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H J Nielsen

Publications and source records attributed to H J Nielsen.

At least 19 recordsLinked to original sources
PubMed2006

Influence of major surgery on the mannan-binding lectin pathway of innate immunity.

The mannan-binding lectin (MBL) pathway of complement activation is important in host defence against pathogens and possibly against cancer. We investigated the effect of major surgery on two central components of the MBL pathway; MBL and the MBL-associated serine protease MASP-2, and for comparison also measured the interleukin (IL)-6 and C-reactive protein (CRP) levels. Serial blood samples were obtained from patients belonging to two different cohorts. Cohort 1 comprised 60 patients undergoing open or laparoscopic colectomy for benign disease (n = 12) or colon cancer (n = 48). Cohort 2 comprised 27 patients undergoing elective, open surgery for colorectal cancer, and was included in order to cover blood sampling between days 2 and 6. As expected, the surgical stress induced a marked acute phase response, as evidenced by a large increase in IL-6 (18-fold) and CRP (13-fold) levels with maximum at 12 h and 2 days, respectively. However, in both cohorts the levels of MBL and MBL-associated serine protease 2 (MASP-2) were largely unaffected, except for a minor but significant increase around day 8 in cohort 1. The preoperative levels of IL-6 and CRP were correlated significantly in both cohorts (r = 0.71, P < 0.0001 and r = 0.65, P = 0.005, respectively). Preoperative MASP-2 correlated with preoperative CRP (r = 0.59, P = 0.001) and IL-6 (r = 0.55, P = 0.02) in cohort 2 only. In contrast to the marked effects on the levels of IL-6 and CRP, the surgery influenced only marginally the two proteins of the MBL pathway.

Acute-Phase Proteins↗
PubMed2005

Influence of open versus laparoscopically assisted colectomy on soluble vascular endothelial growth factor (sVEGF) and its soluble receptor 1 (sVEGFR1).

INTRODUCTION: Minimal invasive colectomy may attenuate surgery-induced immunomodulation. This may in part be due to a reduced postoperative inflammation-mediated angiogenic stimulus directed by the proangiogenic factor VEGF and its neutralizing receptor VEGFR1. Thus, we evaluated perioperative plasma concentrations of soluble VEGF (sVEGF) and soluble VEGFR1 (sVEGFR1) in patients undergoing elective colectomy. METHODS: 60 consecutive patients were randomized to undergo laparoscopically assisted or open right or left sided colectomy. Blood samples were drawn preoperatively, intraoperatively and postoperatively until 30 days after the operation. Commercially available ELISA methods were used for determination of sVEGF and sVEGFR1. RESULTS: Patients with cancer (n = 48) had higher preoperative levels of sVEGF compared to patients with benign disease (n = 12) (p = 0.04), while there was no significant difference in sVEGFR1 levels (p = 0.053). Soluble VEGF (p < 0.0001) and sVEGFR1 (p < 0.0001) levels fluctuated intra- and postoperatively. However, the intra- and postoperative levels of sVEGF and sVEGFR1 were similar at all time points in patients undergoing laparoscopically assisted or open resection. CONCLUSION: Although significant fluctuation in sVEGF and sVEGFR1 concentrations during the perioperative period was shown, patients who underwent laparoscopically assisted resection had similar levels as patients who underwent open resection.

Aged↗
PubMed2005

Bacterial antigen induced release of soluble vascular endothelial growth factor (VEGF) and VEGFR1 before and after surgery.

OBJECTIVE: The influence of surgery on release of soluble vascular endothelial growth factor (sVEGF) and the soluble inhibitory receptor (sVEGFR1) is unknown. The effect of major and minor surgery on variations in sVEGF and sVEGFR1 concentrations in vivo was studied, and on bacterial antigen-induced release of sVEGF and sVEGFR1 from whole blood in vitro. MATERIAL AND METHODS: Sixty-one patients with abdominal diseases undergoing five different surgical procedures were included in the study. Blood samples were drawn from patients before and after the operation. White blood cells and platelets were counted, and plasma sVEGF and sVEGFR1 were determined. Whole blood from each blood sample was stimulated in vitro with bacteria-derived antigens (lipopolysaccharides or protein A) and sVEGF and sVEGFR1 levels were subsequently determined in the supernatants. RESULTS: Neither sVEGF nor sVEGFR1 concentrations in plasma changed during surgery. In vitro stimulation of blood samples with bacteria-derived antigens resulted in a significant increase in sVEGF (p < 0.0001) and a less pronounced but still significant increase in sVEGFR1 (p < 0.01). Bacterial antigen-induced release of sVEGF correlated significantly with neutrophil cell counts (0.53 < r < 0.78; p < 0.0001). Bacterial antigen-induced sVEGFR1 release did not correlate with cell counts. CONCLUSIONS: Plasma sVEGF and sVEGFR1 concentrations did not change during surgery. In vitro bacterial stimulation led to increased release of sVEGF, which was not compensated for by an equivalent increase in sVEGFR1. There was a positive impact of major abdominal surgery on release of sVEGF. The bacterial antigen-induced changes in sVEGF may be related to the number of circulating neutrophils.

Adult↗
PubMed2005

Quantification of tissue inhibitor of metalloproteinases 2 in plasma from healthy donors and cancer patients.

Tissue inhibitor of metalloproteinases (TIMP)-2 is a highly conserved molecule, which binds both active and latent matrix metalloproteinase (MMP)-2. TIMP-2 is also involved in the activation of MMP-2 on the cell surface. A quantitative enzyme-linked immunosorbent assay (ELISA) was established and optimized for measurement of TIMP-2 in plasma. The capturing antibody in the ELISA was a monoclonal, while the detecting antibody was a chicken polyclonal antibody recognizing the native form of human TIMP-2. The levels of TIMP-2 were measured in ethylenediaminetetraacetic acid (EDTA) and citrate plasma from healthy donors. The median values were determined as 163 ng/ml (n = 186) with a range of 109-253 ng/ml for EDTA plasma and 139 ng/ml (n = 77) with a range of 95-223 ng/ml for citrate plasma. The TIMP-2 concentration in citrate plasma from 15 patients with advanced, stage IV breast cancer had a median value of 160 ng/ml, only slightly higher but statistically distinguishable from the level found in citrate plasma from the healthy donors. In addition, the TIMP-2 concentration in EDTA plasma from colorectal cancer patients revealed a significantly higher level in plasma from patients with Dukes stage A (P = 0.01) compared with patients with more advanced Dukes stages.

Adult↗
PubMed2004

Association between preoperative plasma levels of tissue inhibitor of metalloproteinases 1 and rectal cancer patient survival. a validation study.

The level of the tissue inhibitor of metalloproteinases 1 (TIMP-1) has previously been demonstrated to predict the survival of early stage colorectal cancer patients. The present study was undertaken to further validate plasma TIMP-1 as a prognostic marker in rectal cancer. Preoperative plasma from 352 rectal cancer patients were analysed using an immunoassay for TIMP-1. The TIMP-1 immunoassay demonstrated robustness and good reproducibility with low interassay coefficients of variation (CV). The rectal cancer patients had a mean plasma TIMP-1 level of 184 microg/l (standard deviation (SD): 70 microg/l). There were no significant differences in TIMP-1 levels between patients with Dukes' stage A, B or C disease, whereas Dukes' stage D patients had significantly increased TIMP-1 levels (P<0.0001); however, high levels of TIMP-1 were not restricted to those with advanced disease. Univariate analysis demonstrated an increasing risk of mortality with increasing TIMP-1 levels Hazard Ratio (HR)=2.9; 95% Confidence Interval (CI): 1.7-5.0; P<0.0001). Including additional covariates, multivariate analysis identified plasma TIMP-1 as an independent prognostic marker (HR=2.2; 95% CI: 1.2-4.1 (P=0.01). This study showed a highly significant and independent association between preoperative plasma TIMP-1 levels and survival in rectal cancer patients, thus confirming our previous findings. Furthermore, the TIMP-1 immunoassay proved to be stable and reproducible in this confirmatory study.

Adult↗
PubMed2004

Increased activity of the mannan-binding lectin complement activation pathway in patients with colorectal cancer.

BACKGROUND: Postoperative bacterial infectious complications are frequent in patients with colorectal cancer (CRC), with subsequent increased recurrence rates and poor prognosis. Deficiency of the mannan-binding lectin (MBL) complement activation pathway may cause increased risk of infection in certain patient groups. It is hypothesized that a deficient MBL pathway might be more frequent among patients with CRC than in healthy individuals. The MBL pathway was therefore evaluated in serum obtained preoperatively from 193 patients with primary CRC and in serum from 150 healthy volunteers. METHODS: Serum MBL concentrations and MBL/MASP activity were determined using immunofluorometric assays. The levels are presented as the median, inter-quartile range and range. RESULTS: Serum MBL levels were significantly (P < 0.0002) increased in patients with colorectal cancer (1384 (400-2188) ng/mL) (median, inter-quartile range) compared with levels in healthy blood donors (924 (230-1476) ng/mL). Similarly, the MBL/MASP activity was significantly (P < 0.0002) increased in patients (584 (202-914) mU/mL) compared with in blood donors (319 (0-684) mU/mL). This was independent of age, gender, tumour location in the colon or rectum, and disease stages according to Dukes' classification. No statistical difference (P=0.20) in frequency of MBL deficiency was found between the patients (20%) and the donors (27%). CONCLUSIONS: Overall, the MBL complement activation pathway is significantly increased in patients with colorectal cancer compared with healthy persons. However, similar frequencies of MBL pathway deficiency are observed in patients and healthy persons.

Adult↗
PubMed2004

Soluble urokinase plasminogen activator receptor in blood transfusion components.

Post-transfusion infectious complications associated with allogeneic blood components may depend on storage time and may be related to extracellular accumulation of bioactive substances during storage. The glycoprotein, soluble urokinase plasminogen activator receptor (suPAR), which is located in specific granules of neutrophils, plays a role in inflammation and remodelling of the extracellular matrix. Using enzyme-linked immunosorbent assay, suPAR was determined in serum, plasma and blood cell lysates. In addition, suPAR was measured in whole blood (WB), buffy-coat-depleted saline-adenine-glucose-mannitol (SAGM) blood, platelet-rich plasma (PRP) and buffy-coat-derived platelet (BCP) pools with and without pre-storage leucofiltration, and in non-filtered WB, SAGM blood and platelet concentrates prepared using apheresis (APC) at different time points during storage. Mean suPAR concentration was significantly higher in cell lysates, compared to that in a corresponding serum (P = 0.007) and in plasma samples (P = 0.004). Mean suPAR levels in WB, BCP and SAGM were significantly reduced using leucofiltration (WB: 3.4 versus 2.0 ng mL(-1); BCP: 1.6 versus 1.1 ng mL(-1); SAGM: 2.8 versus 0.19 ng mL(-1)), whereas no difference was observed in PRP. In non-filtered WB, SAGM and APC, extracellular suPAR accumulated significantly in a storage-time-dependent manner (WB: P < 0.01; SAGM: P < 0.001; APC: P < 0.001). The present study demonstrates that cell lysates contain significantly more suPAR, compared to both serum and plasma. This can be explained by the release of suPAR from intracellular granules during cell lysis. The amount of suPAR is significantly increased during storage of blood transfusion components, an accumulation that is reduced using pre-storage leucofiltration.

Blood Component Transfusion↗
PubMed2004

Blood loss and transfusion after total mesorectal excision and conventional rectal cancer surgery.

OBJECTIVES: A recent study showed less bleeding and need of transfusion after total mesorectal excision (TME) compared with conventional rectal cancer surgery. The aim of this study was to evaluate this result in more details. PATIENTS AND METHODS: Comparison of transfusion history in rectal cancer resections in two different multicentre-studies. Two hundred and forty-six patients were operated in the period 1991-93 with a conventional technique and 311 patients were operated with TME-technique in the period 1996-98. Peri-operative data, including blood transfusion from one month before until one month after the operation, was recorded prospectively. RESULTS: The median intra-operative blood loss was 1000 ml, range 50-6000 ml, before, and 550 ml, range 10-6000 ml (P < 0.001) after introduction of TME. The overall peri-operative transfusion rate was reduced from 73% to 43% (P < 0.001). When adjusted for blood loss, age, gender, weight, and type of resection, TME significantly reduced the risk of receiving intra or postoperative blood transfusion by 0.4 (CI: 0.3-0.6). The variability in blood loss among 12 TME-centres was more than 400% and not correlated with transfusion requirements within the centres. CONCLUSION: TME results in a reduced blood loss and a reduction of blood transfusion, but additional factors others than blood loss seems to influence the decision of transfusion.

Aged↗
PubMed2003

Recurrence and survival after mesorectal excision for rectal cancer.

BACKGROUND: Mesorectal excision for rectal cancer has resulted in local recurrence rates of 3-11 per cent compared with up to 38 per cent after conventional methods. The results of a prospective Danish study with a historical control group are presented. METHODS: Three hundred and eleven patients with a mobile rectal cancer had mesorectal excision with curative intent performed by certified surgeons and were followed for 3 years. Demographic, perioperative and follow-up data were recorded prospectively. A series of patients who had conventional operations for rectal cancer served as a control group. RESULTS: The cumulative 3-year local recurrence rate was 11 per cent after mesorectal excision compared with 30 per cent after conventional surgery (hazard ratio (HR) 0.33 (95 per cent confidence interval (c.i.) 0.21 to 0.52); P < 0.001). Multivariate regression analysis showed that only advanced age (HR 0.97 (95 per cent c.i. 0.94 to 1.00); P = 0.048) and tumour in the lower third of the rectum (HR 0.21 (95 per cent c.i. 0.04 to 1.97); P = 0.075) were marginal independent predictors of local recurrence after mesorectal excision. The cumulative crude 3-year survival rate was 77 per cent after mesorectal excision and 62 per cent after conventional surgery (HR 0.58 (95 per cent c.i. 0.43 to 0.77); P < 0.001). Age was the only independent predictor of death after mesorectal excision (HR 1.04 (95 per cent c.i. 1.02 to 1.07); P = 0.001). CONCLUSION: Mesorectal excision is associated with a considerably lower risk of local recurrence and a better survival rate than conventional surgery, and is the optimum method for rectal cancer resection.

Adenocarcinoma↗
PubMed2003

The role of tissue factor in colorectal cancer.

The possible role of tissue factor (TF) in colorectal cancer (CRC) is reviewed. A correlation between TF expression and advanced stages of malignancy, and a correlation between TF expression and overall survival have been suggested in CRC. This is supported by experimental studies indicating that TF plays a key role in growth, invasion and dissemination of tumour cells, and in tumour related angiogenesis as well. In addition, the activation of TF in CRC patients in relation to the surgical trauma, perioperative blood transfusion and development of postoperative bacterial infectious complications are discussed. Finally, future directions for the development of anticancer modalities directed against regulation of TF are considered.

Animals↗
PubMed2002

Prognostic impact of matched preoperative plasma and serum VEGF in patients with primary colorectal carcinoma.

In serum, the major part of vascular endothelial growth factor derives from in vitro degranulation of granulocytes and platelets. Therefore, plasma may be preferred for vascular endothelial growth factor measurements. However, which specimen is the best predictor of survival is still debated. The present study analyzed the prognostic value of matched preoperative serum and plasma vascular endothelial growth factor concentrations in patients with colorectal cancer. To establish the reference range among healthy people, vascular endothelial growth factor was analyzed in 50 matched EDTA-plasma and serum samples from healthy blood donors. Preoperatively, in 524 patients with colorectal cancer, matched plasma and serum vascular endothelial growth factor concentrations were analyzed. In the colorectal cancer patients, the median plasma vascular endothelial growth factor concentration (44 pg ml(-1)) was significantly (P=0.01) higher than the median plasma vascular endothelial growth factor concentration (30 pg ml(-1)) in the healthy blood donors. In serum, no significant (P=0.30) difference in the median vascular endothelial growth factor concentration was found between colorectal cancer patients (268 pg ml(-1)) and healthy blood donors (220 pg ml(-1)). The preoperative vascular endothelial growth factor concentrations were dichotomized by the 95th percentile of the healthy blood donors (plasma=112 pg ml(-1), serum=533 pg ml(-1)). In univariate survival analyses, both high plasma vascular endothelial growth factor (>112 pg ml(-1)) and high serum vascular endothelial growth factor (>533 pg ml(-1)) predicted a reduced survival. In multivariate survival analyses, high serum vascular endothelial growth factor (>533 pg ml(-1)) independently predicted a reduced survival (HR=1.65, P=0.015), while high plasma vascular endothelial growth factor (>112 pg ml(-1)) did not (HR=1.27, P=0.23). This study indicates that preoperative serum vascular endothelial growth factor apparently is a better predictor of overall survival than the preoperative plasma vascular endothelial growth factor.

Adult↗
PubMed2002

Elevated plasma levels of vascular endothelial growth factor and plasminogen activator inhibitor-1 decrease during improvement of psoriasis.

OBJECTIVE AND DESIGN: An evaluation of angiogenesis related molecules during open treatment of psoriasis. MATERIALS AND SUBJECTS: Plasma samples and skin biopsies from 16 patients with psoriasis and plasma samples from 13 healthy controls. TREATMENT: Ranitidine 300 mg orally twice daily for 6 months. METHODS: Vascular endothelial growth factor (VEGF) and plasminogen activator inhibitor-1 (PAI-1) were determined by ELISA methods in plasma collected from the patients before treatment and after 1, 3 and 6 months. Vessel counts were performed in biopsies from affected skin areas taken before treatment and after 3 and 6 months. The results were compared to simultaneous PASI scores. RESULTS: Pre-treatment plasma levels of VEGF and PAI-1 were significantly elevated in patients compared with levels in healthy persons (p = 0.02 and p = 0.04, respectively). The plasma levels decreased significantly during treatment (p = 0.03 and p = 0.01, respectively), and the decrease in combined levels correlated with the decrease in PASI score. However, the vessel density in affected skin did not change during treatment. CONCLUSIONS: Increased pre-treatment levels of VEGF and PAI-1 and decrease during improvement of the disease suggest that the two molecules may play a role in pathogenesis of psoriasis.

Adult↗
PubMed2002

Ranitidine as adjuvant treatment in colorectal cancer.

BACKGROUND: Results from short-term studies of histamine type 2 (H2) receptor antagonists on survival of patients with solid tumours are debatable. In this study the efficacy of the H2-receptor antagonist ranitidine on long-term survival of patients with colorectal cancer was evaluated. METHODS: Patients scheduled for elective resection of primary tumours were consecutively included in a randomized double-blind placebo-controlled clinical study designed to evaluate the effect of ranitidine on survival. Before skin incision ranitidine 100 mg or placebo was given intravenously twice daily followed by oral ranitidine 150 mg or placebo twice daily for 5 years. Adjuvant cytotoxic or radiation therapy was not given. An observer-blinded interim analysis performed after 40 months showed that there was no effect of ranitidine on overall survival, and the study was discontinued in accordance with the protocol. The patient cohort has been followed continuously without loss of any patient, and a final statistical analysis was performed on an intention-to-treat basis after more than 5 years; this included a subgroup analysis of perioperative blood transfusion and postoperative infectious complications. RESULTS: The median observation period of the 740 patients included was 6.8 (range 5.4-7.9) years. A univariate analysis of all 740 patients and of the subgroup of 560 who underwent curative resection showed no significant effect of ranitidine on survival. Furthermore, ranitidine had no survival benefit in curatively resected patients who received a perioperative blood transfusion (n = 358), but it improved the survival of non-transfused patients (n = 202; hazard ratio (HR) 0.6 (95 per cent confidence interval (c.i.) 0.4 to 0.9), P = 0.02) and of non-transfused patients who did not develop postoperative infectious complications (n = 170; HR 0.6 (95 per cent c.i. 0.4 to 0.9), P = 0.01). In multivariate analysis of patients who had a curative resection, including Dukes' stage, age, gender, tumour location, blood transfusion, postoperative infectious complications and treatment, ranitidine still had an independent, beneficial effect on survival (HR 0.6 (95 per cent c.i. 0.4 to 1.0), P = 0.04) within the subgroup of patients who did not receive perioperative blood transfusion and did not develop postoperative infectious complications. CONCLUSION: Ranitidine may prolong the survival of patients who undergo curative resection of colorectal cancer and who do not receive perioperative blood transfusion and do not develop postoperative infectious complications.

Adult↗
PubMed2002

Levels of tissue inhibitor of metalloproteinases-1 in blood transfusion components.

Blood transfusion during surgery for solid tumors may reduce patient survival because of various bioactive substances present in blood preparations. The anti-proteolytic protein tissue inhibitor of metalloproteinases-1 (TIMP-1) present in large quantities in platelets has been shown to stimulate cell growth and to inhibit apoptosis and may therefore be considered to influence tumor progression. We measured TIMP-1 levels in blood transfusion preparations. especially in platelet-containing preparations, before and after leucofiltration and at different time-points during storage. The mean TIMP-1 levels in whole blood (WB) and platelet-rich plasma (PRP) were slightly reduced by leucofiltration; WB: 41.6 microg/L versus 34.9 microg/L. PRP: 139.8 microg/L versus 127.2 microg/L. However, with prestorage leucofiltration. TIMP-1 levels in buffy-coat-derived platelet (BCP) pools were significantly reduced from 134.2 microg/L to 102.2 microg/L (p=0.0013). In saline-adenine-glucose-mannitol (SAG-M) blood preparations in which the platelet content is reduced by more than 99%,. TIMP-1 could not be detected. Extracellular TIMP-1 accumulated significantly in non-filtered WB and in aferesis platelet concentrates (APC), but TIMP-1 was at no time detectable in SAG-M blood during storage. In conclusion. TIMP-1 is present in various platelet-containing blood preparations, but not in platelet-free preparations such as SAG-M, indicating that most of the TIMP-1 measured in blood preparations originates from platelets. Furthermore, TIMP-1 levels increased during storage in preparations containing platelets. which suggests a continuous disintegration of platelets. These data imply that information on preoperative blood transfusions should be taken into account when evaluating plasma TIMP-1 levels in patients.

Blood Component Transfusion↗
PubMed2002

Determination of vascular endothelial growth factor (VEGF) in circulating blood: significance of VEGF in various leucocytes and platelets.

AIM: The sources of increased vascular endothelial growth factor (VEGF) concentrations in peripheral blood from cancer patients are not known in detail. The aim of the present study was to evaluate correlations between the VEGF content in isolated leucocyte subpopulations and VEGF concentrations in plasma, serum and lysed whole blood. METHODS: In 51 colorectal cancer (CRC) patients, circulating T-lymphocytes, B-lymphocytes, monocytes, and granulocytes were isolated by means of immunomagnetic separation. Subsequently, the isolated cells were lysed and VEGF contents in the lysates were determined. In corresponding blood samples, automated complete blood count was performed, and the number of each cell type was correlated to VEGF concentrations in plasma, serum and lysed whole blood. Finally, the impact of increasing clotting time on the release of VEGF to serum was analysed. RESULTS: Isolated neutrophils contained considerable amounts of VEGF. In isolated lymphocytes and monocytes, VEGF was not present in measurable amounts. The number of neutrophils was significantly (p<0.0001) correlated to VEGF concentrations in lysed whole blood, but not to VEGF concentrations in plasma or serum. The number of platelets was significantly correlated to VEGF concentrations in serum and lysed whole blood (p=0.002 and p=0.02, respectively) but not to VEGF concentrations in plasma. Finally, in serum, VEGF concentrations increased with increasing clotting time. However, a plateau was reached between 2 and 6 h of in vitro clotting. CONCLUSION: Circulating neutrophils contain considerable amounts of VEGF that contribute to high VEGF levels in lysed whole blood. VEGF in circulating platelets contributes to high VEGF levels in serum and lysed whole blood. Allowing whole blood samples to clot for between 2 and 6 h before serum is collected reduces time-dependent, non-uniform release of VEGF.

Adult↗
PubMed2002

Cytokeratin-positive cells in preoperative peripheral blood and bone marrow aspirates of patients with colorectal cancer.

UNLABELLED: Detection of cytokeratin-positive cells in bone marrow and peripheral blood may have prognostic significance in cancer patients. Furthermore, a correlation between uPAR expression on micrometastases and patient prognosis has been suggested. However, in patients with colorectal cancer, preoperative detection and characterization of tumour cells in bone marrow and peripheral blood, using an immunocytochemical approach, have not yet been substantiated as a prognostic tool. METHODS: Forty-one bone marrow aspirates and 38 peripheral blood aspirates, obtained preoperatively from patients with colorectal cancer, were immunocytochemically screened for cytokeratin-positive cells. Where cytokeratin-positive cells were observed, an additional microslide was double immunostained for simultaneous detection of cytokeratin and uPAR/CD87. RESULTS: Cytokeratin-positive cells were observed in 4 out of 41 bone marrow aspirates (10%). None of the isolated cytokeratin-positive cells expressed uPAR. In peripheral blood, no cytokeratin-positive cells were observed. CONCLUSION: The present study does not support the introduction of a routine immunocytochemical identification of cytokeratin-positive cells in preoperatively obtained bone marrow aspirates or peripheral blood from patients with colorectal cancer.

Adult↗
PubMed2001

Extracellular accumulation of bioactive substances during preparation and storage of various platelet concentrates.

BACKGROUND: Side effects of platelet transfusion may be associated with infusion of bioactive substances. We therefore studied extracellular accumulation of histamine, plasminogen activator inhibitor (PAI)-1, vascular endothelial growth factor (VEGF), and interleukin (IL)-6 during preparation and storage of various platelet concentrates. METHODS: Twenty buffy-coat-derived platelet pools (BCPC) were prepared and stored in platelet additive solutions (PAS). Twelve apheresis platelet (APC) units were prepared using the COBE Spectra LRS, and 14 were prepared using the Fenwal Amicus Separator. After preparation half of the content was drawn from each APC unit. The normal ranges of the substances were determined in plasma from all donors, and the extracellular concentrations of the substances were determined in supernatants collected on days 0, 1, 3, 5, and 7 of storage from all platelet preparations. RESULTS: The platelet counts were not significantly different in BCPC units and APC units. The BCPC units had a significantly higher white cell count than the APC units (P < 0.0001), but the count was significantly higher in the Amicus APC units than in the COBE APC units (P < 0.0001). The extracellular histamine concentration was significantly (P < 0.001) increased in BCPC units after preparation and without further increase during storage, while there was no accumulation of histamine in APC units. After preparation the PAI-1 concentration was significantly (P < 0.02) higher in BCPC units than in APC units, but during storage PAI-1 increased significantly (P < 0.05) more in APC units than in BCPC units. Similarly, VEGF concentration was significantly (P < 0.05) higher in BCPC units than in APC units after preparation. During storage, however, VEGF increased more in BCPC units compared with COBE Spectra APC units (P < 0.05), but compared with Amicus Separator APC units only for the first 3 days of storage. At days 5 and 7 of storage the VEGF concentration was significantly higher in the Amicus APC units than in the COBE APC units (P < 0.05). IL-6 was not detectable in any of the concentrates after preparation or during storage. CONCLUSION: Platelet concentrates prepared by the apheresis method may contain less white cell derived bioactive substances than platelet concentrates prepared by the buffy-coat method. However, a substantial storage time dependent platelet derived bioactive substance accumulation takes place in all platelet concentrates tested, presumably due to platelet disintegration.

Adult↗