Synthesis of protoporphyrin IX induced by 5-aminolevulinic acid in yeast cells in the presence of 2,2;-dipyridyl

5-Aminolevulinic acid (ALA), a precursor of porphyrin synthesis, increased the production of various porphyrin compounds in Candida guilliermondii cells. Metalloporphyrins and protoporphyrin IX (PPIX) were predominantly accumulated, respectively, at ALA concentrations of 0.2-0.4 mM and at those higher than 1.5 mM. 2,2;-Dipyridyl which complexed with bivalent metals significantly increased the content of endogenous PPIX even at ALA concentrations lower than 0.5 mM. Under these conditions, the yeast sensitivity to photodynamic effect of visible light (400-600 nm) dramatically increased due to photosensitization by endogenous PPIX.     

The fibromuscular basket (Sporta perimedullaris musculosa) in renculi of kidneys from the ringed seal, Phoca hispida (Pinnipedia)

The medulla of renculi from kidneys of Ringed seals (Phoca hispida) is completely enclosed by cortex except at the hilum. Within the renculus, the fibromuscular coat of the calyx separates from the transitional epithelium at the level of the corticomedullary junction, where the intrarencular arteries also diverge into the parenchyma. Flat ribbons of this stromal tissue form an arborized framework near the medullary side of the intrarencular arteries and the larger of the arcuate arteries derived from them. The ribbons, which are clearly distinct from periarterial connective tissue, are composed of coarse collagenous fibers, elastic fibers, and smooth muscle cells, all oriented in the direction of the long axes of the ribbons, and myofibroblasts. The proportion of smooth muscle cells decreases and that of myofibroblasts increases with increasing distance from the calyx. At the base of the medullary pyramid, the elements of the framework diminish in width and ultimately blend with the surrounding interstitial tissue. The stromal framework, or basket, is homologous with the Sporta perimedullaris musculosa of cetacean kidneys.