Histopathology of the skin of UV-B irradiated sole (Solea solea) and turbot (Scophthalmus maximus) larvae.

Larval stages of two economically important flatfish, the sole (Solea solea) and turbot (Scophthalmus maximus) were exposed to ambient and elevated levels of UV-B. Sole larvae, which naturally occur in the plankton in early spring, demonstrated skin lesions at elevated levels of UV-B. Histopathology of the sole revealed cellular changes in the integument, characteristic of sunburn damage, with a reduction in the size of mucus-secreting cells and an increased epidermal thickening, especially at the highest doses of UV-B (2.15 KJ bio eff/m2). Pigmentation in the sole is restricted to a few isolated melanocytes. The integrity of the heavily pigmented skin of turbot appeared to be unaffected by comparable doses of UV-B. Both species have protective mechanisms, which minimize the effects of naturally-occurring levels of UV-B. However, sole appear to be poorly adapted to accommodate any further increase in solar radiation.

Continuous measurements of outdoor 222Rn concentrations for three years at one location in Colorado.

Measurements were made of 222Rn concentrations outdoors in Ft. Collins, Colorado, using a continuously sampling scintillation flask between January 1993 and December 1995. These data were analyzed for hourly, daily, and seasonal variations. The average 222Rn concentration at 1 m above the ground was 18 +/- 10 Bq m(-3) with a geometric mean of 15 Bq m(-3) and a geometric standard deviation of 1.7. Hourly averaged data indicated a diurnal pattern with the outdoor 222Rn concentration reaching a maximum in the early morning between 4:00 a.m. and 6:00 a.m. and a broad minimum between 1:00 p.m. and 4:00 p.m. in the afternoon. An analysis also indicated that the outdoor 222Rn concentrations were consistently lowest during the spring (March and April) and highest during the late summer (July-September).

The frequency of salivary progesterone sampling and the diagnosis of luteal phase insufficiency.

A profile of salivary progesterone concentrations, based on daily samples taken over a full menstrual cycle, provides a detailed picture of changes in luteal function, at the expense of analyzing a large number of samples. Strain can be placed on analytical services by assaying daily samples instead of one or a few serum (or saliva) samples. This study sought to determine the minimum number of salivary progesterone determinations which adequately describe luteal function. Daily salivary progesterone levels from 215 cycles, of which 29 cycles had progesterone profiles indicative of luteal phase insufficiency, were analyzed to ascertain the efficiencies of various sampling patterns of reduced frequency. A single mid-luteal salivary progesterone estimation or the mid-luteal Lenton progesterone index (n = 4) satisfactorily reflected the normal luteal phase, but a frequency of one sample every 3 days over the luteal phase (n = 5-6) was necessary to allow recognition of a short luteal phase or poor progesterone surge.

Seasonal variations in parameters of milt production and in plasma concentration of sex steroids of male rainbow trout (Salmo gairdneri).

Concentrations of testosterone (T), 11-ketotestosterone (11-KT) and 17 alpha-hydroxy-20 beta-dihydroprogesterone (17 alpha 20 beta P) were measured by a direct radioimmunoassay technique in the plasma of male rainbow trout, Salmo gairdneri, from two winter-spawning strains and one autumn-spawning strain. There was no evidence that milt production, its volume and density or the ionic composition of the seminal plasma could be related to the levels of 11-KT or T. Peak plasma T levels were reached just before production of milt could first be detected by handstripping. The concentration of 17 alpha 20 beta P remained elevated throughout the period of milt production and there was evidence that this steroid might be associated with the control of the ionic composition of seminal plasma.