PubMed Health⌕ Search

Biomedical subjects

K Werther

Publications and source records attributed to K Werther.

At least 19 recordsLinked to original sources
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↗
PubMed2004

Cryptococcosis outbreak in psittacine birds in Brazil.

An outbreak of cryptococcosis occurred in a breeding aviary in São Paulo, Brazil. Seven psittacine birds (of species Charmosyna papou, Lorius lory, Trichoglossus goldiei, Psittacula krameri and Psittacus erithacus) died of disseminated cryptococcosis. Incoordination, progressive paralysis and difficulty in flying were seen in five birds, whereas superficial lesions coincident with respiratory alterations were seen in two birds. Encapsulated yeasts suggestive of Cryptococcus sp. were seen in faecal smears stained with India ink in two cases. Histological examination of the birds showed cryptococcal cells in various tissues, including the beak, choana, sinus, lungs, air sacs, heart, liver, spleen, kidneys, intestines and central nervous system. High titres of cryptococcal antigen were observed in the serum of an affected bird. In this case, titres increased during treatment and the bird eventually died. Yeasts were isolated from the nasal mass, faeces and liver of one bird. Cryptococcus neoformans var. gattii serovar B was identified based on biochemical, physiological and serological tests. These strains were resistant (minimum inhibitory concentration 64 microg/ml) to fluconazole. This is the first report of C. neoformans var. gattii occurring in psittacine birds in Brazil.

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

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

Trypanosoma evansi experimental infection in the South American coati (Nasua nasua): clinical, parasitological and humoral immune response.

The course of Trypanosoma evansi infection in coatis (Carnivora, Procionidae) was followed for 262 days. Parasites were detected in all infected animals from day 2 post infection until the end of the study. No correlation between temperature and parasitemia was observed. Animals of the infected group demonstrated depression, weakness, lethargy and pale mucous membranes. Indirect fluorescent antibody tests detected anti-T. evansi antibodies within 7 to 14 days post infection and showed high levels until the end of the experimental period. The persistent parasitemia in coati and their relative tolerance to clinical signs suggested that this species develops a chronic disease and plays an important role in the epidemiology of trypanosomosis due to T. evansi in enzootic regions.

Animals↗
PubMed2001

Bacteria-induced release of white cell--and platelet-derived vascular endothelial growth factor in vitro.

BACKGROUND AND OBJECTIVES: Poor prognosis after resection of primary colorectal cancer may be related to the combination of perioperative blood transfusion and subsequent development of infectious complications. White blood cell--and platelet-derived cancer growth substances, including vascular endothelial growth factor (VEGF), may be involved in this process. Therefore, we studied the in vitro release of VEGF from white blood cells and platelets stimulated by bacterial antigens and supernatants from stored red cell components. MATERIALS AND METHODS: Eight units of whole blood (WB) and eight units of buffy-coat-depleted red cell (SAGM) blood were donated by healthy blood donors. Subsequently, half of every unit was leucocyte depleted by filtration, and all 32 half-units were stored under standard conditions for 35 days. Just after storage, and on days 7, 21 and 35 during storage, aliquots of the supernatants were removed from the units and frozen at -80 degrees C. WB from other healthy donors was stimulated for 2 h with sodium chloride (controls), with Escherichia coli lipopolysaccharide (LPS) alone, or with LPS plus supernatants from the non-filtered or prestorage leucofiltered WB units (diluted 1:10), or from non-filtered or prestorage leucofiltered SAGM blood units (diluted 1:20) stored for 0, 7, 21, or 35 days, respectively. Similar assays were performed using Staphylococcus aureus-derived protein A as a stimulatory antigen. The concentration of VEGF was determined in supernatants from stored blood and in assay supernatants by using enzyme-linked immunosorbent assay (ELISA). RESULTS: The concentration of VEGF increased significantly (P < 0.0001) in a storage time-dependent manner in non-filtered WB and SAGM blood, while the increase was abrogated by prestorage leucofiltration. The supernatant concentration of VEGF was significantly increased in LPS-stimulated (P = 0.002) and in protein A-stimulated (P < 0.0001) assays compared with controls. Addition of supernatants from stored, non-filtered WB or SAGM significantly increased the assay supernatant VEGF concentration storage-time dependently (P = 0.006) in LPS assays. In protein A assays, only supernatants from non-filtered WB significantly increased the assay supernatant VEGF concentration storage-time dependently (P = 0.022). This additional effect by supernatants from stored blood components was not observed with prestorage leucofiltered blood. CONCLUSIONS: Extracellular VEGF may accumulate in non-filtered red cell components, but this can be prevented by prestorage leucocyte depletion using filtration. In addition, bacterial antigens appear to induce release of VEGF from white blood cells and platelets. Addition of supernatants from stored, non-filtered WB or SAGM blood may increase the VEGF levels in a storage time-dependent manner, while prestorage leucofiltration may prevent further increase by supernatants.

Adult↗
PubMed2001

Arthroscopic shoulder surgery with epinephrine saline irrigation.

PURPOSE: To determine whether dilute epinephrine saline irrigation (0.33 mg/L) delivered by a pressure-controlled pump would significantly reduce intraoperative bleeding during routine arthroscopic shoulder surgery and, in addition, to investigate potential adverse cardiovascular reactions of adding epinephrine to the irrigation fluid. TYPE OF STUDY: Prospective, randomized, double-blinded, placebo-controlled study. METHODS: Fifty-four patients requiring arthroscopic shoulder surgery were randomly assigned to either an epinephrine group that received dilute epinephrine irrigation by a pressure-controlled pump or to a placebo group that received plain saline irrigation by a pressure-controlled pump. Intraoperative, intra-articular bleeding was estimated by multiplying the total volume of the irrigation fluid used with the hemoglobin concentration in the irrigation fluid. Postoperatively, the surgeon rated the clarity of the visual field during the arthroscopy by a visual analogy scale. RESULTS: Intraoperative bleeding was significantly reduced (P =.008) and the clarity of the visual field was significantly better (P =.0007) in the group of patients receiving dilute epinephrine irrigation compared with the group of patients without epinephrine added to the irrigation fluid. CONCLUSIONS: The addition of epinephrine to irrigation fluid seems to reduce intra-articular bleeding during routine arthroscopic shoulder surgery and may improve visualization. Furthermore, no cardiovascular adverse reactions were observed resulting from the intra-articular epinephrine administration.

Adult↗
PubMed2001

The association between preoperative concentration of soluble vascular endothelial growth factor, perioperative blood transfusion, and survival in patients with primary colorectal cancer.

OBJECTIVE: To investigate a possible association between the preoperative concentration of soluble vascular endothelial growth factor (sVEGF), perioperative blood transfusion, and survival in patients operated on for colorectal cancer. DESIGN: Retrospective study. SETTING: University hospital, Denmark. SUBJECTS: 614 patients operated on for primary colorectal cancer. MAIN OUTCOME MEASURES: Association between preoperative blood transfusion and preoperative concentration of sVEGF. Association between perioperative blood transfusion and survival. RESULTS: Blood transfused up to one month before preoperative serum samples were obtained was significantly (p = 0.02) associated with high preoperative concentrations of sVEGF. The frequency of perioperative blood transfusion was significantly (p = 0.0007) higher in patients with rectal cancer than in patients with colon cancer. A multivariate analysis showed that intraoperative or postoperative blood transfusion or both, were significantly (p = 0.03) associated with poor survival in patients with Dukes stage A, B and C rectal cancers, while this association was not found in patients with colon cancer. CONCLUSIONS: Preoperative blood transfusion may be associated with high preoperative concentrations of sVEGF in patients with colorectal cancer. Transfusion during or after the operation is associated with poor survival in patients with Dukes stage A, B, and C rectal cancers.

Adult↗
PubMed2000

The use of the CELLection kit in the isolation of carcinoma cells from mononuclear cell suspensions.

A study was performed to evaluate in vitro the sensitivity, specificity and variability of a new immunomagnetic microbead isolation technique which provides subsequent immunological staining of captured carcinoma cells. In a mixture of peripheral blood mononuclear cells (PBMCs) and human carcinoma cells the epithelial cancer cells were isolated with the Dynal((R)) RAM IgG1 CELLection Kit using Dynabeads M-280 coated with a rat monoclonal antibody (Mab) against mouse IgG1. The rat Mab was biotinylated and attached to Dynabeads via streptavidin and a DNA linker. The anti-epithelial monoclonal mouse antibody Ber-EP4 was used as the primary capture antibody. In order to permit phenotyping of the isolated carcinoma cells the magnetic beads were removed from the carcinoma cells by DN'ase digestion of the DNA linker between the magnetic bead and the secondary antibody. In an ex vivo model system an average recovery of approximately 60% of a human colon carcinoma cell line HCC-2998 seeded in 5.10(6) PBMCs was obtained, and the recovered cells could subsequently be immunologically stained for the surface antigen CD87 (urokinase plasminogen activator receptor). No positive stained cells were found in control experiments with PBMCs without carcinoma cells. Despite a relatively low recovery, the described method will be valuable for the detection of carcinoma cells in cytospin preparations with subsequent phenotyping of the cells for expression of surface antigens. Depending on the chosen antibodies, the method may be useful for the isolation and characterisation of other cell types in various cell suspensions.

Animals↗
PubMed2000

Soluble vascular endothelial growth factor levels in patients with primary colorectal carcinoma. The Danish RANX05 Colorectal Cancer Study Group.

INTRODUCTION: Angiogenesis is decisive in tumour progression and metastasis. Vascular endothelial growth factor (VEGF) is a potent angiogenic factor, and increased VEGF levels in patients with carcinomas may facilitate growth of both primary and secondary tumours. METHODS: Soluble (s) VEGF levels were determined in serum from 91 volunteer healthy blood donors and from 614 patients scheduled to undergo resection for primary colorectal cancer. None of the patients received pre- and/or post-operative chemo- and/or radiotherapy. The results of sVEGF were analysed with respect to Dukes>> stage, gender, age and topographical tumour localization. RESULTS: Patients with colorectal cancer had significantly (P<0.0001) higher levels of sVEGF, compared to healthy blood donors. Patients with Dukes>> stage D disease had significantly (P=0.01) higher values than patients with Dukes>> stage A, B and C disease, who had comparable values. Patients with the primary tumour localized in the colon had significantly (P<0.0001) higher levels of sVEGF than patients with the primary tumour localized in the rectum. By classifying the patients into two groups, based on the upper limit of the 95(th)percentile of sVEGF of healthy individuals (sVEGF=465 pg/ml), we found a significantly (P<0.0001) reduced overall survival in patients with sVEGF >465 pg/ml compared to patients with sVEGF values below this level. Moreover, in the subgroup of patients with the carcinoma localized in the colon and sVEGF levels above 465 pg/ml, we found a significantly (P<0.0001) reduced overall survival compared to colon cancer patients with lower sVEGF values. In conclusion, data from the present study suggest a biological significance of VEGF in patients with colorectal cancer, and indicate that a high pre-operative sVEGF value is associated with poor outcome, but further research is needed to validate sVEGF as a cancer marker.

Adult↗
PubMed2000

Cat flea (Ctenocephalides felis) infestation in quarantined marsh deer (Blastocerus dichotomus) populations.

Marsh deer (Blastocerus dichotomus) were captured for a research program in Brazil and maintained in quarantine stations. After 60 days, fleas were detected on animals and identified as Ctenocephalides felis felis. Elimination of the infestation was difficult. Animal treatment with a fipronil-based compound was effective, and subsequently captured animals were treated prophylactically. Some animals remained infested, and some died from the infestation.

Animals↗
PubMed1999

Soluble vascular endothelial growth factor in various blood transfusion components.

BACKGROUND: Blood transfusion may reduce survival after curative surgery for solid tumors. This may be related to extracellular content of cancer growth factors present in transfusion components. Vascular endothelial growth factor (VEGF) is a potent stimulator of angiogenesis in solid tumors. The potential content of VEGF in various blood components for transfusion was evaluated. STUDY DESIGN AND METHODS: Soluble VEGF (sVEGF, isotype 165) was determined by an enzyme-linked immunosorbent assay (EIA) in serum and plasma samples and in lysed cells from healthy volunteers. Subsequently, total content of sVEGF was determined in nonfiltered and prestorage white cell-reduced whole blood (WB), buffy coat-depleted saline-adenine-glucose-mannitol (SAGM) blood, platelet-rich plasma (PRP), and buffy coat-derived platelet (BCP) pools obtained from volunteer, healthy blood donors. As a control, total content of platelet-derived soluble plasminogen activator inhibitor type 1 (sPAI-1) was determined by an EIA in the same samples. Finally, the extracellular accumulation of sVEGF was determined in nonfiltered WB and SAGM blood during storage for 35 days and in BCP pools during storage for 7 days. RESULTS: In the healthy volunteers, median total sVEGF content was 97 (range, 20-303) pg per mL in serum and 19 (13-37) pg per mL in plasma (n = 12, p < 0.002) and 445 (280-990) pg per mL in lysed cells. Median total sPAI-1 content was 94 (64-127) ng per mL in serum, 8 (6-11) ng per mL in citrated plasma, and 95 (78-123) ng per mL in lysed cells. In SAGM blood, the median total sVEGF content was 25.3 (3.3-48.4) ng per unit in nonfiltered units and undetectable in white cell-reduced units. Median total sVEGF content was 29.2 (24.8-124.9) ng per unit in nonfiltered PRP and 28.7 (24.5-118.6) ng per unit in white cell-reduced PRP. The sVEGF accumulated significantly in WB, SAGM blood, and BCP pools, depending on the storage time. CONCLUSION: The sVEGF (isotype 165) appears to be present in various blood transfusion components, depending on storage time.

Blood Platelets↗
PubMed1999

Immunoglobulin and enzyme-conjugated dextran polymers enhance u-PAR staining intensity of carcinoma cells in peripheral blood smears.

The presence of disseminated carcinoma cells in bone marrow and peripheral blood has prognostic importance in patients with carcinomas. Much evidence indicates that dissemination of tumor cells may depend on activation of a variety of degradative enzymes. A strong positive correlation has been shown between the expression of tumor cell proteases and tumor invasion. Therefore, phenotypic characterization of disseminated carcinoma cells for expression of protease activators might define the invasive potential of the cells. We present an immunocytochemically enhanced staining method that allows phenotyping of disseminated carcinoma cells in bone marrow and peripheral blood smears. In the first step, the cells were incubated with antibodies against urokinase plasminogen activator receptor (u-PAR) and subsequently with secondary antibodies conjugated to peroxidase-labeled dextran polymers. A brown color reaction was developed with diaminobenzidine as chromogen. In the second step, the cells were incubated with alkaline phosphatase-conjugated murine monoclonal antibodies against a common cytokeratin epitope and a red color reaction was developed with new fuchsin as substrate. This method allows simultaneous and unambiguous immunolabeling of intracellular cytokeratin and of u-PAR intracellularly and on the surface of carcinoma cells. This novel approach can be used for detection and phenotyping of carcinoma cells in blood smears for u-PAR or, presumably, for any other heterogeneously expressed antigen on the surface of the detected cells.

Carcinoma↗
PubMed1998

[Can detection of cancer cells in bone marrow and peripheral blood be used in diagnosis and patient monitoring?].

The prognosis of patients with carcinomas is determined by whether there is dissemination of the primary tumour at the time of diagnosis. A substantial number of patients develop recurrent carcinoma, even though there were no clinical signs of dissemination at the time of primary surgery. Standard methods of tumor staging fail to identify those patients, who are at risk of recurrent disease. Recently several studies have demonstrated that the presence of occult metastatic carcinoma cells in the bone marrow increases the risk of recurrence. This risk is independent of traditional tumour staging, although the findings do not necessarily indicate later development of solid metastases. This review outlines the range of current applications of immunological and molecular methods for detecting disseminated carcinoma cells in blood and bone marrow aspirations, and discusses the applicability and significance of the findings.

Biomarkers, Tumor↗