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Biomedical subjects

T Fleming

Publications and source records attributed to T Fleming.

52 records · Page 3Linked to original sources
PubMed1989

Phase II study of diaziquone in untreated advanced gastric carcinoma. A Southwest Oncology Group Study.

Twenty-nine patients with a diagnosis of advanced adenocarcinoma of the stomach with gross unresectable or measurable residual disease and no prior therapy were entered into a study utilizing diaziquone (AZQ) in an intermittent 3-week schedule of 40 mg/m2. Of 28 eligible patients, 1 (4%) experienced a partial response, 7 (25%) had stable disease of no response, and 18 (64%) developed increasing disease. Two (7%) were unevaluable. Median survival was 3.8 months. Major toxicities were myelosuppression and gastrointestinal, 11 of which were considered to be life-threatening. AZQ used as a single intermittent agent appears to have no significant activity to warrant use in untreated advanced gastric carcinoma. However, recognizing the short plasma half-life of AZQ, significant responses by other schedules of administration are not precluded.

Adenocarcinoma↗
PubMed1988

Expression of genes for platelet-derived growth factor in adult human venous endothelium. A possible non-platelet-dependent cause of intimal hyperplasia in vein grafts and perianastomotic areas of vascular prostheses.

Neointimal fibromuscular hyperplasia (NFH) in vein grafts and perianastomotic zones of vascular prostheses has been attributed to the effects of platelet-derived growth factor (PDGF) released by platelets interacting with bypass conduits. But inhibition of platelet aggregation often fails to prevent NFH, and recurrent growth of intact, platelet-free endothelium over perianastomotic areas where NFH occurs is inconsistent with the concept of sustained PDGF release from platelets causing NFH progression at late times after surgical procedures. Cultured bovine aortic endothelial cells (ECs) and human umbilical vein ECs have been shown to release a PDGF-like molecule. We report that confluent cultured fourth passage adult human saphenous vein ECs (AHSVECs) grown in the presence of heparin (100 micrograms/ml) and retina-derived growth factor (RDGF) studied by Northern blotting transcribed a messenger ribonucleic acid (mRNA) of 3.9 kb, strongly hybridizing to PDGF B chain probes, and two species of 2.0 and 2.6 kb hybridizing to PDGF A chain probes. Withdrawal of RDGF and heparin from these cultures for 48 hours before mRNA extraction amplified the scanning densitometric mRNA signal per cell by 8.0 +/- 7.6 fold (mean +/- SD) (N = 4 cultures) for B chain mRNA and 5.2 +/- 3.6 fold (N = 3 cultures) for A chain mRNA. In addition, AHSVEC cultures released a PDGF-like substance, because 50% vol/vol AHSVEC-conditioned serum-free medium increased tritiated thymidine uptake elevenfold in PDGF receptor-bearing 3T3 cells whereas an excess (50 micrograms/ml) of nonspecific goat anti-human-PDGF antibody significantly reduced this increase by a mean of 30% to 7.0 +/- 3.4 fold (N = 6 trials, p less than 0.001). Flow cytometry determined AHSVEC cultures to be proliferating with a mean of 6.2% +/- 1.9% (N = 3 culture lines) of ECs in S phase even at confluence when deprived of EC mitogens for 48 hours. Adult human ECs, which proliferate on bypass conduits and host vessels after perioperative injury, may play a role in causing NFH by stimulating proliferation of adjacent smooth muscle cells. Prevention of NFH may require not only antiplatelet agents but also ways to prevent EC release of smooth muscle cell mitogens in response to perioperative EC injury.

Animals↗
PubMed1987

The human transforming growth factor type alpha coding sequence is not a direct-acting oncogene when overexpressed in NIH 3T3 cells.

A peptide secreted by some tumor cells in vitro imparts anchorage-independent growth to normal rat kidney (NRK) cells and has been termed transforming growth factor type alpha (TGF-alpha). To directly investigate the transforming properties of this factor, the human sequence coding for TGF-alpha was placed under the control of either a metallothionein promoter or a retroviral long terminal repeat. These constructs failed to induce morphological transformation upon transfection of NIH 3T3 cells, whereas viral oncogenes encoding a truncated form of its cognate receptor, the EGF receptor, or another growth factor, sis/platelet-derived growth factor 2, efficiently induced transformed foci. When NIH 3T3 clonal sublines were selected by transfection of TGF-alpha expression vectors in the presence of a dominant selectable marker, they were shown to secrete large amounts of TGF-alpha into the medium, to have downregulated EGF receptors, and to be inhibited in growth by TGF-alpha monoclonal antibody. These results indicated that secreted TGF-alpha interacts with its receptor at a cell surface location. Single cell-derived TGF-alpha-expressing sublines grew to high saturation density in culture. However, when plated as single cells on contact-inhibited monolayers of NIH 3T3 cells, they failed to form colonies, whereas v-sis- and v-erbB-transfected cells formed transformed colonies under the same conditions. Moreover, TGF-alpha-expressing sublines were not tumorigenic in nude mice. These and other results imply that TGF-alpha exerts a growth-promoting effect on the entire NIH 3T3 cell population after secretion into the medium but little, if any, effect on the individual cell synthesizing this factor. It is concluded that the normal coding sequence for TGF-alpha is not a direct-acting oncogene when overexpressed in NIH 3T3 cells.

Base Sequence↗
PubMed1987

Combined therapies for squamous-cell carcinoma of the esophagus, a Southwest Oncology Group Study (SWOG-8037).

Conservative treatment of esophageal cancer with radiation therapy has afforded few long-term survivors. In order to improve outcome, patients with locoregional disease were treated using a combined modality approach. Patients were treated with chemotherapy consisting of a 96-hour continuous infusion of 5-fluorouracil (5-FU), 1,000 mg/m2/d, days 1 to 4 and days 29 to 32; cisplatin 75 mg/m2, day 1 and 29; and radiation 3,000 rad, days 1 to 19. In the absence of progressive disease, patients underwent esophagectomy. One hundred twenty-eight patients were registered of whom 113 were eligible and 106 were evaluable. Toxicity included gastrointestinal (GI) symptoms, mucositis, and myelosuppression. One hundred two patients completed chemoradiotherapy. Following its completion, 11 patients refused surgery, six were considered poor surgical risks, and 14 had progressive disease. Of the remaining 71 patients, 16 had unresectable disease, 13 had residual disease which was incompletely resected, 24 had disease which could be completely resected, and 18 were without disease on pathologic examination. The overall operability rate was 63% and the overall resectability rate, 49%. Surgical mortality was 11%. Eighty-nine of 113 eligible patients have died, with a median survival of 12 months and a 2-year survival of 28%. The median postsurgical survival for all 71 patients was 14 months and was 32 months for those patients attaining complete remission (CR). Combined modality therapy remains an investigational approach. Attempts should be directed at increasing response rate to initial therapy. A randomized comparison between combined modality treatment and radiation therapy is necessary to definitively determine the usefulness of this more aggressive approach.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1983

Medical consequences of the New Mexico State Penitentiary riot.

On February 2, 1980, a riot broke out among the 1,157 inmates at the New Mexico State Penitentiary and 139 people were injured. Of these, 33 died. Survivors had a variety of problems resulting from blunt or penetrating trauma, acute intoxication with drugs, or smoke inhalation. Fourteen percent of the casualties arrived at local hospitals in serious or critical condition. A study of the injury patterns revealed a significant difference (P less than .001) in the incidence of severe head trauma in those who had died compared to those who survived. Most of the seriously or critically ill survivors suffered from acute poisoning or from penetrating wounds.

Burns, Inhalation↗
PubMedDate not supplied

Radiotherapy technique integrates MRI into CT.

The 1970s saw the introduction of computed tomography, which enabled soft tissue anatomy to be seen. Today simulation of therapeutic fields by x-ray is augmented by radiotherapy treatment planning using CT data. The 1980s brought magnetic resonance imaging with superior soft tissue contrast. This article describes a technique correlating three-dimensional MRI/CT data sets used routinely in treatment planning of tumors in the head.

Brain Neoplasms↗