Very little is known about the evolution of molluskan shell pigments, although Mollusca is a highly diverse, species rich, and ecologically important group of animals comprised of many brightly colored taxa. The marine snail genus Clanculus was chosen as an exceptional model for studying the evolution of shell color, first, because in Clanculus margaritarius and Clanculus pharaonius both shell ...

The author discusses the fate of the Foreign Intelligence Department of the GDR, which he headed for over thirty years, and of its colleagues and agents since the reunification of Germany ten years ago. There was no transformation of this service after the implosion of socialism; instead, it was liquidated, and criminal prosecutions followed which continue to this day. The author describes how ...

It has been reported (1) and confirmed (2) that the production of uroporphyrin III from porphobilinogen, either by heating in acid solution or enzymatically by hemolyzed avian erythrocytes, is accompanied by the formation of formaldehyde from the aminomethyl group of the pyrrole. These observations have been cited as evidence in support of two hypotheses on the mechanism of uroporphyrin III for...

The partial purification of porphobilinogen deaminase from spinach leaf tissue and some details of the action of this enzyme in the synthesis of uroporphyrinogen I, have been reported in earlier communications (2-5). Uroporphyrin I has been found in nature in the escreta of humans and other animals under certain pathological conditions (6, 7). The arrangement of the propionic and acetic acid si...

Oral administration of a commercial PCB mixture to chickens caused a hepatic-type porphyria characterized by hepatic accumulation and urinary excretion of uroporphyrin. To clarify the mechanism of the porphyrinogenic activity of these PCBs, we studied the structural requirement of synthetic PCB for porphyrinogenic activities by using the cultured chick embryo liver cells and examined the relati...

Information on changes in the urinary excretion pattern of porphyrins can be especially useful in the diagnosis of disorders of porphyrin metabolism. Most clinical laboratory procedures are designed for assay of uroporphyrin and coproporphyrin only, and in many cases even these are not cleanly separated. Hence, we developed a "high-performance" liquid-chromatographic procedure to separate and q...

The rat hemidiaphragm was studied in vitro as a test system to evaluate the effects of heme precursors and the uroporphyrins upon neuromuscular excitability. Porphobilinogen and porphobilin had no effect on the resting miniature end-plate potential frequency, but the K(+)-augmented frequency was significantly reduced. Porphobilin and porphobilinogen gave 50% of their maximal effect at concentra...

The maize lesion mimic gene Les22 is defined by dominant mutations and characterized by the production of minute necrotic spots on leaves in a developmentally specified and light-dependent manner. Phenotypically, Les22 lesions resemble those that are triggered during a hypersensitive disease resistance response of plants to pathogens. We have cloned Les22 by using a Mutator-tagging technique. I...

Fine needle aspiration biopsy smears from 19 patients with porphyria cutanea tarda were studied by fluorescence microscopy. Fluorescence was arbitrarily graded from 0 to 4. All patients-those with clinically manifest as well as those with latent disease-showed bright red fluorescence of porphyrin type in the liver cells, though in latent cases the fluorescence commonly was of a low grade. In pa...