A broad oestrogen peak followed by bleeding but without ovulation is shown in Fig. 5C for a woman aged 42 years with a history of regular bleeding cycles.
Figure 5A (from Brown and Matthew, 1962) shows results from two cycles from a subject aged 21 years with a history of regular bleeding cycles.
Figure 6B (from Brown and Matthew, 1962) shows the findings from a woman aged 26 years, who from the age of 13 years had normal regular bleeding cycles.
At age 42 years, she recorded an unusually long period of amenorrhoea following a life-time of regular bleeding cycles and collected urine specimens to discover the cause.
The oestrogen and pregnanediol patterns were similar to those shown in Fig. 2 except that one girl had regular bleeding cycles from the start and ovulated 2 months after her first bleed.
The results shown in Fig 6A (from Brown and Matthew, 1962) are from a woman aged 19 years who, since menarche at age 14 years, had bleeding cycles that were irregular with intervals of 1 3 months.
Among girls born to Yucheng women, and therefore exposed in utero to PCBs/PCDFs, Yang et al. (2005) found irregular menstrual cycles, shorter mean duration of bleeding per cycle, and elevated serum levels of estradiol and follicle-stimulating hormone compared with an age- and neighborhood-matched reference group.
When you have bleeding mid-cycle and you're not on the pill, that's abnormal.
16 This result agrees with that of another study in which a greater proportion of women in groups with estradiol plus drospirenone had bleeding in cycles 1 to 3 compared with those with estradiol monotherapy.
Moreover, biofilms generally follow 'feed-and-bleed' cycles allowing cell growth, which can be significant for growth-dependent product formation [ 11].
Although the samples were collected from planktonic biomass and not the biofilm itself, since the biofilms go through feed-and-bleed cycles, the planktonic cells can be assumed to be representative of the cells in the biofilm.
