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Biomedical subjects

J Odell

Publications and source records attributed to J Odell.

15 recordsLinked to original sources

Identification and expression of isoflavone synthase, the key enzyme for biosynthesis of isoflavones in legumes.

Isoflavones have drawn much attention because of their benefits to human health. These compounds, which are produced almost exclusively in legumes, have natural roles in plant defense and root nodulation. Isoflavone synthase catalyzes the first committed step of isoflavone biosynthesis, a branch of the phenylpropanoid pathway. To identify the gene encoding this enzyme, we used a yeast expression assay to screen soybean ESTs encoding cytochrome P450 proteins. We identified two soybean genes encoding isoflavone synthase, and used them to isolate homologous genes from other leguminous species including red clover, white clover, hairy vetch, mung bean, alfalfa, lentil, snow pea, and lupine, as well as from the nonleguminous sugarbeet. We expressed soybean isoflavone synthase in Arabidopsis thaliana, which led to production of the isoflavone genistein in this nonlegume plant. Identification of the isoflavone synthase gene should allow manipulation of the phenylpropanoid pathway for agronomic and nutritional purposes.

Anthocyanins↗

Effect of sternotomy direction on the incidence of inadvertent pleurotomy.

OBJECTIVE: Median sternotomy was performed by 2 different techniques in order to determine whether there was a difference in the incidence of inadvertent pleural entry. EXPERIMENTAL DESIGN: Patients were prospectively evaluated and reviewed at a mean follow-up interval of 8.2 months. PATIENTS AND METHODS: Ninety five consecutive patients underwent primary sternotomy at a single tertiary referral center. MEASURES: Planned outcome measures included, incidence of pleural entry, length of hospitalization, and chest tube site related postoperative morbidity. RESULTS: Group 1 (n=49) had sternotomy undertaken from the sternal notch proceeding downwards. Group 2 (n=46) underwent sternotomy performed from the xiphoid upwards. Mediastinal evaluation revealed a significant reduction in the incidence of pleural violation for group 1 (3) versus group 2 (11) (p=0.014). This difference was not found to be surgeon specific. CONCLUSIONS: Sternotomy undertaken from the sternal notch proceeding downwards is shown to be associated with a reduced incidence of inadvertent pleural entry. Potential advantages for this approach also include reduced respiratory morbidity, less chest tube site complications and a trend to reduced length of hospitalization.

Adult↗

In vitro-lined endothelium: initial integrity and ultrastructural events.

BACKGROUND: The early fate of in vitro-endothelialized prosthetic vascular grafts was assessed in the nonhuman primate. METHODS: Each of 17 male chacma baboons received a control and a confluently endothelialized 4 mm polytetrafluoroethylene graft in femoro-femoral positions (8.2 +/- 0.8 cm). All experimental grafts were precoated with fibrinolytically inhibited fibrin glue and lined with cultured autologous endothelial cells (EC) from the external jugular vein. The average time period needed to obtain first-passage mass-cultures sufficient for preconfluent graft endothelialization was 19.8 +/- 5.2 days. Before implantation in vitro-lined grafts were kept in culture for another 16.1 +/- 4.3 days to achieve complete confluence and maturation of the EC cytoskeleton. RESULTS: After 9 days of implantation, endothelial-lined grafts still showed a confluent endothelium that was free of any fibrin deposits. However, the EC density was significantly lower than at implantation (39.7 +/- 7.6 x 10(3) versus 59.9 +/- 8.5 x 10(3) EC/cm2; p < 0.05), and occasional 10-microns-wide intercellular gaps with adherent platelets and leukocytes were visible. Transmission electron microscopy showed leukocytes and cell debris in the underlying fibrin glue. After 4 weeks of implantation, the endothelium of experimental prostheses had regained a high cell density (72.7 +/- 10.5 x 10(3) EC/cm2) with a mature and well-differentiated morphologic appearance. At both observation periods, the surface of control grafts showed a wide range from fibrin deposits to an amorphous protein coverage containing spread platelets. CONCLUSIONS: The endothelium of in vitro-endothelialized vascular prostheses remains confluent after implantation and is nonthrombogenic in spite of a moderate initial cell loss.

Animals↗

Severe pneumococcal pneumonia complicated by massive pulmonary gangrene.

Massive pulmonary gangrene is a rare complication of pneumonia, particularly in the postantibiotic era. We report two cases of community-acquired Streptococcus pneumoniae pneumonia in young patients with a background of heavy alcohol abuse, but no other preexisting disease, which failed to respond to appropriate antibiotic therapy and intensive care. In both, there was extensive unilateral involvement, with initial dense consolidation followed by cavitation, but the previously reported classic later radiologic feature of coalescence into a large cavity with free-floating slough was not seen. Owing to ongoing sepsis with the development of multiple organ failure and the obvious failure of appropriate medical therapy, both patients underwent pneumonectomy with a successful outcome. These cases serve to emphasize the role of surgery in the management of massive pulmonary gangrene.

Acute Disease↗

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↗

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↗

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↗

Tissue donation: the benefit of a positive approach.

Unlike organ donation, which enjoys a worthy public profile, tissue transplantation remains relatively unheard of. Here, the authors argue that nurses should promote the value of tissue donation, not only to patients but to colleagues as well.

Contraindications↗