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Biomedical subjects

C W Bell

Publications and source records attributed to C W Bell.

At least 73 records · Page 4Linked to original sources
PubMed1987

Establishment and characterization of five cell lines derived from human malignant gliomas.

We established and characterized five cell lines derived from human malignant gliomas (four glioblastomas multiforme and one highly anaplastic astrocytoma). All cell lines exhibited tumor cell morphology and growth kinetics, and anchorage-independent growth in soft agar. Cytogenetic analysis revealed significant aneuploidy in all five cases as well as clonal chromosomal alterations unique to each cell line. No cell line was tumorigenic in athymic mice. Two of the cell lines were sensitive to carmustine (BCNU) in monolayer and soft-agar cultures. Electron microscopy showed marked variability between cell lines in the number and structure of intracytoplasmic organelles; SF-126 formed collagen fibers in vitro. Immunohistochemical analysis of the surgical specimens showed variable expression of glial fibrillary acidic protein (GFAP) in malignant astrocytes; positive immunostaining for glycoproteins of the extracellular matrix was found predominantly in perivascular regions. In early-passage cultures, only cell line SF-295 expressed GFAP; at establishment, none of the cell lines expressed GFAF or glutamine synthetase. Fibronectin and laminin were expressed by all cell lines in early-passage culture, but expression of these glycoproteins at establishment was variable. Only SF-126 was positively identified by immunostains for procollagen III; this was also the only cell line in which DEAE-cellulose chromatography and SDS-PAGE demonstrated interstitial collagen synthesis. These well-characterized glioma-derived cell lines may now serve as useful tools with which to study the cell biology of gliomas. The synthesis of interstitial collagen by a glioma-derived cell line may suggest a derivation from vascular mesenchymal elements, either reactive or transformed, in the original heterogeneous malignant glioma, rather than from a glial precursor cell.

Adult↗
PubMed1986

Analysis of the length of S-phase required to show sister chromatid differential staining.

In vitro studies of BrdU-dependent sister chromatid differential staining typically employ two cycles of BrdU incorporation. Experiments are described which determined the actual fraction of both S-phases that the rat embryonic fibroblasts (Rat-1) cells had to traverse in order to show distinctive differential staining. Following synchronization of cells by a combination of serum deprivation and hydroxyurea blockage, sister chromatid differential staining, labelling index, mitotic index, and per cent DNA replication are determined. Results indicate that only approximately 50% of the first S-phase is necessary in order to show distinctive differential staining. The importance of this finding to studies of cellular proliferation using BrdU incorporation is discussed.

Animals↗
PubMed1986

Establishment and characterization of a cell line from a human gliosarcoma.

A human gliosarcoma culture was characterized from the time of inception to the time of establishment of the cell line (SF-539 BT). Immunohistochemical analysis of the original tumor showed 2 distinct regions of cells. The gliomatous regions were identified by immunostains for glial fibrillary acidic protein and the sarcomatous regions by immunostains for laminin, collagen type IV, procollagen type III, and fibronectin. In early-passage culture, both types of cells maintained their characteristic immunohistochemical profiles; however, after the fourth subcultivation in monolayer culture, no cells expressing glial fibrillary acidic protein could be identified. All cells had become morphologically uniform and expressed laminin, collagen type IV, procollagen type III, and fibronectin only. The immunostaining profile of clones grown in soft agar was similar to that of cells in monolayer culture. At establishment, SF-539 BT has a saturation density of 1.3 X 10(6) cells/25 sq cm, a doubling time of 32 h, and a plating efficiency of 22% in monolayer culture. The tumor cell line is resistant to 1,3-bis(2-chloroethyl)-1-nitrosourea, has an abnormal karyotype, grows anchorage independently, and forms a tumor that most closely resembles a spindle cell sarcoma in athymic mice. Its ultrastructure in monolayer culture consists of large cells with an expanded rough endoplasmic reticulum and abundant multivesicular bodies; in athymic mice, extracellular collagen fiber formation is prominent. DEAE-cellulose chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis of cultures labeled with [3H] proline demonstrated interstitial collagen formation. We conclude that the cell line at establishment is a collagen-producing spindle cell sarcoma that resembles the sarcomatous regions of the original mixed tumor. Further cell separation and characterization studies are needed to determine the pathogenesis of mixed tumors such as gliosarcoma.

Animals↗
PubMed1985

Cognitive functioning and survival among patients with chronic obstructive pulmonary disease.

An earlier study by the authors had demonstrated neuropsychological impairment among 66 clinically stable patients suffering from chronic obstructive pulmonary disease (COPD), and had found that the deficits were directly associated with the amount of oxygen available to body tissue. We were able to follow 62 of the patients for three years when retrospective analyses were performed to determine the relationship of the neuropsychological test scores with the patients' three-year survival status. Patients who survived had scored significantly (p less than 0.01) higher on the neuropsychological tests than those who had died. Individual analyses of variance indicated that the significant relationship between the neuropsychological tests and survival status was attributable primarily to the Benton Visual Motor Retention Test and the digit symbol subtest of the Wechsler Adult Intelligence Scale. The latter test had, in the earlier study, shown the strongest relationship with partial pressure of oxygen and with a pulmonary function test. These findings suggest that certain neuropsychological tests may reflect both the progress of COPD and three-year survival probability among the patients.

Carbon Dioxide↗
PubMed1982

Structure of the dynein-1 outer arm in sea urchin sperm flagella. II. Analysis by proteolytic cleavage.

The structure of the 21 S latent activity dynein-1 (LAD-1) particle has been investigated by limited proteolytic cleavage with trypsin and with chymotrypsin. The A alpha and A beta heavy polypeptide chains show different characteristic digestion patterns which remain essentially unchanged whether the chains are components of the 21 S LAD-1 particle or are in the form of separated fractions, although changes in their relative digestion rates upon separation suggest that the A beta chain in the 21 S particle is partially protected from digestion by the presence of the A alpha chain and intermediate chains 2 and 3. The progressive digestion of the A chains and intermediate chains causes an eventual dissociation of the 21 S particle to smaller particles sedimenting in the range 10 to 14 S. Within this broad peak, the fragments from the A alpha chain peak in the 10 to 12 S region, while those from the A beta chain peak in the 12 to 14 S region. Digestion of whole axonemes to a stage at which the A alpha chain is substantially digested but the A beta chain remains mostly intact, enables a large amount of 21 S dynein-1 to be solubilized by 3 mM MgATP2(-) in the presence of 0.1 M NaCl, pH 7.0. This indicates that the affinity of the 0.6 M NaCl-sensitive bond of the outer arm to the A-tubule is diminished substantially by the early stages of digestion of the A alpha chain.

Adenosine Triphosphatases↗
PubMed1982

Neuropsychological deficits among patients with chronic obstructive pulmonary disease.

Sixty-six patients with chronic obstructive pulmonary disease (COPD) were evaluated for neuropsychological functioning. While the patients showed normal skills on broad intellectual tasks, they displayed mild cerebral deficits on several neuropsychological tests. Multiple regression analyses revealed that the neuropsychological test battery scores were significantly related to partial pressure of arterial oxygen (PaO2), and to degree of pulmonary impairment. Although the cognitive deficits were real, they were generally small. This result may explain why the widely assumed link between chronic lung disorders and cognitive deficit has been difficult to demonstrate. The general pattern was similar to deficits produced by chronic alcoholism and childhood asthma, with complex skills suffering the greatest insult. Because the cognitive deficits among COPD patients in stable condition are small, it is uncertain whether they have importance clinically or for accomplishing daily activities.

Aged↗
PubMed1979

Polypeptide subunits of dynein 1 from sea urchin sperm flagella.

A high-resolution sodium dodecyl sulfate polyacrylamide gel electrophoresis system has been used to show the presence, in both whole sperm and isolated flagellar axonemes, of eight polypeptides migrating in the 300,000--350,000 molecular weight range characteristic of the heavy chains of dynein ATPase. Previously, only five such chains have been discernible. Extraction of isolated axonemes for 10 min at 4 degrees C with a solution containing 0.6 M NaCl, ph 7, releases a mixture of particles that separate, in sucrose density gradient centrifugation, into a major peak, dynein 1 ATPase, sedimenting at 21S and a minor peak at 12--14S. The polypeptide compositions of these two peaks are different. The dynein 1 peak, which contains most of the protein on the gradient, contains approximately equal quantities of two closely migrating heavy chains, with a small amount of a third, more slowly migrating chain; no other heavy chains appear in this peak. Two groups of smaller polypeptides (three intermediate chains, within the apparent molecular weight range 76,000--122,000 and four newly discovered light chains, within the apparent molecular weight range 14,000--24,000) cosediment with the 21S peak. The heavy chain composition of the 12--14S peak is more complex, all eight heavy chains occurring approximately the same ratios as occur in intact axonemes.

Adenosine Triphosphatases↗