytes on day 8, and the treatment cycle was repeated. Subjective and objective effects were observed, and patients' PBMCs were subjected to FCM and RT-PCR analysis. In vitro analysis revealed that a low concentration of 0.01 microg/ml basiliximab reduced almost all of CD4+CD25high cells, but less of the CD4+ CD25low cells, and augmented IFN-gamma production of activated PBMCs. FOXP3 mRNA expression of PBMCs was not affected with or without basiliximab. An in vivo study of 9 metastatic cancer patients (7 colorectal and 2 esophageal) demonstrated no subjective or objective adverse effects, even under repeated administration of basiliximab. The results suggested that low-dose basiliximab can safely be administered repeatedly, and can target CD4+CD25high Treg cells whilst relatively preserving CD4+CD25low activated T cells. The host conditioning with low-dose basiliximab may augment the efficacy of AIT for cancer using activated autologous lymphocytes.