Extrapolation through hierarchical levels.

1. Translating results from low hierarchical levels to higher orders meets with difficulties with respect to temporal, spatial and organizational scales. 2. Translating stress effects through hierarchical levels has not yet been possible, thus hampering ecological risk assessment. 3. Three approaches to link the various levels are described; the energetics, the endpoint and the minimal structure approach. 4. A concept to integrate these approaches to enable extrapolation of stress across hierarchical levels is described.     

Significance levels in complex inheritance.

A LOD score >=3 is necessary but not sufficient to make a linkage test reliable, and this applies to complex inheritance as well as to major loci. Factors that affect this threshold are considered here. A LOD score as small as 2 is suggestive but is unreliable except as confirmation of either a significant linkage or a strong candidate locus. A threshold as great as 4 is unnecessarily conservative if multipoint tests are used sensibly. Marker density is not a major factor, and biases in the evaluation of LOD scores-especially inadequate allowance for estimation of nuisance parameters in multiple models-are paramount. Allelic association increases resolution for oligogenes within a candidate region and remains the only practical method to locate polygenes. The method sketched here combines multipoint linkage and allelic association to test efficiently for a regional candidate locus.     

Urinary purine levels in suicide.

A high-resolution liquid chromatographic system was utilized to analyze urine samples of twelve nonchemical suicide victims for the relative composition of ultraviolet-absorbing compounds. The analyses demonstrated a decrease in the output of uric acid, characteristic of severe depression, and an increase in the excretion of hypoxanthine. The excretion of 7-methylxanthine was found to be variable and xanthine was normal.     

Plasma corticotrophin levels in addison-schilder's disease.

Raised plasma immunoreactive corticotrophin (ACTH) levels were found in five boys with the sex-linked disorder progressive leucodystrophy associated with adrenal insufficiency (Addison-Schilder''s disease) and in a symptom-free brother of one of them. Similar ACTH concentrations were found using two antisera, one against the N-terminal part of the ACTH molecule and the other against the C-terminal part. In one patient the circulating ACTH had normal biological activity as measured using the cytochemical ACTH bioassay. Immunoreactive beta/-melanocyte-stimulating hormone was also determined in one patient and found to be raised.