Rapid, Simple Bioassay for 5-Fluorocytosine in the Presence of Amphotericin B

It is important that serum levels of 5-fluorocytosine (5FC) be measured to insure therapeutic levels while avoiding toxicity. This is particularly true in patients with renal insufficiency. The concurrent use of amphotericin B and 5FC complicates the measurement of 5FC in the serum, since fungi used in conventional bioassay systems are uniformly susceptible to amphotericin B. This paper describes the development of a simple, reliable, 6-h bioassay for 5FC in the presence of amphotericin B. The assay is based upon the fact that 5FC diffuses readily through yeast nitrogen base agar, whereas amphotericin B apparently does not. This assay allows rapid adjustments in therapy of patients receiving both 5FC and amphotericin B and has permitted us to maintain 5FC serum levels between limits of 25 and 120 μg/ml in patients with altered renal function.     

Antimalarial activity of cyclosporin A

Cyclosporin A has been shown to possess antimalarial activity in mice infected withPlasmodium berghei NK 65 orPlasmodium chabaudi. Significant antimalarial effects were obtained with five daily oral doses of 25 mg/kg. Cyclosporin A treatment started concurrently with the inoculation of parasites was less effective than treatment started when parasitaemia was already established. Evidence so far suggests that the antimalarial action results from a direct toxic effect on the parasite. Combined treatment with Cyclosporin A and Pyrimethamine indicated that the two compounds may act synergistically.     

Functional mapping of GABA A receptor subtypes in the amygdala

The physiological significance of the large diversity of GABA A receptors is poorly understood. Using mice, which carry a point mutation that renders specific subtypes of GABA A receptors diazepam insensitive, it was recently discovered that particular types of GABA A receptors are involved in specific, behaviorally relevant signaling pathways. We have used these mice to study inhibitory synaptic transmission in the amygdala. GABA A receptor-mediated inhibitory postsynaptic currents (IPSCs) per se were not affected by the point mutations. Their modulation by diazepam, however, was altered depending on the genotype of the mice studied. Based on the different responses to diazepam, we found that IPSCs in the lateral/basolateral amygdala were mediated by both alpha2- and alpha1-subunit-containing GABA A receptors whereas those in the central amygdala were mediated only by alpha2-subunit-containing GABA A receptors. Immunohistochemical staining corroborated these findings at a morphological level. To investigate a possible link between interneuron and receptor diversity, we selectively depressed release from the subset of GABAergic terminals carrying type 1 cannabinoid receptors. These receptors are known to modulate amygdala-mediated behavior. Application of a type 1 cannabinoid receptor agonist resulted in a selective reduction of inhibitory current mediated by alpha1-subunit-containing GABA A receptors. Mice with specific diazepam-insensitive GABA A receptor subtypes therefore provide a novel tool to investigate GABA A receptor distribution and the organization of inhibitory circuits at a functional level. The crucial role of the amygdala for the mediation of anxiety is in agreement with the part that alpha2-subunit-containing GABA A receptors play in anxiolysis and their important function in this area of the brain.     

Viennese SIDS prevention campaign-- a quality management project

At the 4th Austrian SIDS Consensus Meeting (1998), consultation was the focus of attention. Secure sleep, the Vienna SIDS prevention campaign, is an information campaign in cooperation with the children's hospitals of Vienna with the aim of reducing the incidence of SIDS in and around Vienna. The campaign was intended to spread awareness concerning care measures to reduce SIDS as well as to reduce SIDS related anxiety (SRA) among anxious parents. The Vienna SIDS prevention campaign is a quality management project, the core of which is consultation. Demands upon the structural quality of a SIDS consultation office include the expertise, communication skills and psychological competence of the consulting team. This can be achieved through interdisciplinary continuing education, international networking and training in communication skills. Priority is given to supporting care for the client by an interdisciplinary team headed by a case manager with the required communication skills. The qualitative outcome is defined by a primary objective medical goal (reduction of SIDS mortality) and a secondary subjective psychological goal (reduction of SRA). It also includes raising effectiveness and efficiency through optimal consultation and, finally, reducing costs by saving expenditure for monitors. The quality of SIDS consultation can be measured by evaluating satisfaction in patients as well as among co-workers.     

The mineralogical and petrographical work of the pharmacists in the Museum

Three famous pharmacists were working in the Muséum national d'histoire naturelle in Paris, in the field of earth sciences: Louis Nicolas Vauquelin (1763-1829), André Laugier (1770-1832) and Alfred Lacroix (1863-1948). Vauquelin, professor of Chemical arts, established the chemical composition of numerous minerals, which led him to the discovery of new chemical elements. He also took a hand in demonstrating the extra-terrestrial origin of meteorites. Laugier, professor of General chemistry, was an admitted expert in the analytical field of these rocks. Lacroix, who held during more than forty years the chair of Mineralogy in the Museum, carried out major scientific work. This field working naturalist who was also famous vulcanologist placed his studies of the mineral species into a petrographical context. He described numerous new minerals, took an interest in their origin and classification of the volcanic rocks, as well as in contact metamorphism. In other respects, he increased the collections in the Museum (minerals, rocks, meteorites). The works of Vauquelin, Laugier and Lacroix contributed to advance those begun by some scientists of the Jardin du Roi, as Buffon or the Rouelle brothers before the French Revolution.     

Reviewing the environmental and human health knowledge base of carbon nanotubes

Carbon nanotubes (CNTs) are considered one of the most promising materials in nanotechnology, with attractive properties for many technologic applications. The different synthesis, purification, and postprocessing methods produce CNTs with different physical characteristics, which can be applied in different fields ranging from composite materials, medical applications, and electronics to energy storage. The widespread projected use of CNTs makes it important to understand their potential harmful effects. In this environmental health review we observed a remarkable range of results of some of the toxicology studies. The comparability should be improved by further standardization and introduction of reference materials. However, at present the findings of this review suggest several key points: a) there are different types of CNTs, and therefore they cannot be considered a uniform group of substances; and b) in environmental compartments, CNTs can be bioavailable to organisms. The properties of CNTs suggest a possible accumulation along the food chain and high persistence. In organisms the absorption, distribution, metabolism, excretion, and toxicity of CNTs depend on the inherent physical and chemical characteristics such as CNT functionalization, coating, length, and agglomeration state that are influenced by the external environmental conditions during CNT production, use, and disposal stages. Characterized exposure scenarios could therefore be useful when conducting toxicologic studies. However, CNTs produce a toxic response upon reaching the lungs in sufficient quantity; this reaction is produced in a time-and dose-dependent manner. The identification of possible risks to human health and environment is a prerequisite for a successful introduction of CNTs in future applications.