We describe a microarray experiment using the MCF-7 breast cancer cell line in two different experimental conditions for which the same number of independent pools as the number of individual samples was hybridized on Affymetrix GeneChips. Unexpectedly, when using individual samples, the number of probe sets found to be differentially expressed between treated and untreated cells was about three times greater than that found using pools. These findings indicate that pooling samples in microarray experiments where the biological variability is expected to be small might not be helpful and could even decrease one's ability to identify differentially expressed genes.

Antineoplastic Agents, Hormonal↗

PubMedDate not supplied

[Active pharmacologic monitoring of oral contraceptives. The Italian experience].

The Active Drug Monitoring project aims to assess the positive and negative effects of drugs following commercialisation. It was decided to use a study on "series of cases" in women who were taking an oral contraceptive containing 0.075 mg of Gestodene and 0.030 mg of Ethynylestradiol (Ginoden, Schering; Minulet, Wyeth). Twenty-seven centres took part in the study. 1166 women were recruited with a total of 10320 cycles studied. A data base was set up on a PC which was then used by each participating centre. Data were transmitted from the various centres using floppy disks. On enrollment a detailed medical history was recorded and, in addition to a careful objective examination, a blood sample was taken to assess biochemical parameters. The monitoring protocol consisted in the assessment of biochemical parameters at the start and end of treatment (12 months), as well as blood pressure, weight and menstrual characteristics after 3, 6 and 12 months. At each visit patients were questioned about the possible onset of collateral effects and their intensity. At the end of the study a reduction was noted in the mean cycle length (29.34 vs 27.45 days) and a parallel reduction in the quantity of menstruation. In spite of an increase in all the biochemical parameters examined, only HDL-cholesterol was statistically significant (p less than 0.01). 122 women decided not to complete the study, but only 72 due to side effects. It is however interesting to note that this decision was usually not related to the severity of symptoms.

Contraceptives, Oral↗

PubMedDate not supplied

Rhythms in the ovulatory cycle. 3rd: Cortisol and dehydroepiandrosterone sulphate (DHEA-S).

The circadian profiles of cortisol and dehydroepiandrosterone sulphate (DHEA-S) were analyzed in a homogeneous group of 15 young normally cycling women, at 4 times of the menstrual cycle: early follicular (EF), late follicular (LF), early luteal (EL) and late luteal (LL) stages. The circatrigintan variations of the same hormones were also evaluated. Population-mean cosinor analysis allowed the demonstration of a highly significant circadian periodicity for both variables in any of the 4 stages of the menstrual cycle; on the other hand, the same computation failed to demonstrate a significant circatrigintan periodicity. In each of the stages considered, the circadian acrophase of DHEA-S was delayed in comparison to that of cortisol, being located in the early afternoon hours. The demonstration of a clear-cut circadian oscillation in serum DHEA-S prompts studies on possible chrono-abnormalities of the steroid production in women with hyperandrogenic diseases.

Adult↗