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Biomedical subjects

G Pierce

Publications and source records attributed to G Pierce.

6 recordsLinked to original sources

Platelet-derived endothelial cell growth factor has thymidine phosphorylase activity.

Platelet-derived endothelial cell growth factor (PD-ECGF), a protein which stimulates angiogenesis in vivo, is shown to have a 39.2% amino acid sequence similarity over a 439 amino acid region with the thymidine phosphorylase of Escherichia coli (E. coli). Using recombinant human PD-ECGF, we show that PD-ECGF has thymidine phosphorylase activity. Analysis by gel chromatography revealed that recombinant human PD-ECGF occurs as a 90 kDa homodimer, similar to other thymidine phosphorylases. In addition to a possible effect on DNA synthesis, PD-ECGF was shown to affect [3H]thymidine assays in a manner which is not related to cell proliferation. The in vitro and in vivo effects of PD-ECGF may thus occur by an indirect mechanism through its enzymatic activity.

Amino Acid Sequence

J774A.1 macrophage cell line produces PDGF-like and non-PDGF-like growth factors for bone cells.

In light of evidence that macrophages participate in the local regulation of bone remodeling, we have examined the production of peptide stimulators of bone cell growth and specialization by the J774A.1 macrophage cell line. Cultured J774A.1 cells secrete growth-promoting activities which have an affinity for heparin. The first partially purified material, termed HEP I, appears to contain platelet-derived growth factor (PDGF)-like activity. It has a molecular weight of about 30,000 daltons, inhibits the binding of labeled PDGF to its receptors, reacts with polyclonal anti-human PDGF antibody, and exhibits mitogenic activity for osteoblasts, which is partially blocked by anti-PDGF antisera. Like PDGF, HEP I is active in a wide variety of mesenchyme-derived cells, including osteoblasts, chondrocytes, smooth muscle cells, fibroblasts, 3T3 cells and NRK cells. The J774A.1 cells contain mRNA, which hybridizes to a v-sis DNA probe, suggesting that they express the c-sis gene, which contains the code for a PDGF-like protein. The second factor, HEP II, has an approximate molecular weight of 20,000 daltons and possesses substantial mitogenic activity for osteoblasts, chondrocytes, and smooth muscle cells, but is not mitogenic for fibroblasts, 3T3 cells, and NRK cells. HEP II appears to be a unique bone cell mitogen, which is distinct from the growth factors presently known. Neither HEP I nor HEP II contained interleukin 1, a macrophage product known to promote bone resorption and perhaps the growth and activity of osteoblasts.

Animals

Pleuroscopy and pleural biopsy with the flexible fiberoptic bronchoscope.

Diagnostic pleuroscopy has been performed under local anesthesia in nine patients using a gas sterilized flexible fiberoptic bronchoscope inserted through a 1 to 2 cm chest incision into the pleural space. Pleuroscopy in one patient excluded recurrent neoplasm on the pleural aspect of a bronchopleural fistula. Another patient had a pleuroscopic biopsy of the lung, which was the only method successful in diagnosing a metastatic renal carcinoma. The other seven patients were studied for pleural effusions which were undiagnosed after study of pleural fluid and/or Abrams needle biopsy. In four of them pleural implants of carcinoma were visualized and proved by biopsy. Three patients had negative pleuroscopy, two of these also being negative at subsequent thoracotomy. One was not explored because of extrathoracic metastases. The procedures were performed with minimal patient discomfort and no serious complications.

Biopsy

Clinical experience with pleuroscopy utilizing the bronchofiberscope.

The gas sterilized bronchofiberscope has been utilized as a pleuroscope for visual exploration of the pleural space and forceps biopsy of abnormal lesions in 16 patients with undiagnosed pleural disease. The instrument was inserted through a small (1-2 cm) incision. Aspiration of pleural fluid and instillation or aspiration of air to produce a controlled pneumothorax are easily accomplished through the instrument's suction channel. In eight patients with undiagnosed pleural effusion, biopsy of visualized nodules established the diagnosis of carcinoma. Three patients with bronchogenic carcinoma and pleural effusion had no pleural metastases at pleuroscopy which was confirmed in two patients who had thoracotomy and lung resection. Parenchymal subpleural nodules of metastatic carcinoma were confirmed by pleuroscopic biopsy in one patient. Biopsy via the pleuroscope was unsuccessful in two patients, one with pleural fibrosis, probably related to asbestosis, and one with mesothelioma. Both required open surgical biopsy of the pleura. There has been minimal patient discomfort and no serious complications.

Adenocarcinoma