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Biomedical subjects

J Odell

Publications and source records attributed to J Odell.

8 recordsLinked to original sources
PubMed1990

Site-directed recombination in the genome of transgenic tobacco.

The plant genome responds to the bacteriophage P1-derived loxP-Cre site-specific recombination system. Recombination took place at loxP sites stably integrated in the tobacco genome, indicating that the Cre recombinase protein, expressed by a chimeric gene also stably resident in the genome, was able to enter the nucleus and to locate a specific 34 bp DNA sequence. An excisional recombination event was monitored by the acquisition of kanamycin resistance, which resulted from the loss of a polyadenylation signal sequence that interrupted a chimeric neomycin phosphotransferase II gene. Molecular analysis confirmed that the excision had occurred. Recombination occurred when plants with the integrated loxP construction were stably re-transformed with a chimeric cre gene and when plants with the introduced loxP construction were cross-bred with those carrying the chimeric cre gene. As assayed phenotypically, site-specific recombination could be detected in 50%-100% of the plants containing both elements of the system. Kanamycin resistance was detected at 2-3 weeks after re-transformation and in the first leaf of hybrid seedlings. This demonstration of the effectiveness of the loxP-Cre system in plants provides the basis for development of this system for such purposes as directing site-specific integration and regulation of gene expression.

Blotting, Northern↗
PubMed1990

In situ cannulation, microgrid follow-up and low-density plating provide first passage endothelial cell masscultures for in vitro lining.

A rapid and reliable harvest and culture technique was developed to provide a sufficient number of autologous endothelial cells for the confluent in vitro lining of cardiovascular prostheses. Enzymatic endothelial cell detachment was achieved by the in situ application of collagenase to short vessel segments. This harvest technique resulted in a complete lack of contaminating smooth muscle cells in all of 124 cultures from nonhuman primates and 13 cultures from human adults. The use of a microgrid technique enabled the daily in situ quantification of available endothelial cells. To assess ideal plating densities after passage the population doubling time was continuously related to the cell density. Surprisingly, a low plating density of 1.5 X 10(3) endothelial cells/cm2 achieved 43% shorter cell cycles than the usual plating density of 1.0 X 10(4) endothelial cells/cm2. Moreover, low density plating enabled mass cultures after one single cell passage, thereby reducing the cell damaging effect of trypsin. When the growth characteristics of endothelial cells from five anatomically different vessel sites were compared, the external jugular vein--which would be easily accessible and dispensable in each patient--proved to be an excellent source for endothelial cell cultures. By applying in situ administration of collagenase, low density plating and microgrid follow-up to adult human saphenous vein endothelial cells, 14,000,000 first passage endothelial cells--sufficient for the in vitro lining of long vascular prostheses--were obtained 26.2 days after harvest. (95% confidence interval:22.3 to 32.2 days).

Animals↗
PubMed1984

Penetrating neck trauma with tracheal and oesophageal injuries.

Failure to recognize early that penetrating neck wounds include the cervical oesophagus greatly increases morbidity and mortality. From an analysis of experience over 5 years (1978-1983) it emerges that, while tracheal wounds are usually recognized early, cervical oesophageal injuries are not. It is empyema which complicates such oesophageal injury and which prompts referral to a Department of Thoracic Surgery, the patients by this time being mortally ill, with septicaemia and malnutrition. Neck penetration is usually left-sided, the injuring agent usually a knife, driven downwards and medially by a right-handed assailant. Empyema is usually right-sided. Early recognition and prompt referral are associated with a low morbidity and low mortality. Late recognition and late referral carry a high morbidity rate, prolonged convalescence in those who survive, and a mortality rate of nearly 25 per cent.

Adolescent↗