Zebrafish retinal mutants

BACKGROUND: Development of coronary artery disease in cardiac allograft recipients is the major cause of graft failure after the first year of transplantation. Unfortunately, there is no noninvasive method of identifying patients at greatest risk of developing this disease. We have asked whether serum concentrations of cardiac troponin-T predict development of coronary artery disease. METHODS: Annual coronary angiograms, serial endomyocardial biopsies, and serum cardiac troponin-T concentrations were obtained from 68 cardiac transplant patients who were followed for 68.8+/-11.9 months after surgery. Troponin-T concentrations were measured by using an enzyme-linked immunosorbent assay, and biopsies were assessed histologically for rejection grades and immunohistochemically for cellular infiltrates, arteriolar endothelial activation, fibrin deposits, and vascular fibrinolytic and anticoagulant components. RESULTS: Troponin-T values did not associate with demographic, clinical, or laboratory findings, but they significantly associated with arteriolar endothelial activation (P<0.001), fibrin deposition (P<0.001), depletion of vascular fibrinolytic (P=0.007) and anticoagulant components (P=0.02), and infiltration of macrophages (P <0.001) but not T lymphocytes (P=0.36). Troponin-T concentrations also significantly associated with future development of coronary artery disease (P<0.001). Patients with persistent troponin-T values of 0.10 ng/ml or greater were found to develop the disease within 8.7+/-2.1 months, whereas patients who had initial troponin-T values of 0.10 ng/ml or greater and subsequently fell and remained below 0.10 ng/ml did not develop coronary artery disease in 40 months. CONCLUSIONS: Troponin-T concentrations significantly associated with macrophage infiltrates, microvascular fibrin deposits, arteriolar endothelial activation, depletion of vascular fibrinolytic and anticoagulant components, and the future development of coronary artery disease. The troponin-T assay is an outpatient procedure performed on small amounts of blood at little cost, risk, or inconvenience, and it appears to be the first biochemical predictor of transplant-induced coronary artery disease.     

A computer model for the analysis of DNA replication intermediates by two-dimensional agarose gel electrophoresis

We present a computer model to predict the patterns expected for the replication intermediates (RIs) of DNA fragments analyzed by neutral/neutral two-dimensional (2D) agarose gel electrophoresis. The model relies on the mode of replication (uni- or bi-directional), the electrophoretic mobility of linear DNA fragments and the retardation caused by the three-dimensional shape of non-linear molecules. The utility of this model is demonstrated with two examples: replication analysis of the plasmids pBR322 and pHH5.8 in Escherichia coli after digestions with EcoRI and HindIII, respectively.     

Differentiating keratinocytes express a novel cytochrome P450 enzyme, CYP2B19, having arachidonate monooxygenase activity

The novel cytochrome P450, CYP2B19, is a specific cellular marker of late differentiation in skin keratinocytes. CYP2B19 was discovered in fetal mouse skin where its onset of expression coincides spatially (upper cell layer) and temporally (day 15.5) with the appearance of loricrin-expressing keratinocytes during the stratification stage of fetal epidermis. CYP2B19 is also present postnatally in the differentiated keratinocytes of the epidermis, sebaceous glands, and hair follicles. CYP2B19 mRNA is tightly coupled to the differentiated (granular cell) keratinocyte phenotype in vivo and in vitro. In primary mouse epidermal keratinocytes, it is specifically up-regulated and correlated temporally with calcium-induced differentiation and expression of the late differentiation genes loricrin and profilaggrin. Recombinant CYP2B19 metabolizes arachidonic acid and generates 14,15- and 11, 12-epoxyeicosatrienoic (EET) acids, and 11-, 12-, and 15-hydroxyeicosatetraenoic (HETE) acids (20, 35, 18, 7, and 7% of total metabolites, respectively). Arachidonic acid metabolism was stereoselective for 11S,12R- and 14S,15R-EET, and 11S-, 12R-, and 15R-HETE. The CYP2B19 metabolites 11,12- and 14,15-EET are endogenous constituents of murine epidermis and are present in similar proportions to that generated by the enzyme in vitro, suggesting that CYP2B19 might be the primary enzymatic source of these EETs in murine epidermis.