Social transfer of pathogenic fungus promotes active immunisation in ant colonies.

Due to the omnipresent risk of epidemics, insect societies have evolved sophisticated disease defences at the individual and colony level. An intriguing yet little understood phenomenon is that social contact to pathogen-exposed individuals reduces susceptibility of previously naive nestmates to this pathogen. We tested whether such social immunisation in Lasius ants against the entomopathogenic fungus Metarhizium anisopliae is based on active upregulation of the immune system of nestmates following contact to an infectious individual or passive protection via transfer of immune effectors among group members--that is, active versus passive immunisation.

Precision and long-term stability of different estradiol immunoassays assessed in a multi-center quality control study.

Background: Because of the vast range of physiological relevant estradiol concentrations the requirements to be met by an estradiol assay are high. In the present study the performance of various commercially available estradiol assays was evaluated with regard to imprecision and long-term stability.

Methods: Precision and long-term stability of 7 commercially available estradiol immunoassays were assessed in a multi-centre quality control study based on the repeated measurement of liquid BIOREF estradiol control sera by 18 laboratories during a 14-month study period.

Multicentre evaluation of performance of C-reactive protein analysis over a one-year period.

This communication deals with a longitudinal evaluation of C-reactive protein (CRP) analysis during a one-year period using a single lot of liquid control sera (3 levels) (BIOREF-CRP levels 1, 2 and 3) in different laboratories. A total of 652 sets of data were returned from 20 participating laboratories using 13 different reagent-measuring device combinations. The use of the control materials was defined in a standard operating procedure.

Corticotropin-releasing hormone decreases feeding, oxygen consumption and activity of genetically obese (ob/ob) and lean mice.

Acute effects of intracerebroventricularly administered corticotropin-releasing hormone (CRH) on deprivation-induced food intake, whole-body oxygen consumption, brown adipose tissue metabolism, and several locomotive behaviors were examined in 6- to 7-wk-old female genetically obese (ob/ob) and lean mice. Corticotropin-releasing hormone depressed food intake in a dose-dependent manner, with a tendency for greater suppression of intake in intact ob/ob mice than in lean mice. Adrenalectomy abolished this tendency for CRH to be more potent in ob/ob mice than in lean mice.

[Iron resorption and the effects of iron supplementation in blood donors].

Topical values for some haematological factors such as Hb and Ery as well as transferrin and ferritin were determined in 7 female blood donors and 8 male blood donors during the years of their work as blood donors. Subsequently, an iron resorption test was carried out which unexpectedly resulted in low rates of resorption ranging from 5.6% in men to 3.