Time resolved applications for Cryo-EM; approaches, challenges and future directions.

Developments within the cryo-EM field have allowed us to generate higher-resolution "static" structures and pull out different conformational states which exist at equilibrium within the sample. Moreover, to trap non-equilibrium states and determine conformations that are present after a defined period of time (typically in the ms time frame) new approaches have been developed for the application of time-resolved cryo-EM. Here we give an overview of these different approaches and the limitations and strengths of each whilst identifying some of the current challenges to achieve higher resolutions and trap states within faster time frames.

Maintaining the momentum in cryoEM for biological discovery.

Cryo-electron microscopy (cryoEM) has been transformed over the last decade, with continual new hardware and software tools coming online, pushing the boundaries of what is possible and the nature and complexity of projects that can be undertaken. Here we discuss some recent trends and new tools which are creating opportunities to make more effective use of the resources available within facilities (both staff and equipment). We present approaches for the stratification of projects based on risk and known information about the projects, and the impacts this might have on the allocation of microscope time.

Incidence of migraine relative to menstrual cycle phases of rising and falling estrogen.

Objective: To investigate the association between urinary hormone levels and migraine, with particular reference to rising and falling levels of estrogen across the menstrual cycle in women with menstrual and menstrually related migraine.

Methods: Women with regular menstrual cycles, who were not using hormonal contraception or treatments and who experienced between one and four migraine attacks per month, one of which regularly occurred on or between days 1 +/- 2 of menstruation, were studied for three cycles. Women used a fertility monitor to identify ovulation, conducting a test each day as requested by the monitor, using a sample of early morning urine.

Sequential classification of endocrine stages during reproductive aging in women: the FREEDOM study.

Objective: Reproductive aging involves complex endocrine changes affecting women's fertility, health, and well-being; however, understanding of the specific changes involved is limited by the lack of detailed quantitative studies. We undertook a thorough study with the aim of characterizing the different endocrine stages involved in female reproductive aging.

Design: FREEDOM is a cohort study designed to determine the endocrine changes during reproductive aging in women.

Predicting menstrual migraine with a home-use fertility monitor.

A home-use fertility monitor was used to time perimenstrual prophylaxis in 27 women with menstrual or menstrually related migraine. Cycle length variability was mostly caused by follicular phase variability; the postovulatory luteal phase was relatively constant. The monitor accurately identified ovulation in >90% of cycles, enabling prediction of menstruation and precise timing of perimenstrual prophylaxis.

Comparison between creatinine and pregnanediol adjustments in the retrospective analysis of urinary hormone profiles during the human menstrual cycle.

Measurement of reproductive hormones in urine is a practical way of obtaining large amounts of information; however, there is still controversy on how to overcome problems derived from volume fluctuations between samples. Creatinine adjustment is a widely accepted solution, however, it introduces an extra cost, and large studies involving multiple sequential determinations would benefit from more economical solutions. We determined the value of creatinine adjustment, and compared it with a mathematical method that uses the smoothed profile of pregnanediol (PdG) as a reference to adjust other hormonal markers.

Origins and consequences of the elongation of the human menstrual cycle during the menopausal transition: the FREEDOM Study.

The menopausal transition is characterized by the appearance of elongated cycles, which become longer and more frequent as menopause approaches. Several endocrine abnormalities have been attributed to these cycles; however, no quantitative studies of their causes and consequences exist to date. This study is based on sequential daily urinary concentrations of FSH, LH, estrone 3-glucuronide (E1G), and pregnanediol 3-glucuronide (PdG) from 34 women with perimenopausal menstrual irregularity (total of 289 cycles).

The onset of the initial rise in follicle-stimulating hormone during the human menstrual cycle.

Background: The rise in FSH (FSHr) that leads to the recruitment of a cohort of follicles during the menstrual cycle occurs during the luteal-follicular transition, however, it is unclear whether it consistently occurs on one particular day, or is subjected to reproductive ageing.

Methods: We determined the FSHr in 836 complete menstrual cycles from 102 women with regular menses using an algorithm, and additionally compared the relative variation in FSH during the last 14 days of the cycle. Possible effects of reproductive ageing on the onset of FSHr were also investigated.

Relationship between follicle-stimulating hormone levels at the beginning of the human menstrual cycle, length of the follicular phase and excreted estrogens: the FREEDOM study.

Although reproductive aging has been separately related to elevated FSH and shorter follicular phase (FP), the direct association between both parameters has not been investigated. Also, the exact effects of increased FSH on estrogen production are yet to be established.A large database of daily urinary concentrations of FSH, LH, and estrone 3-glucuronide (E1G) from 37 regularly menstruating women (median 11 cycles per patient) was used.

Statistical model for assessing the proportion of subjects with subjective sensitisations in adverse reactions to foods.

The outcome from a Double-Blind Placebo-Controlled Food Challenge is often of a subjective nature and cannot be measured directly. Reactions to placebo challenges are frequently observed, implying that some of the responses in the study are in fact 'false responses'. In order to adjust for these false responses, previous studies have used various methods, including removing subjects from the analysis who reacted to the placebo.

Effects of hot tea, coffee and water ingestion on physiological responses and mood: the role of caffeine, water and beverage type.

Psychopharmacological studies using caffeinated beverages or caffeine have rarely considered temporal effects on psychological and physiological function or the specific contribution of caffeine, hot water, or beverage type to the observed effects. The effect of 400 ml hot tea, coffee, and water consumption on systolic and diastolic blood pressure (SBP and DBP), heart rate, skin conductance (a measure of sympathetic nervous system activation), skin temperature, salivary cortisol, and mood were monitored in 16 healthy caffeine-withdrawn (14 h) subjects in a complete crossover design. Beverages were ingested with/without 100 mg caffeine and milk (tea/coffee only).

The prognostic value of early CA125 serum assay in epithelial ovarian carcinoma.

We examined the prognostic value of early serum CA125 assay in 58 patients with advanced epithelial ovarian cancer together with residual disease, age, tumour grade, performance status, and the presence of ascites or adhesions at primary surgery. CA125 was a highly significant predictor of both progression free and overall survival after the first cycle and throughout primary chemotherapy. After the first cycle, CA125 was by far the most significant predictor of progression free survival (P < 0.

The value of the human milk fat globule membrane antigen HMFG2 in epithelial ovarian cancer monitoring: comparison with CA125.

We assayed serum HMFG2 in serial samples from 215 primary epithelial ovarian cancer patients using an 'in-house' single determinant ELISA, 45% of patients with stage I, 54% with stage II, 61% with stage III and 75% with stage IV disease had elevated serum HMFG2. Post-operative levels were significantly related with residual tumour volume (P < 0.005), and fell in the majority of responders, although the association with response to first-line chemotherapy was not significant.

Serological monitoring of epithelial ovarian cancer.

Serum CA125 measurement has an established role in monitoring epithelial ovarian cancer patients, assisting in determining response to chemotherapy and providing a lead time to clinical relapse. Over the past few years there has been a decrease in the use of second-look laparotomy to determine response; however, this is largely due to the lack of impact that this procedure has on survival rather than the growing use of less invasive scanning techniques or CA 125 assay to determine disease status. The value of a marker lead time depends ultimately on a patient's remaining therapeutic options; the influence on survival of therapeutic intervention at pre-clinical diagnosis of relapse remains to be tested in a randomized controlled trial.