Contrast-Enhanced Ultrasound (CEUS) of the Kidneys by Using the Bosniak Classification.

Ultrasound is the most used interdisciplinary non-ionizing imaging technique in clinical routine. Therefore, ultrasound has a special value in the diagnosis and monitoring of cystic renal lesions, which can be classified as non-complicated or complicated and by means of occurrence as solitary or multifocal lesions. The Bosniak classification (I-IV) classifies renal cysts in 5 different categories with the help of ultrasound and computed tomography image criteria and is used for decisions of further clinical treatment. Additionally to normal native B-mode sonography, several new methods are in clinical use to improve diagnostic accuracy of unclear cases. Contrast enhanced ultrasound and MRI/CT are able to find and characterize difficult pathologies. This review explains the most important pathologies of cystic lesions of the kidney and stresses the different imaging methods of native B-mode sonography and the new techniques of contrast enhanced ultrasound.

Interspecific advantage results in intraspecific disadvantage: Chemical protection versus cannibalism inUtetheisa ornatrix (Lepidoptera: Arctiidae).

This study suggests that alkaloid deficiency inUtetheisa (Lepidoptera: Arctiidae) is a main cause of cannibalism; moreover, cannibalism can be predicted on the basis of alkaloid deficiency and of systemic alkaloid accumulation. This chemical plays a central role in the life of this species, because, first, it provides acquired chemical protection from potential predators, and, second, it determines mating success (as the alkaloid is an essential precursor of the male pheromone). Consequently, losers in the larval sequestering of alkaloids, which would result in a lack of chemical protection and in decreased mating success, tend to target conspecific winners, which are normally substantially protected against a variety of predators; by cannibalizing those accumulated alkaloid sources the losers tend to become the winners of cannibalistic encounters while making up their shortfall of these chemicals. What is a presumptive advantage in selection under high predation pressures and/or high alkaloid availabilities could become a disadvantage under high conspecific population densities and shortages of alkaloid supplies for larval uptake. Cannibalism may be expected to have general ecological importance in the evolutionary play ofUtetheisa and may contribute to a balanced regulation of the acquired alkaloid contents in these arctiid populations.

Chemical basis of pupal cannibalism in a caterpillar (Utetheisa ornatrix).

The moth Utetheisa ornatrix derives protection against predation from systemic pyrrolizidine alkaloids (PAs) that it sequesters as a larva from its foodplants (Leguminosae, Crotalaria spp.). We here show, in laboratory tests, that Utetheisa deficient in body PA can make up for the chemical shortfall by cannibalizing pupae. We present evidence indicating that cannibalism in larvae is elicited not by hunger, but possibly by PA deficiency itself, and that in making cannibalistic choices larvae prefer PA-containing over PA-free pupae. PAs themselves, either in crystalline form or as additives to food items, proved phagostimulatory to larvae. In nature Utetheisa tend to pupate away from their foodplant, essentially out of reach of larval attack. The threat of cannibalism may have contributed to the evolution of this pupation behavior.

A potential kairomone stimulates pheromone-responsive receptor neurons inUtetheisa ornatrix (Lepidoptera: Arctiidae).

The olfactory receptor neurons in basiconic sensilla on the antennae ofUtetheisa ornatrix, which, in females, had earlier been shown to be responsive to stimulation with hydroxydanaidal (HD), are here shown to be responsive to volatile substances in samples of pyrrolizidine alkaloids (PAs). These latter substances are secondary plant metabolites present in the host plant of the larvae. Their sequestration during larval life serves to protect all life stages from predation. In males, the PAs also provide precursors for the production of the male pheromone, HD. In females, basiconic receptor neurons begin to respond to stimulus cartridges containing 1 ng of (R)-(-)-hydroxydanaidal, 100 ng of its isomer, (S)-(+)-hydroxydanaidal, and to volatiles emanating from 10µg of the alkaloids monocrotaline and heliotrine. Receptor neurons in males are generally responsive to the same array of substances but with reduced sensitivity. The dietary background of the adult moths with respect to prior ingestion of PAs does not influence the response capabilities of basiconic receptor neurons to HD or to the volatile components of PAs. Earlier studies in another arctiid (Rhodogastria), had indicated that trace amounts of HD are present in PAs, presumably as their hydrolysis product. Thus we assume that, under natural conditions, HD may be an active component of the volatiles from PAs and may serve as both a male pheromone and a kairomone. Sensitivity to HD could thereby provide information about the location and PA content of potential mates and food plants. Mechanisms that may have resulted in the evolution of a signaling system with these properties are discussed.

Chemical basis of egg cannibalism in a caterpillar (Utetheisa ornatrix).

Larvae of the mothUtetheisa ornatrix are shown to cannibalize eggs in the laboratory. They proved most cannibalistic if they were systemically deficient in pyrrolizidine alkaloid (PA), the defensive agent that protectsUtetheisa at all stages of development against predation, and whichUtetheisa acquire as larvae from their food plant. In exercising cannibalistic choice,Utetheisa larvae feed preferentially on eggs that are PA-Iaden rather than PA-free. Egg cannibalism can therefore provideUtetheisa with a supplemental means of PA procurement. Moreover, presence of PA in the egg, while providing the egg with defense against predation, can increase its vulnerability to cannibalism. Although evidence is presented thatUtetheisa larvae cannibalize eggs in nature, it is argued that such feeding may occur only opportunistically in the wild, rather than as a matter of course.

CO2 sensitive receptors on labial palps of Rhodogastria moths (Lepidoptera: Arctiidae): physiology, fine structure and central projection.

The tips of the labial palps of Rhodogastria possess a pit housing uniform sensilla, histologically characterized by wall-pores and receptor cells with lamellated outer dendrites. The receptor cell axons project to glomeruli in the deutocerebrum which are not innervated by antennal receptors. From their histology as well as from their central projection these sense organs are identical with palpal pit organs of other Lepidoptera (Lee et al. 1985; Kent et al. 1986; Lee and Altner 1986). Physiologically, the palp-pit receptors respond uniformly; they are most excitable by stimulation with carbon dioxide while they exhibit relatively moderate responses to various odorants. The responses to CO2 show a steep dose-response characteristic. In ambient atmosphere (i.e., ca. 0.03% CO2) the cells are in an excited condition already; the seeming 'spontaneous activity' exhibited in air is decreased if the preparation is kept under N2 or O2 or CO2-free air. There is hardly any adaptation of the responses to continuous or repeated stimulation. Perhaps CO2 sensitivity is correlated with sensilla characterized by both wall-pores and lamellated dendrites. Pilot tests indicate that CO2 perception might be widespread in the Lepidoptera, but the biological significance remains obscure.