Biomedical subjects

D Matei

Publications and source records attributed to D Matei.

13 recordsLinked to original sources

PubMed2006

Autocrine activation of PDGFRalpha promotes the progression of ovarian cancer.

Platelet-derived growth factor receptor (PDGFR)alpha expression was found in ovarian cancer cells and tumors by microarray hybridization. This led us to test whether ovarian cancers also produce ligands for this receptor, as this would demonstrate that such malignancies support their own growth and spread through autocrine activation. We assayed the expression of ligands for the PDGFR in ovarian tumors, cell lines and peritoneal fluid using RT-PCR, immunohistochemistry (IHC) and ELISA. We detected strong mRNA expression for the PDGFRalpha ligands in most ovarian tumors. Receptor and ligand expressions (PDGFRalpha and PDGF AB) were also detected by IHC in, respectively, 34 and 32 of 47 ovarian tumors. The stainings for PDGFRalpha and PDGF AB were strongly correlated (P-value=0.014), suggesting that an autocrine loop is functional in ovarian cancer. PDGF AA and BB were quantified in peritoneal fluid by ELISA. Both ligands are secreted at higher levels in ovarian cancer ascites specimens (n=54) than in fluid from nonmalignant disorders (n=8). PDGF was detected in media conditioned by ovarian cancer cells. Such conditioned media induced activation of the PDGFR, Akt and MAPK and stimulated cell proliferation. A neutralizing PDGF antibody blocked these effects. Specific PDGFR inhibition by siRNA or a neutralizing antibody to the receptor inhibited PDGF-stimulated receptor activation and cell proliferation, suggesting that receptor targeting has a role in ovarian cancer treatment.

Ascitic Fluid↗

PubMed2001

Acquired thrombophilic syndromes.

As the biochemical mechanisms of hypercoagulable states are revealed, the syndromes of venous thromboembolism have been increasingly associated with specific aberrations. Most of these changes involve an increase in procoagulant potential, for example, by activation of the coagulation cascade, or by a defect or decrease in natural inhibitors of clotting. Similar abnormalities of the fibrinolytic pathways may contribute, as can loss of inhibitory mechanisms of endothelial cells, as well as changes in vascular anatomy and rheologic patterns of blood flow. All of these factors can directly influence thrombus formation and/or the physiologic response to the thrombus.(1)

Humans↗

PubMed2001

Analysis of thorium and its progeny by gamma ray spectrometry and alpha track methods.

Samples originating from an EU sponsored intercomparison exercise were analysed by gamma ray spectrometry (a thorium solution sample, a zircon sand sample and a thorium ore sample). An alpha track method was also used to analyse the solution sample. The detection efficiency calibration for the gamma ray spectrometry measurements on the solid samples was established using an in-house standard of thorium nitrate. A GESPECOR Monte Carlo simulation program was utilised in the analysis of the solution sample. The in-house thorium nitrate standard was also used to prepare standards for the alpha track method. The relative differences between the 232Th activity concentration values determined in these intercomparison samples and values supplied by the NPL, UK, were found to be less than 5% when determined by the gamma ray spectrometry method and less than 8% when determined by the alpha track method.

Alpha Particles↗

PubMed1999

Actual 5-year survival of patients with stage IIIB breast carcinoma: phase II trial of methotrexate, vinblastine, adriamycin, cisplatin, and folinic acid.

Patients with stage IIIB breast carcinoma represent only a small proportion of women with breast cancer in western countries but may constitute up to 50% of cases in underdeveloped countries. The prognosis remains poor despite aggressive treatment. Nineteen patients (11 with inflammatory breast carcinoma) received at least three courses of neoadjuvant chemotherapy of methotrexate, vinblastine, adriamycin, cisplatin, and folinic acid (MVAC/FA) followed by mastectomy. Six months of cyclophosphamide, methotrexate, and 5-fluorouracil were given after surgery. Radiation therapy followed chemotherapy. Seventy percent of patients achieved complete and 14% partial response after MVAC/FA chemotherapy alone. Eleven patients (58%) survived 5 years, and 30% survived at least 8 years. The addition of cisplatin in combination chemotherapy used as first-line treatment for stage IIIB breast carcinoma was well tolerated, resulted in higher response rates, and appeared to have an effect on overall survival.

Adult↗

PubMed1995

Preclinical and clinical evaluation of 5-fluorouracil biochemical modulation with folinic acid and hydroxyurea for patients with colorectal carcinoma.

BACKGROUND: Approximately 140,000 new cases of colorectal carcinoma will be diagnosed in 1995 in the United States, and more than one-third of these patients will die from progressive disease. Despite the modest improvement in response rate with chemotherapy, little improvement in patient survival has been noted. Consequently, the evaluation of new agents, modalities, and combinations is needed. METHODS: Two cell lines, HCT 116 and COLO 320 HSR, were treated with various concentrations of 5-fluorouracil (5-FU), folinic acid (FA), and hydroxyurea (HU). Subsequently, 41 patients with advanced, measurable metastatic colorectal carcinoma were enrolled in the study. Patients were treated with oral doses of HU (500 mg) every 8 hours on Days 1 and 2, 5-FU (400-500 mg/m2) intravenously Day 2 and FA (100 mg/m2) intravenously on Day 2 of every week for 6 consecutive weeks, followed by a 2-week rest period. All patients were evaluable for toxicity, and 40 were evaluable for response. RESULTS: In both cell lines, the combination of 5-FU/FA/HU consistently produced the best cytotoxic effect. Clinically, the maximum tolerated dose of 5-FU was established at a level of 500 mg/m2 (450 mg/m2 for patients older than 70 years of age). Ten patients experienced Grade 3 or 4 toxicity, consisting mainly of diarrhea. Eleven of 40 evaluable patients responded (three complete responses, eight partial responses), with a median survival of 12+ months and time to progression of 8.5+ months. CONCLUSION: The biochemical modulation of 5-FU with FA and HU were significantly effective in treating patients with metastatic colorectal carcinoma. Overall, this regimen was well tolerated with only moderate toxicity. Further studies incorporating intravenous HU as well as a randomized Phase III study of 5-FU/FA/HU versus 5-FU/FA are recommended.

Antimetabolites, Antineoplastic↗

PubMed1995

Emphysematous septic arthritis: case report and review of the literature.

We describe a patient with Escherichia coli infectious arthritis associated with intraarticular emphysema. The implications of this finding and previous experience with this entity are reviewed.

Aged↗

PubMed1990