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Biomedical subjects

L M Ellis

Publications and source records attributed to L M Ellis.

At least 73 records · Page 4Linked to original sources
PubMed1999

Radiofrequency ablation of unresectable primary and metastatic hepatic malignancies: results in 123 patients.

OBJECTIVE: To describe the safety and efficacy of radiofrequency ablation (RFA) to treat unresectable malignant hepatic tumors in 123 patients. BACKGROUND: The majority of patients with primary or metastatic malignancies confined to the liver are not candidates for resection because of tumor size, location, or multifocality or inadequate functional hepatic reserve. Local application of heat is tumoricidal; therefore, the authors investigated a novel RFA system to treat patients with unresectable hepatic cancer. PATIENTS AND METHODS: Patients with hepatic malignancies were entered into a prospective, nonrandomized trial. The liver tumors were treated percutaneously or during surgery under ultrasound guidance using a novel LeVeen monopolar array needle electrode and an RF 2000 generator. All patients were followed to assess complications, treatment response, and recurrence of malignant disease. RESULTS: RFA was used to treat 169 tumors (median diameter 3.4 cm, range 0.5 to 12 cm) in 123 patients. Primary liver cancer was treated in 48 patients (39.1%), and metastatic liver tumors were treated in 75 patients (60.9%). Percutaneous and intraoperative RFA was performed in 31 patients (35.2%) and 92 patients (74.8%), respectively. There were no treatment-related deaths, and the complication rate after RFA was 2.4%. All treated tumors were completely necrotic on imaging studies after completion of RFA treatments. With a median follow-up of 15 months, tumor has recurred in 3 of 169 treated lesions (1.8%), but metastatic disease has developed at other sites in 34 patients (27.6%). CONCLUSIONS: RFA is a safe, well-tolerated, and effective treatment to achieve tumor destruction in patients with unresectable hepatic malignancies. Because patients are at risk for the development of new metastatic disease after RFA, multimodality treatment approaches that include RFA should be investigated.

Adult↗
PubMed1999

Vascular endothelial growth factor levels and induction of permeability in malignant pleural effusions.

Vascular endothelial growth factor (VEGF) is an important mediator of angiogenesis and vascular permeability. We hypothesized that malignant pleural effusions may contain high levels of VEGF protein as well as other cytokines implicated in these processes. Pleural effusions cytologically proven to be malignant were collected from 39 patients with various types of cancer, and VEGF, interleukin-8, and angiogenin levels in the effusions were determined by immunoassay. Negative controls were nonmalignant ascites and serum samples from healthy individuals. VEGF levels were significantly higher than those of control samples in pleural effusions secondary to breast, mesothelioma, and non-small cell lung cancer and when all malignant pleural effusion samples were pooled. Neither interleukin-8 nor angiogenin levels were elevated in malignant pleural effusions relative to the control samples. Vascular permeability, which was measured by using the Miles assay in nude mice, was increased proportionately with VEGF levels in the malignant pleural effusions; this increase in permeability induced by injection of recombinant VEGF or the malignant effusions was reduced by pretreating the mice with a VEGF receptor antibody.

Angiogenesis Inducing Agents↗
PubMed1999

Relative expression of E-cadherin and type IV collagenase genes predicts disease outcome in patients with resectable pancreatic carcinoma.

We examined the expression level of several genes that regulate distinct steps of metastasis in formalin-fixed, paraffin-embedded, archival specimens of primary human pancreatic carcinomas from patients undergoing curative surgery. The expression of epidermal growth factor receptor, E-cadherin, type IV collagenase [matrix metalloproteinase (MMP) 2 and MMP-9), basic fibroblast growth factor, vascular endothelial growth factor/vascular permeability factor, and interleukin 8 was examined by a colorimetric in situ mRNA hybridization technique. Down-regulation of E-cadherin and up-regulation of type IV collagenase (MMP-9 and MMP-2) at the periphery of the neoplasms (P = 0.0167, 0.0102, and 0.0349, respectively) had significant prognostic value. The ratio of type IV collagenase expression (mean of the expression of MMP-2 and MMP-9) to E-cadherin expression (MMP:E-cadherin ratio) at the periphery of the tumors was significantly higher in patients with recurrent disease (4.7 +/- 2.1) than in patients who were disease free (2.3 +/- 1.7; P = 0.0008). Death from pancreatic cancer was significantly associated with a high MMP:E-cadherin ratio (>3.0) by overall survival analysis (P < 0.0002), whereas a low MMP:E-cadherin ratio (<3.0) was found in seven of eight patients alive 28-64 months after surgery. Multivariate analysis of overall survival showed that the MMP:E-cadherin ratio was a significant independent prognostic factor, whereas stage, nodal metastasis, and histological type were not. These data show that multiparametric analysis for several metastasis-related genes may allow physicians to assess the metastatic potential and hence predict the clinical outcome of individual patients with resectable pancreatic carcinoma.

Adenocarcinoma↗
PubMed1998

Regulation of vascular endothelial growth factor expression in human colon cancer by insulin-like growth factor-I.

We investigated the role of insulin-like growth factor (IGF)-I and IGF-binding proteins (IGFBPs) in the regulation of vascular endothelial growth factor (VEGF) expression in colon cancer cells and the mechanism by which this regulation occurs. HT29 human colon cancer cells were treated with IGF-I for various time periods. VEGF mRNA expression increased within 2 h and peaked at 24 h. SW620 colon cancer cells exhibited a peak induction of VEGF mRNA 8 h after IGF-I treatment. IGF-I induction of VEGF was confirmed at the protein level. In experiments using transient transfection of VEGF promoter-reporter constructs into HT29 cells, IGF-I increased the activity of the VEGF promoter, and pretreatment of HT29 cells with dactinomycin abrogated the induction of VEGF mRNA by IGF-I. The half-life of VEGF mRNA was not prolonged by treatment with IGF-I. Blocking the activity of IGFBP-4 did not significantly modulate the effect of IGF-I induction of VEGF mRNA in HT29 cells. Treating cells with des-(1-3)-IGF-I (an active derivative of IGF-I that does not bind to binding proteins) had effects on VEGF mRNA expression that were similar to those of IGF-I. These findings suggest that IGF-I regulates VEGF expression in human colon cancer cells by induction of transcription of the VEGF gene. IGFBPs do not significantly affect IGF-I induction of VEGF.

Colonic Neoplasms↗
PubMed1998

Adenovirus-mediated wild-type p53 gene transfer down-regulates vascular endothelial growth factor expression and inhibits angiogenesis in human colon cancer.

Recent studies have indicated that angiogenesis may be regulated, in part, by p53 tumor suppressor gene function. We hypothesized that wild-type p53 replacement would down-regulate vascular endothelial growth factor (VEGF) expression and inhibit angiogenesis. KM12L4 and SW620, human colon cancer cell lines with p53 mutations, were transduced with a replication-defective adenoviral vector containing the wild-type p53 gene (Ad5/CMV/p53). Reverse transcription-PCR confirmed the presence of p53 in Ad5/CMV/p53-transduced cells. Transduction of colon cancer cells with wild-type p53 decreased VEGF RNA expression compared with that of controls. The decrease in VEGF expression in SW620 cells was dose dependent, with a 49% decrease observed at a multiplicity of infection of 50, and a 71% decrease observed at a multiplicity of infection of 100. Similar effects were seen in KM12L4 cells. VEGF supernatant protein levels were significantly reduced compared with those in nontransduced controls 48 h after the introduction of wild-type p53. Ad5/CMV/p53 inhibited tumor cell-induced angiogenesis in vivo. Restoration of wild-type p53 expression may decrease tumor growth by inhibiting the angiogenic response. These findings may explain, in part, the bystander effect seen with p53 tumor suppressor gene therapy.

Adenoviridae↗
PubMed1998

p53, vessel count, and vascular endothelial growth factor expression in human colon cancer.

We previously demonstrated an association between vascular endothelial growth factor (VEGF), vessel counts and metastasis in human colon cancer specimens. Mutant p53 has been implicated in the regulation of angiogenesis. Immuno-histochemical detection of p53 protein has been associated with p53 gene mutations. We sought to determine a correlation between p53 protein detection (i.e., mutant p53), VEGF expression and vessel counts in human colon cancer. Surgical specimens from 93 patients with colon cancer were stained immuno-histochemically for p53, VEGF and factor VIII. Vessel counts were greater in metastatic tumors than in nonmetastatic tumors and adenomas, and greater in nonmetastatic tumors than in adenomas. Vessel counts were highest in tumors with the highest VEGF expression. Vessel counts and VEGF expression were greater in p53-positive tumors than in p53-negative tumors. p53 expression correlated with both VEGF expression and vessel count. The association of p53 expression with VEGF and vessel count suggests that the poor prognosis associated with p53 mutations may be due, in part, to the role of mutant p53 in promoting angiogenesis.

Adenoma↗
PubMed1998

Down-regulation of vascular endothelial growth factor in a human colon carcinoma cell line transfected with an antisense expression vector specific for c-src.

Vascular endothelial growth factor (VEGF) is implicated in the angiogenesis of human colon cancer. Recent evidence suggests that factors that regulate VEGF expression may partially depend on c-src-mediated signal transduction pathways. The tyrosine kinase activity of Src is activated in most colon tumors and cell lines. We established stable subclones of the human colon adenocarcinoma cell line HT29 in which Src expression and activity are decreased specifically as a result of a transfected antisense expression vector. This study determined whether VEGF expression is decreased in these cell lines and whether the smaller size and reduced growth rate of antisense vector-transfected cell lines in vivo might result, in part, from reduced vascularization of tumors. Northern blot analysis of these cell lines revealed that VEGF mRNA expression was decreased in proportion to the decrease in Src kinase activity. Under hypoxic conditions, cells with decreased Src activity had a <2-fold increase in VEGF expression, whereas parental cells had a >50-fold increase. VEGF protein in the supernatants of cells was also reduced in antisense transfectants compared with that from parental cells. In nude mice, subcutaneous tumors from antisense transfectants showed a significant reduction in vascularity. These results suggest that Src activity regulates the expression of VEGF in colon tumor cells.

Animals↗
PubMed1998

Angiogenesis in poorly differentiated medullary carcinoma of the stomach.

We studied the role of angiogenesis in patients with medullary type poorly differentiated adenocarcinoma (MTPDA) of the stomach. Immunohistochemical analyses were conducted using antibodies against factor VIII (endothelial cells), vascular endothelial growth factor (VEGF) and its receptors (KDR andflt-1), and basic fibroblast growth factor (bFGF) and its receptors (bek andflg). Archival specimens of MTPDA (n=22) and non-MTPDA (n=47) were studied. The expression of VEGF and bFGF, the vessel count, and positivity of KDR on endothelium were all significantly higher in MTPDA than in non-MTPDA. The vessel count correlated with the VEGF expression in MTPDA. The vessel count and VEGF expression increased with the increasing stage of disease in MTPDA but not in non-MTPDA. The expression of bFGF and its receptors did not correlate with the vessel count and stage of disease in either type. These findings thus suggest that the biological behavior of medullary type poorly differentiated adenocarcinoma of the stomach is angiogenesis-dependent. The correlation of the VEGF expression and its endothelial receptors with the vessel count and the stage of disease thus suggests that VEGF is a factor responsible for the induction of angiogenesis in this type.

Adult↗
PubMed1998

Clinical, pathologic, and economic parameters of laparoscopic colon resection for cancer.

BACKGROUND: The appropriateness of laparoscopic colon resection (LCR) as treatment for malignancy has been questioned. METHODS: From 1992 to 1997, 91 patients were entered into a prospective study of LCR for cancer. Clinical, pathologic, and economic parameters of LCR were compared in a cohort of patients matched for age, tumor stage, and type of colectomy who underwent open colon resection (OCR) during the same time period. RESULTS: With a median follow-up of 26 months, there were no significant differences in survival rate for patients in the LCR, converted colon resection, and OCR groups. There were no port-site recurrences and the number of lymph nodes harvested was similar among the procedures. Hospital stay was significantly shorter if laparoscopic resection was successful. Total hospital costs were similar for LCR and OCR; however, the costs were significantly higher for converted colon resection. CONCLUSIONS: LCR is a sound oncologic procedure that can be performed with costs similar to OCR.

Adult↗
PubMed1998

Vessel counts and vascular endothelial growth factor expression in pancreatic adenocarcinoma.

Angiogenesis is essential for growth and metastasis of solid malignancies. In several tumours, tumour vessel count and expression of vascular endothelial growth factor (VEGF), a potent angiogenic factor, have been associated with prognosis. To determine if vessel count and VEGF expression are prognostic factors in pancreatic cancer, we examined these parameters in resected tumour specimens from 22 patients who did not receive pre-operative therapy. Paraffin-embedded tumour specimens were immunohistochemically stained for factor VIII (surrogate for vessels) and VEGF. Vessel counts and VEGF expression were evaluated without knowledge of patient outcome. The median follow-up for the entire group had not been reached as of 23.1 months (range 10-69 months). The mean vessel count and VEGF expression were no different between those patients who had recurrences and those who did not. By linear regression analysis, the correlation of VEGF expression with vessel count did not reach statistical significance (P = 0.0685). Survival and time to recurrence were similar in patients with high and low vessel counts and VEGF expression of 1, 2 or 3. Tumour differentiation or lymph node positivity had no effect on either VEGF expression or vessel count. Our data suggest that, in contrast to findings in other solid malignancies, vessel count and VEGF expression are not predictors of survival or recurrence in patients with resectable adenocarcinoma of the pancreas.

Adenocarcinoma↗
PubMed1998

Regulation of vascular endothelial growth factor receptor KDR in vitro by a soluble factor in confluent endothelial cells.

Hypoxia regulates the expression of both vascular endothelial growth factor (VEGF) and its receptor (KDR). We have shown that cell density regulates VEGF expression in colon cancer and hypothesized that a similar mechanism regulates KDR in endothelial cells. Human umbilical vein endothelial cells were grown as sparse and confluent monolayers. Northern blot analysis revealed that KDR and VEGF mRNA expression in confluent cells was more than two-fold greater than in sparse cells. In contrast, flt-1 expression increased only slightly in cells grown to confluence. Cells were then plated at various concentrations and subjected to semi-quantitative PCR; KDR mRNA expression increased as cell density increased. Serum-free conditioned medium from cells grown to confluency for 48 h was added to sparsely plated cells, and KDR expression in the sparse cells increased twofold. We conclude that cell density regulates KDR endothelial cell expression via an unidentified soluble factor.

Blotting, Northern↗
PubMed1998

Significance of platelet-derived endothelial cell growth factor in the angiogenesis of human gastric cancer.

We have previously shown that platelet-derived endothelial cell growth factor (PD-ECGF) is associated with angiogenesis of human colon cancer; this factor is expressed at high levels in vascular tumors that express low levels of vascular endothelial growth factor (VEGF). In these colon cancers, the major source of PD-ECGF is the infiltrating cells. In this study, we examined the role of PD-ECGF in the angiogenesis of human gastric cancer. Immunostaining for PD-ECGF was done on 93 gastric cancers previously stained for VEGF, basic fibroblast growth factor, and factor VIII-related antigen (specific for endothelial cells). To determine the cell type expressing PD-ECGF, double staining was done using antibodies to both PD-ECGF and CD68 (specific for macrophages). PD-ECGF was expressed more frequently in infiltrating cells (positive CD68 staining; 53.8%) than in tumor epithelium (9.7%; P < 0.0001). Infiltrating cells simultaneously stained positive for both PD-ECGF and CD68. An association between PD-ECGF expression in infiltrating cells, VEGF expression in tumor epithelium, and vessel count was observed in intestinal-type gastric cancer but not in diffuse-type gastric cancer. Vessel count was greater in tumors with high expression of both PD-ECGF and VEGF than in those with high expression of either factor alone (P = 0.002). Multiple angiogenic factors expressed by both tumor cells and infiltrating cells may play a role in the regulation of angiogenesis in intestinal-type gastric cancer.

Adult↗
PubMed1997

Expression of epidermal growth factor receptor and human papillomavirus E6/E7 proteins in cervical carcinoma cells.

BACKGROUND: Epidermal growth factor receptor (EGF-R) proteins are highly expressed in many tumors, including those of the cervix. We have observed previously that the introduction of a transcription unit containing an antisense sequence for the E6/E7 genes of human papillomavirus (HPV) 18, along with a transcription unit containing a sense complementary DNA sequence for the wild-type retinoblastoma (Rb) gene, decreased the growth of human cervical carcinoma HeLa cells (HPV 18 positive) both in vitro and in vivo. To clarify the regulatory mechanisms by which this reduction in cell proliferation occurred, we studied the expression of EGF-R proteins in these cells. METHODS: Western blot and northern blot techniques were used to measure EGF-R expression, and a pulse-chase immunoprecipitation assay was used to measure the stability of EGF-R protein in HeLa cells and HeLa cells that had been transfected with the antisense E6/E7 or sense Rb sequences. Cell proliferation was measured by use of a tetrazolium-based colorimetric assay for numbers of viable cells. RESULTS: The introduction of sense Rb or antisense E6/E7 transcription units or a combination of these two transcription units into HeLa cells dramatically decreased the level of EGF-R proteins in these cells; EGF-R levels were not affected at the transcriptional level but at the post-transcriptional level. Addition of the anti-EGF-R-specific monoclonal antibody 225mAb to HeLa cells caused 53% (95% confidence interval = 44%-62%) growth inhibition. CONCLUSIONS: These results suggest that HeLa cervical carcinoma cells are dependent on EGF-R for proliferation and that changes in functional levels of the E6/E7 HPV proteins and endogenous Rb proteins may alter the growth rate of cervical cancer cell lines by reducing the stability of EGF-R at the post-transcriptional level.

Blotting, Northern↗
PubMed1997

Carcinoid tumors of the rectum: effect of size, histopathology, and surgical treatment on metastasis free survival.

BACKGROUND: The purpose of this study was to determine the clinical course, effects of specific tumor histopathologic characteristics, and extent of surgical treatment on the metastatic rate in patients with rectal carcinoids. METHODS: Medical records of 44 patients who presented with rectal carcinoids were retrospectively reviewed. Primary tumors were classified by size (< 1 cm, 1-2 cm, and > 2 cm), and tumor histopathologic features (atypical or typical). Extensive surgery was defined as abdominoperineal or low anterior resection of the rectum or laparotomy with intent of curative resection. RESULTS: Median follow-up for patients who presented without metastasis was 84 months. Thirteen of the 44 patients (30%) presented with metastatic disease. The 5-year metastasis free survival rates for those patients presenting without metastatic disease were 100% for patients with tumors < 1 cm (n = 16), 73% for those with tumors 1-2 cm (n = 8), and 25% for those with tumors > 2 cm (n = 4) (P = 0.04 comparing < 1 cm with 1-2 cm and P = 0.05 comparing 1-2 cm with > 2 cm); tumor size data were not available for 3 patients. The 5-year metastasis free survival rate for patients presenting without metastatic disease with typical histology (n = 20), regardless of size, was 100%, compared with 50% for patients with tumors with atypical histology (n = 11) (P = 0.001). Nine patients underwent extensive surgery for rectal carcinoid tumors but no survival benefit was demonstrated. CONCLUSIONS: Atypical histopathologic features and a tumor size > 1 cm are associated with aggressive behavior of rectal carcinoid tumors. Extensive surgery offers no survival advantage over local excision for patients with rectal carcinoid tumors.

Adult↗
PubMed1997

Vessel counts and expression of vascular endothelial growth factor as prognostic factors in node-negative colon cancer.

BACKGROUND: The value of these prognostic factors was compared with that of other clinicopathologic factors such as tumor grade, tumor stage, mucin production, vascular invasion, perineural invasion, and lymphatic invasion. OBJECTIVE: To determine whether the development of distant recurrence in patients with node-negative colon cancer could be predicted using vessel count and vascular endothelial growth factor (VEGF) expression. DESIGN: Paraffin-embedded colon cancers were immunostained for factor VIII, VEGF, basic fibroblast growth factor, and proliferating cell nuclear antigen; slides were reviewed for differentiation, mucin production, and the presence of vascular, lymphatic, and/or perineural invasion. SETTING: A large academic cancer referral center where 27 patients with node-negative colon cancer were operated on during 1988 and 1989. MAIN OUTCOME MEASURE: The development of and interval to recurrence. RESULTS: Eight patients developed liver, lung, or lymph node metastases at a median of 24 months. The median follow-up for patients without cancer recurrence was 60 months. The mean tumor vessel count for those patients who remained disease-free was significantly fewer than for those patients who suffered a recurrence (20 vs 33, respectively). By univariate analysis, 3 factors- perineural invasion, vessel count, and VEGF expression- were correlated with time to recurrence. By multivariate analysis, only vessel count was significantly related to differences in time to recurrence. Expression of VEGF correlated with vessel count. CONCLUSION: Vessel count and expression of VEGF may be useful for predicting distant recurrence in patients with node-negative colon cancer.

Adult↗