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Biomedical subjects

E T Sandberg

Publications and source records attributed to E T Sandberg.

6 recordsLinked to original sources

Deficiency of inflammatory cell adhesion molecules protects against atherosclerosis in mice.

Leukocyte and endothelial cell adhesion molecules (CAMs) are essential for emigration of leukocytes, with the selectins mediating the initial step of leukocyte "rolling" and the beta 2-(CD18) integrins and intercellular adhesion molecule-1 (ICAM-1) being important for firm adhesion and emigration. On the basis of evidence for an inflammatory component in the pathogenesis of atherosclerosis, including increased expression of CAMs, cytokines, and growth factors, we tested the hypothesis that decreased expression of inflammatory CAMs would reduce susceptibility to atherosclerosis. Using C57BL/6 mice fed a high-fat diet, we observed a 50% to 75% reduction in atherosclerotic fatty streaks in mice with homozygous mutations for ICAM-1, P-selectin, CD18, both ICAM-1 and CD18, or both ICAM-1 and P-selectin. In contrast to previous evidence of increased expression of CAMs in atherosclerotic lesions, which does not prove a cause-and-effect relationship, these data indicate directly that the level of expression of CAMs can determine the susceptibility to the formation of atherosclerotic fatty streaks. The results suggest that genetic variation at these loci could influence susceptibility to atherosclerosis and that pharmacological reduction of the expression or function of these CAMs might protect against atherosclerosis.

Animal Feed↗

Novel isoforms of murine intercellular adhesion molecule-1 generated by alternative RNA splicing.

Intercellular adhesion molecule-1 (ICAM-1)-deficient mice, produced by homologous recombination and previously recognized to be devoid of the common form of ICAM-1, are shown to express residual amounts of ICAM-1 Ag in thymus and lung. We demonstrate that this expression of ICAM-1 is possible because the mutated exon 5 in these animals has been skipped by alternative splicing of RNA. Three different alternative isoforms of ICAM-1 are expressed in mutant mice. Moreover, two of these isoforms are expressed in wild-type mice together with two additional alternative isoforms that cannot be produced in mutant mice. All alternatively spliced isoforms of ICAM-1 detected are missing complete extracellular Ig domains. In both mutant and wild-type mice, expression of alternatively spliced isoforms is up-regulated following stimulation of animals with LPS. Furthermore, all alternative isoforms of ICAM-1, except one, retain the ability to bind to the well-recognized ICAM-1 counter-receptor LFA-1. These findings, along with the restricted tissue distribution in mutant mice, indicate that alternative isoforms of ICAM-1 are significant physiologic adhesion structures which could play a distinct role in the functioning of the immune system of intact animals.

Alternative Splicing↗

Gene targeting for inflammatory cell adhesion molecules.

Using gene targeting in mouse embryonic stem cells, it is possible to introduce diverse mutations into specific genes. Using these methods, various laboratories have reported mutations for a variety of inflammatory cell adhesion molecules including CD18, alpha 5 integrin, ICAM-1, P-selectin, and L-selectin; preliminary reports of other mutations are also available. Mutations in CD18 and ICAM-1 cause impaired inflammatory and immune responses, mutations in P-selectin and L-selectin cause decreased leukocyte rolling and emigration, and a mutation in alpha 5 integrin causes embryonic lethality. Gene targeting complements other approaches for analyzing the function of inflammatory cell adhesion molecules.

Animals↗

Dose ranging study of cefpimizole (U-63196E) for treatment of uncomplicated gonorrhea in men.

We conducted a two-center dose ranging study to evaluate the efficacy, tolerance, and toxicity of cefpimizole, a new cephalosporin, in the treatment of uncomplicated gonorrhea in 96 males. Twelve patients at each center were treated intramuscularly with single doses of 1.0, 0.5, 0.25, and 0.125 g of cefpimizole. All urethral infections were cured at the highest dose, but lower doses produced progressively decreasing cure rates of 90% (0.5 g), 83% (0.25 g), and 71% (0.125 g). Treatment failures of rectal and pharyngeal infections occurred at the highest dose level. Geometric mean MICs for cefpimizole for successfully and unsuccessfully treated volunteers were 0.088 and 0.282 micrograms/ml, respectively. A prominent adverse effect was clinically significant pain at the injection site, which occurred in 57 (59%) of 96 patients. Results of the study demonstrate that cefpimizole offers no advantage over currently available antibiotics in the treatment of uncomplicated gonorrhea in men.

Adolescent↗