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G Cannon

Publications and source records attributed to G Cannon.

34 records · Page 2Linked to original sources
PubMed1986

Plastid DNA content in a cultured soybean line capable of photoautotrophic growth.

The levels of chloroplast DNA in a cultured photoautotrophic soybean (Glycine max [L.] Merr. v Corsoy) cell line were determined by molecular hybridization. The cells were also grown photomixotrophically and heterotrophically as suspension cultures and the level of plastid DNA was found to be constant at approximately 26% of the total cellular DNA in all three growth modes. By comparison, total cellular DNA extracted from plants of the same variety used as the explant source for the cultured cells contained 12.3 to 18.9% (leaves and seeds) and 6.1 to 8.9% (roots) plastid DNA.

Journal Article↗
PubMed1985

Quantitative molecular hybridization on nylon membranes.

A study of DNA hybridization to DNA covalently bound to nylon membranes was made in order to develop a quantitative method for molecular hybridization using a nylon-based matrix. Chloroplast DNA was covalently attached to nylon membranes by irradiation at 254 nm. Under hybridization conditions the initial rate of DNA loss from the nylon membranes was 5-10% per 24 h, while under comparable conditions DNA bound to nitrocellulose membranes was lost at a rate of 38 to 61% per 24 h. Several sets of hybridization conditions were examined to select one giving reasonable hybridization rates and minimal loss of bound DNA. Under the conditions selected [Denhardt's solution (D. Denhardt, 1966, Biochem. Biophys. Res. Commun. 23, 641-646), 0.5 M NaCl, 0.1% sodium dodecyl sulfate, and 31.4% formamide at 50 degrees C for 92 h], hybridization was observed to be 29% more efficient on nylon membranes than on nitrocellulose. Several attempts to remove previously hybridized DNA from nylon membranes proved only partially successful. Reuse of the membranes, therefore, was of limited value. Quantitative hybridization of total radiolabeled tobacco cellular DNA to cloned tobacco chloroplast DNA attached to nylon yielded results similar to those previously reported using nitrocellulose membranes. However, use of nylon membranes greatly facilitated the manipulations required in the procedure.

Binding Sites↗
PubMed1985

The sugar lobby.

Explore the source record for details and available documents.

Carbohydrates↗
PubMed1985

Chloroplast DNA synthesis during the cell cycle in cultured cells of Nicotiana tabacum: inhibition by nalidixic acid and hydroxyurea.

The effects of nalidixic acid and hydroxyurea on nuclear and chloroplast DNA formation in cultured cells of Nicotiana tabacum were investigated. At low concentrations (5 and 20 micrograms/ml) nalidixic acid, an inhibitor of DNA gyrase, exhibited a greater inhibitory effect on plastid DNA synthesis than on nuclear DNA formation. Since the plastid genome is a circular double-stranded DNA, this is consistent with the proven involvement of a DNA gyrase in the replication of closed circular duplex DNA genomes in procaryotic cells. At a high concentration of nalidixic acid (50 micrograms/ml), DNA synthesis in both the plastid and nuclear compartment was rapidly inhibited. Removal of the drug from the culture medium led to the resumption of DNA synthesis in 8 h. Hydroxyurea, an inhibitor of ribonucleoside diphosphate reductase, also depresses nuclear as well as plastid DNA formation. Removal of hydroxyurea from the blocked cells leads to a burst of nuclear DNA synthesis, suggesting that the cells had been synchronized at the G1/S boundary. The recovery of plastid DNA synthesis occurs within the same time frame as that of nuclear DNA. However, whereas plastid DNA formation is then maintained at a constant rate, nuclear DNA synthesis reaches a peak and subsequently declines. These results indicate that the synthesis of plastid DNA is independent of the cell cycle events governing nuclear DNA formation in cultured plant cells.

Cell Cycle↗
PubMed1983

Patient-controlled inhalational analgesia in prehospital care: a study of side-effects and feasibility.

A clinical trial of a 50:50 mixture of nitrous oxide and oxygen for pain relief was carried out to determine the feasibility of its use in a field setting and the side-effects produced by this sedative/analgesic. The gas mixture was delivered from a single-tank system using a demand-valve apparatus which was triggered by the patient's inspiratory effort. This "patient-controlled" sedation/analgesia was provided to 1243 patients over a period of 18 months. Of the 1201 patients evaluated, 20.6% reported minor side-effects consisting of nausea or vomiting (5.7%), dizziness or lightheadedness (10.3%), excitement (3.7%), and numbness (0.3%). Ninety-one (7.6%) patients became drowsy or fell into a light sleep but all were readily aroused by verbal command. All retained the ability to cough or swallow on command. No consistent or clinically adverse changes were found in BP or pulse rates. The trial supports the concept that this agent is a promising sedative/analgesic for the relief of mild to moderate pain and anxiety. Because of its safety, it is particularly suited to use in prehospital emergency care.

Analgesia↗
PubMed1983

Renal epithelial fragments in urine from a nephrostomized patient: a case report.

Renal epithelial fragments, an infrequently reported entity, were observed by cytologists in urine sediment from a patient who underwent nephrostomy for the relief of a ureteral obstruction. This case report describes the occurrence and various cytomorphologic features of exfoliated renal fragments. Urine specimens obtained following the insertion of a nephrostomy tube can provide the cytologist a unique opportunity to study and distinguish renal epithelial fragments from those of urothelial origin.

Epithelium↗
PubMed1980

Procollagens as markers for the cell of origin of human bone tumors.

Cells derived from osteogenic sarcomas and from Ewing's sarcomas, two malignant bone tumors, were examined for the types of collagens they elaborated into the tissue culture media. Type I procollagen was the predominant species from all osteogenic sarcoma cell lines, a finding consistent with bone cell origin. The Ewing's sarcoma cells contained a prominent peak of type III procollagen and resembled the profile of vascular smooth muscle cells. Fibroblasts derived from skin biopsies taken from amputation specimens synthesized both type I and type III procollagens at the expected ratio of approximately 3:1. The examination of matrix proteins may provide a general classification scheme for human sarcomas and permit distinction of one tumor from another, as well as from normal fibroblasts.

Bone Neoplasms↗
PubMed1979

Deoxyribonucleic acid in Nitrobacter carboxysomes.

Carboxysomes were isolated from Nitrobacter winogradskyi and Nitrobacter agilis. The icosahedral particles contained double-stranded deoxyribonucleic acid (DNA). In the presence of ethidium bromide and cesium chloride, the particle-bound DNA had a buoyant density of rho 25 = 1.701 g/cm3. Electron microscopy revealed the DNA to be a 14-micron circular molecule.

Centrifugation, Density Gradient↗
PubMed1978

Delayed hypersensitivity reactions of cancer patients to antigens on lymphoid cell lines.

Four-hundred and fifty nine cancer patients were skin tested with extracts from five lymphoid cell lines. More than 50% of patients with lymphoma had positive skin tests with the extracts prepared from the cell line derived from Burkitt's lymphoma (BL) and more than 50% of nasopharyngeal carcinoma (NPC) patients reacted to the NPC-derived cell line extracts. Although the significant association between patient diagnosis and orgin of cell lines suggested that tumor-associated antigens were responsible for the pattern of delayed hypersensitivity, problems in standardization of antigen potency and non-specificity need to be resolved before this in vivo assay achieves its full potential.

Antigens, Neoplasm↗
PubMed1975

Location by immunoelectron microscopy of carcinoembryonic antigen on cultured adenocarcinoma cells.

The tissue-culture cell line HT-29, derived from a primary colon adenocarcinoma and previously shown to secrete carcinoembryonic antigen (CEA), was examined by immunoelectron microscopy for the location of CEA in relation to the cells. CEA was closely adjacent to the plasma membrane, a location indistinguishable from that of alloantigens and other tumor-associated antigens.

Adenocarcinoma↗