Evaluation of effects on the peritoneum after intraperitoneal α-radioimmunotherapy with (211)At.

The introduction of the short-lived α-emitter (211)At to intraperitoneal radioimmunotherapy has raised the issue of the tolerance dose of the peritoneum. The short range of the α-particles (70 µm) and the short half-life (7.21 h) of the nuclide yield a dose distribution in which the peritoneum is highly irradiated compared with other normal tissues. To address this issue, mice were injected with (211)At-trastuzumab to irradiate the peritoneum to absorbed doses ranging between 0 and 50 Gy and followed for up to 34 weeks. The peritoneum-to-plasma clearance of a small tracer, (51)Cr-ethylenediamine tetraacetic acid, was measured for evaluation of the small solute transport capacity of the peritoneal membrane. The macroscopic status of the peritoneum and the mesenteric windows was documented when the mice were sacrificed. Biopsies of the peritoneum were taken for morphology and immunohistochemical staining against plasminogen activator inhibitor-1 and calprotectin. Peritoneum-to-plasma clearance measurements indicated a dose-dependent decrease in peritoneal transport capacity in irradiated mice. However, macroscopic and microscopic evaluations of the peritoneal membrane showed no difference between irradiated mice versus controls. The results imply that the peritoneal membrane tolerates absorbed doses as high as 30-50 Gy from α-particle irradiation with limited response.

Bowel obstruction after laparoscopic and open colon resection for cancer: results of 5 years of follow-up in a randomized trial.

BACKGROUND: Postoperative bowel obstruction caused by intra-abdominal adhesions occurs after all types of abdominal surgery. It has been suggested that the laparoscopic technique should reduce the risk for adhesion formation and thus for postoperative bowel obstruction. This study was designed to compare the incidence of bowel obstruction in a randomized trial where laparoscopic and open resection for colon cancer was compared. METHODS: A retrospective analysis was performed, collecting data of episodes of bowel obstruction with or without surgery. Only episodes treated in the hospital where the index surgery took place were included. Data for 786 patients were collected for the 5-year period after cancer surgery. RESULTS: Baseline characteristics for the evaluated laparoscopic (n = 383) and open (n = 403) groups were comparable. The cumulative obstruction percentages at 5 years for the open and laparoscopic groups were 6.5 and 5.1% respectively and did not significantly differ from each other. Tumor stage seemed to influence the risk for bowel obstruction: 2.8% in stage I, 6.6% in stage II, and 7% in stage III, but the differences were not significant. CONCLUSIONS: This analysis does not support the hypothesis that laparoscopy leads to fewer episodes of bowel obstruction compared with open surgery.

Tissue proteolysis in appendicitis with perforation.

BACKGROUND: Matrix metalloproteinases (MMPs) and serine proteases are able to degrade the extracellular matrix (ECM) and modulate immune responses in the gastrointestinal tract. The purpose of this study was to investigate local proteolysis in perforated appendicitis and its association with the appendix perforation. MATERIALS AND METHODS: Biopsies were taken at the sites of perforation (n = 15) and with a gradually increased distance from it. The expression and distribution of MMP-1, -2, and -9, the tissue inhibitor of metalloproteinases type (TIMP-1), plasminogen activator inhibitor type1 (PAI-1), and urokinase plasminogen activator (uPA) were measured by ELISA. The distribution of MMP-9, TIMP-1, uPA, and PAI-1 in perforated, nonperforated, and uninflamed appendix was investigated by immunohistochemistry with monoclonal antibody technique. RESULTS: MMP-1 expression was highest close to the perforation and was gradually decreased in biopsies in more distal locations (P < 0.01). MMP-9 showed a similar pattern being highest at the sites of perforation (P < 0.05), while MMP-2 expression showed a trend in the opposite direction without statistically significance. The expression of TIMP-1 trended lower at the sites of perforation. PAI-1 was highest at the sites of perforation (P < 0.01) and the uPA expression was similarly elevated close to and at the perforation. CONCLUSIONS: These data indicate a key role of MMP in the pathogenesis of appendix perforation. A local imbalance between MMP-9 and the inhibitor TIMP-1 could potentially contribute to the tissue injury leading to an appendix perforation. The overexpression of PAI-1 at the sites of perforation may also contribute to tissue damage.

Decreased peritoneal expression of active transforming growth factor ß1 during laparoscopic cholecystectomy with heated carbon dioxide.

BACKGROUND: Laparoscopic surgery involves the establishment of a pneumoperitoneum, mostly using carbon dioxide. Cooling of the peritoneum, due to insufflation, may traumatize the peritoneum and disturb local biological processes. The current study was performed to assess the effect of the temperature of carbon dioxide on peritoneal transforming growth factor ß1 (TGF-ß1) expression. DESIGN: Patients were randomized into 2 groups. In one group, a pneumoperitoneum was created with carbon dioxide at room temperature; in the other, with carbon dioxide at body temperature. Peritoneal biopsy specimens were taken at the start and end of surgery. SETTING: Community hospital. PATIENTS: Thirty patients scheduled for laparoscopic cholecystectomy. MAIN OUTCOME MEASURES: Tissue concentrations of total and active TGF-ß1 were measured using enzyme-linked immunosorbent assays. RESULTS: At the start of surgery, there were no significant differences between groups in the total and active fractions of TGF-ß1. At the end of the procedure, the peritoneal active TGF-ß1 concentrations were significantly lower (P = .03) in patients receiving carbon dioxide at body temperature. In contrast, the concentrations of total TGF-ß1 did not differ between groups. A slight, nonsignificant increase in total and active TGF-ß1 levels was observed in patients receiving unheated carbon dioxide. The ratio of active to total TGF-ß1 did not change during procedures, and there were no differences between groups. CONCLUSIONS: Heating of carbon dioxide, used for insufflation, to body temperature decreases the expression of active TGF-ß1 in the peritoneum. Considering the broad biological effects of TGF-ß1, including the regulation of peritoneal healing and oncological processes, this observation might have clinical repercussions.

Peritoneal transforming growth factor beta-1 expression during prolonged laparoscopic procedures.

BACKGROUND: Laparoscopic surgery may affect peritoneal physiology. Short-term laparoscopic surgery does not affect peritoneal transforming growth factor beta (TGF-b1) expression. The current study was conducted to evaluate the hypothesis that prolonged laparoscopic surgery may affect peritoneal TGF-b1 expression. STUDY DESIGN: In the first study, 24 patients scheduled for a right colonic resection were enrolled in the trial. Twelve underwent conventional surgery (CCR) and 12 were operated on laparoscopically (LCR). In the second study, 12 patients undergoing laparoscopic gastric bypass (LGB) surgery for morbid obesity were included. Biopsies of the parietal peritoneum were taken at standardized moments during the procedures. Tissue concentrations of active and total TGF-b1 were measured by using enzyme-linked immunosorbent assays. RESULTS: During the LCR, there was a significant increase in peritoneal active TGF-b1 levels (P < 0.05). A similar, but not significant, trend was observed during the CCR. A similar pattern was seen in the total TGF-b1 concentrations during both procedures. The LGB procedure did not affect peritoneal active or total TGF-b1 concentrations. During the procedure, both the active and total TGF-b1 levels were significantly higher in the LCR, when compared to the LGB, group (P < 0.05). CONCLUSIONS: Prolonged laparoscopic surgery may affect peritoneal TGF-b1 expression, depending on the procedure performed. Considering the role of TGF-b1 in various biologic processes, including adhesiogenesis and oncology, these results may have clinical consequences.

A novel polypeptide derived from human lactoferrin in sodium hyaluronate prevents postsurgical adhesion formation in the rat.

OBJECTIVE: The objective of the study was to evaluate whether a peptide derived from human lactoferrin, PXL01 could act safely to reduce the formation of peritoneal adhesions in the rat model and to map the molecular mechanisms of its action. SUMMARY BACKGROUND DATA: Adhesion formation is a significant problem within every surgical discipline causing suffering for the patients and major cost for the society. For many decades, attempts have been made to reduce postsurgical adhesions by reducing surgical trauma. It is now believed that major improvements in adhesion prevention will only be reached by developing dedicated antiscarring products, which are administrated in connection to the surgical intervention. METHODS: Anti-inflammatory as well as fibrinolytic activities of PXL01 were studied in relevant human cell lines. Using the sidewall defect-cecum abrasion model in the rat, the adhesion prevention properties of PXL01 formulated in sodium hyaluronate were evaluated. Large bowel anastomosis healing model in the rat was applied to study if PXL01 would have any negative effects on intestine healing. RESULTS: PXL01 exhibits an inhibitory effect on the most important hallmarks of scar formation by reducing infections, prohibiting inflammation, and promoting fibrinolysis. PXL01 formulated in sodium hyaluronate markedly reduced formation of peritoneal adhesions in rat without any adverse effects on wound healing. CONCLUSIONS: A new class of synthetically derived water soluble low molecular weight peptide compound, PXL01 showed marked reduction of peritoneal adhesion formation in an animal model without any negative effects on healing. On the basis of these data, a comprehensive adhesion prevention regimen in clinical situation is expected.

Preoperative radiotherapy and extracellular matrix remodeling in rectal mucosa and tumour matrix metalloproteinases and plasminogen components.

BACKGROUND. Preoperative radiotherapy reduces recurrence but increases postoperative morbidity. The aim of this study was to explore the effect of radiotherapy in rectal mucosa and rectal tumour extracellular matrix (ECM) by studying enzymes and growth factors involved in ECM remodeling. MATERIALS AND METHODS. Twenty patients with short-term preoperative radiotherapy and 12 control patients without radiotherapy were studied. Biopsies from rectal mucosa and tumour were collected prior to radiotherapy and at surgery. Tissue MMP-1, -2, -9, TIMP-1, uPA, PAI-1, TGF-beta1 and calprotectin were determined by ELISA. Biopsies from irradiated and non-irradiated peritoneal areas were also analysed. RESULTS. Radiotherapy increased the tissue levels of MMP-2 and PAI-1 in both the rectal mucosa and tumours while calprotectin and uPA showed an increase only in the mucosa after irradiation. The increase of calprotectin was due to an influx of inflammatory cells as revealed by immunohistochemistry. Prior to irradiation, the tumour tissues had increased levels of MMP-1, -2, -9, total TGF-beta1, uPA, PAI-1 and calprotectin compared to mucosa, while TIMP-1 and the active TGF-beta1 fraction showed no statistical difference. CONCLUSIONS. This study indicates a radiation-induced effect on selected ECM remodeling proteases. This reaction may be responsible for early and late morbidity. Interference of this response might reduce these consequences.

Differential prognostic impact of uPA and PAI-1 in colon and rectal cancer.

BACKGROUND AND OBJECTIVES: Degradation of extracellular matrix is important for tumour growth and invasion, which in part is regulated by the plasminogen activation system. The aim of the study was to evaluate the protein expression of urokinase plasminogen activator (uPA) and plasminogen-activating inhibitor-1 (PAI-1) in plasma, tumour-free mucosa and tumour tissue regarding their prognostic value in colon and rectal cancer. METHODS: Patients (n = 221) undergoing surgery for colorectal cancer were prospectively included. Samples were assayed by ELISA technique. RESULTS: PAI-1 in tumour tissue (p = 0.006), plasma (<0.0001) and uPA in tumour-free mucosa (p = 0.006) were associated with survival in rectal cancer in univariate analysis. An uPA expression level below 1.1 ng/mg (log rank test, p < 0.0001) in tumour-free mucosa was associated with poor survival in rectal cancer. This was true also for patients without disseminated disease (M(0), p = 0.02). PAI-1 in plasma correlated with metastatic disease (p < 0.0001). uPA and PAI-1 were not associated with survival in either tumour tissue, mucosa or plasma in patients with colon cancer. CONCLUSIONS: uPA and PAI-1 have a differential prognostic impact in colon and rectal cancer. Preoperative mucosal uPA and plasma PAI-1 protein expression could possibly be used as prognostic factors in rectal cancer.

Progress of tissue injury in appendicitis involves the serine proteases uPA and PAI-1.

OBJECTIVE: Serine proteases and the matrix metalloproteinases (MMPs) are key factors in the proteolytic cascade and participate in extracellular matrix (ECM) degradation. Fibrinolytic activators and inhibitors may have an effect on inflammatory cells, thereby modulating the inflammatory response. It is reasonable to assume that they may be implicated in the tissue injury in acute appendicitis that subsequently leads to appendix perforation. The purpose of this study was to investigate the expression and distribution of urokinase-type plasminogen activator (uPA) and plasminogen-activator inhibitor type 1 (PAI-1) in appendicitis. MATERIAL AND METHODS: Expression of uPA and expression of PAI-1 were measured in tissue specimens from patients with appendicitis (n=30) and in control specimens (n=9), using the quantitative ELISA technique. Distribution of enzymes was studied with immunohistochemistry. The uPA and PAI-1 levels in the subgroups of appendicitis and controls were compared. RESULTS: The overall expressions of uPA and PAI-1 were greater in appendicitis than in control specimens (p <0.001 and p<0.0001, respectively). Expressions of uPA and PAI-1 in phlegmonous (n=15), gangrenous (n=6) and perforated appendicitis (n=9) were all higher than those in controls (n=9), (p<0.01). Moreover, the PAI-1 level was elevated in perforated appendicitis compared with phlegmonous appendicitis (p<0.01). uPA staining was observed in connection with vascular endothelial cells and the serosa stained intensely in specimens from perforated appendicitis. CONCLUSIONS: The expression of uPA and especially the over-expression of PAI-1 seem to correlate to the progression of local inflammatory response in acute appendicitis.

Studies of TGF-beta(1-3) in serosal fluid during abdominal surgery and their effect on in vitro human mesothelial cell proliferation.

BACKGROUND: Increased transforming growth factor-beta (TGF-beta) levels are associated with fibrosis, affected cell proliferation, and postsurgical adhesion development, but the knowledge regarding TGF-beta response to the surgical trauma is limited. This study investigated TGF-beta(1-3) isoforms and fibrinolytical factors in peritoneal serosal fluid during abdominal surgery, together with the in vitro effect of TGF-beta(1-3) on human mesothelial cell proliferation. MATERIALS AND METHODS: Total as well as biologically active TGF-beta(1-3) and fibrinolytic factors: t-PA, uPA, and PAI-1 were measured in serosal fluid and plasma from 23 patients undergoing colorectal cancer surgery. In vitro proliferation of human primary mesothelial cell cultures upon TGF-beta(1-3) stimulation was also investigated. RESULTS: Total TGF-beta1 and TGF-beta2 levels were similar in serosal fluid and plasma while active fractions were increased in serosal fluid. In contrast, total fraction of TGF-beta3 was higher in serosal fluid compared with plasma, while levels of active fractions did not differ. Plasminogen activators (t-PA, uPA) were elevated while the inhibitor (PAI-1) was decreased in serosal fluid compared with plasma. The in vitro mesothelial cell proliferation studies revealed that high TGF-beta(1-3) concentrations decreased cell proliferation, while lower concentrations of TGF-beta1 increased mesothelial cell proliferation. CONCLUSIONS: This human study shows increased active TGF-beta levels in peritoneal serosal fluid, compared with plasma, during abdominal surgery and that TGF-beta1 at physiological concentrations increased human mesothelial cell proliferation in vitro. TGF-beta cytokines may be involved in postsurgical adhesion formation.

uPA and PAI-1 in rectal cancer--relationship to radiotherapy and clinical outcome.

BACKGROUND: It is well known that the fibrinolytic system is of importance in inflammation, wound healing, and fibrosis development. However, it is also important in the process of tumor invasion and metastasis. We have investigated protein levels of urokinase plasminogen activator (uPA) and plasminogen activator inhibitor-1 (PAI-1) in rectal cancer and effects of radiotherapy, links to clinical outcome, and potential use as prognostic factors. MATERIALS AND METHODS: Ninety-one patients with rectal cancer were studied. Blood samples and biopsies were taken during surgery and assayed with enzyme-linked immunosorbent assay for uPA and PAI-1, and patients were followed prospectively (0-96 mo). RESULTS: Higher levels of uPA (P < 0.0001) and PAI-1 (P < 0.0001) were found in tumor compared with mucosa. Mucosa exposed to radiotherapy had higher levels of uPA (P < 0.0001) and of PAI-1 (P < 0.0001). Irradiated tumor tissue had higher levels of PAI-1 (P < 0.001). PAI-1 in tumor was correlated with T stage (P < 0.001) and N stage (P < 0.01). PAI-1 in plasma was higher in patients with synchronous distant metastases (P < 0.001). Cox regression was used to identify high levels of PAI-1 in tumor as an independent factor related to short disease-free survival (P < 0.01) and the ratio of uPA/PAI-1 to development of metastases (P < 0.01). CONCLUSIONS: There is a relationship between PAI-1 in plasma and rectal cancer metastases. PAI-1 in tumor tissue is correlated to histopathological data and to outcome of rectal cancer. If these findings can be confirmed in larger trials, there will be a possibility to use PAI-1 as a prognostic factor.

A local imbalance between MMP and TIMP may have an implication on the severity and course of appendicitis.

BACKGROUND: Matrix metalloproteinases (MMPs) and the tissue inhibitors of MMPs (TIMPs) have been demonstrated to be involved in inflammatory conditions in the intestine. The purpose of this study was to investigate whether the alterations of the MMP/TIMP balance might reflect the course of the inflammatory process in acute appendicitis and if the expression and localisation of MMPs and TIMP is variable in the various clinical manifestations of appendicitis. MATERIALS AND METHODS: The study comprises 40 patients (26 men and 14 women) having emergency appendectomy and a control group constituting of 10 patients (5 men and 5 women) having a hemicolectomy for other reasons. MMP and TIMP expressions were assessed and compared in tissue specimens from phlegmonous (n = 15), gangrenous (n = 7), perforated appendicitis (n = 11) and controls with noninflamed appendices (n = 10) by means of enzyme-linked immunosorbent assay technique. Localisation of the enzymes was performed by immunohistochemistry. RESULTS: MMP-1 was significantly higher in gangrenous and perforated appendicitis compared with phlegmonous appendicitis and controls (p < 0.05) while MMP-2 was significantly lower in gangrenous appendicitis compared with phlegmonous appendicitis and controls. MMP-2 was also lower in perforated appendicitis when compared with controls (p < 0.01). Elevated expression of MMP-9 was demonstrated in all groups of appendicitis compared with the controls (p < 0.001). CONCLUSIONS: MMP-9 is the most abundantly expressed MMP of those investigated in inflamed appendix. We postulate that a local imbalance between MMP-9 and TIMP-1 may trigger a perforation. These results suggest that MMPs might be useful as biomarkers of appendices prone to perforation.

Increased TGF-beta 1 protein expression in patients with advanced colorectal cancer.

INTRODUCTION: There is evidence that TGF-beta 1 plays a role as a tumor suppressor in early disease and has pro-oncogenic effects in advanced tumor stage. The aim of the study was to correlate TGF-beta 1 in plasma and tissue to clinical and pathological parameters in patients with various stages of disease progression. METHODS: One hundred sixty-nine patients who underwent surgery for a colorectal carcinoma were prospectively included. Blood samples, tumor free mucosa and tumor biopsies were assayed. RESULTS: TGF-beta 1 protein expression in tumors increased with increasing T-stage regardless of whether patients with metastatic disease were included or not (P = 0.0006). Patients with metastatic disease showed elevated TGF-beta 1 protein expression in both tumor tissue (P = 0.004) and plasma (P = 0.001) compared to those without metastatic disease. TGF-beta 1 protein expression was higher in the colon compared with the rectum in both tumor tissue and tumor-free bowel (P = 0.03), regardless of whether patients with metastatic disease were included or not. This difference was mainly attributable to a higher TGF-beta 1 protein expression in non-metastatic patients with lymph node positivity (P = 0.005). CONCLUSIONS: Higher TGF-beta 1 protein expression is associated with increasing T-stage and metastatic disease, indicating that TGF-beta 1 is of importance in tumor progression. The localization of the tumor seems to influence the TGF-beta 1 protein expression in patients with tumor cell-positive lymph nodes.

Transforming growth factor beta-1 in rectal tumour, mucosa and plasma in relation to radiotherapy and clinical outcome in rectal cancer patients.

BACKGROUND: Rectal cancer patients are treated with surgery and sometimes radiotherapy. Transforming growth factor-beta1 (TGF-beta1) acts both as an inhibitor of tumour growth and as a promoter of tumour progression. The aim of this study was to determine the levels of TGF-beta1 in tumour tissue, adjacent mucosa and plasma in rectal cancer patients and relate these to the effect of radiotherapy and clinical outcome. MATERIALS AND METHODS: One hundred and ten patients scheduled for rectal cancer surgery were included, 49% received pre-operative radiotherapy three-field treatment 5 x 5 Gy. Blood samples and biopsies were taken during surgery and later assayed with enzyme-linked immunosorbent assay for total TGF-beta1 and active TGF-beta1. Patients were then followed for 3 years. RESULTS: Total and active TGF-beta1 was higher in tumour tissue compared with rectal mucosa (p < 0.0001). Active TGF-beta1 in tumour tissue and rectal mucosa was lower in the irradiated group (p = 0.007; p < 0.0001). Total TGF-beta1 was higher in patients with metastases at primary diagnosis (p = 0.005) compared to patients without. In patients who later developed metastases, the levels of active TGF-beta1 in plasma were lower (p = 0.004). Local recurrence was associated with lower levels of total TGF-beta1 in the rectal mucosa (p = 0.038). CONCLUSIONS: Higher levels of total TGF-beta1 in tumour tissue at surgery may be indicative of distant metastases, and low levels of active TGF-beta1 in plasma may indicate a risk of developing secondary metastases. Lower levels of total TGF-beta1 in rectal mucosa may influence risk of local recurrence. Measurement of TGF-beta1 in rectal cancer patients may be of clinical use in the future.

Increased concentration of tissue-degrading matrix metalloproteinases and their inhibitor in complicated diverticular disease.

OBJECTIVE: Complicated diverticular disease is associated with extensive structural changes of the colonic wall. Turnover of extracellular matrix (ECM) plays a pivotal role in this process. Proteolytic enzymes, including matrix metalloproteinases (MMPs), are capable of degrading most components of ECM. Their activity is regulated by inhibitors, tissue inhibitors of metalloproteinases (TIMPs). Disturbances of the MMP-TIMP balance can cause tissue degradation or fibrosis. The aim of this study was to assess the concentration and distribution of MMPs and TIMPs in colonic biopsies. MATERIAL AND METHODS: Twenty-seven patients who had undergone sigmoid colectomy were included in the study. Full-thickness biopsies from affected and non-affected parts of each resected specimen were collected. Expressions of the proteins MMP-1, -2, -3, -9, TIMP-1 and TIMP-2 were quantified by ELISA and localized by immunohistochemistry. RESULTS: The concentrations of MMP-1, MMP-2 and TIMP-1 were significantly higher in affected tissue than concentrations in non-affected tissue (MMP-1 p=0.005, MMP-2 p=0.0003 and TIMP-1 p<0.0001). In affected segments in general, there was an increased expression in the entire bowel wall, predominantly for MMP-2, MMP-3 and TIMP-1. CONCLUSIONS: Concentrations of MMP-1, MMP-2 and TIMP-1 were increased in intestinal segments affected by complicated diverticular disease and distributed throughout the entire bowel wall, which may explain the structural changes.

Matrix metalloproteinases in rectal mucosa, tumour and plasma: response after preoperative irradiation.

BACKGROUND: In rectal cancer treatment, preoperative radiotherapy has led to reduction of local recurrence, but it is associated with morbidity and increased risk for secondary tumours. Matrix metalloproteinases (MMPs) are associated with tumour progression through tissue remodeling. The aim of this study was to investigate tissue remodeling after preoperative radiotherapy and to explore possible correlations with clinical outcome. MATERIALS AND METHODS: Ninety-one patients scheduled for rectal cancer surgery were included; 49% received preoperative radiotherapy three-field treatment, 5 x 5 Gy. Blood samples and biopsies from tumour and adjacent mucosa were taken during surgery. Biopsies and plasma were assayed with ELISA for MMP-1, MMP-2 and MMP-9. Clinical outcome was reviewed focusing on infections, perineal healing, fistula formation, anastomotic dehiscence, small bowel obstruction, local recurrence and distant metastases. RESULTS: Compared to non-irradiated mucosa, MMP-2 (p < 0.0001), MMP-1 (p = 0.03) and MMP-9 (p = 0.04) were significantly higher in irradiated normal mucosa. Tumour tissue had higher levels of MMP-2 if irradiated (p < 0.0001). A correlation between MMP-2 levels and wound infection (p = 0.02) as well as fistula formation (p = 0.04) was found. MMP-1 in mucosa (p = 0.02) and tumour (p = 0.04) were higher in patients developing distant metastases. Plasma levels were not influenced by irradiation, but MMP-2 was higher in patients who were later developing distant metastases (p = 0.007). CONCLUSIONS: Extracellular matrix remodeling after radiotherapy seems to be correlated to postoperative morbidity; MMP-2 is associated with both wound infections and fistula formation. High levels of MMP-1 in tumour and mucosa as well as MMP-2 in plasma may be correlated to risk of developing distant metastases.

Increased plasma MMP-2 protein expression in lymph node-positive patients with colorectal cancer.

BACKGROUND: Degradation of the extracellular matrix plays an important part during the invasion of cancer cells into the surrounding tissue. The matrix metalloproteinases (MMPs) have a central role in this process as demonstrated in different malignancies. The aim of this study was to investigate the presence of several MMPs from tumour, adjacent tumour-free colon segment and from plasma, in order to evaluate how these factors might be used as predictors in colorectal malignancy. METHODS: Seventy-two patients who underwent surgery because of a colorectal carcinoma were included. Biopsies from the tumour, macroscopically tumour-free bowel and plasma samples were analysed with enzyme-linked immunosorbent assay tests (ELISAs) quantifying protein expression of several MMPs. RESULTS: We found highly elevated concentrations of MMP-1, MMP-2, MMP-3 and MMP-9 protein expression in tumour tissue compared with tumour-free tissue (p<0.0001). Elevated MMP-1 tumour levels were found in patients with Dukes' C cancers (p=0.02). Lymph node status correlated with the expression of MMP-2 in plasma, which was significantly increased in patients with lymph node metastasis compared with those without (p=0.002). MMP-2 in plasma was higher in T3 and T2 tumours than in T4 tumours (p=0.0083). CONCLUSION: The MMPs we investigated were strongly elevated in tumour tissue compared with tumour-free bowel wall. Our results indicate that MMP-2 in plasma may possibly be used as a predictor in colorectal malignancy. The use of MMP-2 as a predicting tool in combination with different imaging techniques may give important preoperative information in patients with colorectal cancer.

Plasminogen activator/plasminogen activator inhibitor-1 and cytokine modulation by the PROACT System.

OBJECTIVE: To examine the effects of the PROACT treatment on the fibrinolytic system and inflammatory cytokines in human peritoneum. DESIGN: Controlled clinical study. SETTING: University hospital. PATIENT(S): Nine subjects undergoing laparotomy had peritoneal samples taken at the incision. INTERVENTION(S): The PROACT applicator was inserted through the peritoneal incision, and treatment of peritoneum was performed twice. A peritoneal sample was taken from one treated area. At closure, the second treated sample and an additional control sample were taken. All four samples were snap frozen in liquid nitrogen. Samples were homogenized and protein content extracted. MAIN OUTCOME MEASURE(S): Concentrations of total and active transforming growth factor-beta 1 (TGF-beta1), tumor necrosis factor-alpha (TNF-alpha), tissue-type plasminogen activator (t-PA), urokinase plasminogen activator (uPA), and plasminogen activator inhibitor 1 (PAI-1) were obtained. RESULT(S): Total TGF-beta1 at opening was 30% less in treated samples. At closure, active TGF-beta1 increased significantly (163%) in control samples and not in treated samples. Tumor necrosis factor alpha was detectable only in control samples at closure. During surgery, tPA levels showed a marked decrease in control samples vs. a small increase in treated samples. Levels of uPA increased significantly only in the control samples. In control samples, tPA/PAI-1 ratio was two thirds of treated sample ratio. CONCLUSION(S): Heating of the peritoneum with the PROACT System modulates the biologic tissue response to induce effects that would be consistent with inhibition of postoperative adhesion development.

Examination gloves affect secretion of matrix metalloproteinases and their inhibitors from human abdominal skin fibroblasts.

Overexpression of matrix metalloproteinases (MMPs) has been observed in chronic, compared to acute, wounds and altered levels might impair healing. During treatment of wounds, examination gloves are routinely used, and the wound environment thus gets exposed to gloves. The aim of this study was to characterize secretion of MMPs and tissue inhibitors of metalloproteinases (TIMPs) in cultured fibroblasts with or without exposure to gloves. Cultures were exposed to glove washings from powdered or powder-free latex examination gloves and compared to untreated controls. MMP-1, -2, -3, -9 and their inhibitors TIMP-1 and -2 were assayed in conditioned media. Cells exposed to gloves reduced their release of MMP-1, -2, and -3 with no differences between the manufacturers of the gloves. The inhibitor TIMP-1 was reduced to 10-15% of untreated control values (p < 0.001), being less affected by the powder-free than by the powdered glove (p < 0.05). MMP-9 and TIMP-2 were not significantly altered. We therefore conclude that secretion of MMPs and TIMPs from cultured fibroblasts were affected by glove washings. Powdered and powder-free gloves had similar effects, except for a less pronounced reduction of TIMP-1 production by the powder-free glove. Examination gloves might therefore affect wound healing, with the least pronounced effect observed using the powder-free glove.