Transmyocardial laser revascularization

Transmyocardial laser revascularization is a new treatment modality for patients with chronic angina that is refractory to traditional management. A laser is used to create full-thickness channels through areas of ischemic myocardium. Transmyocardial laser revascularization is performed in an effort to improve myocardial oxygenation, eliminate or reduce angina, and improve functional status. Transmyocardial laser revascularization currently is undergoing clinical trials. Early results have demonstrated significant reduction in anginal symptoms. Long-term efficacy of transmyocardial laser revascularization remains to be determined.

Toxoplasma gondii: uptake of fetuin and identification of a 15-kDa fetuin-binding protein

Lectin-binding studies demonstrated the presence of a 68-kDa glycoprotein in tachyzoites of Toxoplasma gondii harvested from P388D1 macrophage cell cultures but not in tachyzoites maintained in peritoneal cavities of NMRI mice. This protein was identified as the embryonic protein fetuin that regularly is contained in fetal calf serum, a component of cell-culture media. Uptake of fetuin by T. gondii was demonstrated by intracellular localization of this protein. As shown by latex agglutination and immunofluorescence, no specific binding of fetuin to the parasite's surface was detected. Using affinity chromatography on fetuin-agarose, it was demonstrated that fetuin bound specifically to a 15-kDa antigen of tachyzoites. As revealed by inhibition studies with sialic acid and the lectin Sambucus nigra agglutinin, the 15-kDa protein probably recognized glycan structures of fetuin.

Specific inhibition of Physarum polycephalum DNA-polymerase-alpha-primase by poly(L-malate) and related polyanions

Poly(L-malate) is an unusual polyanion found in nuclei of plasmodia of Physarum polycephalum. We have investigated, by enzymatic and fluorimetric methods, whether poly(L-malate) and structurally related polyanions can interact with DNA-polymerase-alpha-primase complex and with histones of P. polycephalum. Poly(L-malate) is found to inhibit the activities of the DNA-polymerase-alpha-primase complex and to bind to histones. The mode of inhibition is competitive with regard to DNA in elongation and noncompetitive in the priming of DNA synthesis. Spermidine, spermine, and histones from P. polycephalum and from calf thymus bind to poly(L-malate) and antagonize the inhibition. The polyanions poly(vinyl sulfate), poly(acrylate), poly(L-malate), poly(D,L-malate), poly(L-aspartate), poly(L-glutamate) have been examined for their potency to inhibit the DNA polymerase. The degree of inhibition is found to depend on the distance between neighboring charges, given by the number of atoms (N) interspaced between them. Poly(L-malate) (N = 5) and poly(D,L-malate) (N = 5) are the most efficient inhibitors, followed by poly(L-aspartate) (N = 6), poly(acrylate) (N = 3), poly(L-glutamate) (N = 8), poly(vinyl sulfate) (N = 3). It is proposed that poly(L-malate) interacts with DNA-polymerase-alpha-primase of P. polycephalum. According to its physical and biochemical properties, poly(L-malate) may alternatively function as a molecular chaperone in nucleosome assembly in the S phase and as both an inhibitor and a stock-piling agent of DNA-polymerase-alpha-primase in the G2 phase and M phase of the plasmodial cell cycle.