A numerical approach to 14C wiggle-match dating of organic deposits: best fits and confidence intervals

14C wiggle-match dating (WMD) of peat deposits uses the non-linear relationship between 14C age and calendar age to match the shape of a sequence of closely spaced peat 14C dates with the 14C calibration curve. A numerical approach to WMD enables the quantitative assessment of various possible wiggle-match solutions and of calendar year confidence intervals for sequences of 14C dates. We assess the assumptions, advantages, and limitations of the method. Several case-studies show that WMD results in more precise chronologies than when individual 14C dates are calibrated. WMD is most successful during periods with major excursions in the 14C calibration curve (e.g., in one case WMD could narrow down confidence intervals from 230 to 36 yr).

Two intronic mutations in the adrenoleukodystrophy gene

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Signs of testicular insufficiency in adrenomyeloneuropathy and neurologically asymptomatic x-linked adrenoleukodystrophy: a retrospective study

X-linked adrenoleukodystrophy (X-ALD) is characterized by central nervous system demyelination, and impaired steroidogenesis in the adrenal cortex and testis. Most patients develop adrenocortical insufficiency. We studied retrospectively the frequency and severity of testicular dysfunction in 26 men with X-ALD. Twenty-one had adrenomyeloneuropathy and five patients were neurologically asymptomatic. In addition to obtaining a routine history and physical examination, we studied plasma levels of testosterone, sex hormone binding globulin, the free androgen index, and the plasma concentrations of dehydroepiandrosterone-sulphate, LH and FSH. In a subset of patients, the testosterone response to hCG and the LH and FSH responses to GnRH were also determined. Clinical signs of gonadal dysfunction were manifested by diminished libido (46%), largely overlapping with erectile dysfunction (58%), and failure of the testes to descend (15%). Physical examination revealed diminished body sexual hair (50%), gynaecomastia (35%), and small testes (12%). Laboratory studies showed low plasma total testosterone levels in 12%, and an insufficient increase after stimulation with hCG in 88% (15 of 17 patients tested). Plasma LH concentration was increased in 16%, and the plasma FSH level was elevated in 32%. The response of LH concentrations to GnRH stimulation was abnormally high in 47% (nine of 19 patients studied), and the response of FSH levels was too low in 16% (three of 19 patients tested). In conclusion, in a retrospective study of 26 men' with X-ALD, in 20 some signs of clinical hypogonadism were found. Plasma testosterone values were generally in the normal range, but upon testing of the hypothalamo-pituitary-testis axis some abnormalities became apparen

X linked adrenoleukodystrophy: clinical presentation, diagnosis, and therapy

X linked adrenoleukodystrophy (X-ALD) is an inherited disorder of peroxisomal metabolism, biochemically characterised by accumulation of saturated very long chain fatty acids. Accumulation of these fatty acids is associated with cerebral demyelination, peripheral nerve abnormalities, and adrenocortical and testicular insufficiency. The lowest estimated birth incidence is one per 100,000. At least six phenotypes can be distinguished, of which the two most frequent are childhood cerebral ALD and adrenomyeloneuropathy. The X-ALD gene has been identified, but thus far no relation between genotype and phenotype has been found. Diagnosis is relatively easy and can be confirmed reliably, and prenatal testing is possible in affected families. Several therapeutic options, some with promising perspectives, are available. Neurologists and other physicians seem not to be familiar with the many facets of X-ALD. In this review, the clinical presentation, the relative frequencies of the different phenotypes, and the diagnostic and therapeutic options are presente