Chemotherapy through Lysosomes with a DNA-Daunorubicin Complex

WHEN a drug can pass freely across cell membranes, it becomes distributed throughout the body fluids whichever its route of administration and invades all cells by diffusion at comparable rates. But if it is firmly associated with a non-permeant, pino-cytizable and digestible carrier, it will tend to remain confined within a smaller fluid space determined by its route of administration, its excretion will be slow and its intracellular penetration will be restricted to the endocytic route (Fig. 1). Free drug will then appear first within lysosomes, following digestion of the carrier. From the lysosomes it will diffuse into the other parts of the cells and eventually into the extracellular fluids. The intracellular concentration of the drug thus becomes dependent on the pinocytic activity of the cells and on the digestive potential of their lysosomes and must exceed the extracellular concentration in the most active cells. Obviously, this model requires the complex to be stable in the body fluids and to dissociate inside lysosomes. The drug itself must be resistant to lysosomal inactivation.     

Accuracy of Lightweight Satellite Telemetry: A Case Study in the Iberian Peninsula

Abstract: Here we provide the first assessment of the accuracy of lightweight satellite transmitters (<80 g) under actual operating conditions and the performance of the Argos system in southern Europe. To estimate transmitter accuracy we used transmitters equipped with a Global Positioning System (GPS) and compared the location estimates provided by Argos with the estimates provided by the GPS. Using the 68th percentile to define the accuracy of locations estimates, observed accuracy was 4 km for Location Class (LC) 1, 15 km for LC 0, 20 km for LC A, and 59 km for LC B, which is in line with estimates reported by other authors. Yet, the error of the remaining 32% of the data ranged between 4 km and 11 km, 15 km and 217 km, 20 km and 145 km, and 59 km and 493 km, respectively, suggesting that using the 68th percentile to estimate accuracies might give misleading confidence on the accuracy of location estimates. Using the 90th percentile is probably more appropriate. Less than 10% of the locations we obtained corresponded to the more accurate LCs (3, 2, and 1), with Argos failing to provide a position estimate in 45% of the attempts. The low number of high-quality location estimates is likely a consequence of the electromagnetic interference reported for our study area, rather than a defect of the Platform Transmitter Terminals (PTTs), which under good conditions of signal reception seem to be as reliable as heavier ones. The recent advent of lightweight GPS transmitters overrides most of these problems. Yet, whereas the smallest Argos-GPS PTTs weigh 30 g, which restricts their use to animals weighting > 1,000 g, conventional PTTs can be as small as 9.5 g, allowing their use with animals weighting 250-300 g.     

Multispecies interactions among a plant parasite,a pollinator and a seed predator affect the reproductive output of an invasive plant,Cytisus scoparius

Interactions between species pairs are almost always mediated by interactions with other species. The outcomes of these multispecies interactions are often difficult to predict and are rarely studied. In addition to their theoretical importance, multispecies interactions are also important for management situations. Where multiple agents are used to control invasive species, interactions between agents may either enhance or reduce the impacts on the target species, or may simply have additive effects. In this study, conducted in a Mediterranean‐type woodland in Australia, we examined how the interaction between an invasive legume, Cytisus scoparius (Leguminosae), its pollinator, Apis mellifera and a seed predator, Bruchidius villosus (Bruchidae), are modified by a native hemiparasitic vine, Cassytha pubescens (Loranthaceae). The parasite had a direct negative effect on C. scoparius, reducing flowering by 50% and consequently fruit and seed production. Despite having fewer flowers, infected plants had the same proportion of ‘tripped’ flowers, an indirect measure of pollinator visitation, as uninfected plants; although fruit formed on infected plants it was more likely to abort prematurely. Seed predation by B. villosus was lower on parasite‐infected C. scoparius plants than in uninfected plants. Although Ca. pubescens had an antagonistic effect on B. villosus, in consort, the two agents reduced overall seed production by an average of 62%. The acquired parasite Ca. pubescens was more effective in reducing reproductive output than the introduced seed predator, B. villosus, and shows potential as a biocontrol agent for C. scoparius. We documented a subadditive effect of two biological enemies on the invasive species, where the acquired parasite had a stronger effect than the introduced seed predator.     

Factors predicting drop‐out in community mental health centres

This study aimed to identify treatment, therapist and patient factors associated with dropping out of treatment in four outpatient mental health services. The experimental group comprised all 789 individuals who attended for the first time the mental health services during one year and dropped out of treatment in the same year or during the two following ones. The control group consisted of the same number of individuals, chosen at random from patients who, in the same year, attended for the first time the services and did not subsequently drop out of treatment. The overall drop-out rate was 33.2%. According to logistic regression analysis, the predictive factors of dropping out were: being treated in a particular centre, the involvement of more than one therapist in treatment, having no previous history of psychiatric disorders, being young and being male.